Usefulness of dipyridamole-thallium-201 perfusion scanning for distinguishing ischemic from nonischemic cardiomyopathy

Abstract To determine noninvasively the etiology of left ventricular (LV) dysfunction, 22 patients with a diagnosis of cardiomyopathy determined via cardiac catheterization and 5 normal control subjects underwent radionuclide ventriculography and intravenous dipyridamole-thallium-201 perfusion scanning. Both ischemically and nonischemically induced LV dysfunction had comparable global LV ejection fractions (24 ± 6 vs 23 ± 8%, respectively) and extent of segmental wall motion abnormalities. Right ventricular ejection fraction was significantly better in the group with an ischemic etiology of LV dysfunction (41 ± 26 vs 13 ± 10%, p