DOPPLER-DERIVED RATE OF LEFT-VENTRICULAR PRESSURE RISE - ITS CORRELATION WITH THE POSTOPERATIVE LEFT-VENTRICULAR FUNCTION IN MITRAL REGURGITATION

A new Doppler-derived index of the rate of left ventricular (LV) pressure rise (ΔP/Δt) was evaluated for the prognostic stratification of patients with chronic mitral regurgitation. The index is derived from the continuous wave Doppler mitral regurgitation signal by dividing magnitude of LV-left atrial pressure gradient rise (Δp) between 1 and 3 m/sec of the mitral regurgitation velocity signal by the time taken (Δt) for this change. We studied the LV ΔP/Δt and other echocardiographic indexes of LV function before and after mitral valve surgery in 25 patients with chronic, severe mitral regurgitation in the absence of significant coronary artery disease. There was a good correlation between postoperative ejection fraction (EF) and the derived LV ΔP/Δt (r = 0.75, p < 0.001). The other echocardiographic parameters that correlated with postoperative EF were LV end-systolic dimension (r = .0.7, p < 0.001), end-systolic volume (r = -0.69, p < 0.001), end-diastolic dimension (r = -0.58, p < 0.01), end-diastolic volume (r = -0.57, p < 0.01), preoperative EF (r = 0.69, p < 0.001), end-systolic wall stress (r = -0.61, p < 0.01), and end-systolic wall stress normalized for end-systolic volume index (r = -0.45, p < 0.05). With multiple regression, the LV ΔP/Δt and LV end-systolic dimension (ESD) were shown to be independent predictors of postoperative EF. The postoperative EF could be defined by the equation: 43+0.8√(ΔP/Δt)-0.53 ESD (mm) (r = 0.86). We conclude that the Doppler-derived index of LV ΔP/Δt and end-systolic dimension are afterload-independent predictors of postoperative EF in patients with chronic, severe mitral regurgitation.