Early changes in right ventricular longitudinal function in chronic asymptomatic alcoholics revealed by two-dimensional speckle tracking echocardiography

The quest for determination of standard reference values of right ventricular longitudinal systolic strain: a systematic review and meta-analysis

Right ventricular function is strongly associated with clinical outcomes in many conditions, and the evaluation of right ventricle (RV) structure and function in patients with cardiopulmonary disorders is an essential component of clinical management. The objective of this study was to determine the normal ranges of right ventricular longitudinal strain (RVLS) measurements derived by two-dimensional (2D) speckle tracking echocardiography (STE) through a systematic review and meta-analysis. A systematic review was performed using PubMed, Cochrane, ClinicalKey, and CINAHL. Search terms covered the concepts of right ventricle, strain, speckle-tracking, and 2D echocardiography with additional filtering for humans and adults over the last decade. The RV four-chamber longitudinal strain (RV4CLS), RV free wall longitudinal strain (RVFWLS), and free wall longitudinal segmental strain values of healthy individuals without cardiopulmonary diseases from 28 studies were assessed. Weighted means were estimated using random-effects models in a meta-analysis. The results show for RV4CLS -24,91%[CI  - 25.94;  - 23.88, I² 98%], for RVFWLS -27.63%[CI  - 28.78;  - 26.48, I² 98%], for basal RVFWLS -26.65%[CI  - 30.57;  - 22.73, I² 99%], mid RVFWLS -27.61%[CI  - 30.99;  - 24.22, I² 99%] and apical RVFWLS -24.54%[CI  - 26.70;  - 22.38, I² 98%]. This systematic review and meta-analysis showed longitudinal strain values of 2D STE derived RV. No clear reference value for RV strain can be distilled from the literature search due to high statistical heterogeneity between the studies. However, all results of our analysis suggest that the lower reference values for RVLS in the current recommendations with a cut-off value of  - 20% is underestimated.

Left Ventricular Segmental Strain Identifies Unique Myocardial Deformation Patterns After Intrinsic and Extrinsic Stressors in Mice

We used segmental strain analysis to evaluate whether intrinsic (diet-induced obesity [DIO]) and extrinsic (unpredictable chronic mild stress [UCMS]) stressors can alter deformational patterns of the left ventricle. Six-week-old male C57BL/6J mice were randomized into the lean or obese group (n = 24/group). Mice underwent 12 wk of DIO with a high-fat diet (HFD). At 18 wk, lean and obese mice were further randomized into UCMS and non-UCMS groups (UCMS, 7 h/d, 5 d/wk, for 8 wk). Echocardiography was performed at baseline (6 wk), post-HFD (18 wk) and post-UCMS (26 wk). Machine learning was applied to the DIO and UCMS groups. There was robust predictive accuracy (area under the receiver operating characteristic curve [AUC] = 0.921) when comparing obese with lean mice, with radial strain changes in the lateral (-64%, p ≤ 0.001) and anterior free (-53%, p < 0.001) walls being most informative. The ability to predict mice that underwent UCMS, irrespective of diet, was assessed (AUC = 0.886), revealing longitudinal strain rate of the anterior midwall and radial strain of the posterior septal wall as the top features. The wall segments indicate a predilection for changes in deformation patterns to the free wall (DIO) and septal wall (UCMS), indicating disease-specific alterations to the myocardium.