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  • 101.
    Manouras, Aristomenis
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Shahgaldi, Kambiz
    Winter, Reidar
    Nowak, Jacek
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Comparison between colour-coded and spectral tissue Doppler measurements of systolic and diastolic myocardial velocities: effect of temporal filtering and offline gain setting2009In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 10, no 3, p. 406-413Article in journal (Refereed)
    Abstract [en]

    Colour tissue Doppler (TD) has been reported to underestimate the longitudinal myocardial motion velocities measured with spectral TD. This study evaluates the effect of temporal smoothing and offline gain settings on the results of velocity measurements with these two methods and the difference between them. In 57 patients, 2D data and left ventricular velocity profiles were acquired using spectral and colour TD for a subsequent offline analysis. Longitudinal myocardial velocities were measured at unsaturated, 50%-saturated and fully saturated gain, and before and after temporal smoothing using 30, 50, and 70 ms filters, respectively. Gain level and filter width altered significantly the measured velocities. Peak systolic and early diastolic velocities were significantly higher (P < 0.001) and E/E' ratio was significantly lower (P < 0.001) with spectral TD than with colour TD, although there was a good correlation between the results of both TD modalities. The differences between the methods increased at increasing filter width and gain level. Despite good correlation of the results, spectral TD produces significantly higher myocardial velocity values and lower E/E' ratio than colour TD modality. Increasing gain and temporal smoothing alter significantly the results of velocity measurements and accentuate the difference between the two TD methods.

  • 102.
    Manouras, Aristomenis
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Shala, Arben
    Nyktari, Evangelia
    Shahgaldi, Kambiz
    Winter, Reidar
    Vardas, Panagiotis
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Nowak, Jacek
    Are measurements of systolic myocardial velocities and displacement with colour and spectral Tissue Doppler compatible?2009In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 7, p. 29-Article in journal (Refereed)
    Abstract [en]

    Background: Tissue Doppler (TD) in pulsed mode (spectral TD) and colour TD are the two modalities today available in tissue velocity echocardiography (TVE). Previous studies have shown poor agreement between these two methods when measuring myocardial velocities and displacement. In this study, the concordance between the myocardial velocity and displacement measurements using colour TD and different spectral TD procedures was evaluated. Methods: Left ventricular (LV) longitudinal systolic myocardial velocities and displacement during ejection period were quantified at the basal septal and lateral wall in 24 healthy individuals (4 women and 20 men, 34 +/- 12 years) using spectral TD, colour TD and M-mode recordings. Mean, maximal and minimal spectral TD systolic velocities and the corresponding displacement values were obtained by measurements at the outer and inner borders of the spectral velocity signal. The results were then compared with those obtained with the two other modalities used. Results: Systolic myocardial velocities derived from mean spectral TD frequencies were highly concordant with corresponding colour TD measurements (mean difference 0.10 +/- 0.54 cm/sec in septal and 0.09 +/- 0.97 cm/sec in lateral wall). Similarly, the agreement between spectral and colour TD (mean difference 0.22 +/- 0.74 mm in septal and 0.02 +/- 0.86 mm in lateral wall) as well as M-mode was good when mean spectral velocities were temporally integrated and the results did not differ statistically. Conversely, displacement values from the inner or outer border of the spectral signal differed significantly from values obtained with colour TD and M-mode (p < 0.001, in both cases). Conclusion: LV systolic myocardial measurements based on mean spectral TD frequencies are highly concordant with those provided by colour TD and M-mode. Hence, in order to maintain compatibility of the results, the use of this particular spectral TD procedure should be advocated in clinical praxis.

  • 103. Mattsson, C. M.
    et al.
    Lind, Britta
    KTH, School of Technology and Health (STH), Medical Engineering.
    Enqvist, J. K.
    Mårtensson, Mattias
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Ekblom, B.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    No evidence of cardiac fatigue in tissue velocity curves at rest after 6 days of ultra-endurance exercise2010In: European Heart Journal, ISSN 0195-668X, E-ISSN 1522-9645, Vol. 31, p. 304-305Article in journal (Refereed)
  • 104. Monnier, Andreas
    et al.
    Larsson, Helena
    Djupsjobacka, Mats
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Ang, Bjorn O.
    Musculoskeletal pain and limitations in work ability in Swedish marines: a cross-sectional survey of prevalence and associated factors2015In: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 5, no 10, article id e007943Article in journal (Refereed)
    Abstract [en]

    Objectives To estimate the prevalence of self-rated musculoskeletal pain and pain limiting work ability in Swedish Armed Forces (SAF) marines, and to study factors potentially associated with pain limiting work ability for the most prevalent pain regions reported. Design Population-based, cross-sectional survey. Participants There were 272 SAF marines from the main marine battalion in Sweden included in the study. Outcomes Self-assessed musculoskeletal pain and pain limiting the marines' work ability within a 6-month period, as obtained from structured questionnaires. The association of individual, health and work-related factors with musculoskeletal pain limiting work ability was systematically regressed with multiple logistic models, estimating OR and 95% CI. Results Musculoskeletal pain and pain limiting work ability were most common in the back, at 46% and 20%, and lower extremities at 51% and 29%, respectively. Physical training 1day/week (OR 5.3, 95% CI 1.7 to 16.8); body height 1.80m (OR 5.0, 95% CI 1.6 to 15.1) and 1.86m (OR 4.4, 95% CI 1.4 to 14.1); computer work 1/4 of the working day (OR 3.2, 95% CI 1.0 to 10.0) and 1/2 (OR 3.3, 95% CI 1.1 to 10.1) of the working day were independently associated with back pain limiting work ability. None of the studied variables emerged significantly associated with such pain for the lower extremities. Conclusions Our findings show that musculoskeletal pain and resultant limitations in work ability are common in SAF marines. Low frequency of physical training emerged independently associated with back pain limiting work ability. This suggests that marines performing physical training 1day per week or less are suitable candidates for further medical evaluation and secondary preventive actions. While also associated, body height and computer work need further exploration as underlying mechanisms for back pain limiting work ability. Further prospective studies are necessary to clarify the direction of causality.

  • 105.
    Mårtensson, Mattias
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Bjällmark, Anna
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Evaluation of tissue Doppler-based velocity and deformation imaging: a phantom study of ultrasound systems.2011In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 12, no 6, p. 467-476Article in journal (Refereed)
    Abstract [en]

    AIMS: The objective of this study was to test the accuracy and diagnostic interchangeability of tissue Doppler-based displacement, velocity, strain, and strain rate measurements in commercially used ultrasound (US) systems. METHODS AND RESULTS: Using an in-house made phantom, four different US scanner models were evaluated. Two different scanners of the same model were tested, and one scanner acquisition was tested twice with two generations of the same workstation giving six test results in total. The scanners were in active clinical use and are subject to regular maintenance checks. There were three displacement and four velocity results that stood out from the rest and could be regarded as accurate and interchangeable. Among the deformation measurements, three acceptable strain results were found while there were no acceptable strain rate results. Furthermore, the study showed that measurements from scanners of the same model, same acquisition post-processed on different workstations and repeated measurements from the same scanner, can yield disparate results. CONCLUSION: Measurements that are accurate and of interchangeable use can be found for displacement and velocity measurements, but are less likely to be found for strain and strain rate measurements. It is strongly recommended that the ability of each individual US scanner to measure displacement, velocity, strain, and strain rate is evaluated before it is introduced into clinical practice, and it must always be evaluated together with the workstation the scanner is intended to be used in conjunction with.

  • 106.
    Mårtensson, Mattias
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Olsson, Mats
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Ultrasound transducer function: annual testing is not sufficient2010In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 11, no 9, p. 801-805Article in journal (Refereed)
    Abstract [en]

    The objective was to follow-up the study 'High incidence of defective ultrasound transducers in use in routine clinical practice' and evaluate if annual testing is good enough to reduce the incidence of defective ultrasound transducers in routine clinical practice to an acceptable level. A total of 299 transducers were tested in 13 clinics at five hospitals in the Stockholm area. Approximately 7000-15 000 ultrasound examinations are carried out at these clinics every year. The transducers tested in the study had been tested and classified as fully operational 1 year before and since then been in normal use in the routine clinical practice. The transducers were tested with the Sonora FirstCall Test System. There were 81 (27.1%) defective transducers found; giving a 95% confidence interval ranging from 22.1 to 32.1%. The most common transducer errors were 'delamination' of the ultrasound lens and 'break in the cable' which together constituted 82.7% of all transducer errors found. The highest error rate was found at the radiological clinics with a mean error rate of 36.0%. There was a significant difference in error rate between two observed ways the clinics handled the transducers. There was no significant difference in the error rates of the transducer brands or the transducers models. Annual testing is not sufficient to reduce the incidence of defective ultrasound transducers in routine clinical practice to an acceptable level and it is strongly advisable to create a user routine that minimizes the handling of the transducers.

