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 onset at both the mitral valve and the apex has been shown to be present in patients with a severely dilated and poorly contracting left ventricle and those with acute myocardial infarction with abnormal apical wall motion, but the delay has been absent in normal subjects. Nevertheless, whether there is a delay between the flow onset at both regions in the presence of impaired left ventricular relaxation remains unknown. 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 function and Doppler characteristics of impaired relaxation of the left ventricle and 17 age- and sex-matched healthy control subjects were included. Range ambiguity was used to simultaneously record the phantom Doppler signals from the mitral valve region and the true ones from the apex. 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 both the mitral valve and the apex in both the controls and the patients (47 +/- 13 msec vs 85 +/- 19 msec, P < 0.001). The inflow wave propagation velocity was 160 +/- 50 cm/sec and 90 +/- 20 cm/sec in the control subjects and the patients, respectively (P < 0.001). Multiple linear regression analyses of the significantly correlated variables stepwisely selected the deceleration time of the E wave (R(2) = 0.53, P < 0.001) and age (R(2) = 0.06, P = 0.039) as the significant determinants of the left ventricular inflow wave propagation velocity. In conclusion, the application of the range ambiguity offers a new method of determining the left ventricular inflow wave propagation velocity, and Doppler characteristics of impaired left ventricular relaxation are associated with a slower inflow wave propagation from the mitral valve to the apex.
Voon
Wen-Chol
WC
Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical College, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan.
Sheu
Sheng-Hsiung
SH