ASSESSMENT OF INFERIOR ST SEGMENT DEVIATION FROM ECG TO DETERMINE THE SITE OF LEFT ANTERIOR DESCENDING CORONARY ARTERY OCCLUSION IN ANTERIOR ST SEGMENT ELEVATION MYOCARDIAL INFARCTION

Abstract

Background: The anterior ST segment elevation myocardial infarction (STEMI) is the most commonly found of STEMI, which involves the left anterior descending (LAD) coronary artery. The occlusion on the proximal part of LAD is known to have worse prognosis than distal occlusion, because it relates with extended of infarction area. Therefore knowing early the site of occlusion through admission ECG before coronary angiography procedure, can provide us the important information, especially for further treatment.

Methods: This study involved 66 patients of anterior STEMI with the onset of symptoms ≤ 24 hours whom admission at emergency department of Pusat Jantung Terpadu RSUP Haji Adam Malik Medan. Then, deviation of the inferior ST segment on admission ECG be assessed based on ECG criteria A as a group I (depression of ST segment on lead III + aVF ≥ 2.5 mm) and ECG criteria B as a group II (elevation/isoelectric on lead III, aVF), and then the site of LAD coronary artery occlusion determined by coronary angiography procedure who performed during hospitalization. Statistical analysis was conducted using the Chi square correlation test and the under the Curve (AUC) curve of the receiver operating curve (ROC).

Results: From 66 subjects result 32 patients in group I (48.4%) and 34 patients in group II (51.5%). There is a significant relation between ECG criteria and the site of LAD coronary artery occlusion in the anterior STEMI patient (p < 0.05). The group I that predict coronary angiography showed sensitivity and specificity of 74,3% and 80,6% respectively with positive predictive values and negative predictive values of 81% and 73,5%. While group II that predict coronary angiography showed sensitivity and specificity 80,6% and 74,3% respectively with positive predictive and negative predictive values of 73,5% and 81% respectively. The ECG criteria can be used as a strong predictor to predict the site of LAD coronary artery occlusion in the anterior STEMI patient, with an under the curve area of 0775 ((95% CI 0,658-0.892., p < 0.05).

Conclusion: ECG criteria in anterior STEMI patient based on ST‑segment deviations in inferior lead allowed to predict the site of occlusion with good accuracy.