  • 107.
    Mårtensson, Mattias
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Olsson, Mats
    Segall, Björn
    Fraser, Alan G.
    Winter, Reidar
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    High incidence of defective ultrasound transducers in use in routine clinical practice2009In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 10, no 3, p. 389-394Article in journal (Refereed)
    Abstract [en]

    The objective was to evaluate the function of ultrasound transducers in use in routine clinical practice and thereby estimating the incidence of defective transducers. The study comprised a one-time test of 676 transducers from 7 manufacturers which were in daily use in clinical departments at 32 hospitals. They were tested with the Sonora FirstCall Test System; 39.8% exhibited a transducer error. Delamination was detected in 26.5% and break in the cable was detected in 8.4% of the tested transducers. Errors originating from the piezoelectrical elements were unusual. Delamination and short circuit occurred without significant differences between transducers from all tested manufacturers, but the errors break in the cable, weak and dead element showed a statistically significant higher frequency in transducers from certain manufacturers. The high error frequency and the risk for incorrect medical decisions when using a defective transducer indicate an urgent need for increased testing of the transducers in clinical departments.

  • 108.
    Mårtensson, Mattias
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Winter, Reidar
    Cederlund, Kerstin
    Ripsweden, Jonaz
    Mir-Akbari, Habib
    Nowak, Jacek
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Assessment of left ventricular volumes using simplified 3-D echocardiography and computed tomography - a phantom and clinical study2008In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 6Article in journal (Refereed)
    Abstract [en]

    Objectives: To compare the accuracy of simplified 3-dimensional (3-D) echocardiography vs. multi-slice computed tomography (MSCT) software for the quantification of left ventricular (LV) volumes. Design: Three-D echocardiography (3-planes approach) and MSCT-CardIQ software were calibrated by measuring known volumes of 10 phantoms designed to closely mimic blood-endocardium interface. Subsequently, LV volumes were measured with both the methods in 9 patients referred routinely for coronary angiography and the agreement between the measurements was evaluated. Results: Simplified 3D-echocardiography provided higher degree of agreement between the measured and true phantom volumes (mean difference 0 +/- 1 ml, variation range + 4 to -4 ml) than MSCT software (mean difference 6 +/- 5 ml; variation range + 22 to -10 ml). The agreement between LV measurements in the patients was considerably poorer, with significantly larger volumes produced by MSCT (mean difference - 23 +/- 40 ml, variation between + 93 and -138 ml). Conclusion: Simplified 3-D echocardiography provides more accurate assessment of phantom volumes than MSCT-CardIQ software. The discrepancy between the results of LV measurements with the two methods is even greater and does not warrant their interchangeable diagnostic use.

  • 109. Nilsson, B.
    et al.
    Henningsson, R.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Wandt, B.
    Transesophageal echocardiographic acquisition of mitral annulus motion during monitoring of left ventricular function in anesthetized patients2006In: Journal of the American Society of Echocardiography, ISSN 0894-7317, E-ISSN 1097-6795, Vol. 19, no 5, p. 499-506Article in journal (Refereed)
    Abstract [en]

    Objective. We investigated the feasibility and reproducibility of transesophageal (TE) recordings of displacements and velocities of 4 sites of the mitral annulus in anesthetized patients. Correlations to transthoracic measures and influence of the respiratory cycle were also investigated. Methods: A total of 24 patients without heart disease were included. Another 10 patients were enrolled for the reproducibility study. Systolic and diastolic velocities and amplitude of motion were extracted from color-coded Doppler tissue recordings. Results: The reproducibility was not acceptable for the anterior site or for late diastolic velocities. Transthoracic values were higher than TE values. A somewhat higher displacement during inspiration in spontaneous respiration and during expiration in positive pressure ventilation was seen. Conclusions: The anterior site should be omitted when TE recordings of the mitral annulus are used. TE values are about 15% lower than transthoracic values. There is no need to take the respiratory cycle into account.

  • 110. Peolsson, Anneli
    et al.
    Brodin, Lars-Ake
    KTH, School of Technology and Health (STH), Medical Engineering.
    Peolsson, Michael
    KTH, School of Technology and Health (STH), Medical Engineering.
    A tissue velocity ultrasound imaging investigation of the dorsal neck muscles during resisted isometric extension2010In: Manual Therapy, ISSN 1356-689X, E-ISSN 1532-2769, Vol. 15, no 6, p. 567-573Article in journal (Refereed)
    Abstract [en]

    Persons with neck pain exhibit altered patterns of muscle patterning, but limited investigations have been carried out on these alterations or muscle patterning in healthy volunteers. This study investigated the tissue motion of the dorsal neck muscles at the C4 segmental level in 15 healthy subjects during manually resisted head extension. Doppler-based tissue velocity ultrasound imaging (TVI) was used to detect regional tissue deformation, providing indirect evidence of inter-muscular movement patterning. The deep muscles, multifidus and semispinalis, had different muscular movement patterning than the superficial muscles, especially the trapezius muscle. The semispinalis cervicis (SSCerv) was the first deformed upon exercise initiation, followed by multifidus and semispinalis capitis (SSCap). The semispinalis muscles, notably capitis, exhibited a high rate of deformation during the exercise. The trapezius muscle exhibited the least and lowest deformation rate. In conclusion, TVI provided detailed information on regional tissue activity and muscle movement patterning among the dorsal neck muscles. In future studies, data from patients with neck disorders will have to be matched to data from healthy volunteers in a variety of situations and activities.

  • 111.
    Peolsson, Michael
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Ake
    KTH, School of Technology and Health (STH), Medical Engineering.
    Peolsson, Anneli
    Tissue motion pattern of ventral neck muscles investigated by tissue velocity ultrasonography imaging2010In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 109, no 5, p. 899-908Article in journal (Refereed)
    Abstract [en]

    We designed this experimental study to investigate tissue motions and thus infer the recruitment pattern of the ventral neck muscles [sternocleidomastoid (SCM), longus capitis (Lca), and longus colli (Lco)] at the C4-C5 level in healthy volunteers during isometric manual resistance of the head in flexion in a seated position. This exercise is used in the physiotherapeutic treatment of neck pain and is assumed to activate the deep ventral muscles, but the assumption has not been clearly evaluated. Neck flexors of 16 healthy volunteers (mean age 24 years, SD 3.7) were measured using ultrasonography with strain and strain rate (SR) tissue velocity imaging (TVI) during isometric contraction of flexor muscles. TVI involves using Doppler imaging to study tissue dynamics. All three muscles showed a deformation compared to rest. Except for the initial contraction phase, Lco exhibited a lower strain than Lca and SCM but was the only muscle with a significant change in SR between the phases. When the beginning of the contraction phase was analysed, Lco was the first to be deformed among most volunteers, followed by Lca and then SCM. The exercise investigated seems to be useful as a "stabilizing" exercise for Lco. Our suggestion is that in further research, Lco and Lca should be investigated as separate muscles. TVI could be used to study tissue motions and thus serve as an indicator of muscle patterning between the neck flexors, with the possibility of separating Lco and Lca.

  • 112.
    Peolsson, Michael
    et al.
    KTH, School of Technology and Health (STH), Centres, Centre for Technology in Medicine and Health, CTMH.
    Larsson, Britt
    Brodin, Lars-Ake
    KTH, School of Technology and Health (STH), Medical Engineering.
    Gerdle, Björn
    A pilot study using Tissue Velocity Ultrasound Imaging (TVI) to assess muscle activity pattern in patients with chronic trapezius myalgia2008In: BMC Musculoskeletal Disorders, ISSN 1471-2474, E-ISSN 1471-2474, Vol. 9Article in journal (Refereed)
    Abstract [en]

    Background: Different research techniques indicate alterations in muscle tissue and in neuromuscular control of aching muscles in patients with chronic localized pain. Ultrasound can be used for analysis of muscle tissue dynamics in clinical practice. Aim: This study introduces a new muscle tissue sensitive ultrasound technique in order to provide a new methodology for providing a description of local muscle changes. This method is applied to investigate trapezius muscle tissue response especially with respect to specific regional deformation and deformation rates - during concentric shoulder elevation in patients with chronic trapezius myalgia and healthy controls before and after pain provocation. Methods: Patients with trapezius myalgia and healthy controls were analyzed using an ultrasound system equipped with tissue velocity imaging (TVI). The patients performed a standardized 3-cm concentric shoulder elevation before and after pain provocation/exercise at a standardized elevation tempo (30 bpm). A standardized region of interest (ROI), an ellipsis with a size that captures the upper and lower fascia of the trapezius muscle (4 cm width) at rest, was placed in the first frame of the loop registration of the elevation. The ROI was re-anchored frame by frame following the same anatomical landmark in the basal fascia during all frames of the concentric phase. In cardiac measurement, tissue velocities are measured in the axial projection towards and against the probe where red colour represents shortening and red lengthening. In the case of measuring the trapezius muscle, tissue deformation measurements are made orthogonally, thus, indirectly. Based on the assumption of muscle volume incompressibility, blue represents tissue contraction and red relaxation. Within the ROI, two variables were calculated as a function of time: deformation and deformation rate. Hereafter, max, mean, and quadratic mean values (RMS) of each variable were calculated and compared before and after pain provocation/exercise. Results: This new methodology seems valuable when looking at local muscle changes and studying the mechanism behind chronic muscle pain. The univariate analyses indicate that patients with chronic trapezius myalgia after pain provocation due to exercise at group level showed decreased strain and unchanged strain rate while healthy controls had unchanged strain and increased strain rate. However, the multivariate analysis indicates that most patients showed lower levels according to both strain and strain rate after exercise compared to most controls. Conclusion: Tissue velocity imaging can help describe musculoskeletal tissue activity and dynamics in patients with chronic pain conditions. An altered muscle tissue dynamic after pain provocation/exercise among the majority of trapezius myalgia patients compared with the healthy controls was found.

