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  • 1.
    Govind, Satish C.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Myocardial Effects of Type 2 Diabetes, Co-morbidities, and Changing Loading Conditions: a Clinical Study by Tissue Velocity Echocardiography2007Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Ever since the validation of the tissue velocity echocardiography (TVE) technique more than a decade ago the modality has been used rather successfully in various clinical situations, at rest as well as during stress echocardiography. Hitherto, dobutamine stress echocardiography has been the hallmark of all forms of stress procedures, now with TVE, quantification of the longitudinal motions of the left ventricle shows far superiority, with improved sensitivity and specificity in the functional diagnosis of coronary artery disease. Morever there has been continued interest in this technique for even assessing subclinical myocardial systolic and diastolic function in clinical scenarios like diabetes, hypertension and chronic kidney disease.

    The aim of the present study was to evaluate left ventricular myocardial functions by applying TVE in human subjects having type 2 diabetes with or without co-morbidities and during changing loading conditions. The effects of changing loading conditions were analyzed during hemodialysis and following oral administration of an AT1 receptor blocker. The studied subjects included individuals with diabetes as well as those with associated hypertension, coronary artery disease, microalbuminuria and end-stage renal disease. All patients with type 2 diabetes and co-morbidities underwent TVE enhanced dobutamine stress echocardiography while load dependant left ventricular functions were analyzed at rest. There were 270 subjects in the study of type 2 diabetes and associated cardiovascular diseases and 101 subjects in the study of changing loading conditions.

    Patients with type 2 diabetes revealed subclinical left ventricular dysfunction characterized by reduced functional reserve. This influence becomes quantitatively more pronounced in the presence of coexistent coronary artery disease and hypertension. The coexistence of type 2 diabetes and hypertension appears to have additive negative effect on both systolic and diastolic left ventricular function, even in the absence of coronary artery disease. The presence of microalbuminuria in type 2 diabetes patients does not worsen diminished myocardial functional reserve. A single session of hemodialysis improves left ventricular function in patients with end-stage renal disease only in the absence of type 2 diabetes and co-morbidities, while a single dose of an AT1 receptor blocker valsartan results in reduction of afterload and, subsequently, in improvement of left ventricular function. TVE appears to be a sensitive tool for objective assessment of left ventricular function and can be successfully applied for the clinical evaluation of the effect of type 2 diabetes and co-morbidities on myocardial performance.

  • 2.
    Govind, Satish C.
    et al.
    BMJ Heart Center, Bangalore, India.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Nowak, J.
    Karolinska Institute, Department of Clinical Physiology, Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Arvind, S. R.
    BMJ Heart Center, Bangalore, India.
    Ramesh, S. S.
    BMJ Heart Center, Bangalore, India.
    Netyö, A.
    Karolinska Institute, Department of Clinical Physiology, Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Prasad, K.Y.M.
    BMJ Heart Center, Bangalore, India.
    Saha, S.
    Karolinska Institute, Department of Clinical Physiology, Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Microalbuminuria and Left Ventricular Functions in Type 2 Diabetes: A Quantitative Assessment by Stress Echocardiography in the Myocardial Doppler in Diabetes (MYDID) Study III2007In: International Journal of Cardiology, ISSN 0167-5273, E-ISSN 1874-1754, Vol. 41, no 6, p. 363-369Article in journal (Refereed)
    Abstract [en]

    Background. Left ventricular (LV) function might be altered in type 2 diabetes (DM) and microalbuminuria (MA) may accentuate the abnormalities. We sought to investigate whether additional LV dysfunction could be unmasked using tissue Doppler (TVE)-enhanced dobutamine stress echocardiography (TVE-DSE) in patients with DM+MA. Methods. Twenty seven DM subjects with MA, (DM+MA), 31 DM subjects without MA (DM-MA), and 13 Controls were evaluated using TVE-DSE. LV basal peak systolic (PSV), early (E') and late (A') diastolic velocities (cm/sec) at rest and peak stress were post-processed. LV filling pressure was assessed using E/E'ratio. Results. PSV and E'velocity at peak stress in the respective three groups were 13.7±1.0, 10.1±1.1, 10.0±1.2 for PSV; and 10.0±1.6, 5.0±1.4, 4.8±1.4 for E' (p < 0.001 for controls vs. both groups). E/E' at rest was 7.9±0.7 in the controls, 10.8±2.4 in DM-MA, and 11.0±2.2 in DM+MA (p < 0.01 Controls vs. both the DM groups). Conclusions. Patients with DM+MA do not have additional LV regional systolic and diastolic dysfunctions compared with DM-MA, as revealed by TVE-DSE, when controlled for glycemia levels, lipids, and treatment strategies.

