Biventricular performance in adults with a systemic right ventricle: new insights from myocardial work analysis

To evaluate biventricular mechanics by means of echo-derived myocardial work (MW) analysis in patients with a systemic right ventricle (sRV). Comprehensive echo data were collected in all patients with a sRV who underwent transthoracic echocardiography at our tertiary centre between 2020 and 2021 including sRV function indices, global longitudinal strain (GLS) of right and left ventricle (RV/LV), biventricular MW, and atrial strain in those with congenitally corrected transposition of the great arteries (ccTGA). Fifty-six patients (37 [30.97-45.87]years, 59% male) and 49 healthy individuals matched per age and sex were included for comparison. Global work index (GWI:1106 [869.80-1293.10] Vs 314.2 [281.5-358.2]mmHg%, p < 0.0001) and global constructive work(GCW: 1542.50 [1338.9-1718.50] Vs 416.4 [365.70-464]mmHg%, p < 0.0001) were both increased for sRV compared to normal RV, reflecting exposition to a systemic afterload, with a contemporary raise in wasted work (GWW:197 [138.50-322.20] Vs 26.09 [17.80-43.48]mmHg%, p < 0.0001) and impaired efficiency (GWE:89 [83-93.54] Vs 93.67 [91.67-96] %, p < 0.0001). Conversely, sRV showed reduced MW indices in comparison to normal LV(p < 0.0001 for all). Non-systemic LV demonstrated normal GLS values (19.51 ± 3.9%), but reduced GWI (479 [368-665] Vs 2172 [1978-2386]mmHg%, p < 0.0001) and GCW (708 [490-815]mmHg% Vs 86.5 [59.25-118], p < 0.0001). Nevertherless, non-systemic LV showed also impaired efficiency (91 [88-94] Vs 95 [94-97]%, p < 0.0001). LVGLS values were related to RVGLS (R = 0.5, p = 0.00019), suggesting a consistent interventricular dependency. Atrial strain could be assessed in 16 out of 20 (80%) patients with ccTGA: both atria had reduced strain values compared to their normal counterparts. Moreover, pulmonary atrial strain during the reservoir phase was related to LVGWE (R = 0.58, p = 0.047) and inversely related to LVGLS (R = - 0.71, p = 0.0043). MW analysis is feasible in sRV and may provide additional clinical data. In our cohort MW revealed biventricular impairment, in particular for non-systemic LV, in spite of normal GLS values.