Echocardiographic Evaluation of Regional Wall Motion Nonuniformity and Phase Difference in Asymmetric Septal Hypertrophy

BACKGROUND: A regional wall motion nonuniformity and a phase difference between LV posterior wall motion and transmitral flow are present during normal rapid filling period and are thought to be an evidence for involvement of ventricular restoring forces. To assess the role of nonuniformity on diastolic funtional impairment of asymmetric septal hypertrophy(ASH), the time relations between left ventricular regional wall motions and filling velocity were studied. METHOD: We measured the time intervals from A2 to peak rate of LV posterior wall(short axis) thinning(A2-(-)dpw/dt), peak rate of medial mitral annulus (long axis dimension) lengthening(A2-dL/dt) and peak mitral flow(A2-E) by M-mode and Doppler echocardiography. Result: In ASH patients, A2-(-)dpw/dt(106+/-6msec, mean SE) and the regional wall motion nonuniformity((-)dpw/dt-dL/dt, 89+/-11msec, mean SE) were increased significantly when compared with normal control values(88+/-4, 28+/-5msec, mean SE, p<0.01,respectively).In normal controls, peak mitral flow velocity lagged peak rate of regional wall motion, so the phase differences were present((-)dpw/dt-E :71+/-8msec, dL/dt-E:44+/-6msec). In ASH patients, (-)dpw/dt-E was present(90+/-16msec) but dL/dt-E was not present or reversed(-21+/-18 msec). So these chacteristic phase differences were disturbed. CONCLUSION: These data suggested that the relaxation nonuniformity of regional wall motion in ASH may act as an energy dissipating factor of restoring forces during rapid filling period.

Echocardiographic Measurement of Early Diastolic Time Intervals in Patients with Hypertension: With Reference to Regional Nonuniformity and Restoring Forces

BACKGROUND: It is known that left ventricular(LV) wall motion is not uniform even in normal heart, and the restoring forces make phase differences between LV wall motion and mitral flow velocity during rapid filling period. METHOD: To investigate the regional nonuniformity and restoring forces in 46 patients with hypertension(HT)(group:normal wall thickiness.n=12,II:LVH with fractional shortening(FS)>25%. n=22. III:FS<25%.n=12). We measured the time intervals from A2 to peak thinning rate point of LV posterior wall(A2-(-)dpw/dt).to mitral flow starting point (IRT).and to peak mitral flow velocity(A2-E) by M-mode and Doppler echocardiography. RESULTS: The noniformity((-)dpW/dt-dL/dt)and phase differance((-)dpw/dt-E) were increased in HT(control:HT.22+/-7.8 vs. 49+/-5.2msec, 63+/-4.5 vs, 86+/-6.2msec, p<0.05 respectively).In group comparison, nonuniformity increased in group II and III(group I: group II, III, 35+/-5.1 vs. 50+/-7.1,70+/-14msec, p<0.05 respectively). but phase difference increased only in group II(groupII: group I, III, 93+/-6.0 vs. 75+/-5.2, 80+/-20msec, p<0.05, respectively). CONCLUSION: We interpreted these data that in HT with hypertrophy or not, the nonuniformity of LV wall motion working on the restoring forces which can be expressed as phase difference between LV wall motion and mitral flow. But in HT with hypertensive heart failure group, no significant changes of phase difference and it's suggest that other mechanism could be also working on early diastolic filling.