Myocardial perfusion assessed with thallium-201 and left heart volume measured by radiocardiogram at rest and during exercise in patients with coronary artery disease.

In coronary artery disease, non-invasive measurement of left heart volume by compartment analysis of radiocardiogram with 131 I-labeled human serum albumin (RCG) was assessed in 32 patients. Although left heart volume includes mean left atrial and ventricular volume, there was a good correlation between left heart volume and left ventricular end-diastolic volume by left cineventriculography (r = 0.94). Both thallium-201 (201 Tl) myocardial imaging and RCG were performed at rest in 87 patients and during bicycle ergometer exercise in 21 of these patients, the objective being to investigate the relationship between myocardial perfusion and left heart volume. Eighty-seven patients were divided into subgroups after 201 Tl-myocardial perfusion images at rest were studied. Left heart volume, right heart volume and total blood volume were increased and stroke volume index was decreased in proportion to the size of imaging defects (p less than 0.005, F greater than 4.07). New exercise-induced imaging defects on myocardial images correlated with the increase in left heart volume by exercise (p less than 0.001). These findings demonstrate the relationship between myocardial perfusion and left ventricular function, in the presence of bi-ventricular heart failure.