  • 3.
    Govind, Satish C.
    et al.
    BMJ Heart Center, Bangalore, India.
    Brodin, Lars-Åke
    Department of Clinical Physiology, Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Nowak, J.
    Department of Clinical Physiology, Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Quintana, M.
    Department of Clinical Physiology, Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Raumina, S.
    Department of Clinical Physiology, Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Ramesh, S.S.
    BMJ Heart Center, Bangalore, India.
    Keshava, R.
    BMJ Heart Center, Bangalore, India.
    Saha, S.
    Department of Clinical Physiology, Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Isolated Type 2 Diabetes mellitus Causes Myocardial Dysfunction That Becomes Worse in the Presence of Cardiovascular Diseases: Results of the Myocardial Doppler in Diabetes (MYDID): Study 12005In: Cardiology, ISSN 0008-6312, E-ISSN 1421-9751, Vol. 103, no 4, p. 189-195Article in journal (Refereed)
    Abstract [en]

    Aims: Patients with type 2 diabetes mellitus (DM) often suffer disproportionately and have a worse outcome when burdened with cardiovascular complications compared with those without DM. A specific heart muscle disease reportedly caused by DM per se may explain this. We sought to investigate whether an echo Doppler diagnosis of such a myocardial disease is clinically relevant in DM with or without coexistent coronary artery disease (CAD) and/or hypertension ( HTN). Subjects and Methods: Two hundred subjects (127 males, 73 females, 56 +/- 10 years) including controls (n=23), patients with HTN (n=20), CAD (n=35), uncomplicated DM (n=59), DM+HTN (n=27), DM+ CAD (n=16) and DM+CAD+HTN (n=20) underwent tissue Doppler-enhanced dobutamine stress echocardiography. Myocardial function was assessed by measuring left ventricular myocardial peak systolic velocity (PSV) and early diastolic velocity at rest and during peak stress, besides measurements of standard Doppler variables. Results: Average left ventricular PSV at rest was significantly lower in CAD (4.7 +/- 1.5) compared with controls (5.7 center dot +/- 1.2) and in DM+CAD+HTN (4.6 +/- 1.4) compared with DM (5.6 +/- 1.3; all p < 0.05). During peak stress, lower PSV persisted in CAD (9.5 +/- 3.1) and DM+CAD+HTN (8.1 +/- 2.7), while appearing de novo in DM (11.3 +/- 2.6) and HTN (11.0 +/- 2.3) unlike in the controls (12.5 +/- 2.5; all p < 0.001). When pooled together, DM subjects with CAD and/or HTN or both had significantly lower PSV (9.1 +/- 2.7) than those without (10.0 +/- 2.8; p < 0.001). Early diastolic velocity response was equally lower in both groups compared with the controls. Conclusion: The results suggest that dobutamine stress unmasks myocardial functional disturbances caused by uncomplicated DM. The discrete disturbances become quantitatively more pronounced in the presence of coexistent cardiovascular diseases.

  • 4.
    Govind, Satish C.
    et al.
    BMJ Heart Center, Department of Non-invasive Cardiology, Bangalore, India.
    Brodin, Lars-Åke
    Department of Clinical Physiology, Karolinska University Hospital at Huddinge.
    Nowak, J.
    BMJ Heart Center, Department of Non-invasive Cardiology, Bangalore, India.
    Ramesh, S. S.
    BMJ Heart Center, Department of Non-invasive Cardiology, Bangalore, India.
    Saha, S. K.
    Department of Clinical Physiology, Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Acute administration of a single dose of valsartan improves left ventricular functions: a pilot study to assess the role of tissue velocity echocardiography in patients with systemic arterial hypertension in the TVE-valsartan study I2006In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 26, no 6, p. 351-356Article in journal (Refereed)
    Abstract [en]

    Background The advent of colour-coded tissue velocity echocardiography (TVE) has now made it possible to quantify left ventricular (LV) functions in patients with systemic arterial hypertension (HTN).

