The aim of this study was to use Doppler myocardial imaging, a new ultrasonic technique, to determine whether the direct assessment of transmural velocities can distinguish patients with secondary left ventricular (LV) hypertrophy from those with hypertrophic cardiomyopathy (HCM). To test this hypothesis in a prospective study we measured the velocity gradient (VG) across the LV' posterior wall in 22 patients with HCM (mean age 52 ±13 years), 21 patients (mean age 56 ± 10 yeacs) with LV hypertrophy due to systemic hypertension (HBP) and 26 age-matched normal subjects (N). The VG across the LV posterior wall was measured during the following sequential phases of the cardiac cycle in systole and diastole: ventricular ejection (VE), isovolumic relaxation (IR). rapid ventricular filling (RVF) and atrial contraction (AC). Results are expressed as mean ± SD (s&). VE IR RVF AC HCM 0.4 ±1.5*t -1. 1 ±0.7 1.5 ±0.9*t 2.0 ±0.9 |§ HBP 4.5 ±2.0 -1.0 ±0.51 3.8 ±1.8 3.1 ±1.4 N 5.0 ±2.3 -0.5 ±0.4 4.1 +1.6 2.8 ±1.4 * p<0.001 versus N; t p<0.001 versus HBP; $ p<0.05 versus N; § p<0.05 versus HBP. Standard grey scale echocardiographic measurements showed a similar extent of thickening ant thinning of the LV posterior wall in patients from both groups with hypertrophy. By measuring the VG we could consistently differentiate HCM patients. Thus, it appears that this technique may be useful clinically in distinguishing HCM from secondarv hypertrophy of the LV.
