[Duration of complete atrioventricular block complicating inferior wall infarction treated with fibrinolysis]

The aim of this study was to determine the duration of complete atrioventricular block complicating inferior wall acute myocardial infarction after the administration of fibrinolytic therapy.

From 1 January 1992 to 31 January 2002 a total of 449 patients were admitted directly to our hospital with inferior wall acute myocardial infarction in the first 6 hours; 282 of them (64%) received fibrinolytic therapy. Complete atrioventricular block appeared in 39 of these 282 patients (13.8%, group A). Of the 167 patients who did not receive thrombolytic therapy, complete atrioventricular block appeared in 13 (8%, control group). We compared the two groups by analyzing the duration of heart block, time to appearance, hemodynamic repercussion, and treatment required.

On admission, 38% of the patients in group A and 61% (P=NS) of those in the control group had complete atrioventricular block. Median duration of the block was 75 minutes (10 minutes to 48 hours) in group A and 24 hours (15 minutes to 9 days) in the control group (P=.004). After fibrinolytic therapy was administered, median duration of the block was 45 minutes (5 minutes to 48 hours). A temporary pacemaker was implanted in 43% of the group A patients and 84.6% of the control group patients (P=.01).

Complete atrioventricular block appears as a complication of inferior myocardial infarction within the first hours after the event. Duration of the block seems to be shorter in patients treated with fibrinolytic therapy.