OBJECTIVES: Decreased right ventricular (RV) longitudinal function following coronary artery bypass grafting (CABG), as assessed by tricuspid annular systolic excursion (TAPSE) and RV peak systolic velocity (RVS') is a known condition. We aimed to explore the feasibility of the right ventricular index of myocardial performance (RIMP) in the assessment of RV function after CABG at rest and during peak dobutamine stress echocardiography (DSE). METHODS: Forty-two patients indicated for CABG were included in this study. Coronary angiography, DSE and exercise bicycle test were performed within 6 weeks before and 3 months after CABG. The RIMP, RVS' and TAPSE at the lateral tricuspid annulus were also assessed. The results were presented as mean +/- standard deviation. RESULTS: The RIMP improved after CABG both at rest (0.45 +/- 0.11 before vs 0.38 +/- 0.08 after CABG, P= 0.013) and during DSE (0.75 +/- 0.23 vs 0.49 +/- 0.14, P < 0.001). TAPSE declined significantly when comparing the values from before CABG to after CABG both at rest (23.9 +/- 4.46 vs 14.6 +/- 3.67, P < 0.001) and during DSE (20.9 +/- 4.16 vs 11.9 +/- 3.60, P < 0.001). RVS' also decreased after CABG both at rest (11.9 +/- 2.40 vs 8.5 +/- 1.93, P < 0.001) and during DSE (15.6 +/- 4.30 vs 10.5 +/- 3.21, P <0.001). On the other hand, exercise capacity improved after CABG compared with baseline (128.4 +/- 40.12 W vs 142.1 +/- 46.73 W, P = 0.014). CONCLUSIONS: RIMP improved after CABG both at rest and during DSE. The reduction in TAPSE and RVS' after CABG indicate reduced regional mechanical RV function along the long axis rather than reduced global RV function.

Objective Minimally invasive aortic valve replacementsurgery (MIAVR) is an alternative surgical technique to conventional aortic valve replacement surgery (AVR) in selected patients. The randomised study Cardiac Function after Minimally Invasive Aortic Valve Implantation (CMILE) showed that right ventricular (RV) longitudinal function was reduced after both MIAVR and AVR, but the reduction was more pronounced following AVR. However, postoperative global RV function was equally impaired in both groups. The purpose of this study was to explore alterations in RV mechanics and contractility following MIAVR as compared with AVR. Methods A predefined post hoc analysis of CMILE consisting of 40 patients with severe aortic valve stenosis who were eligible for isolated surgical aortic valve replacement were randomised to MIAVR or AVR. RV function was assessed by echocardiography prior to surgery and 40 days post-surgery. Results Comparing preoperative to postoperative values, RV longitudinal strain rate was preserved following MIAVR (-1.5 +/- 0.5 vs -1.5 +/- 0.4 1/s, p=0.84) but declined following AVR (-1.7 +/- 0.3 vs -1.4 +/- 0.3 its, p<0.01). RV longitudinal strain reduced following AVR (-27.4 +/- 2.9% vs -18.8%+/- 4.7%, p<0.001) and MIAVR (-26.5 +/- 5.3% vs -20.7%+/- 4.5%, p<0.01). Peak systolic velocity of the lateral tricuspid annulus reduced by 36.6% in the AVR group (9.3 +/- 2.1 vs 5.9 +/- 1.5 cm/s, p<0.01) and 18.8% in the MIAVR group (10.1 +/- 2.9 vs 8.2 +/- 1.4 cm/s, p<0.01) when comparing preoperative values with postoperative values. Conclusions RV contractility was preserved following MIAVR but was deteriorated following AVR. RV longitudinal function reduced substantially following AVR. A decline in RV longitudinal function was also observed following MIAVR, however, to a much lesser extent.

BACKGROUND: A novel polymer-shelled contrast agent (CA) with multimodal imaging and target specific potential was developed recently and tested for its acoustical properties using different in-vitro setups.

OBJECTIVE: The aim of this study was to investigate the elimination of three types of the novel polymer-shelled CA, one unmodified and two shell modified versions, in rats.