  • 113. Quintana, M.
    et al.
    Saha, S.
    Govind, S.
    Brodin, Lars-Åke
    Patients with both diabetes and hypertension have diminished systolic and diastolic functional reserve: results of the myocardial Doppler in diabetes study (MYDID) II2005In: European Heart Journal, ISSN 0195-668X, E-ISSN 1522-9645, Vol. 26, p. 232-232Article in journal (Other academic)
  • 114. Quintana, M.
    et al.
    Saha, S. K.
    Rohani, M.
    Del Furia, F.
    Bjernby, J.
    Lind, Britta
    Department of Clinical Physiology, Karolinska Institute, Huddinge University Hospital.
    Brodin, Lars-Åke
    Department of Clinical Physiology, Karolinska Institute, Huddinge University Hospital.
    Assessment of the longitudinal and circumferential left ventricular function at rest and during exercise in healthy elderly individuals by tissue-Doppler echocardiography: relationship with heart rate2004In: Clinical Science, ISSN 0143-5221, E-ISSN 1470-8736, Vol. 106, no 5, p. 451-457Article in journal (Refereed)
    Abstract [en]

    Tissue-Doppler echocardiography (TDE) has been introduced to quantify stress echocardiography by means of assessing the left ventricular (LV) segmental myocardial velocities and excursion. The interaction between LV long- and short-axis function during physical exercise has not been elucidated completely. The aim of the present study was to investigate long- and short-axis LV function, as assessed by myocardial velocities and excursions at rest and during exercise and its possible relationship with heart rate in healthy elderly individuals by TIDE Twenty-seven individuals underwent an exercise test in the supine position on a bicycle ergometer. The initial workload was 30 Watts, followed by 20-Watt increments every third minute. Standard echocardiographic images with super-imposed colour TDE were digitized at the end of each step. The following variables were studied in the LV long- and short-axis: myocardial peak systolic velocity (PSV) and excursion, isovolumic contraction and relaxation times, peak velocity at early diastole (E-wave) and peak velocity at late diastole (A'-wave) and the E'/A' ratio. Increments in myocardial peak systolic velocity and excursion in the LV long-axis were more pronounced during low workloads. The increase in those variables in the short-axis occurred mainly, at higher exercise loads. The improvement in LV long- and short-axis functions was closely related to the increase in the heart rate. Shortening of the isovolumic contraction and relaxation times occurred only at the initial stages of exercise. An increase in the long-axis E'/A' ratio occurred during exercise, whereas this ratio was unchanged in the short-axis. In conclusion, during exercise, the LV long- and short-axis functions behave differently, and increases in LV long- and short-axis functions are related to changes in heart rate. Therefore, in the interpretation of echocardiographic findings during exercise stress echocardiography, these facts have to be taken into account.

  • 115. Quintana, M.
    et al.
    Saha, S.
    Rohani, M.
    del Furia, F.
    Roumina, S.
    Lind, Britta
    Department of Clinical Physiology, Huddinge University Hospital.
    Hayashi, S.
    Brodin, Lars-Åke
    Department of Clinical Physiology, Huddinge University Hospital.
    Electromechanical coupling, uncoupling, and ventricular function in patients with bundle branch block: A tissue-doppler echocardiographic study2004In: Echocardiography, ISSN 0742-2822, E-ISSN 1540-8175, Vol. 21, no 8, p. 687-698Article in journal (Refereed)
    Abstract [en]

    Background: Left bundle branch block (LBBB) is associated with impaired left ventricular (LV) function and increased morbidity and mortality, especially in patients with structural heart diseases. The mechanisms are poorly understood. Subjects and Methods: Subjects with isolated LBBB (n = 20), right bundle branch block (RBBB, n = 20), and controls (C, n = 20) were studied with standard two-dimentional (2D), and color-encoded tissue-Doppler echocardiography (TDE). Inter- and intraventricular systolic and diastolic coordination were assessed from the TDE velocity profiles. LV function was assessed by 2D echocardiography, by TDE-derived peak systolic velocities, and the atrioventricular (AV) plane displacement. Results: Subjects with LBBB had longer electromechanical delays and longer isovolumic relaxation times than did the C and RBBB groups (P < 0.001). For the LBBB subjects compared with the RBBB and C groups, ejection times were shorter, peak systolic velocities and AV plane displacements were lower, they had larger LV end-systolic volumes and lower LV ejection fraction (all P < 0.001), and the atrial contribution to A-V plane displacement was higher (P < 0.01). There were no differences in diastolic or filling times among the groups. Conclusions: In patients with LBBB, delayed regional electromechanical coupling and uncoupling leads to generalized intra- and interventricular asynchrony, thereby explaining the depressed regional and global LV functions. Assessment of the electromechanical coupling and uncoupling processes and their consequences on cardiac function in patients with BBB and structural heart diseases may be possible using TDE.

  • 116. Quintana, Miguel
    et al.
    Lindell, Peter
    Saha, Samir K
    del Furia, Francesca
    Lind, Britta
    Department of Clinical Physiology, Karolinska University Hospital.
    Govind, Satish
    Brodin, Lars-Ake
    Department of Clinical Physiology, Karolinska University Hospital.
    Assessment of atrial regional and global electromechanical function by tissue velocity echocardiography: a feasibility study on healthy individuals2005In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 3, no 18 February 2005Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The appropriate evaluation of atrial electrical function is only possible by means of invasive electrophysiology techniques, which are expensive and therefore not suitable for widespread use. Mechanical atrial function is mainly determined from atrial volumes and volume-derived indices that are load-dependent, time-consuming and difficult to reproduce because they are observer-dependent.

    AIMS: To assess the feasibility of tissue velocity echocardiography (TVE) to evaluate atrial electromechanical function in young, healthy volunteers.

    SUBJECTS AND METHODS: We studied 37 healthy individuals: 28 men and nine women with a mean age of 29 years (range 20-47). Standard two-dimensional (2-D) and Doppler echocardiograms with superimposed TVE images were performed. Standard echocardiographic images were digitized during three consecutive cardiac cycles in cine-loop format for off-line analysis. Several indices of regional atrial electrical and mechanical function were derived from both 2-D and TVE modalities.

    RESULTS: Some TVE-derived variables indirectly reflected the atrial electrical activation that follows the known activation process as revealed by invasive electrophysiology. Regionally, the atrium shows an upward movement of its walls at the region near the atrio-ventricular ring with a reduction of this movement towards the upper levels of the atrial walls. The atrial mechanical function as assessed by several TVE-derived indices was quite similar in all left atrium (LA) walls. However, all such indices were higher in the right (RA) than the LA. There were no correlations between the 2-D- and TVE-derived variables expressing atrial mechanical function. Values of measurement error and repeatability were good for atrial mechanical function, but only acceptable for atrial electrical function.

    CONCLUSION: TVE may provide a simple, easy to obtain, reproducible, repeatable and potentially clinically useful tool for quantifying atrial electromechanical function.

  • 117. Quintana, Miguel
    et al.
    Saha, Samir
    Govind, Satish
    Brodin, Lars-Åke
    Karolinska University Hospital, Huddinge, Stockholm, Sweden.
    del Furia, Francesca
    Bertomeu, Vicente
    Cardiac incoordination induced by left bundle branch block: its relation with left ventricular systolic function in patients with and without cardiomyopathy2008In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 6Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Although left bundle branch block (LBBB) alters the electrical activation of the heart, it is unknown how it might change the process of myocardial coordination (MC) and how it may affect the left ventricular (LV) systolic function. The present study assessed the effects of LBBB on MC in patients with LBBB with and without dilated (DCMP) or ischemic cardiomyopathy (ICMP).

    METHODS: Tissue Doppler echocardiography (TDE) was performed in 86 individuals: 21 with isolated LBBB, 26 patients with DCMP + LBBB, 19 patients with ICMP + LBBB and in 20 healthy individuals (Controls). MC was assessed analyzing the myocardial velocity profiles obtained from six basal segments of the LV using TDE. The LV systolic function was assessed by standard two-dimensional echocardiography and by TDE.

    RESULTS: Severe alterations in MC were observed in subjects with LBBB as compared with controls (P < 0.01 for all comparisons); these derangements were even worse in patients with DCMP and ICMP (P < 0.001 for comparisons with Controls and P < 0.01 for comparison with individuals with isolated LBBB). Some parameters of MC differed significantly between DCMP and ICMP (P < 0.01). A good or very good correlation coefficient was found between variables of MC and variables of LV systolic function.

