The left ventricular (LV) posterior wall in patients with asymmetric septal hypertrophy or prior anteroseptal myocardial infarction (A-MI) frequently demonstrates normal or supernormal motion to compensate for hypokinesis of the interventricular septum. This study evaluated the systolic motion velocity of the posterior wall in these conditions using a pulsed tissue Doppler imaging system. The study population consisted of 30 patients with hypertrophic cardiomyopathy (HC) and asymmetric septal hypertrophy, 25 with prior A-MI and 30 normal controls. The systolic excursion of the posterior wall was obtained by M-mode echocardiography. The endocardial motion velocities of the posterior wall were obtained by pulsed tissue Doppler imaging. The systolic excursion of the posterior wall was significantly greater in the A-MI and HC groups than in the control group, and was significantly greater in the A-MI group than in the HC group. The peak systolic velocity of the posterior wall was significantly lower in the HC group than in the control and A-MI groups, and the time from the electrocardiographic Q wave to the peak of the systolic wave of the posterior wall was significantly longer in the HC group than in the other groups. There were rough negative and positive correlations between the LV end-diastolic pressure and the peak systolic velocity and time from the Q wave to the peak of the systolic wave, respectively. In conclusion, LV myocardial contractility in HC patients was impaired when compared to A-MI patients despite similar posterior wall motion on the M-mode echocardiogram. Pulsed tissue Doppler imaging method may provide new insights and allow further evaluation of myocardial dysfunction.