Long-term prognostic significance of atrioventricular block in inferior acute myocardial infarction.

Among 477 consecutive patients admitted for inferior acute myocardial infarction (AMI), 2nd or 3rd degree atrioventricular (AV) block developed in 88 (20%). Compared with the 359 without AV block, these 88 patients presented a higher incidence of Killip class greater than 1 (52% vs 28%, P less than 0.001), pericarditis (30% vs 17%, P less than 0.01), atrial fibrillation (26% vs 11%, P less than 0.01), complete bundle branch block (12% vs 4%, P less than 0.01) and in-hospital mortality (24% vs 4%, P less than 0.001). The 3-year post-hospital mortality was not significantly different in the two groups (12% vs 15%). Among the 88 patients with AV block, those who died at hospital were older (66 +/- 11 vs 59 +/- 11 years, P less than 0.05), had a higher incidence of Killip class greater than 1 (86% vs 42%, P less than 0.001) and bundle branch block (29% vs 7%, P less than 0.05). Thus, patients with inferior AMI who developed AV block had a poor hospital outcome but long-term prognosis was similar in hospital survivors who had AV block and in those without this complication.