Exercise Techniques for Radionuclide Angiocardiography

Abstract

Evaluation of cardiac function during stress exercise provides important information unavailable from studies performed at rest. A dequate data are difficult to obtain during exercise because of the brief duration of the cardiac cycle, the rapid transit of tracer through the heart, and patient motion during exercise. During rest and exercise, we performed radionuclide angiocardiograms in the erect position on normal subjects and patients with coronary artery disease (CAD). The electrocardiogram (ECG) was telemetered and the blood pressure was monitored at regular intervals. A prior treadmill exercise test in all subjects with CAD had documented the heart rate-blood pressure (HR-BP) product at which ischemic myocardial changes occurred on ECG. A bicycle ergometer provided a gradually increasing work load from 200 kilopond meters/min to 700 kpm/min to achieve 80% of the maximal HR-BP product achieved during treadmill testing. Cardiac chamber wall motion and volume changes during individual cardiac contractions were assessed at heart rates greater than 200 beats/min. When properly performed, resting and exercise initial transit radionuclide angiocardiograms provide a large amount of important hemodynamic information with little patient risk or discomfort.