Myocardial stress perfusion scintigraphy with rubidium-81 versus stress electrocardiography.

Fifty-six patients who subsequently underwent selective coronary angiography were studied noninvasively with relative myocardial perfusion scintigraphy with rubidium-81 and graded stress electrocardiography in an attempt to evaluate the ability of these tests to identify the presence of significant ischemia and, indirectly, coronary stenosis. Both the sensitivity (0.91) and specificity (0.91) of perfusion scintigraphy were impressive and better than the sensitivity (0.79) and specificity (0.64) of stress electrocardiography, the specificity of scintigraphy significantly so (P less than 0.05). Additionally, perfusion scintigraphy yielded excellent localizing information and was reliable even in the presence of drug effect, conduction abnormalities and nonspecific electrocardiographic abnormalities. Rare cases of triple vessel disease, prior myocardial infarction or single vessel disease with widespread collateral vessels were causes of scintigraphic misdiagnosis. Although ribidium-81 perfusion scintigraphy with the scintillation camera requires special collimation and significant quality control, it provides well resolved images and may prove particularly useful in facilitating quick successive multiple scintigraphic cardiac studies.