The concept of "normalized velocity" has been applied in this study to the echocardiographic (echo) assessment of left ventricular (LV) function in 87 patients. The following normalized velocities were calculated from the ultrasound recording of LV wall motion: 1) the mean circumferential fiber shortening rate (mean V_CF), 2) the mean normalized posterior wall velocity (V_PW), and 3) the mean normalized interventricular septal velocity (V_IVS). Systolic ejection fraction (SEF), and mean (non-normalized) posterior wall velocity (PWV) were also determined. There were 19 patients with normal LV function, 5 with atrial septal defect (mean V_CF, V_IVS and SEF were not calculated in these patients), 16 with LV volume overload, 29 with myocardial disease, 6 with hypertrophic cardiomyopathy and 12 with coronary artery disease (CAD). Single plane cineangiographic (angio) determinations of mean V_CF and SEF were obtained in 50 of the 87 patients (including all 12 patients with CAD).

Mean V_CF and SEF done by echo correlated very well with mean V_CF and SEF done by angio in the patients without CAD (r = 0.94 and 0.91, respectively). Mean V_CF (by echo or by angio) adequately separated normal from abnormal LV function. Although correlation between mean V_CF and SEF was good, mean V_CF was reduced while SEF was well preserved in several patients. In spite of LV asynergy, most of the patients with CAD had good correlation between echo and angio measurements of mean V_CF and SEF. Although PWV correlated with echo and angio mean V_CF in the patients without CAD, the overlap of normal and abnormal values made PWV an unreliable index of LV function. In contrast, V_PW proved to be a reliable indicator of LV performance in patients without LV asynergy. Agreement between V_PW and mean V_CF (by echo or angio) was seen in 94% of the patients; in the presence of CAD, however, greater discrepancy was seen between these two measurements. Agreement between V_IVS and V_PW was present in 90% of the patients without CAD, but in only 58% of the patients with CAD.

The analysis of LV wall motion by echocardiography utilizing the "normalized velocity" concept appears to be a rational and practical method for evaluation of LV performance. In the absence of asynergy, V_PW provides a reliable index of LV performance which may be of particular value when abnormal septal motion precludes the determination of SEF and mean V_CF. In the presence of asynergy, however, mean V_CF, V_PW and V_IVS may reflect only the performance of the visualized segment of myocardium.