Comparison between exercise myocardial perfusion and wall motion using 201T1 and 191Irmsimultaneously

By exploiting the ultrashort half-life 191Irmas tracer for left ventricular first-pass angiocardiography and 201T1 as myocardial perfusion agent, direct comparison between myocardial perfusion and regional wall motion was obtained during the same exercise stress test in patients with non-significant coronary artery disease, in patients with recent myocardial infarction, and in patients six weeks after successful percutaneous transluminal coronary angioplasty (PTCA). A good agreement between regional myocardial perfusion and regional wall motion was observed in patients with non-significant coronary artery disease and in most patients with recent myocardial infarction. In contrast, discrepancies occurred at maximal exercise in patients studied six weeks after successful PTCA: only 38 of the patients with no evidence of restenosis and with a completely normal myocardial perfusion scintigraphy had a normal regional wall motion at maximal exercise stress. According to these results, a normal uptake of 201T1 six weeks after PTCA would mean that the circulation has been successfully re-established but without predicting the functional capacities of the myocardial cells which remain altered at least six weeks after the revascularization procedure in about two-thirds of the patients. We conclude that 191Irmin combination with 201T1 offers the opportunity of performing myocardial perfusion and wall motion studies simultaneously both at rest and during exercise.