[Simultaneous test of ventricular function and myocardial perfusion, during exercise, using a new agent labeled with Tc99m].

Abstract

One a tribute of a Tc 99m labeled myocardial agent is the possibility to measure both ventricular function and myocardial perfusion with a single injection. To assess this, normal volunteers, 14 patients with coronary artery disease (CAD) and two suffering from cardiomyopathy with normal coronaries, were injected with 8-10 mci carbomethoxy-isopropyl-isonitrile or 20 mci Rp-30 Tc 99m at peak semi-recumbent bicycle exercise and again at rest. Thirty msec per frame first pass data, and 5 min static anterior, 40(0-) and 70(0-) left anterior oblique images were obtained. Standard Thallium 201 stress test were also done, within one month, and were at the same level of exercise. The left ventricular ejection fraction (EF) increased with exercise (69%-76%) in normal patients. All studies showed normal myocardial perfusion on exercise. In CAD patients the EF increased in some patients who had ischemia. Perfusion images with Tc 99m during exercise and at rest had an identical correlation with Thallium 201. The results support the concept of dual ventricular function and perfusion studies using a single Tc 99m labelled myocardial agent, and suggest that this could become the standard radionuclide stress tests in the future.