A new electrocardiographic approach to identify the coronary artery responsible for acute inferior myocardial infarction: a study in 100 patients.

OBJECTIVE

The objective of this study is to analyze the value of the electrocardiogram in the identification of the coronary artery responsible for acute inferior myocardial infarction.

MATERIAL AND METHODS

One hundred consecutive patients with acute inferior myocardial infarction were studied, 67 with a lesion in the right coronary artery and 33 in the circumflex artery. The ST segment changes in the inferior, lateral, precordial and right-chest leads were analyzed, as well as the arithmetic sum of the ST segment in the inferior and V2 leads (II + V2, III + V-2 and aVF + V2). We also developed a diagnostic process based on a stepwise approach of three electrocardiographic criteria: a) elevation of the ST segment in DI; b) arithmetic sum of the ST magnitude in DIII + V2 < 0; c) depression of the ST segment in V4R.

RESULTS

This study shows that the most useful parameters to predict (with a specificity of 100%) the lesioned coronary artery in acute inferior myocardial infarction are: a) the arithmetic sum of the ST segment: aVF + V2 > 0, for the right coronary artery; b) the arithmetic sum of the ST segment: III + V2 < 0, for the circumflex artery; c) the arithmetic sum of the ST segment: aVF + V2 > 1 mm, for the proximal right coronary artery.

CONCLUSIONS

The incorporation of these three criteria in an algorithm diagnostic system allows us to locate the coronary artery responsible for acute myocardial infarction with 100% sensitivity and specificity.