    Hypothesis In this project, we have studied the cardiac effects of a single dose of orally administered valsartan in patients with known HTN.

    Methods Fifty-five patients with HTN with a mean age of 56 +/- 10 years were given an early morning dose of 80 mg valsartan withholding regular antihypertensive medications on the day of investigation. TVE images, acquired on VIVID systems were digitized for postprocessing of longitudinal and radial peak systolic velocities, strain rate, and systolic and diastolic time intervals before (pre) and 5 h after (post) administration of the drug.

    Results Blood pressure (mmHg) pre and post, respectively, were 147 +/- 15 versus 137 +/- 14 systolic and 90 +/- 7 versus 86 +/- 7 diastolic (all P < 0.01). LV longitudinal systolic velocities (cm s(-1)) were significantly higher post in LV septum (5.7 +/- 1.1 versus 6.4 +/- 1.6; P < 0.001) with similar results obtained in other LV walls. Radial strain rate (1 s(-1)) was significantly higher post compared with pre valsartan (2.1 +/- 0.6 versus 2.3 +/- 0.9; P < 0.01). Regional diastolic filling and ejection times (ms) were significantly shorter post (390 +/- 122 versus 370 +/- 120 and 275 +/- 32 versus 163 +/- 36 respectively; all P < 0.05).

    Conclusions Within 5 h after oral administration of valsartan, improvement in regional myocardial systolic functions could be registered. Although the changes could well be secondary to afterload reduction, additional effects of the drug, evidenced by improved strain rate that is relatively load-independent, may have contributed in this improvement.

  • 5. Govind, Satish C.
    et al.
    Gopal, Aasha S.
    Netyo, Anita
    Nowak, Jacek
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Patrianakos, Alexandros
    Ramesh, S. S.
    Saha, Samir
    Quantification of low-dose dobutamine stress using speckle tracking echocardiography in coronary artery disease2009In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 10, no 5, p. 607-612Article in journal (Refereed)
    Abstract [en]

    Aims We sought to evaluate the utility of speckle tracking echocardiography (STE) for detecting left ventricular (LV) mechanical abnormalities during low-dose (20 mu g) dobutamine stress (DSE). Methods and results Twenty-nine patients (56 +/- 12 years) with a history of recent acute coronary events (ACE) underwent STE-DSE. Left ventricular images, sampled at frame rates 70-100 Hz, were analysed off-line (Echopac BT 6.0.0). Velocity, strain, and rotational imaging were performed. Twenty patients had LV ejection fraction (EF) >40% (Group 1) whereas nine patients had LVEF <40% (Group 2). Average heart and frame rates were identical during DSE in the two groups (P = ns). Global circumferential strain (%) was significantly lower in Group 2 compared with Group 1 (10.65 +/- 5.30 vs. 16.82 +/- 6.61; P < 0.05) at rest and during peak stress (14.72 +/- 6.51 vs. 21.13 +/- 7.2; P < 0.05). The global peak rotation rate (degree/s) was, however, higher at rest in Group 2 (70 +/- 97 vs. 19 +/- 67; P < 0.05) and 20 mu g stress. Peak systolic velocity increased in three of the four LV walls at 20 mu g ( in Groups 1 and 2). A global rotational rate increased significantly at 20 mu g during systole in both the groups, but was unchanged in Group 2 during diastole. Conclusions Speckle tracking echocardiography dobutamine stress appears to provide comprehensive information on LV mechanical status in the aftermath of ACE. The modality may help risk stratify such patients.

  • 6.
    Govind, Satish C.
    et al.
    Bhagwan Mahavir Jain Heart Center, Bangalore, India.
    Roumina, S.
    Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Nowak, J.
    Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Ramesh, S. S.
    Bhagwan Mahavir Jain Heart Center, Bangalore, India.
    Saha, S. K.
    Karolinska University Hospital at Huddinge, Stockholm, Sweden.
    Differing myocardial response to a single session of hemodialysis in end-stage renal disease with and without type 2 diabetes mellitus and coronary artery disease2006In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 4, no 9Article in journal (Refereed)
    Abstract [en]

