Strain and Strain Rate Imaging by Echocardiography – Basic Concepts and Clinical Applicability

Echocardiographic strain and strain-rate imaging (deformation imaging) is a new non-invasive method for assessment of myocardial function. Due to its ability to differentiate between active and passive movement of myocardial segments, to quantify intraventricular dyssynchrony and to evaluate components of myocardial function, such as longitudinal myocardial shortening, that are not visually assessable, it allows comprehensive assessment of myocardial function and the spectrum of potential clinical applications is very wide. The high sensitivity of both tissue Doppler imaging (TDI) derived and two dimensional (2D) speckle tracking derived myocardial deformation (strain and strain rate) data for the early detection of myocardial dysfunction recommend these new non-invasive diagnostic methods for extensive clinical use. In addition to early detection and quantification of myocardial dysfunction of different etiologies, assessment of myocardial viability, detection of acute allograft rejection and early detection of allograft vasculopathy after heart transplantation, strain and strain rate data are helpful for therapeutic decisions and also useful for follow-up evaluations of therapeutic results in cardiology and cardiac surgery. Strain and strain rate data also provide valuable prognostic information, especially prediction of future reverse remodelling after left ventricular restoration surgery or after cardiac resynchronization therapy and prediction of short and median-term outcome without transplantation or ventricular assist device implantation of patients referred for heart transplantation

Surrogates for myocardial power and power efficiency in patients with aortic valve disease

We aimed to assess surrogate markers for left ventricular (LV) myocardial power and efficiency in patients with isolated aortic stenosis (AS) and combined stenosis/regurgitation (AS/AR). In AS (n = 59), AS/AR (n = 21) and controls (n = 14), surrogates for LV myocardial power and circulatory/external myocardial efficiency were obtained from cardiac MRI. Median surrogate LV myocardial power was increased in AS, 7.7 W/m2 (interquartile range 6.0-10.2; p = 0.010) and AS/AR, 10.8 W/m2 (8.9-13.4; p < 0.001) when compared to controls, 5.4 W/m2 (4.2-6.5), and was lower in AS than AS/AR (p < 0.001). Surrogate circulatory efficiency was decreased in AS, 8.6% (6.8-11.1; p < 0.001) and AS/AR, 5.4% (4.1-6.2; p < 0.001) when compared to controls, 11.8% (9.8-16.9). Surrogate external myocardial efficiency was higher in AS, 15.2% (11.9-18.6) than in AS/AR, 12.2% (10.1-14.2; p = 0.031) and was significantly lower compared to controls, 12.2% (10.7-18.1) in patients with reduced ejection fraction (EF), 9.8% (8.1-11.7; p = 0.025). In 16% of all cases, left ventricular mass/volume indices and EF were within normal ranges, wheras surrogate LV myocardial power was elevated and patients were symptomatic. Although influenced by pressure/volume load, the myocardium is additionally affected by remodelling processes. Surrogates for circulatory efficiency and LV myocardial power gradually reflect alterations in patients with AS and AS/AR, even when surrogate external myocardial efficiency, EF, mass and volume indices still remain compensated

Myocardial Work Assessment for the Prediction of Prognosis in Advanced Heart Failure

