Key Points and Pitfalls in Electrocardiographic Diagnosis of Acute Myocardial Infarction

Abstract

Abstract: Since electrocardiographic features of acute myocardial infarction vary temporally and spatially among patients, there are many pitfalls in electrocardiographic diagnosis of this condition. In order to avoid overlooking acute myocardial infarction, it is necessary to consider characteristic findings, such as augmentation of Twave amplitude, ST elevation, and the appearance of abnormal Qwaves, in light of the time after onset. Observation of time-course changes allows us to noninvasively understand the presence/absence of recanalization and pathological conditions including infarct extension, infarct expansion, and retention of pericardial effusion, as well as to three-dimensionally diagnose the infarct site from changes in waveform in various leads. The latter findings reflect the anatomy of the artery responsible for the infarction. In addition, it is possible to determine the infarct site and the infarct-related artery from the waveforms of premature beats. In recent years, visualized diagnosis of coronary heart disease has become possible by means of improved techniques including coronary angiography and intravascular ultrasound. However, it seems that the well-established qualitative diagnosis of myocardial infarction by electrocardiography will continue to be important