Objective: Indication of temporary pacemakers in patients during acute myocardial infarction was widely studied in the pre-thrombolytic era without having determined whether the generalization of fibrinolysis might have changed the overall incidence and significance of temporary pacemakers. Our aim was to determine the incidence and the prognostic significance of insertion of temporary pacemakers in patients with acute myocardial infarction.
Patients and methods: In a study involving 1,239 patients consecutively admitted to hospital with acute myocardial infarction we studied clinical characteristics and prognosis depending on temporary pacemaker insertion or not. We performed an univariate analysis on in-hospital mortality and those selected variables were introduced in to a logistic regression analysis.
Results: A temporary pacemaker was indicated in 55 patients (4.4%), prophylactically in 22% and therapeutically in 78%. Temporary pacemakers were inserted in 55% of the patients with advanced AV block and in the 10% of the patients with bundle-branch block. Pacemaker insertion was associated with higher number of affected leads in the ECG, and higher CK peak, regardless of the association with thrombolysis. The following complications were more often observed in patients with temporary pacemakers: atrial fibrillation, heart failure, right bundle-branch block, advanced atrioventricular block and in-hospital mortality (45.4 vs 10.2%; p < 0.001). Need for a temporary pacemaker was less frequent in patients treated with thrombolytics compared with those not treated (3.0 vs 6.1%; p < 0.02). Pacemaker insertion had an independent value for predicting in-hospital mortality (OR = 5.51; 95% CI, 2.71-11.19).
Conclusion: The insertion of a temporary pacemaker in acute myocardial infarction is less frequent nowadays than on the pre-thrombolytic era. Pacemaker insertion is associated with higher indices of infarct extension and in-hospital mortality, having independent prognostic value on the in-hospital mortality.