Acute myocardial infarction (AMI) associated with left main coronary artery (LMCA) occlusion frequently results in poor prognosis because of the extensive area at risk with anterolateral wall involvement. Early diagnosis and subsequent treatment are essential to rescue these patients. In the current study, we retrospectively compared ECG findings in patients with LMCA occlusion, to those with proximal coronary artery occlusion.

METHODS

Of the 1880 patients undergoing coronary angiography within 24 hours of onset of AMI, 25 patients had LMCA occlusion. ECG findings on admission in these patients were compared to those in 30 consecutive patients with proximal coronary artery occlusion. Patients with previous AMI, left ventricular hypertrophy, or ⩾ 75% stenosis in non-infarct arteries were excluded from this study. Patients with right bundle branch block (RBBB) were included, but those with left bundle branch block were excluded because of the difficulty of diagnosing AMI. ST elevation or depression was considered present if ST deviation was ⩾ 0.1 mV. Left anterior fascicular block (LAFB) was defined by the mean QRS axis deviated to the left < 30° in the frontal plane. The culprit lesion was determined by coronary angiography and confirmed later by two cardiologists who were not aware of any ECG findings.

Data …