Left ventricular systolic and diastolic flow abnormalities determined by doppler echocardiography in obstructive hypertrophic cardiomyopathy

Abstract

To analyze the relation of systolic anterior motion (SAM) of the mitral valve, peak left ventricular (LV) outflow tract velocity, aortic flow and mitral flow, 17 patients with obstructive hypertrophic cardlomyopathy (HC) (8 men, 9 women), aged 19 to 88 years (mean 45), were studied using M-mode and 2-dimensional echocardiography and pulsed and continuous-wave Doppler echocardiography and results were compared with those from 18 age-matched normal subjects. SAM was present in all patients with HC and absent in normal subjects. Time to peak outflow velocity as a percentage of LV ejection time was 63% in patients with HC and 29% in normal subjects (p <0.001). In 13 patients, time from the R-wave peak to the closest approximation of the mitral valve to the ventricular septum or initial contact during SAM was determined and was 242 ± 66 ms and time from the R-wave peak to the peak LV outflow tract velocity was 242 ± 73 ms (r = 0.90). In 11 patients time from the R-wave peak to cessation of flow in the ascending aorta was measured and was 286 ± 80 ms; time from the R-wave peak to the peak LV outflow tract velocity was 246 ± 75 ms. The ratio of early to late diastolic filling velocities of the left ventricle was 1.47 :L 0.40 in the normal subjects and 1.26 ± 0.84 in patients with HC (difference not significant).. The early to late ratio of the 12 patients without mitral regurgitation was 0.99 ± 0.52 (p < 0.01 vs normal subjects). These data suggest that in HC, SAM of the mitral valve Is temporally related to both the peak LV outflow pressure gradient and cessation of flow in the ascending aorta. Diastolic filling abnormalities are present in patients without mitral regurgitation, but tend to normalize in the presence of mitral regurgitation.