    Background: Though hemodialysis (HD) acutely improves cardiac function, the impact of background diseases like coronary artery disease (CAD) and Type 2 diabetes (DM) in the setting of end-stage renal disease (ESRD) is not known. Tissue velocity echocardiography (TVE) offers a fast choice to follow changes in myocardial function after HD in ESRD with concomitant DM and/or CAD. Methods: 46 subjects (17 with ESRD, Group 1; 15 with DM, Group 2; 14 with DM+CAD, Group 3) underwent standard and TVE prior to and shortly after HD. Besides standard Doppler variables, regional myocardial systolic and diastolic velocities, as well as systolic strain rate were post processed. Results: Compared with pre-HD, post-HD body weight (kg) significantly decreased in all the three groups (51 ± 9 vs. 48 ± 8, 62 ± 10 vs.59 ± 10, and 61 ± 9 vs. 58 ± 9 respectively; all p < 0.01). Left ventricular end diastolic dimensions (mm) also decreased post- HD (46 ± 5 vs. 42 ± 7, 53 ± 7 vs. 50 ± 7, 51 ± 7 vs. 47 ± 8 respectively; all p < 0.01). Regional longitudinal peak systolic velocity in septum (cm/s) significantly increased post-HD in Group 1(5.7 ± 1.6 vs. 7.2 ± 2.3; p < 0.001) while remained unchanged in the other two groups. Similar trends were noted in other left ventricular walls. When the myocardial velocities (cm/s) were computed globally, the improvement was seen only in Group 1 (6.3 ± 1.5 vs. 7.9 ± 2.0; p < 0.001). Global early regional diastolic velocity (cm/s) improved in Group 1, remained unchanged in Group 2, while significantly decreased in Group 3(-5.9 ± 1.3 vs. -4.1 ± 1.8; p < 0.01). Global systolic strain rate (1/sec) increased in the first 2 Groups but remained unchanged (-0.87 ± 0.4 vs. -0.94 ± 0.3; p = ns) in Group 3. Conclusion: A single HD session improves LV function only in ESRD without coexistent DM and/or CAD. The present data suggest that not only dialysis-dependent changes in loading conditions but also co-existent background diseases determine the myocardial response to HD.

  • 7.
    Govind, Satish C.
    et al.
    Department of Clinical Physiology, Karolinska Institute, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
    Saha, S.
    Department of Clinical Physiology, Karolinska Institute, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
    Brodin, Lars-Åke
    Department of Clinical Physiology, Karolinska Institute, Karolinska University Hospital, Huddinge.
    Ramesh, S. S.
    BMJ Heart Center, Bangalore, India.
    Arvind, S. R.
    BMJ Heart Center, Bangalore, India.
    Quintana, M.
    Department of Clinical Physiology, Karolinska Institute, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
    Impaired Myocardial Functional Reserve in Hypertension and Diabetes Mellitus Without Coronary Artery Disease: Searching for the Possible Link With Congestive Heart Failure in the Myocardial Doppler in Diabetes (MYDID) Study II2006In: American Journal of Hypertension, ISSN 0895-7061, E-ISSN 1941-7225, Vol. 19, no 8, p. 851-857Article in journal (Refereed)
    Abstract [en]

    Background: Although the impact of type 2 diabetes mellitus (DM) and hypertension (HTN) on myocardial function has recently been studied using tissue Doppler echocardiography (TDE), the independent role of both conditions, and the influence of other risk factors on myocardial function has not been completely defined, particularly in absence of coronary artery disease (CAD). The aim of this study was to assess the myocardial functional reserve in patients with DM or HTN with apparently normal left ventricular (LV) systolic function.

    Methods: Standard and dobutamine stress echocardiography using TDE was performed in 128 subjects: 59 had DM, 20 had HTN, 27 had both DM and HTN (HTN + DM), and 22 subjects were controls (C). Subjects with known CAD and depressed LV function were excluded. In addition, standard two-dimensional and Doppler measurements, LV regional peak systolic (PSV), early (E') and late (A') diastolic velocities, strain (S%) and strain rate (SR), were assessed at rest and peak stress.

    Results: The LV mass did not differ, although relative wall thickness was significantly higher in subjects with HTN + DM and HTN. The PSV did not differ at rest but was lowest in subjects with HTN + DM at peak stress. The E' wave velocity was significantly lower in subjects with HTN + DM both at rest and during peak stress, as were S% and SR.

