Regional dysfunction by equilibrium radionuclide angiocardiography: a clinicopathologic study evaluating the relation of degree of dysfunction to the presence and extent of myocardial infarction.

The relation of degree of regional wall motion abnormality by equilibrium radionuclide angiocardiography to the presence and mural extent of regional necrosis or scar at autopsy was evaluated in 23 autopsy patients who had a history of myocardial infarction and had equilibrium radionuclide angiocardiography within 40 days of death. Of the 228 regions evaluated by equilibrium radionuclide angiocardiography, 135 had abnormal regional wall motion and 102 (76%) of these 135 regions had evidence of myocardial infarction at autopsy. The overall sensitivity, specificity and predictive values of regional wall motion abnormality for regional necrosis or scar were 69, 59 and 76%, respectively. Of the 33 false positive regions, 20 (61%) had severe narrowing of the coronary artery supplying that region, 13 (39%) were adjacent to a region with a myocardial infarction and almost half (16 [48%]) were in the lateral wall. Eighty-three (36%) of the 228 regions were akinetic or dyskinetic, 52 (23%) were hypokinetic and 93 (41%) were normal. Sixty-three (76%) of the 83 akinetic/dyskinetic segments had transmural myocardial infarction at autopsy, 14 (17%) had nontransmural myocardial infarction and only 6 (7%) contained no necrosis or scar. In contrast, 14 (27%) of 52 hypokinetic segments had transmural myocardial infarction, 11 (21%) had nontransmural myocardial infarction and 27 (52%) were normal. Thus, the most severe regional wall motion abnormality (akinesia/dyskinesia) almost always indicates regional myocardial infarction which is usually transmural whereas less severe dysfunction (hypokinesia) is not necessarily associated with regional necrosis or scar. The severity of regional dysfunction must be considered if equilibrium radionuclide angiocardiography is used to evaluate the presence and mural extent of myocardial infarction within a region.