Noninvasive right ventricular myocardial work by pressure-strain loop: a new perspective on right ventricular function and cardiac resynchronization therapy.

Background: Myocardial work (MW) by noninvasive pressure-strain loop (PSL) is a novel echocardiographic tool that provides a more precise estimation of right ventricular (RV) performance by accounting for the RV loading conditions. The study sought to investigate the impact of cardiac resynchronization therapy (CRT) on RV function and explore the role of RV MW indices in predicting CRT response.

Methods and results: Ninety-one CRT-candidates were prospectively enrolled. left ventricular (LV) MW parameters, RV global longitudinal strain (RV GLS) and RV free wall strain (RV FWS) were obtained. RV MW indices, including RV global work index (RV GWI), RV global constructive work (RV GCW), RV global wasted work (RV GWW), and RV global work efficiency (RV GWE), were measured by PSL analysis. Response to CRT was defined as a reduction in left ventricular end-systolic volume of ≥15% at follow-up. RV GWI significantly increased in responders. CRT caused significant improvements in RV GWI, RV GCW, and RV GWE (P < 0.05). In multivariate analysis, RV GWI (adjusted odds ratio (OR): 1.010; 95% CI: 1.003-1.017; P < 0.05), and LV GCW (adjusted OR: 1.002; 95% CI: 1.000-1.003; P < 0.05) were associated with CRT response. Adding RV GWI to the basal model yielded a significant improvement in continuous net reclassification improvement at 0.284 (p=0.032), while other function parameters failed to improve reclassification.

Conclusion: RV MW indices provide a new reference for the quantitative evaluation of RV myocardial performance before and after CRT. Although both RV GWI and LV GCW have prognostic value, RV GWI may better predict the response to CRT.