The Use of Electrocardiogram for the Identification of Diagonal and Marginal Branches Such as the Infarct Related Artery

Abstract

Previous studies gave information on electrocadiographic indicators of the main branches of left coronary artery common infarct related arteries (IRA) in patients with ST-elevation myocardial infarction. There is lack of evidence for electrocadiographic feature for diagonal (DG) and marginal (MG) branches of left coronary artery as IRA. From the registry of 300 consecutive STEMI patients, treated with the primary angioplasty, we selected 13 patients with DG and 19 with MG. The baseline electrocardiograms were evaluated. in DG most specific (sensitivity 93%) combination of ST segment changes was: ST elevation in V2 and V3; (mean 1,21 mm, maximum 1,67 mm) and ST depression in II, III (mean 0,88 mm; maximum 1,50 mm). For MG most specific (sensitivity 64%) was: ST depression in V6 and V5 (mean 0,88 mm, maximum 1 mm) and ST depression in II (mean 0,65 mm, maximum 0,83 mm In the DG such as IRA the electrocardiographic presentation is similar to that observed in the left anterior descending coronary artery and in MG such as IRA similar to that in the left circumflex coronary artery. The ST segment deviations are slight and usually smaller than 1 mm. The patients presented with chest pains and borderline ST segment deviations should be diagnosed for occluded DG or MG.