Mitral valve early diastolic closing velocity in the echocardiogram: relation to sequential diastolic flow and ventricular compliance

Abstract

Uncertainty exists regarding the determinants of mitral valve early diastolic closing velocity (E-F slope) in the echocardiogram. Accordingly, the mitral E-F slope, sequential atrioventricular flow in each third of diastole in the cineangiogram and an index of ventricular compliance (delta volume/delta pressure normalized by end-diastolic volume) were obtained in 10 normal subjects, 10 patients with coronary artery disease and marked dyssynergy and 9 patients with hypertrophic cardiomyopathy. The E-F slope of 103 +/- 20 mm/sec (mean +/- standard deviation) in normal subjects was greatly reduced in patients with coronary artery disease and hypertrophic cardiomyopathy (54 +/- 22 and 27 +/- 16 mm/sec, respectively, P less than 0.001). Transmitral flow of 52 +/- 25 cc during the initial third of diastole in normal subjects represented 48 +/- 10 percent of total flow and was diminished in patients with coronary artery disease and hypertrophic cardiomyopathy: 23 +/- 16 cc (25 +/- 24 percent) and 24 +/- 20 cc (20 +/- 11 percent), respectively (both P less than 0.001). The ventricular compliance index in normal subjects of 0.064 +/- 0.02 was also decreased identically in patients with coronary artery disease and hypertrophic cardiomyopathy: 0.029 (both P less than 0.001). The E-F slope was correlated with transmitral flow during the first third of diastole (r = 0.87) but was decreased to a slightly greater extent for any given reduction in flow in patients with hypertrophic cardiomyopathy than in patients with coronary artery disease. Although the E-F slope could not be related to compliance in individual patients, patients with an E-F slope of less than 75 mm/sec nearly always had diminished compliance. Thus, mitral E-F slope is primarily related to transmitral flow in the initial third of diastole. Reduced ventricular diastolic compliance usually results in diminished flow, and thus a decreased E-F slope, in patients with coronary artery disease or hypertrophic cardiomyopathy. The greater reduction in E-F slope for any decrement of flow in hypertrophic cardiomyopathy than in coronary disease may be due either to interference with vortex streaming or to alterations in the relation of the papillary muscles to the mitral valve induced by altered ventricular geometry; the finding indicates that factors in addition to flow may influence the E-F slope.