Non-invasive assessment of left ventricular function in coronary artery disease by Doppler stress testing

Left ventricular (LV) function in 62 patients presenting with chest pain typical of angina was studied non-invasively at rest and at maximum-tolerated supine exercise using the continuous-wave Doppler technique of transcutaneous aorto-velography (TAV). The signals were analysed to derive peak velocity (Vp), systolic velocity integral [an index of stroke volume or stroke distance (Sd)], and minute distance (Md; index of cardiac output = Sd X heart rate). Comparison was made with results obtained from 66 normal volunteers. The percentage change in stroke distance with exercise (% delta Sd) was significantly related to the resting ejection fraction (EF) calculated from left ventriculography (r = 0.84), and was below 6% (lowest value observed in normal volunteers) in all of the 23 patients with coronary artery disease (CAD) whose EF was below 60%. No significant difference was observed in the % delta Sd between normal individuals and the 12 patients presenting with chest pain but who had normal coronary arteriograms. However, the % delta Vp, delta % Sd and % delta Md in the 50 patients with CAD were significantly lower than the normal individuals and the 12 patients with normal coronary arteriograms. Lower TAV measurements were observed with exercise, rather than at rest, with increasing number of coronary arteries with significant stenoses and the presence of history of myocardial infarction (linear trend p less than 0.003). These results suggest that Doppler recording of aortic blood velocity with exercise is a clinically useful non-invasive technique for studying LV performance in patients with CAD.(ABSTRACT TRUNCATED AT 250 WORDS)