Objectives: The aim of this study was to investigate whether echocardiographic assessment of myocardial work is a predictor of outcome in advanced heart failure. Background: Global work index (GWI) and global constructive work (GCW) are calculated bymeans of speckle tracking, blood pressuremeasurement, and a normalized reference curve. Their prognostic value in advanced heart failure is unknown. Methods: Cardiopulmonary exercise testing and echocardiography with assessment of GWI and GCW was performed in patients with advanced heart failure caused by ischemic heart disease or dilated cardiomyopathy (n = 105). They were then followed up repeatedly. The combined endpoint was all-cause death, implantation of a left ventricular assist device, or heart transplantation. Results: The median patient age was 54 years (interquartile range [IQR]: 48–59.9). The mean left ventricular ejection fraction was 27.8 ± 8.2%, the median NT-proBNP was 1,210 pg/ml (IQR: 435–3,696). The mean GWI was 603 ± 329 mmHg% and the mean GCW was 742 ± 363 mmHg%. The correlation between peak oxygen uptake and GWI as well as GCW was strongest in patients with ischemic cardiomyopathy (r = 0.56, p = 0.001 and r = 0.53, p = 0.001, respectively). The median follow-up was 16 months (IQR: 12–18.5). Thirty one patients met the combined endpoint: Four patients died, eight underwent transplantation, and 19 underwent implantation of a left ventricular assist device. In themultivariate Cox regression analysis, only NYHA class, NT-proBNP and GWI (hazard ratio [HR] for every 50 mmHg%: 0.85; 95% CI: 0.77–0.94; p = 0.002) as well as GCW (HR for every 50 mmHg%: 0.86; 95% CI: 0.79–0.94; p = 0.001) were identified as independent predictors of the endpoint. The cut-off value for predicting the outcome was 455 mmHg% for GWI (AUC: 0.80; p < 0.0001; sensitivity 77.4%; specificity 71.6%) and 530 mmHg% for GCW (AUC: 0.80; p < 0.0001; sensitivity 74.2%; specificity 78.4%). Conclusions: GWI and GCW are powerful predictors of outcome in patients with advanced heart failure

Myocardial Work Assessment for the Prediction of Prognosis in Advanced Heart Failure

Objectives: The aim of this study was to investigate whether echocardiographic assessment of myocardial work is a predictor of outcome in advanced heart failure.Background: Global work index (GWI) and global constructive work (GCW) are calculated by means of speckle tracking, blood pressure measurement, and a normalized reference curve. Their prognostic value in advanced heart failure is unknown.Methods: Cardiopulmonary exercise testing and echocardiography with assessment of GWI and GCW was performed in patients with advanced heart failure caused by ischemic heart disease or dilated cardiomyopathy (n = 105). They were then followed up repeatedly. The combined endpoint was all-cause death, implantation of a left ventricular assist device, or heart transplantation.Results: The median patient age was 54 years (interquartile range [IQR]: 48–59.9). The mean left ventricular ejection fraction was 27.8 ± 8.2%, the median NT-proBNP was 1,210 pg/ml (IQR: 435–3,696). The mean GWI was 603 ± 329 mmHg% and the mean GCW was 742 ± 363 mmHg%. The correlation between peak oxygen uptake and GWI as well as GCW was strongest in patients with ischemic cardiomyopathy (r = 0.56, p = 0.001 and r = 0.53, p = 0.001, respectively). The median follow-up was 16 months (IQR: 12–18.5). Thirty one patients met the combined endpoint: Four patients died, eight underwent transplantation, and 19 underwent implantation of a left ventricular assist device. In the multivariate Cox regression analysis, only NYHA class, NT-proBNP and GWI (hazard ratio [HR] for every 50 mmHg%: 0.85; 95% CI: 0.77–0.94; p = 0.002) as well as GCW (HR for every 50 mmHg%: 0.86; 95% CI: 0.79–0.94; p = 0.001) were identified as independent predictors of the endpoint. The cut-off value for predicting the outcome was 455 mmHg% for GWI (AUC: 0.80; p &lt; 0.0001; sensitivity 77.4%; specificity 71.6%) and 530 mmHg% for GCW (AUC: 0.80; p &lt; 0.0001; sensitivity 74.2%; specificity 78.4%).Conclusions: GWI and GCW are powerful predictors of outcome in patients with advanced heart failure

Author’s response

We are grateful to Demirkol et al. for their appreciativeletter regarding our paper ”Clinical, haemodynamic and echocardiographicfeatures of early cardiac graft dysfunction” [

Circulatory efficiency in patients with severe aortic valve stenosis before and after aortic valve replacement

