Accuracy of the Electrocardiographic Criteria for Predicting the Right or Left Circumflex Coronary Artery as the Culprit Coronary Artery in Acute Inferior Myocardial Infarction

Jang, Soon Bong; Choi, Hyuk Joong; Im, Tai Ho; Sin, Jin Ho

Abstract

PURPOSE
New electrocardiographic criteria to predict the culprit coronary artery in acute inferior myocardial infarction have been developed. We tested the effectiveness of these criteria by verifying their diagnostic accuracy.
METHODS
The seven electrocardiographic criteria are STsegment depressions (1) in leads I > 0.5 mm, (2) in aVL > 1 mm, and (3) in V6 under the isoelectric line; higher ST-segment elevations (4) in lead III than in lead II, (5) in V1 than in V6, (6) in the sum of V(1 + 2 + 3) > or = V(4 + 5 + 6); and (7) ST-segment elevation > 1 mm in V1, and were analyzed by comparing the ST-segment deviation with the location of the infarcted coronary artery in 43 patients with acute inferior myocardial infarction.
RESULTS
The culprit coronary artery consisted of the right coronary artery in 72.1% of the cases, the left circumflex artery in 23.3% of the cases, and the left anterior descending artery in 4.6% of the cases. There was a significant correlation between the criteria and the culprit coronary artery, except for two criteria, ST-segment depression in lead I > 0.5 mm and elevation in lead V1 > 1 mm (p=0.00 to 0.02). Criteria such as ST-segment depressions in lead aVL > 1 mm and V6 under the isoelectric line and a higher ST-segment elevation in the sum of V(1 + 2 + 3) > or = V(4 + 5 + 6) had relatively high specificities (80%, 100%), but a low sensitivities (51.6%, 67.7%). Criteria such as higher ST-segment elevations in lead III than in II and in V1 than in V6 had not only high sensitivities (80.6%, 100%) and specificities (70%, 90%) but also relatively high diagnostic accuracies (95.1%, 82.9%).
CONCLUSION
Higher ST-segment elevations in lead III than in II and in V1 than in V6 are sensitive & specific criteria for correctly predicting the culprit coronary artery in acute inferior myocardial infarction.