Doppler-derived rate of left ventricular pressure rise. Its correlation with the postoperative left ventricular function in mitral regurgitation.

Abstract

A new Doppler-derived index of the rate of left ventricular (LV) pressure rise (delta P/delta t) 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 (delta p) between 1 and 3 m/sec of the mitral regurgitation velocity signal by the time taken (delta t) for this change. We studied the LV delta P/delta t 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 delta P/delta t (r = 0.75, p less than 0.001). The other echocardiographic parameters that correlated with postoperative EF were LV end-systolic dimension (r = -0.7, p less than 0.001), end-systolic volume (r = -0.69, p less than 0.001), end-diastolic dimension (r = -0.58, p less than 0.01), end-diastolic volume (r = -0.57, p less than 0.01), preoperative EF (r = 0.69, p less than 0.001), end-systolic wall stress (r = -0.61, p less than 0.01), and end-systolic wall stress normalized for end-systolic volume index (r = -0.45, p less than 0.05). With multiple regression, the LV delta P/delta t and LV end-systolic dimension (ESD) were shown to be independent predictors of postoperative EF. The postoperative EF could defined by the equation: 43 + 0.8 square root delta P/delta t--0.53 ESD (mm) (r = 0.86).(ABSTRACT TRUNCATED AT 250 WORDS)