Diagnostic flowchart to estimate the morphology of left descending artery lesions by initial electrocardiogram in ST-elevation myocardial infarction

Background: ST-segment deviations in an initial 12-lead electrocardiogram provide anatomical information in ST-elevation myocardial infarction (STEMI). A diagnostic flowchart was formulated to estimate the anatomical characteristics of a culprit left anterior descending artery (LAD).

Methods: The present study analyzed 252 STEMI patients whose culprit lesions were confirmed to be LAD as an observational study. LAD morphology, wrapped (n = 26) or not (n = 226), and the positional relationship to first diagonal branch (n = 162 in proximal, n = 90 in distal lesions) were assessed. Their ST-segment deviations and such anatomical characteristics were examined.

Results: Reciprocal ST depression in nonwrapped LAD was frequent in patients without diagonal branch flow (49.3%-18.8% in II, p < .01; 66.4%-36.3% in III, p < .01; 63.7%-30.0% in aVF, p < .01). ST elevation in inferior leads was the characteristics of wrapped LAD but was not the case in patients without diagonal flow (50%-0% in II, 60%-0% in III, and 60%-0% in aVF). ST elevation in lateral leads to the diagonal branch in nonwrapped LAD is more frequent for proximal than distal lesions (36.3% vs. 15.0% in I, p < .01; 50.7% vs. 16.3% in aVL, p < .01), but this was not observed for wrapped LAD (18.8% vs. 20.0% in I, p = .72; 31.3% vs. 10.0% in aVL, p = .21). Positive and negative predictive values for the diagnostic accuracy of suggested diagnostic flow based on the above results were 0.794 and 0.478, respectively.

Conclusions: Our suggested diagnostic flowchart provides enough diagnostic accuracy to estimate culprit morphology.