The prognostic significance of complete atrioventricular block in patients with acute inferior myocardial infarct. A study in the era thrombolytics]

Complete atrioventricular block (CAVB) during inferior acute myocardial infarction (AMI), characterizes a high-risk subgroup of patients. This study was designed to determine the incidence and meaning of CAVB associated with inferior AMI and their peculiarities in relation to thrombolytic therapy.Prospective and multicenter, involving 605 patients consecutively admitted with inferior AMI. We studied clinical characteristics and complications occurring during hospitalization and one-year follow-up were monitored.CAVB was found in 57 (9.4%) patients and was more frequently associated with: right ventricular involvement (35% vs 10%; p < 0.001), higher indexes of infaret size: ST elevated ECG leads (4.67 +/- 1.67 vs 4.1 +/- 1.4; p < 0.01) and peak of creatinkinase (2,219 +/- 1,543 vs 1,589 +/- 1,203; p < 0.01). Patients with CAVB had a higher incidence of cardiogenic shock (14% vs 5%; p < 0.05) and in-hospital mortality (21% vs 8.7%). CAVB had an independent value for predicting in-hospital mortality (odds ratio 2.7, 95% confidence interval, 1.3-5.5). CAVB appeared more frequently in the first hour of evolution (91% vs 41%; p < 0.01); its duration was shorter than 6 hours in a higher ratio (80% vs 5%; p < 0.01), and in- hospital mortality was lower (8.5 vs 40.9%; p < 0.05), in patients receiving thrombolytic treatment compared with patients without this treatment.CAVB is a relatively frequent complication of inferior AMI and is often associated with larger infarcts, high incidence of complications and mortality. Earlier appearance, shorter duration and fewer in-hospital mortalities seem to characterize those CAVBs occurring in patients treated with thrombolytics.