Clinical significance of smoking in acute inferior wall myocardial infarction complicated by third degree atrioventricular block

Inferior wall myocardial infarction accounts for 40-50% of all acute myocardial infarctions. Association of acute inferior wall myocardial infarction and third degree atrio ventricular block (AVB) was established, but the effect modifiers are still not known. We assessed the predictors of patients presenting with acute inferior wall myocardial infarction and third degree atrioventricular block. We conducted a prospective cross sectional study on patients presented within 0.04 sec in duration in lead II,III and aVF with reciprocal ST segment depression in the lateral and/or high lateral leads ( I, aVL, V5 and V6).Out of 115 patients with acute inferior wall myocardial infarction ,70(80.5%)patients were male. Mean age was 47.5 ±7.47 yearsand duration of symptoms was 4.6 ±1.28 hours. Diabetes was found in 57.4% patients, 72.2% were hypertensive, and 50.4% patients were smokers. Third degree AVBwas observed in 13.0% patients. Smoking status was significantly associated with third degree AVB (OR: 2.1, 95%CI: 87% , p-value: 0.01).Among patients with acute inferior wall myocardial infarction, third degree AVB occurred in 15(13%),and has significant association with smoking. Generalizabilty of results is limited because it was a single centre, non randomized study with small size.