    CONCLUSION: LBBB induces severe derangement in the process of MC that are more pronounced in patients with cardiomyopathies and that significantly correlates with the LV systolic function. The assessment of MC may help in the evaluation of the etiology of dilated cardiomyopathy.

  • 118. Rajs, J.
    et al.
    Brodin, Lars-Åke
    Hertzeld, I.
    Larsen, F. F.
    Death related to coronary artery fistula after rupture of an aneurysm to the coronary sinus2001In: American Journal of Forensic Medicine and Pathology, ISSN 0195-7910, E-ISSN 1533-404X, Vol. 22, no 1, p. 58-61Article in journal (Refereed)
    Abstract [en]

    Large coronary fistulas are considered to cause myocardial ischemia due to diversion of the coronary blood flow. In this case the authors report the reverse effect-the spontaneous closure of a large fistulation between the left circumflex artery and the coronary sinus evoked angina pectoris in a middle aged man, who died several years later. Postmortem examination revealed a coronary aneurysm that had ruptured and dissected into the coronary sinus and finally thrombosed. The origin of the aneurysm could be congenital but perhaps also represents a healed stage of Kawasaki disease.

  • 119. Ressner, M.
    et al.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Jansson, T.
    Hoff, L.
    Ask, P.
    Janerot-Sjoberg, B.
    Effects of ultrasound contrast agents on Doppler tissue velocity estimation2006In: Journal of the American Society of Echocardiography, ISSN 0894-7317, E-ISSN 1097-6795, Vol. 19, no 2, p. 154-164Article in journal (Refereed)
    Abstract [en]

    The combination of Doppler tissue imaging and myocardial contrast echocardiography has the potential to provide information about motion and perfusion of the myocardium in a single examination. The purpose of this study was to establish how the presence of ultrasound contrast agent (UCA) affects measurements of Doppler tissue velocities in vivo and in vitro. We performed echocardiography in 12 patients with ischemic heart disease before and immediately after a slow intravenous infusion of the UCA Optison, using color Doppler tissue imaging to examine the effect of contrast agents in vivo. The myocardial peak systolic velocities and their integrals were analyzed in digitally stored cineloops before and after contrast administration. To distinguish between methodologic and physiologic factors affecting the measurement of tissue velocity in vitro, experiments with a rotating disk and a flow cone phantom were also carried out for the 3 contrast agents: Optison, Sonovue, and Sonazoid. in vivo results show that the values for peak systolic velocity increased by about 10% during contrast infusion, from mean 5.2 +/- 1.8 to 5.7 +/- 2.3 cm/s (P = .02, 95% confidence interval 2%-16%). The increase in myocardial peak systolic velocities was verified in experimental models in which the UCA increased the estimated mean velocity in the order of 5% to 20% for the motion interval of 5 to 7 cm/s, corresponding to the myocardial velocities studied in vivo. The response was similar for all 3 contrast agents and was not affected by moderate variations in concentration of the agent. We have shown that the presence UCA will affect Doppler tissue measurements in vivo and in vitro. The observed bias is presumed to be an effect of harmonic signal contribution from rupturing contrast agent microbubbles and does not indicate biologic or physiologic effects.

  • 120. Sadigh, Bita
    et al.
    Quintana, Miguel
    Sylvén, Christer
    Berglund, Margareta
    Brodin, Lars Åke
    Institution of Laboratory Medicine, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
    The ischemic preconditioning effect of adenosine in patients with ischemic heart disease2009In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 7Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: In vivo and in vitro evidence suggests that adenosine and its agonists play key roles in the process of ischemic preconditioning. The effects of low-dose adenosine infusion on ischemic preconditioning have not been thoroughly studied in humans.

    AIMS: We hypothesised that a low-dose adenosine infusion could reduce the ischemic burden evoked by physical exercise and improve the regional left ventricular (LV) systolic function.

    MATERIALS AND METHODS: We studied nine severely symptomatic male patients with severe coronary artery disease. Myocardial ischemia was induced by exercise on two separate occasions and quantified by Tissue Doppler Echocardiography. Prior to the exercise test, intravenous low-dose adenosine or placebo was infused over ten minutes according to a randomized, double blind, cross-over protocol. The LV walls were defined as ischemic if a reduction, no increment, or an increment of < 15% in peak systolic velocity (PSV) was observed during maximal exercise compared to the baseline values observed prior to placebo-infusion. Otherwise, the LV walls were defined as non-ischemic.

    RESULTS: PSV increased from baseline to maximal exercise in non-ischemic walls both during placebo (P = 0.0001) and low-dose adenosine infusion (P = 0.0009). However, in the ischemic walls, PSV increased only during low-dose adenosine infusion (P = 0.001), while no changes in PSV occurred during placebo infusion (P = NS).

    CONCLUSION: Low-dose adenosine infusion reduced the ischemic burden and improved LV regional systolic function in the ischemic walls of patients with exercise-induced myocardial ischemia, confirming that adenosine is a potential preconditioning agent in humans.

  • 121. Saha, S. K.
    et al.
    Brodin, Lars-Åke
    Dept. of Clin. Physiology/Cardiology, Karolinska Univ. Hosp. at Huddinge.
    Lind, Britta
    Dept. of Clin. Physiology/Cardiology, Karolinska Univ. Hosp. at Huddinge.
    Svedenhag, J.
    Straat, E.
    Gunnes, S.
    Myocardial velocities measured during adenosine, dobutamine and supine bicycle exercise: a tissue Doppler study in healthy volunteers2004In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 24, no 5, p. 281-288Article in journal (Refereed)
    Abstract [en]

    Background: Dobutamine stress echocardiography (DSE) quantified by tissue Doppler (TVI) have improved the diagnostic capacity of the procedure. Quantification of other stress modalities, e.g. adenosine stress echo (ASE) and exercise stress echocardiography (ESE) are necessary for assessing any pathophysiological differences in different forms of stress. Methods: Ten healthy individuals underwent ASE, DSE, and ESE during a span of 2-5 days. Left ventricular (LV) apical images at rest and peak stress (max) were postprocessed using TVI on a GE System FiVe equipment. ECG-derived QRS duration (QRSD, ms), heart rate (HR, bpm), TVI-estimated basal systolic velocities (S2V, cm s(-1)), ejection time (S2T, ms) and strain (S, %) were computed off-line and compared. Longitudinal displacement imaging, tissue tracking, was also made. Results: Data for ASE, DSE and ESE during peak stress were (HR: 84 +/- 12***, 142 +/- 19, 137 +/- 27; P0.05) response at a much lower HR indicates that adenosine has minor effects on contraction presumably secondary to vasodilatation. Powerful chronotropic response to DSE and ESE is probably prerequisite for strong velocity response at the expense of strain and displacement. TVI-assisted stress echocardiography thereby shows different LV systolic response in healthy individuals, depending on stress modality.

  • 122. Saha, Samir
    et al.
    Nowak, Jacek
    Storaa, Camilla
    Mädler, C. F.
    Fraser, Alan
    Roumina, Simin
    Lind, Britta
    Department of Clinical Physiology, Karolinska University Hospital, Huddinge.
    Brodin, Lars-Ake
    Department of Clinical Physiology, Karolinska University Hospital, Huddinge.
    Functional diagnosis of coronary stenosis using tissue tracking provides best sensitivity and specificity for left circumflex disease: experience from the MYDISE (myocardial Doppler in stress echocardiography) study.2005In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 6, no 1, p. 54-63Article in journal (Refereed)
    Abstract [en]

    AIMS: To evaluate the diagnostic capacity of quantitative analysis of segmental longitudinal myocardial displacement images (tissue tracking, TT) during dobutamine stress echocardiography for the detection of patients with coronary artery disease (CAD).

    METHODS AND RESULTS: TT-generated colour-coded maps of systolic segmental longitudinal displacement were obtained by post-processing of echocardiographic data from 105 patients with CAD and 90 low risk individuals selected from MYDISE database. Quantitative analysis of the distribution pattern of segmental displacement during dobutamine stress was most successful when a ratio of basal (high amplitude) to apical (low amplitude) colour-coded displacement bands (B/A ratio) was employed. Applied in four different left ventricular sectors, the B/A ratio provided a significant discrimination of patients with CAD (p<0.05 in the anterior and p<0.001 in the inferior wall) as assessed by receiver operating characteristic analysis. The procedure was most sensitive when applied in inferior wall for the detection of left circumflex coronary artery disease, the B/A ratio of 0.8 giving the best combination of sensitivity (77+/-8%) and specificity (77+/-5%) values.

    CONCLUSION: Quantification of dobutamine stress echocardiography using TT is an efficient diagnostic approach and a valuable additional modality in functional cardiac imaging for the initial identification of patients suspected for CAD.

