ABNORMAL INFLOW WAVE-PROPAGATION IN PATIENTS WITH DOPPLER CHARACTERISTICS OF IMPAIRED LEFT-VENTRICULAR RELAXATION - ASSESSMENT BY A NOVEL METHOD THROUGH APPLICATION OF THE RANGE AMBIGUITY

With application of the range ambiguity, a delay between the flow onse t at both the mitral valve and the apex has been shown. to be present in patients with a severely dilated and poorly contracting left ventri cle and those with acute myocardial infarction with abnormal apical wa ll motion, but the delay has been. absent in. normal subjects. Neverth eless, whether there is a delay between the flow onset at both regions in the presence of impaired left ventricular relaxation remains unkno wn. This study was undertaken to evaluate the left ventricular inflow wave propagation. in control subjects and patients with impaired left ventricular relaxation. Eighteen. patients with normal systolic functi on and Doppler characteristics of impaired relaxation of the left vent ricle and 17 age- and sex-matched healthy control subjects were includ ed. Range ambiguity was used to simultaneously record the phantom Dopp ler signals from the mitral valve region and the true ones from the ap ex. The inflow wave propagation. velocity was derived from the inflow wave propagation distance divided by the time between the mitral valve and the apex. There was always some delay between the flow onset at b oth the mitral valve and the apex in both the controls and the patient s (47 +/- 13 msec vs 85 +/- 19 msec, P < 0.001). The inflow wave propa gation velocity was 160 +/- 50 cm/sec and 90 +/- 20 cm/sec in the cont rol subjects and the patients, respectively (P < 0.001). Multiple line ar regression analyses of the significantly correlated variables stepw isely selected the deceleration time of the E wave (R-2 = 0.53, P < 0. 001) and age (R2 = 0.06, P = 0.039) as the significant determinants of the left ventricular inflow wave propagation, velocity. In. conclusio n, the application. of the range ambiguity offers a new method of dete rmining the left ventricular inflow wave propagation, velocity, and Do ppler characteristics of impaired left ventricular relaxation are asso ciated with a slower inflow wave propagation from the mitral valve to the apex.