Exercise-Stress Echocardiography and Effort Intolerance in Asymptomatic/Minimally Symptomatic Patients With Degenerative Mitral Regurgitation Combined Invasive-Noninvasive Hemodynamic Monitoring

Background Effort intolerance, measured objectively by reduced peak oxygen consumption (Vo ), has been considered as an important prognosticator in degenerative mitral regurgitation (MR). However, its mechanism is unknown. Methods and Results In 25 asymptomatic/minimally symptomatic patients with grade III+ or greater degenerative MR undergoing semisupine invasive exercise testing, Doppler estimates and invasive measurement of systolic (SPAP) and mean pulmonary artery pressure (MPAP) and cardiac output (CO) were simultaneously obtained. Echocardiographic estimates of SPAP, MPAP, and CO correlated well with invasive measurement at peak exercise (bias, SPAP, -0.7±7.4 mm Hg; MPAP, 1.2±6.3 mm Hg; CO, 0.2±2.5 L/min). Heart rate reserve (β, 3.997; 95% CI, 2.704-5.290 per 41.5% increase; P