  • 123. Sahlen, A.
    et al.
    Abdula, G.
    Norman, M.
    Manouras, Aristomenis
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Lund, L. H.
    Shahgaldi, Kambiz
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Winter, Reidar
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Altered arterial haemodynamics during exercise in elderly female hypertensives with poor stroke volume reserve2011In: European Heart Journal, ISSN 0195-668X, E-ISSN 1522-9645, Vol. 32, p. 10-11Article in journal (Other academic)
  • 124. Sahlen, Anders
    et al.
    Abdula, Göran
    Norman, Mikael
    Manouras, Aristomenis
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Ake
    KTH, School of Technology and Health (STH), Medical Engineering.
    Lund, Lars H.
    Shahgaldi, Kambiz
    KTH, School of Technology and Health (STH), Medical Engineering.
    Winter, Reidar
    KTH, School of Technology and Health (STH), Medical Engineering.
    Arterial vasodilatory and ventricular diastolic reserves determine the stroke volume response to exercise in elderly female hypertensive patients2011In: American Journal of Physiology. Heart and Circulatory Physiology, ISSN 0363-6135, E-ISSN 1522-1539, Vol. 301, no 6, p. H2433-H2441Article in journal (Refereed)
    Abstract [en]

    Sahlen A, Abdula G, Norman M, Manouras A, Brodin LA, Lund LH, Shahgaldi K, Winter R. Arterial vasodilatory and ventricular diastolic reserves determine the stroke volume response to exercise in elderly female hypertensive patients. Am J Physiol Heart Circ Physiol 301: H2433-H2441, 2011. First published September 16, 2011; doi:10.1152/ajpheart.00555.2011.-Elderly female hypertensives with arterial stiffening constitute a majority of patients with heart failure with preserved ejection fraction (HFpEF), a condition characterized by inability to increase cardiac stroke volume (SV) with physical exercise. As SV is determined by the interaction between the left ventricle (LV) and its load, we wished to study the role of arterial hemodynamics for exertional SV reserve in patients at high risk of HFpEF. Twenty-one elderly (67 +/- 9 yr) female hypertensive patients were studied at rest and during supine bicycle stress using echocardiography including pulsed-wave Doppler to record flow in the LV outflow tract and arterial tonometry for central arterial pressure waveforms. Arterial compliance was estimated based on an exponential relationship between pressure and volume. The ratio of aortic pressure-to-flow in early systole was used to derive characteristic impedance, which was subsequently subtracted from total resistance (mean arterial pressure/cardiac output) to yield systemic vascular resistance (SVR). It was found that patients with depressed SV reserve (NoRes; reserve <15%; n = 10) showed decreased arterial compliance during exercise, while patients with SV reserve >= 15% (Res; n = 11) showed increased compliance. Exercise produced parallel increases in LV end-diastolic volume and arterial volume in Res patients while NoRes patients exhibited a lesser decrease in SVR and a drop in effective arterial volume. Poor SV reserve in elderly female hypertensives is due to simultaneous failure of LV preload and arterial vasodilatory reserves. Abnormal arterial function contributes to a high risk of HFpEF in these patients.

  • 125. Sarkar, N.
    et al.
    Ruck, A.
    Kallner, G.
    Y-Hassan, S.
    Blomberg, P.
    Islam, K. B.
    Van Der Linden, J.
    Lindblom, D.
    Nygren, A. T.
    Lind, B.
    Brodin, Lars-Åke
    Drvota, V.
    Sylven, C.
    Effects of intramyocardial injection of phVEGF-A(165) as sole therapy in patients with refractory coronary artery disease - 12-month follow-up: Angiogenic gene therapy2001In: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 250, no 5, p. 373-381Article in journal (Refereed)
    Abstract [en]

    Objective. To test the safety and bioactivity of phVEGF-A(165) after intramyocardial injection during 12-month follow-up. Design. Open-labelled study. Subjects. Inclusion criteria were angina pectoris, Canadian Cardiovascular Society (CCS) class III-IV, unamenable to further revascularization, ejection fraction (EF) >30%, perfusion defects extending over >10% of the anterolateral left ventricle wall detectable with adenosine single photon emission computerized tomography (SPECT) and at least one patent vessel visible by coronary angiography. Seven of 39 patients referred for gene therapy were included. Intervention. Via a mini-thoracotomy under general anaesthesia, phVEGF-A(165) was injected directly into the myocardium at four sites in the anterolateral region of the left ventricle. Results. Operative procedures were uneventful. Perioperative release of myocardial markers and electrocardiogram (ECG) changes were detected in two patients. There were no perioperative deaths but one patient died 7 months postoperatively because of myocardial infarction. Plasma vascular endothelial growth factor (VEGF)-A levels increased two to threefold peaking 6 days postoperatively (P<0.004) and returning to baseline by day 30. A significant reduction in angina pectoris was reported. The CCS class improved from 3.30.2 to 1.9 +/-0.3 (P<0.01) and nitroglycerine intake decreased from 3915 to 12 +/-5 tablets week(-1) (P<0.001) 2 months after gene transfer. Improvements remained after 12 months when nitroglycerine consumption approached zero. Improved myocardial function in the phVEGF-A(165) injection region was documented in all patients (P<0.016) by tissue velocity imaging (TVI). Reduced reversible ischaemia was detected by adenosine SPECT in four patients. Improved collateralization was detected in four patients with coronary angiography. Conclusion. Intramyocardial injection of phVEGF-A(165) is safe and may lead to improved myocardial perfusion and function with longstanding symptomatic relief in end-stage angina pectoris. Based on these results this therapeutic potential is being tested in a double-blind placebo controlled multicentre trial, EUROINJECT ONE.

  • 126. Shahgaldi, K.
    et al.
    Söderqvist, E.
    Ostenfeld, E.
    Winter, R.
    Nowak, J.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Flow-volume loops from three-dimensional echocardiography: A novel technique for assessment of left ventricular function and hemodynamics2006In: Journal of the American College of Cardiology, ISSN 0735-1097, E-ISSN 1558-3597, Vol. 47, no 4, p. 141A-141AArticle in journal (Other academic)
  • 127. Shahgaldi, Kambiz
    et al.
    Gudmundsson, Petri
    Manouras, Aristomenis
    Brodin, Lars-Ake
    KTH, School of Technology and Health (STH), Medical Engineering.
    Winter, Reidar
    Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography2009In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 7Article in journal (Refereed)
    Abstract [en]

    Background: Visual assessment of left ventricular ejection fraction (LVEF) is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS) measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing) is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE) and triplane echocardiography (TPE) using quantitative real-time three-dimensional echocardiography (RT3DE) as the reference method.

    Methods: Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE.

    Results: There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively) without any significant bias (-0.5 +/- 3.7% and -0.2 +/- 2.9% respectively). Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP.

    Conclusion: Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant.

  • 128.
    Shahgaldi, Kambiz
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Manouras, Aristomenis
    KTH, School of Technology and Health (STH), Medical Engineering.
    Abrahamsson, Anna
    Gudmundsson, Petri
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Winter, Reidar
    Three-dimensional echocardiography using single-heartbeat modality decreases variability in measuring left ventricular volumes and function in comparison to four-beat technique in atrial fibrillation2010In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 8, no 1Article in journal (Refereed)
    Abstract [en]

    Background: Three dimensional echocardiography (3DE) approaches the accuracy of cardiac magnetic resonance in measuring left ventricular (LV) volumes and ejection fraction (EF). The multibeat modality in comparison to single-beat (SB) requires breath-hold technique and regular heart rhythm which could limit the use of this technique in patients with atrial fibrillation (AF) due to stitching artifact. The study aimed to investigate whether SB full volume 3DE acquisition reduces inter-and intraobserver variability in assessment of LV volumes and EF in comparison to four-beat (4B) ECG-gated full volume 3DE recording in patients with AF.

    Methods: A total of 78 patients were included in this study. Fifty-five with sinus rhythm (group A) and 23 having AF (group B). 4B and SB 3DE was performed in all patients. LV volumes and EF was determined by these two modalities and inter-and intraobserver variability was analyzed.

    Results: SB modality showed significantly lower inter-and intraobserver variability in group B in comparison to 4B when measuring LV volumes and EF, except for end-systolic volume (ESV) in intraobserver analysis. There were significant differences when calculating the LV volumes (p < 0.001) and EF (p < 0.05) with SB in comparison to 4B in group B.

    Conclusion: Single-beat three-dimensional full volume acquisition seems to be superior to four-beat ECG-gated acquisition in measuring left ventricular volumes and ejection fraction in patients having atrial fibrillation. The variability is significantly lower both for ejection fraction and left ventricular volumes.

