Objectives: Peak systolic mitral annular velocities correlate with left ventricular ejection fraction (EF) regardless of mitral regurgitation severity. Peak systolic tricuspid annular velocity (RV-Sm) and tricuspid annular plane systolic excursion (TAPSE) are used to assess right ventricular (RV) EF (RVEF). We investigated whether tricuspid regurgitation (TR) affects the relationship among RV-Sm, TAPSE, and RVEF.
Methods: Patients (n = 625) underwent echocardiography and Doppler tissue studies. Left ventricular EF and RVEF were estimated by Simpson's rule. Because of confounding, we excluded patients with diseases that influence mitral annular motion or left ventricular function. We finally enrolled 225 patients: 125 with mild TR, 50 with moderate TR, and 50 with severe TR. Forty study patients (20 with mild TR, 10 with moderate TR, and 10 with severe TR) received radionuclide ventriculography.
Results: The RVEF estimated by Simpson's method correlated strongly to that estimated by the radionuclide method (r = 0.793, r2 = 0.629, P < .0001). With mild or moderate TR, RV-Sm correlated well to RVEF (mild TR group: r = 0.765, r2 = 0.59, P < .0001; moderate TR group: r = 0.756, r2 = 0.57, P < .0001). RV-Sm had no significant correlation to RVEF in patients with severe TR (r = 0.212, r2 = 0.05, P = .167). Over a range of TR severities, the relationship between TAPSE and RVEF showed a similar trend to that between RV-Sm and RVEF.
Conclusion: Severe TR has a significant impact on the relationship between RV-Sm and RVEF and between TAPSE and RVEF. TAPSE and RV-Sm in patients with severe TR show poor correlation to RVEF. When applying Doppler tissue method or TAPSE to assess RV function, severe TR is a significantly confounding factor.