Exercise echocardiography: detection of wall motion abnormalities during ischemia.

Abstract

To assess the feasibility of detecting wall motion abnormalities with echocardiography during exercise-induced ischemia, echocardiograms were performed on 13 patients with angiographically documented coronary artery disease at rest and during supine bicycle exercise at increasing work loads until angina or ischemic ECG changes appeared. Echocardiographic indices of regional left ventricular function were analyzed in these patients and 11 age- and heart rate-matched normal volunteers. In the 13 patients, 22 of 25 echocardiographically defined wall segments (13 septa, 9 posterior left ventricular walls) were supplied by coronary arteries with .gtoreq. 70% stenosis then compared with the corresponding 22 segments from the 11 normals. Mean systolic septal thickening increased in the 22 segments of normals from 56 .+-. 3% (SEM) at rest to 77 .+-. 7% in exercise (P < 0.01) while in the patients'' 22 wall segments supplied by stenotic vessels the mean value fell during peak exercise from 59 .+-. 6 to 35 .+-. 3% (P < 0.005). Mean systolic posterior left ventricular wall thickening rose similarly in normals from 89 .+-. 9 to 115 .+-. 8% (P < 0.005) but fell during peak exercise from 75 .+-. 9 to 54 .+-. 9% (P < 0.01) in the patients'' 9 abnormally perfused segments. Diastolic wall thinning Vmax rose from rest to exercise in the septa and posterior left ventricular walls of normals from 5.5 .+-. 0.3 to 7.7 .+-. 0.6 cm/s (P < 0.005) and from 8.4 .+-. 0.8 to 11.8 .+-. 1.2 cm/s (P < 0.001), respectively. In patients, these same indices fell at peak exercise from 5.9 .+-. 0.5 to 4.3 .+-. 0.4 cm/s (P < 0.05) and from 8.3 .+-. 1.2 to 6.2 .+-. 1.4 cm/s (P < 0.005 vs. normals in exercise), respectively. The percent systolic change in left ventricular internal diameter increased from rest to exercise in normals from 38 .+-. 2 to 44 .+-. 2% (P < 0.001), but fell in patients during peak exercise from 35 .+-. 2 to 28 .+-. 2% (P < 0.001). Exercise echocardiography in these patients appears to be sensitive in detecting wall motion abnormalities during exercise-induced ischemia, and may be applicable in patients in whom exercise ECG is equivocal, or where the functional significance of a coronary arterial lesion is uncertain.