  • 129.
    Shahgaldi, Kambiz
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Manouras, Aristomenis
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Winter, Reidar
    Direct measurement of left ventricular outflow tract area using three-dimensional echocardiography in biplane mode improves accuracy of stroke volume assessment2010In: Echocardiography, ISSN 0742-2822, E-ISSN 1540-8175, Vol. 27, no 9, p. 1078-1085Article in journal (Refereed)
    Abstract [en]

    Aims: The aim of the study was to investigate whether left ventricular stroke volume (LVSV) assessment using direct measurement of left ventricular outflow tract area (LVOTA) is superior to conventional methods for SV calculation. Methods and results: Thirty patients were included in the study (39 +/- 12 years). LVSV was assessed by multiplying LVOT velocity time integral (VTI) by LVOTA provided by direct plani-metrical measurements from real time three-dimensional echocardiography (RT3DE) in biplane mode (SV2). These measurements were compared to conventional methods using either the LVOT diameter for LVOTA multiplied with VTI (SV1) or biplane Simpson (SV3). Direct SV measurements by RT3DE were used as gold standard (SVref). There was an excellent correlation and agreement between SV determined by SV2 and 3DE (r = 0.98, mean difference 0.5 +/- 3.3 mL). However, the concordance of the traditional methods (SV1 and SV3) with 3DE was weaker (r = 0.38, mean difference -2.0 +/- 17.6 mL, r = 0.84, mean difference -7.6 +/- 8.7 mL, respectively). Furthermore, cardiac output (CO) measurements performed by the different modalities were not concordant with wide limits of agreement, except by SV2 the mean difference of CO by SV1 was -0.12 +/- 1.05 L/min, 0.03 +/- 0.20 L/min by SV2, and -0.45 +/- 0.52 L/min by SV3. Conclusions: SV and CO calculations using direct measurement of LVOT area is a feasible, accurate and reproducible method and correlates extremely well with 3DE volume measurements. SV and CO calculation by LVOTA is therefore an appealing method for LVSV assessment in clinical routine.

  • 130. Shahgaldi, Kambiz
    et al.
    Söderqvist, Emil
    Gudmundsson, Petri
    Winter, Reidar
    Nowak, Jacek
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Flow-volume loops derived from three-dimensional echocardiography: a novel approach to the assessment of left ventricular hemodynamics2008In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 6Article in journal (Refereed)
    Abstract [en]

    Background: This study explores the feasibility of non-invasive evaluation of left ventricular (LV) flow-volume dynamics using 3-dimensional (3D) echocardiography, and the capacity of such an approach to identify altered LV hemodynamic states caused by valvular abnormalities.

    Methods: Thirty-one patients with moderate-severe aortic (AS) and mitral (MS) stenoses (21 and 10 patients, respectively) and 10 healthy volunteers underwent 3D echocardiography with full volume acquisition using Philips Sonos 7500 equipment. The digital 3D data were post-processed using TomTec software. LV flow-volume loops were subsequently constructed for each subject by plotting instantaneous LV volume data sampled throughout the cardiac cycle vs. their first derivative representing LV flow. After correction for body surface area, an average flow-volume loop was calculated for each subject group.

    Results: Flow-volume loops were obtainable in all subjects, except 3 patients with AS. The flow-volume diagrams displayed clear differences in the form and position of the loops between normal individuals and the respective patient groups. In patients with AS, an "obstructive" pattern was observed, with lower flow values during early systole and larger end-systolic volume. On the other hand, patients with MS displayed a "restrictive" flow-volume pattern, with reduced diastolic filling and smaller end-diastolic volume.

    Conclusion: Non-invasive evaluation of LV flow-volume dynamics using 3D-echocardiographic data is technically possible and the approach has a capacity to identify certain specific types of alteration of LV flow-volume pattern caused by valvular abnormalities, thus reflecting underlying hemodynamic states specific for these abnormalities.

  • 131.
    Shirley, Hayashi
    et al.
    KTH. Karolinska Inst, Div Renal Med & Baxter Novum, Stockholm, Sweden.;Royal Inst Technol, Dept Med Engn, Stockholm, Sweden..
    Marcelo, Nascimento
    Evangel Med Sch, Curitiba, Parana, Brazil..
    Lind, Brita
    KTH, School of Technology and Health (STH), Medical Engineering.
    Larsson, Matilda
    KTH, School of Technology and Health (STH), Medical Engineering.
    Bjällmark, Anna
    KTH, School of Technology and Health (STH), Medical Engineering.
    Nowak, Jacek
    KTH, School of Technology and Health (STH), Medical Engineering.
    Seeberg, Astrid
    Karolinska Inst, Div Renal Med & Baxter Novum, Stockholm, Sweden..
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Lindholm, Bengt
    Karolinska Inst, Div Renal Med & Baxter Novum, Stockholm, Sweden..
    The Prevalence of Intraventricular Dyssynchrony, Detected by Tissue Synchronization Imaging, In HD, PD and CKD Patients Stages 3 and 42009In: Blood Purification, ISSN 0253-5068, E-ISSN 1421-9735, Vol. 28, no 4, p. 325-325Article in journal (Other academic)
  • 132.
    Shirley, Hayashi
    et al.
    Karolinska Inst, Div Renal Med & Baxter Novum, Stockholm, Sweden..
    Nascimento, Marcelo
    Evangel Med Sch, Curitiba, Parana, Brazil..
    Lind, Britta
    KTH, School of Technology and Health (STH), Medical Engineering.
    Seeberg, Astrid
    Karolinska Inst, Div Renal Med & Baxter Novum, Stockholm, Sweden..
    Nowak, Jacek
    KTH, School of Technology and Health (STH), Medical Engineering.
    Larsson, Matilda
    KTH, School of Technology and Health (STH), Medical Engineering.
    Bjällmark, Anna
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Lindholm, Bengt
    Karolinska Inst, Div Renal Med & Baxter Novum, Stockholm, Sweden..
    Improvement of Left Ventricular Synchronicity Assessed by Tissue Synchronization Imaging after a Single HD Session2009In: Blood Purification, ISSN 0253-5068, E-ISSN 1421-9735, Vol. 28, no 4, p. 306-306Article in journal (Other academic)
  • 133. Storaa, C.
    et al.
    Aberg, P.
    Lind, B.
    Brodin, Lars-Åke
    Effect of angular error on tissue Doppler velocities and strain2003In: Echocardiography, ISSN 0742-2822, E-ISSN 1540-8175, Vol. 20, no 7, p. 581-587Article in journal (Refereed)
    Abstract [en]

    One of the major criticisms of ultrasound Doppler is its angle dependency, that is its ability to measure velocity components directly to or from the transducer only. The present article aims to investigate the impact of this angular error in a clinical setting. Apical two- and four-chamber views were recorded in 43 individuals, and the myocardium was marked by hand in each image. We assume that the main direction of the myocardial velocities is longitudinal and correct for the angular error by backprojecting measured velocities onto the longitudinal direction drawn. Strain was calculated from both corrected and uncorrected velocities in 12 segments for each individual. The results indicate that the difference between strain values calculated from corrected and uncorrected velocities is insignificant in 5 segments and within a decimal range in 11 segments. The biggest difference between measured and corrected strain values was found in the apical segments. Strain is also found to be more robust against angular error than velocities because the difference between corrected and uncorrected values is smaller for strain. Considering that there are multiple sources of noise in ultrasound Doppler measurements, the authors conclude that the angular error has so little impact on longitudinal strain that correction for this error can safely be omitted.

  • 134. Storaa, C.
    et al.
    Lind, Britta
    Department of Clinical Physiology, Karolinska Univ. Hospital Huddinge.
    Brodin, Lars-Åke
    Department of Clinical Physiology, Karolinska Univ. Hospital Huddinge.
    Distribution of left ventricular longitudinal peak systolic strain and impact of low frame rate2004In: Ultrasound in Medicine and Biology, ISSN 0301-5629, E-ISSN 1879-291X, Vol. 30, no 8, p. 1049-1055Article in journal (Refereed)
    Abstract [en]

    The myocardium has complex 3-D motion that is frequently described using ultrasound (US) Doppler techniques that are limited to recording velocities in one dimension only. Studies using 3-D tagged magnetic resonance show that the myocardium has strain components with varying angles throughout the myocardium. Despite this, there seems to be a belief that the left ventricular longitudinal strain distribution should be homogeneous. When measuring myocardial strain, there are several parameters for the clinician to decide on, one of them being recording frame rate. The current study aims to further investigate the alleged homogeneity of the longitudinal myocardial strain distribution and to discover the impact that the frame rate has on these measurements. Myocardial strain was measured in 43 healthy individuals at different frame rates. Analysis of variance results clearly demonstrate that the strain is not uniformly distributed over the wall; there seems to be an increasing strain from apex toward the base. However, subjects exist with different distributions; thus, it is not possible to conclude that certain strain patterns are normal. Reduced frame rate had a highly significant impact on the measured strain results and it is seen that, at low frame rates, the strain values were reduced. (E-mail: Camilia.Storaa@labmed.ki.se)

  • 135. Storaa, Camilla
    et al.
    Cain, Peter
    Olstad, Bjørn
    Lind, Britta
    Department of Clinical Physiology, Karolinska University Hosp. Huddinge.
    Brodin, Lars-Ake
    Division of Medical Engineering, Karolinska Institutet.
    Tissue motion imaging of the left ventricle--quantification of myocardial strain, velocity, acceleration and displacement in a single image2004In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 5, no 5, p. 375-385Article in journal (Refereed)
    Abstract [en]

    AIMS: Several methods of parametric imaging of left ventricular function including tissue velocity imaging (TVI) and strain rate imaging (SRI) have previously been presented, however, they have the limitation that they can, respectively, portray only one physiological myocardial parameter. The aims of this pilot study were to implement and validate tissue motion imaging (TMI) for the first time, a visualization technique which permits acceleration, velocity, displacement and strain to be interpreted quantitatively or semi-quantitatively in a single image.

