A noninvasive radiographic technique for evaluation of exercise-induced changes in cardiac function.

An electrocardiographic-triggered radiographic technique for obtaining a single image of the heart at both end-systole and end-diastole was used in conjunction with upright bicycle exercise to detect stress-induced changes in 1) systolic and diastolic cardiac transverse diameter, and 2) regional motion of the free left ventricular wall. Twenty-one patients were studied; 10 had normal coronary arteries and 11 had significant coronary artery disease. Twenty patients (10 with normal coronary arteries and 10 with coronary artery disease) also had multigated radionuclide blood pool scans at rest and with exercise. All patients without coronary disease showed a decrease in systolic cardiac transverse diameter with exercise and a slight increase in amplitude of motion of the left ventricular free wall. Eight (73%) of the 11 patients with coronary artery disease showed an increase in systolic transverse cardiac diameter with exercise (p less than 0.001), and 5 developed either new regional left ventricular asynergy or deterioration of segments with rest asynergy. Eight of the 10 patients with coronary artery disease who had rest and exercise radionuclide scans had an abnormal ejection fraction response to exercise. However, only 4 of the 10 control patients who had multigated scans had a normal ejection fraction response, although all showed normal regional wall motion with exercise. This new approach is inexpensive and easily performed. These preliminary data suggest that it may be a useful adjunct to cardiac stress testing and is worthy of further study.