METHODS: The blood elimination time was estimated by measuring the image intensity, from ultrasound images of the common carotid artery, over time after a bolus injection of the three types of the novel CA. The commercially available CA SonoVue was used as a reference. The subcellular localization of the three CAs was investigated using transmission electron microscopy.

RESULTS: The ultrasound measurements indicated a blood half-life of 17–85 s for the different types of the novel CA, which was significant longer than the blood half-life time for SonoVue. Additionally, CAs were exclusively found in the circulatory system, either taken up by, or found in the vicinity of macrophages.

CONCLUSIONS: Compared to the commercially available CA SonoVue, the blood circulation times for the three types of the novel polymer-shelled CA were prolonged. Moreover, macrophages were suggested to be responsible for the elimination of the CA.

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.

Combinations of microbubbles (MBs) and superparamagnetic iron oxide nanoparticles (SPIONs) are used to fabricate dual contrast agents for ultrasound and MRI. This study examines the viscoelastic and oscillation characteristics of two MB types that are manufactured with SPIONs and either anchored chemically on the surface (MBs-chem) or physically embedded (MBs-phys) into a polymer shell. A linearized Church model was employed to simultaneously fit attenuation coefficients and phase velocity spectra that were acquired experimentally. The model predicted lower viscoelastic modulus values, undamped resonance frequencies and total damping ratios for MBs-chem. MBs-chem had a resonance frequency of approximately 13 MHz and a damping ratio of approximately 0.9; thus, MBs-chem can potentially be used as a conventional ultrasound contrast agent with the combined functionality of MRI detection. In contrast, MBs-phys had a resonance frequency and damping of 28 MHz and 1.2, respectively, and requires further modification of clinically available contrast pulse sequences to be visualized.

Background: A novel polymer-shelled contrast agent (CA) with multimodal and target-specific potential was developed recently. To determine its ultrasonic diagnostic features, we evaluated the endocardial border delineation as visualized in a porcine model and the concomitant effect on physiological variables. Methods: Three doses of the novel polymer-shelled CA (1.5 ml, 3 ml, and 5 ml [5 x 10(8) microbubbles (MBs)/ml]) and the commercially available CA SonoVue (1.5 ml [2-5 x 10(8) MBs/ml]) were used. Visual evaluations of ultrasound images of the left ventricle were independently performed by three observers who graded each segment in a 6-segment model as either 0 = not visible, 1 = weakly visible, or 2 = visible. Moreover, the duration of clinically useful contrast enhancement and the left ventricular opacification were determined. During anesthesia, oxygen saturation, heart rate, and arterial pressure were sampled every minute and the effect of injection of CA on these physiological variables was evaluated. Results: The highest dose of the polymer-shelled CA gave results comparable to SonoVue. Thus, no significant difference in the overall segment score distribution (2-47-95 vs. 1-39-104), time for clinically sufficient contrast enhancement (20-40 s for both) and left ventricular overall opacification was found. In contrast, when comparing the endocardial border delineation capacity for different regions SonoVue showed significantly higher segment scores for base and mid, except for the mid region when injecting 1.5 ml of the polymer-shelled CA. Neither high nor low doses of the polymer-shelled CA significantly affected the investigated physiological variables. Conclusions: This study demonstrated that the novel polymer-shelled CA can be used in contrast-enhanced diagnostic imaging without influence on major physiological variables.

Aims: Myocardial performance index (MPI) is a measure of combined systolic and diastolic myocardial function. In patients with coronary artery disease (CAD) an increase in MPI is consistent with myocardial dysfunction. The objectives of this study were to characterize the changes in MPI after coronary artery bypass graft (CABG) at rest and at peak dobutamine stress echocardiography (DSE). Methods and Results: Thirty-six patients diagnosed with CAD and accepted for CABG were studied by standard echocardiography and DSE 1 month prior and 3 month after CABG. The MPI was calculated using pulsed-wave tissue Doppler imaging (PW-TDI) of the left ventricular (LV) wall-motion velocity. At baseline, ejection fraction (EF; 42.7 ± 8%) and wall-motion score index (WMSI; 1.1 ± 0.2) were impaired at rest as well as at peak DSE (EF; 49.2 ± 9 and WMSI 1.4 ± 0.2). MPI was prolonged both at rest (0.61 ± 0.13) and at peak DSE (0.78 ± 0.16). After CABG, EF and WMSI did not improve at rest (43.7 ± 8% and 1.1 ± 0.2, respectively). On the other hand, MPI improved substantially both at rest (0.45 ± 0.08; P < 0.001) and at peak DSE (0.56 ± 0.1; P < 0.001). At peak DSE an improvement of EF (54.2 ± 9; P < 0.05) and WMSI (1.1 ± 0.16; P < 0.001) was seen as well. Conclusion: Myocardial performance index shows significant improvement after CABG in patients with CAD both at rest and peak DSE and appears to be a sensitive measure of myocardial function.