    Conclusions: The addition of DM to HTN has a negative effect on LV systolic and diastolic functions. A depressed myocardial functional reserve might be postulated as one of the pathophysiologic mechanisms for the excessive occurrence of congestive heart failure in patients with DM or HTN.

  • 8.
    Venkateshvaran, Ashwin
    et al.
    KTH, School of Technology and Health (STH).
    Sola, S.
    Govind, Satish Chandra
    KTH, School of Technology and Health (STH).
    Dash, P. K.
    Barooah, B.
    Shahgaldi, Kambiz
    KTH, School of Technology and Health (STH).
    Sahlén, Anders
    KTH, School of Technology and Health (STH).
    Lund, L.
    Winter, Reidar
    KTH, School of Technology and Health (STH).
    Nagy, A. I.
    Manouras, Aristomenis
    KTH, School of Technology and Health (STH).
    The impact of arterial load on left ventricular performance: An invasive haemodynamic study in severe mitral stenosis2015In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 593, no 8, p. 1901-1912Article in journal (Refereed)
    Abstract [en]

    Key points: A hallmark of mitral stenosis (MS) is the markedly altered left ventricular (LV) loading. As most of the methods used to determine LV performance in MS patients are influenced by loading conditions, previous studies have shown conflicting results. The present study calculated LV elastance, which is a robust method to quantify LV function. We demonstrate that LV loading in MS patients is elevated but normalizes after valve repair and might be a result of reflex pathways. Additionally, we show that the LV in MS is less compliant than normal due to a combination of right ventricular loading and the valvular disease itself. Immediately after valve dilatation the increase in blood inflow into the LV results in even greater LV stiffness. Our findings enrich our understanding of heart function in MS patients and provide a simple reproducible way of assessing LV performance in MS. Left ventricular (LV) function in rheumatic mitral stenosis (MS) remains an issue of controversy, due to load dependency of previously employed assessment methods. We investigated LV performance in MS employing relatively load-independent indices robust to the altered loading state. We studied 106 subjects (32 ± 8 years, 72% female) with severe MS (0.8 ± 0.2 cm2) and 40 age-matched controls. MS subjects underwent simultaneous bi-ventricular catheterization and transthoracic echocardiography (TTE) before and immediately after percutaneous transvenous mitral commisurotomy (PTMC). Sphygmomanometric brachial artery pressures and TTE recordings were simultaneously acquired in controls. Single-beat LV elastance (E<inf>es</inf>) was employed for LV contractility measurements. Effective arterial elastance (E<inf>a</inf>) and LV diastolic stiffness were measured. MS patients demonstrated significantly elevated afterload (E<inf>a</inf>: 3.0 ± 1.3 vs. 1.5 ± 0.3 mmHg ml-1; P < 0.001) and LV contractility (E<inf>es</inf>: 4.1 ± 1.6 vs. 2.4 ± 0.5 mmHg ml-1; P < 0.001) as compared to controls, with higher E<inf>a</inf> in subjects with smaller mitral valve area (≤ 0.8 cm2) and pronounced subvalvular fusion. Stroke volume (49 ± 16 to 57 ± 17 ml; P < 0.001) and indexed LV end-diastolic volume (LVEDV<inf>index</inf>: 57 ± 16 to 64 ± 16 ml m-2; P < 0.001) increased following PTMC while E<inf>es</inf> and E<inf>a</inf> returned to more normal levels. Elevated LV stiffness was demonstrated at baseline and increased further following PTMC. Our findings provide evidence of elevated LV contractility, increased arterial load and increased diastolic stiffness in severe MS. Following PTMC, both LV contractility and afterload tend to normalize.

  • 9.
    Venkateshvaran, Ashwin
    et al.
    KTH, School of Technology and Health (STH).
    Sola, Srikanth
    Govind, Satish Chandra
    Dash, Pravat Kumar
    Vyavahare, Sagar
    Lund, Lars H.
    la Merkely, Be
    Nagy, Anik Ilona
    Manouras, Aristomenis
    Arterial-ventricular and interventricular interaction in isolated post-capillary and combined pulmonary hypertension in severe mitral stenosis2016In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 116, no 8, p. 1545-1554Article in journal (Refereed)
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