    METHODS AND RESULTS: TMI is achieved by the color coding of temporal tissue velocity integrals. The principles behind this technique are validated, and case examples demonstrating its use in the clinical setting are provided. Limitations of the method as well as future applications and improvements are discussed.

    CONCLUSION: As this method allows representation of a multitude of variables and is visually attractive, it may facilitate more widespread use of myocardial quantitation in everyday practice.

  • 136.
    Sturm, Dennis
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Yousaf, Khurram
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Halvorsen, Kjartan
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701). Uppsala University, Uppsala, Sweden .
    Wireless kayak on-water ergometry - Part 1: Paddle blade force2013In: Sports Technology, ISSN 1934-6182, E-ISSN 1934-6190, Vol. 6, no 1, p. 29-42Article in journal (Refereed)
    Abstract [en]

    The aim of this work was to present a new wireless paddle force measurement system and to evaluate this measurement system. The system is redeveloped from a previous design and includes inertial motion sensors, which allows for the movement and inertia of the paddle to be taken into account. The system consists of two sensor nodes, designed for quick attachment to virtually any kayak paddle and an Android phone or tablet. Each sensor node measures the bending of the shaft in one plane. We derive the expressions necessary for computing the force on the paddle blade in two directions, ignoring the force in the direction of the shaft. Two different schemes for calibrating the system are presented. The accuracy and reliability of the system is evaluated in a laboratory setting using a material testing machine. An average error of 0.4% can be achieved for force measurements following directly after calibration. When the sensors are removed and reattached between calibration and measurements, average error between loading and measured force increased to 2.0% (linear model) and 1.8% (quadratic model). The limits of agreement depend on the position of the sensor nodes along the shaft and the feather angle if transverse sensitivity of the sensors is used to determine two-dimensional force on the paddle blade. On-water stroke force is presented, averaged over 10 strokes for each side with force levels >200 N to show the applicability of the study. The accuracy of the measurement is affected by the calibration method, placement of the paddle nodes and the shaft's properties.

  • 137. Sundstedt, M.
    et al.
    Hedberg, P.
    Jonason, T.
    Ringqvist, I.
    Brodin, Lars-Åke
    Department of Clinical Physiology, Huddinge University Hospital, Stockholm, Sweden.
    Henriksen, E.
    Left ventricular volumes during exercise in endurance athletes assessed by contrast echocardiography2004In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 182, no 1, p. 45-51Article in journal (Refereed)
    Abstract [en]

    Aim: The objective was to assess left ventricular (LV) volumes at rest and during upright submaximal exercise in endurance athletes to see whether changes in heart volume could explain the large predicted increase in cardiac output in endurance athletes. Method: Contrast echocardiography was used to assess changes in LV volumes during upright bicycle exercise in 24 healthy male endurance athletes. Maximal oxygen uptake and oxygen pulse were measured by using cardiopulmonary exercise testing. Results: From rest to exercise at a heart rate of 160 beats min(-1) end-diastolic volume increased by 18% (P < 0.001) and end-systolic volume decreased by 21% (P = 0.002). Stroke volume showed an almost linear increase during exercise (45% increase, P < 0.001). The increase in end-diastolic volume contributed to 73% of the increase in stroke volume. No significant differences were observed between stroke volume calculated from LV volumes with contrast echocardiography and stroke volume calculated from oxygen pulse at heart rates of 130 and 160 beats min(-1). Using the linear regression equation between oxygen uptake and cardiac output assessed by echocardiography during exercise (r = 0.87, P = 0.002), cardiac output at maximal exercise was estimated at 33 +/- 3 L min(-1), with an estimated increase in stroke volume by 69% from rest to maximal exercise. Conclusion: By using contrast echocardiography, a large increase in stroke volume in endurance athletes could be explained by an almost linear increase in end-diastolic volume and an initial small decrease in end-systolic volume during incremental upright exercise.

  • 138. Sylven, C.
    et al.
    Sarkar, N.
    Ruck, A.
    Drvota, V.
    Y-Hassan, S.
    Lind, B.
    Nygren, A.
    Kallner, G.
    Blomberg, P.
    van der Linden, J.
    Lindblom, D.
    Brodin, Lars-Åke
    Islam, K. B.
    Myocardial Doppler tissue velocity improves following myocardial gene therapy with VEGF-A(165) plasmid in patients with inoperable angina pectoris2001In: Coronary Artery Disease, ISSN 0954-6928, E-ISSN 1473-5830, Vol. 12, no 3, p. 239-243Article in journal (Refereed)
    Abstract [en]

    Background Myocardial tissue velocity and perfusion were studied in patients with severe angina pectoris following gene therapy by intramyocardial injection of phVEGF-A(165) via thoracotomy. Plasma concentrations of VEGF-A increased postoperatively. Two months after treatment anginal status and myocardial tissue velocity improved and perfusion showed a tendency to improve. Tissue velocity imaging appears to be a sensitive, objective method for detecting changes in myocardial function following gene therapy. Objective To study effects on myocardial tissue velocity and perfusion in patients with angina pectoris following intramyocardial injection of phVEGF-A(165) via thoracotomy. Design Open label, phase I/II. Methods Six patients with Canadian Cardiovascular Society (CCS) angina pectoris functional Glass III - IV and with major defects at adenosine stress single-photon emission computerized tomography (SPECT) were studied. In addition to SPECT, coronary angiography and dobutamine stress echocardiography with tissue Doppler velocity imaging were performed before and two months after gene transfer. Results Plasma concentrations of VEGF-A increased 2 to 3 times (P < 0.04) over baseline from 2 to 14 days after injection with normalization after 4 weeks. The CCS class improved about 40%, from 3.3 +/- 0.2 to 2.0 +/- 0.3 (P < 0.02) and nitroglycerine consumption decreased 30 - 40%, from 44 +/- 17 to 15 +/- 5 tablets per week (P < 0.05). The maximal systolic myocardial tissue velocity increased in all patients about 25% (P < 0.02) but did not reach the reference range. Myocardial perfusion at SPECT improved in four of the six patients. Conclusions Anginal status, myocardial tissue velocity and perfusion can be improved by phVEGF-A(165) intramyocardial injection. Tissue velocity imaging appears to be a sensitive, objective method for detecting changes in myocardial function following gene therapy. Coron Artery Dis 12:239-243

  • 139.
    Söderqvist, Emil
    et al.
    Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
    Cain, Peter
    Lind, Britta
    Division of Clinical Physiology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
    Winter, Reidar
    Nowak, Jacek
    Brodin, Lars-Åke
    Division of Clinical Physiology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
    Feasibility of creating estimates of left ventricular flow-volume dynamics using echocardiography2006In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, no 4:40Article in journal (Refereed)
    Abstract [en]

    Background:This study explores the feasibility of non-invasive assessment of left ventricular volume and flow relationship throughout cardiac cycle employing echocardiographic methods.

    Methods:Nine healthy individuals and 3 patients with severe left-sided valvular abnormalities were subject to resting echocardiography with automated endocardial border detection allowing real-time estimation of left ventricular volume throughout the cardiac cycle. Global and regional (6 different left ventricular segments) estimates of flow-volume loops were subsequently constructed by plotting acquired instantaneous left ventricular 2-D area data (left ventricular volume) vs. their first derivatives (flow).

    Results:Flow-volume loop estimates were obtainable in 75% of all echocardiographic images and displayed in normal individuals some regional morphological variation with more pronounced isovolumic events in the paraseptal segments and significantly delayed maximal systolic flow paraapically. In patients with aortic stenosis, maximal systolic flow occurred at a lower estimated left ventricular systolic volume whereas in mitral stenosis, maximal diastolic flow was observed at a higher estimated left ventricular diastolic volume. Aortic regurgitation caused a complex alteration of the estimated flow-volume loop shape during diastole.

    Conclusion:Non-invasive assessment of left ventricular flow-volume relationship with echocardiography is technically feasible and reveals the existence of regional variation in flow-volume loop morphology. Valvular abnormalities cause a clear and specific alteration of the estimates of the normal systolic or diastolic flow-volume pattern, likely reflecting the underlying pathophysiology.

