Myocardial perfusion scintigraphy as an aid in understanding electrocardiographic changes of ischemia and infarction.

In summary, myocardial perfusion scintigraphy with either thallium or the isonitriles has added substantially to electrocardiographic definition of both myocardial infarction and acute and chronic myocardial ischemia. Using perfusion scintigraphy, one can define infarct zones, risk zones, and the presence of reperfusion following thrombolytic therapy. When perfusion scintigraphy is combined with physiologic or pharmacologic stress, myocardial ischemia can be documented, irrespective of electrocardiographic documentation of the phenomenon. Delayed imaging may be important for defining viability even in the presence of significant Q waves. Myocardial perfusion scintigraphy provides prognostic evaluation of patients with both acute and chronic coronary syndromes. When the current cumulative experience is looked at critically, it is clear that myocardial perfusion scintigraphy has helped in the development of an understanding of the limitations of electrocardiography in the diagnostic and functional categorization of patients with acute and chronic coronary disease.