Noninvasive detection of left ventricular diastolic dysfunction using M-mode echocardiography to assess left ventricular posterior wall kinetics in hypertrophic cardiomyopathy

Abstract

In patients with hypertrophic cardiomyopathy (HC), it is difficult to determine the severity of left ventricular (LV) diastolic dysfunction. Three different patterns of LV posterior wall motion were found by M-mode echocardiography in patients with HC, and the use of these patterns is proposed as a new noninvasive index of the severity of LV diastolic dysfunction. M-mode echocardiograms were recorded prospectively from 35 patients with HC, and the posterior wall motion pattern in late systole and early diastole was classified into the following 3 types: (1) normal motion (n = 9); (2) flat motion — flat motion from late systole to early diastole, followed by rapid backward movement (n = 13); and (3) downward motion — slow backward movement from late systole (n = 13). There were no differences in the severity or type of hypertrophy, LV systolic function and pulsed Doppler indexes of LV filling among these 3 groups. However, LV end-diastolic pressure was increased in the groups with flat (15 ± 6 mm Hg) and downward (16 ± 9 mm Hg) motion. Furthermore, the maximal rate of decrease in LV pressure (normal 1,450 ± 300, flat 1,250 ± 300 and downward 860 ± 80 mm Hg/s) and the time constant of LV pressure reduction (normal 60 ± 15, flat 70 ± 25 and downward 101 ± 34 ms) showed a stepwise deterioration from the normal to the flat and then to the downward motion groups. Determination of the pattern of LV posterior wall motion appears to be useful for semiquantitatively assessing the presence and severity of LV diastolic dysfunction in HC, especially during relaxation and early diastolic filling.