COMPARATIVE ANALYSIS OF ELECTROCARDIOGRAPHIC PATTERNS IN LEFT CIRCUMFLEX ARTERY OCCLUSION IN PATIENTS WITH ACUTE INFERIOR MYOCARDIAL INFARCTION

Abstract

Aim: To determine electrocardiographic patterns in patients with angiographically confirmed left circumflex artery (LCx) occlusion who present with acute inferior myocardial infarction (AMI).

Study Design: It was a prospective, single-center, observational study

Study Place and Duration: The study was conducted at People’s University of Medical and Health sciences for women Nawabshah during August 2024 to August 2025.

Methods: The current study involved 75 consecutive patients with inferior ST-elevation myocardial infarction (STEMI) undergoing first-line coronary angiography (CA). The inclusion criteria were symptoms lasting less than 12 hours, confirmed inferior STEMI, and angiographic evidence of LCx. ECGs were classified based on ST elevation in lead II compared to ST depression in lead aVR. ECGs were independently scored by two cardiologists. Statistical analysis was performed using SPSS v28, t-tests, Chi-square/Fisher exact tests, and ROC curves (p < 0.05, statistically significant).

Results: Of the 75 patients, 60 (80%) had LCx occlusion, and 15 (20%) had RCA occlusion. No significant differences in demographics (mean age 57.10 ± 10.25 vs. 55.90 ± 11.80 years, p=0.58; males 75% vs. 66.7%, p=0.64) or comorbidities (hypertension 38.3% vs. 46.7%, p=0.49). ST elevation II > III was more prevalent in 43.3% LCx than 46.7% RCA (p=0.03); aVR depression in 25% LCx than 60% RCA (p=0.03). The outcomes did not differ (cardiac events: 16.7% vs. 20%, p = 1.00; mortality: 8% vs. 6.7%, p = 1.00). ROC for II > III yielded AUC 0.89 (95% CI 0.78-0.97, p<0.001), sensitivity 82%, specificity 91%.

Conclusion: ST elevation II > III is one of the most diagnostic ECG patterns of LCx occlusion that results in inferior AMI and promotes timely therapeutic interventions. These findings need to be validated through larger studies.