Right ventricular myocardial work: a step forward for the assessment of right ventricular to pulmonary artery coupling

Abstract

Abstract Background Right ventricular myocardial work (RVMW) is a novel method for non-invasive assessment of right ventricular (RV) function. By integrating RV global longitudinal strain as systolic function parameter, pulmonary systolic and diastolic pressures as afterload indices, and pulmonary and tricuspid valves timings, RVMW could provide a more comprehensive evaluation of RV function. Purpose The aim of this study was to assess patterns of RVMW indices in patients with preserved and impaired RV to pulmonary artery (PA) coupling (RVAC), as assessed by RV free wall longitudinal strain/pulmonary artery systolic pressure (RVFWLS/PASP) ratio. Methods We studied by echocardiography 158 consecutive patients with stable HF and left ventricular (LV) systolic dysfunction (LV ejection fraction < 50%). RVAC was assessed by RVFWLS/PASP and patients were grouped according to the median value. Four parameters of RVMW were obtained: RV global work index (RVGWI), RV global constructive work (RVGCW), RV global wasted work (RVGWW) and RV global work efficiency (RVGWE). Results According to RVFWLS/PASP ratio, patients were divided into two groups: A) preserved RVAC (RVFWLS/PASP ratio ≥ 0.51; N=84) and B) impaired RVAC (RVFWLS/PASP ratio < 0.51; N= 74). Both RVGWI (371±156 vs 384±207 mmHg%, P=NS) and RVGCW (449±171 vs 516±249 mmHg%, P=NS) did not significantly differ between the two groups (figure 1). However, group B (impaired RVAC) showed significantly greater RV wasted work (94±69 vs 44±30 mmHg%, P=0.0001) and significantly lower RV work efficiency (80±13 vs 88±8 %, P=0.0001) compared to group A (preserved RVAC, figure 2). Conclusions RVMW provided new insight in the RV function assessment, highlighting lower efficiency due to higher wasted work in RV to PA uncoupled patients.Figure 1Figure 2