A Dangerous Duo: Complete Heart Block Triggered by Anterior Wall Myocardial Infarction

Complete heart block (CHB) is an uncommon but life-threatening complication of anterior ST-elevation myocardial infarction (STEMI). We report a case of a 62-year-old male who presented to the emergency department with severe chest pain, profound bradycardia, and an undetectable blood pressure. Initial electrocardiogram demonstrated complete atrioventricular dissociation, and emergent transcutaneous pacing and vasopressor support were initiated. The patient subsequently developed ventricular tachycardia degenerating into recurrent conduction abnormalities with evolving ST-segment elevation. Emergent coronary angiography revealed a proximal left anterior descending (LAD) artery occlusion, and percutaneous coronary intervention with drug-eluting stent placement was performed. A transvenous pacemaker and an intra-aortic balloon pump were placed to stabilize cardiogenic shock. This case highlights the rarity and severity of CHB caused by proximal LAD occlusion, emphasizing the importance of rapid rhythm stabilization, early recognition of ischemic conduction disturbances, and immediate revascularization. Clinicians should maintain a high index of suspicion for conduction system compromise even in anterior infarction, as timely intervention is critical to preventing irreversible hemodynamic collapse.