Background: Circulatory efficiency reflects the ratio between total left ventricular work and the work required for maintaining cardiovascular circulation. The effect of severe aortic valve stenosis (AS) and aortic valve replacement (AVR) on left ventricular/circulatory mechanical power and efficiency is not yet fully understood. We aimed to quantify left ventricular (LV) efficiency in patients with severe AS before and after surgical AVR. Methods: Circulatory efficiency was computed from cardiovascular magnetic resonance (CMR) imaging derived volumetric data, echocardiographic and clinical data in patients with severe AS (n = 41) before and 4 months after AVR and in age and sex-matched healthy subjects (n = 10). Results: In patients with AS circulatory efficiency was significantly decreased compared to healthy subjects (9 +/- 3% vs 12 +/- 2%; p = 0.004). There were significant negative correlations between circulatory efficiency and LV myocardial mass (r = - 0.591, p < 0.001), myocardial fibrosis volume (r = - 0.427, p = 0.015), end systolic volume (r = - 0.609, p < 0.001) and NT-proBNP (r = - 0.444, p = 0.009) and significant positive correlation between circulatory efficiency and LV ejection fraction (r = 0.704, p < 0.001). After AVR, circulatory efficiency increased significantly in the total cohort (9 +/- 3 vs 13 +/- 5%; p < 0.001). However, in 10/41 (24%) patients, circulatory efficiency remained below 10% after AVR and, thus, did not restore to normal values. These patients also showed less reduction in myocardial fibrosis volume compared to patients with restored circulatory efficiency after AVR. Conclusion: In our cohort, circulatory efficiency is reduced in patients with severe AS. In 76% of cases, AVR leads to normalization of circulatory efficiency. However, in 24% of patients, circulatory efficiency remained below normal values even after successful AVR. In these patients also less regression of myocardial fibrosis volume was seen. Trial Registration clinicaltrials.gov NCT03172338, June 1, 2017, retrospectively registered

Impaired Relaxation and Reduced Lusitropic Reserve in Atrial Myocardium in the Obese Patients

Background: Obesity can influence the structure and function of the atrium, but most studies focused on the relationship of body mass index (BMI) and overt left atrium (LA) dysfunction as assessed by clinical imaging. We combined the assessment of right atrium (RA) function in vivo and in vitro in obese and non-obese patients scheduled for elective cardiac surgery. Methods: Atrial structure and function were quantified pre-operatively by echocardiography. RA tissue removed for the establishment of extracorporeal support was collected and RA trabeculae function was quantified in vitro at baseline and with adrenergic stimulation (isoproterenol). Fatty acid-binding protein 3 (FABP3) was quantified in RA tissue. Results were stratified according to the BMI of the patients. Results: About 76 patients were included pre-operatively for the echocardiographic analysis. RA trabeculae function at baseline was finally quantified from 46 patients and RA function in 28 patients was also assessed with isoproterenol. There was no significant correlation between BMI and the parameters of atrial function measured by the clinical echocardiography. However, in vitro measurements revealed a significant correlation between BMI and a prolonged relaxation of the atrial myocardium at baseline, which persisted after controlling for the atrial fibrillation and diabetes by the partial correlation analysis. Acceleration of relaxation with isoproterenol was significantly lower in the obese group (BMI ≥ 30 kg/m(2)). As a result, relaxation with adrenergic stimulation in the obese group remained significantly higher compared to the overweight group (25 kg/m(2) ≤ BMI < 30 kg/m(2), p = 0.027) and normal group (18.5 kg/m(2) ≤ BMI < 25 kg/m(2), p = 0.036). There were no differences on impacts of the isoproterenol on (systolic) developed force between groups. The expression of FABP3 in the obese group was significantly higher compared to the normal group (p = 0.049) and the correlation analysis showed the significant correlations between the level of FABP3 in the RA trabeculae function. Conclusion: A higher BMI is associated with the early subclinical changes of RA myocardial function with the slowed relaxation and reduced adrenergic lusitropy