  • 140.
    Söderqvist, Emil
    et al.
    KTH, Superseded Departments, KTH Syd.
    Carlsson, Camilla
    Brodin, Lars-Åke
    Conductance measurements in the left ventricle: a pressure-flow approach2002In: IFMBE proc., 2002, p. 1012-3Conference paper (Refereed)
  • 141.
    Söderqvist, Emil
    et al.
    Department of Medical Engineering, Karolinska Institutet, Stockholm, Sweden.
    Hultman, Jan
    Källner, Göran
    Nowak, Jacek
    Brodin, Lars-Åke
    Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden.
    The assessment of acute load and contractility changes by left ventricular pressure measurements2006In: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, Vol. 27, no 12, p. 1281-1292Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to establish whether analysis of the left ventricular pressure waveform provides indicative information about cardiac load and contractility and to develop an algorithm for computer-based assessment of changes in these variables. In eight healthy standard breed anaesthetized open-chest pigs, a high frequency response guide-wire mounted pressure sensor was introduced into the left ventricle. Preload reduction was induced by vena cava occlusion, afterload increase by an i.v. injection of phenylephrine and increased contractility by an i.v. injection of adrenalin. Left ventricular pressure waveform analysis was performed by plotting the slope of the pressure curve during the systolic ejection period versus maximal systolic pressure. The analysis revealed characteristic changes in left ventricular pressure and pressure waveform and identified easily discernible reaction patterns in the slope versus maximal pressure plot, specific for each provocation. Analysis of the left ventricular waveform provides indicative information about loading conditions and contractility. The proposed algorithm can easily be implemented in pressure monitoring systems allowing real-time assessment and discrimination of acute changes in preload, afterload and myocardial performance.

  • 142.
    Söderqvist, Emil
    et al.
    KTH, Superseded Departments, KTH Syd.
    Lang, Helmuth
    Källner, Göran
    Hultman, Jan
    Lind, Britta
    KTH, Superseded Departments, KTH Syd. KTH, School of Technology and Health (STH).
    Brodin, Lars-Åke
    Left ventricular pressure indicies help to evaluate loading conditions and contractility2002In: IFMBE proc, ISSN 1680-0737, p. 1014-5Article in journal (Refereed)
  • 143.
    Söderqvist, Emil
    et al.
    KTH, Superseded Departments, KTH Syd.
    Storaa, Camilla
    KTH, School of Engineering Sciences (SCI), Physics.
    Ericsson, Anders B.
    Brodin, Lars-Åke
    Ultrasound tissue doppler measurements imply that conductance changes in the left ventricle during isovolumic phases are due to tissue motion.2002In: IFMBE proc.,, 2002, p. 1016-7Conference paper (Refereed)
  • 144. Torp, A. H.
    et al.
    Rabben, S. I.
    Stoylen, A.
    Ihlen, H.
    Andersen, K.
    Brodin, Lars-Åke
    Huddinge University Hospital, Stockholm, Sweden.
    Olstad, B.
    Automatic detection and tracking of left ventricular landmarks in echocardiography2004In: 2004 IEEE Ultrasonics Symposium, Vols 1-3 / [ed] Yuhas, MP, 2004, p. 474-477Conference paper (Refereed)
    Abstract [en]

    We introduce a method for automatic detection and tracking of the apex and two landmarks defining the atrioventricular plane in apical views of the left ventricle. The method is based on using tissue Doppler to track a set of candidate points in a cardiac cycle. Each candidate point is given a score based on the gray-scale, the velocity, and depth profiles. The landmarks with the lowest costs are selected, and measurements are calculated automatically. The method is evaluated by comparing with manual selection by four cardiologists, and the presented results show that the method is robust and extracted measurements are comparable with manual selection.

  • 145.
    Valastyán, Iván
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Elmqvist, Håkan
    KTH, School of Technology and Health (STH), Medical Engineering.
    Kerek, Andras
    KTH, School of Technology and Health (STH), Medical Engineering.
    Molnar, J.
    Novak, D.
    Ribbe, T.
    Gated tomographic imaging in ectomography using a dynamic heart phantom2007In: Nuclear Science Symposium Conference Record, 2007. NSS '07. IEEE, IEEE , 2007, p. 3414-3417Conference paper (Refereed)
    Abstract [en]

    A new computer controlled dynamic heart phantom and the connection of an ECG unit to a tomographic gamma camera system, developed for ectomographic imaging, is presented. The phantom is used for validation of the camera. Measurements were performed to test the phantom as well as to study the feasibility of gated imaging in ectomography. The camera is intended for early diagnosis of myocardial and cerebral infarctions.

  • 146. Valzania, Cinzia
    et al.
    Gadler, Fredrik
    Winter, Reidar
    Braunschweig, Frieder
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Gudmundsson, Petri
    Borian, Giuseppe
    Eriksson, Maria J.
    Effects of cardiac resynchronization therapy on coronary blood flow: Evaluation by transthoracic Doppler echocardiography2008In: European Journal of Heart Failure, ISSN 1388-9842, E-ISSN 1879-0844, Vol. 10, no 5, p. 514-520Article in journal (Refereed)
    Abstract [en]

    Background: Relatively limited and conflicting data are available on the effects of cardiac resynchronization therapy (CRT) on coronary blood flow (CBF). Aims: To investigate changes in the left anterior descending coronary artery (LAD) flow under different CRT pacing modes by means of transthoracic Doppler echocardiography (TTE). Methods: Twenty-two responders to CRT (67 11 years) with idiopathic dilated cardiomyopathy underwent TTE assessment of LAD flow and Tissue Velocity Imaging during 4 programming modes: intrinsic conduction (IC), right ventricular pacing (RV), simultaneous biventricular pacing (BVP), BVP with left ventricular (LV) pre-activation. Results: Mean coronary flow velocity (CFV) was increased by simultaneous BVP (p = 0.0063 vs. IC) and BVP with LV pre-activation (p<0.0001 vs. IC; p=0.027 vs. simultaneous BVP). Peak CFV and LAD flow velocity/time integral were highest during BVP with LV pre-activation. A reduction in septal-to-lateral delay and an increase in peak systolic velocity in the basal septum were observed during simultaneous BVP and BVP with LV pre-activation. Conclusions: In CRT responders with idiopathic dilated cardiomyopathy, an increase in LAD flow, assessed by TTE, was observed during simultaneous BVP and BVP with LV pre-activation. This was associated with an improvement in regional myocardial contraction and a decrease in intraventricular dyssynchrony.

  • 147. Wandt, B.
    et al.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Lundback, S.
    Misinterpretation about the contribution of the left ventricular long-axis shortening to the stroke volume2006In: American Journal of Physiology. Heart and Circulatory Physiology, ISSN 0363-6135, E-ISSN 1522-1539, Vol. 291, no 5, p. H2550-H2550Article in journal (Refereed)
  • 148. Westholm, Carl
    et al.
    Bjällmark, Anna
    KTH, School of Technology and Health (STH), Medical Engineering.
    Larsson, Matilda
    KTH, School of Technology and Health (STH), Medical Engineering.
    Jacobsen, Per
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Winter, Reidar
    Velocity tracking, a new and user independent method for detecting regional function of the left ventricle2009In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 29, no 1, p. 24-31Article in journal (Refereed)
    Abstract [en]

    The use of two-dimensional echocardiography (2D echo) for detection of ischaemia is limited due to high user dependency. Longitudinal motion is sensitive for ischaemia and usable for quantitative measurement of longitudinal myocardial function but time consuming. Velocity tracking (VeT) is a new method that gives an easy three-dimensional understanding of both systolic and diastolic regional motion, using colour coded bull's eye presentation of longitudinal velocity, derived from colour coded tissue Doppler. The aim of this study was to test the accuracy of VeT in detecting ischaemia in non-ST-segment elevation myocardial infarction (NSTEMI) patients bedside. Twenty patients with NSTEMI and 10 controls were included. Echocardiography was performed within 24 h of symptoms and prior to coronary angiography. Bull's eye plots presenting the peak systolic velocity (PSV) and the sum of PSV and the E-wave-velocity (PSV+E) were created using our developed software. VeT was compared to expert wall motion scoring (WMS) and bedside echo. We used the clinical conclusion based on ECG, angiography and clinical picture as 'gold standard'. Sensitivity for ischaemia with VeT (PSV+E) was 85% and specificity 60%. The corresponding sensitivities for expert WMS were 75% (specificity 40%). For regional analysis VeT and WMS showed comparable results with correct regional outcome in 11/20 of patients both superior to bedside echo. Velocity tracking is a promising technique that provides an easily understandable three-dimensional bull's eye plot for assessment of regional left ventricular longitudinal velocity with great potential for detection of regional dysfunction and myocardial ischaemia.

  • 149. Willenheimer, R.
    et al.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering. Karolinska Universitetssjukhuset Huddinge, Sweden.
    Boman, K.
    Hagerman, I.
    Dahlström, U. L. F.
    Definition av diastolisk hjärtsvikt2007In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 104, no 34, p. 2333-2337Article in journal (Refereed)
  • 150. Winter, R.
    et al.
    Mobasseri, Y.
    Nowak, J.
    Saha, S.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Colour-coded tissue tracking is an accurate, fast, and simple tool for identification of non-ischemic patients in the hand of inexperienced stress echocardiography reader2006In: Journal of the American College of Cardiology, ISSN 0735-1097, E-ISSN 1558-3597, Vol. 47, no 4, p. 124A-124AArticle in journal (Other academic)
1234 101 - 150 of 154
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