Electrocardiographic features and prognosis in acute diagonal or marginal branch occlusion

The aim of our study was to analyze electrocadiographic changes in patients with acute myocardial infarction related to the occlusion of diagonal (DG) or marginal (MG) branch. We selected 13 cases with DG and 12 with MG occlusion on angiography and evaluated their electrocardiogram (ECG) patterns on admission obtained in emergency department (ED) of university hospital with catheterization laboratory serving everyday interventional cardiology duty for ACS. Most characteristic ECG changes in acute occlusion of DG observed in 12 patients (92.3%) included ST-segment elevation in leads V(2) and V(3) (mean, 1.2 +/- 0.5 mm; maximum, 1.7 mm) and ST-segment depression in leads II and III (mean, 0.9 +/- 0.4 mm; maximum, 1.5 mm). Most characteristic ECG changes for acute occlusion of MG were ST-segment depression in leads V(5) and V(6) (mean, 0.9 +/- 0.4 mm; maximal, 1 mm) observed in 11 (91.7%) patients, ST-segment depression in lead II (mean, 0.7 +/- 0.2 mm; maximal, 0.8 mm) in 10 (83.3%,) and in leads V(2) and V(3), and aVF in 8 (66.7%) of cases. Risk of complications including cardiogenic shock and death was high in both groups especially during acute phase of myocardial infarction. Prevalence of borderline ECG changes in patients with acute coronary occlusion confirms how important is precise ECG interpretation usually initially done by ED physician.