Value and limitations of electrocardiogram in diagnosis of slight and subacute coronary attacks.

The electrocardiogram recorded at the initial consultation was compared with the final diagnosis in 211 consecutive suspected slight or sub-acute coronary attacks in 206 patients.In 77 (36%) of the 211 episodes, acute (or subacute) myocardial infarction was finally diagnosed. The initial E.C.G. showed a diagnostic pattern in only 19 (25%) of these 77 episodes; in 39 (50%) it was abnormal but not diagnostic of recent infarction; while in 19 (25%) the E.C.G. showed no abnormality classified under the Minnesota Code, though in 16 of these there were definite minor changes.In 61 (29%) of the 211 episodes acute myocardial infarction was excluded and an alternative diagnosis was made. The E.C.G. was strictly normal in only 23 (38%) of these 61 episodes; in 15 (25%) it showed minor abnormalities, and in 23 (38%) it was grossly abnormal.