Objective: Tissue Doppler imaging (TDI) is a promising echocardiographic modality allowing quantification of myocardial performance. However, the prognostic potential of TDI in patients with acute myocardial infarction (AMI) is not yet investigated. We sought to explore the ability of TDI in identifying patients at risk for new cardiovascular events after AMI. Methods: One hundred and nineteen patients with AMI were recruited prospectively (mean age 61 years; range 32-81 years of age). Patients with diabetes mellitus (DM) were excluded. Echocardiography was performed 3-12 months after AMI. Two-dimensional (2-D) and TDI variables were recorded. The patients were followed during a mean period of 4·6 years (range 1-8 years). The primary end-point was defined as any of the following: death from any cause, non-fatal reinfarction or stroke, unstable angina pectoris, congestive heart failure requiring hospitalization and coronary revascularization procedure. Results: Thirty patients had some form of cardiovascular events during follow-up. Seven patients had cardiovascular death, 13 patients had reinfarction and four patients had a stroke. New angina or unstable angina was recorded in 21 patients. Of these patients, 13 underwent percutaneous coronary angioplasty (PCI) or coronary artery bypass grafting (CABG). The early diastolic myocardial velocity (Em) emerged as the only echocardiographic variable that offered a clear differentiation between patients that presented with new cardiovascular (CV) events as compared to the corresponding group without any CV events at follow-up (P&lt;0·05). In multivariate statistical analysis and after adjustment for age, sex, total cholesterol, body mass index (BMI) and other baseline characteristics, Em remained as independent predictors of CV events (HR, 1·18, 95% CI, 1·02-1·36; P&lt;0·05). However, none of the investigated variables evolved as an independent predictor of cardiovascular morbidity and mortality. Conclusion: Em appears to be a sensitive echocardiographic index in identifying non-diabetic patients with AMI at risk of new cardiovascular events.

Ultrasound speckle tracking for carotid strain assessment has in the past decade gained interest in studies of arterial stiffness and cardiovascular diseases. The aim of this study was to validate and directly contrast carotid strain assessment by speckle tracking applied on clinical and high-frequency ultrasound images in vitro. Four polyvinyl alcohol phantoms mimicking the carotid artery were constructed with different mechanical properties and connected to a pump generating carotid flow profiles. Gray-scale ultrasound long-and short-axis images of the phantoms were obtained using a standard clinical ultrasound system, Vivid 7 (GE Healthcare, Horten, Norway) and a high-frequency ultrasound system, Vevo 2100 (FUJIFILM, VisualSonics, Toronto, Canada) with linear-array transducers (12L / MS250). Radial, longitudinal and circumferential strains were estimated using an in-house speckle tracking algorithm and compared with reference strain acquired by sonomicrometry. Overall, the estimated strain corresponded well with the reference strain. The correlation between estimated peak strain in clinical ultrasound images and reference strain was 0.91 (p < 0.001) for radial strain, 0.73 (p < 0.001) for longitudinal strain and 0.90 (p < 0.001) for circumferential strain and for high-frequency ultrasound images 0.95 (p < 0.001) for radial strain, 0.93 (p < 0.001) for longitudinal strain and 0.90 (p < 0.001) for circumferential strain. A significant larger bias and root mean square error was found for circumferential strain estimation on clinical ultrasound images compared to high frequency ultrasound images, but no significant difference in bias and root mean square error was found for radial and longitudinal strain when comparing estimation on clinical and high-frequency ultrasound images. The agreement between sonomicrometry and speckle tracking demonstrates that carotid strain assessment by ultrasound speckle tracking is feasible.