The time to reversal of complete atrioventricular block and its predictors in acute ST-segment elevation myocardial infarction

Objective: The purpose of this study was to determine the time to reversal of complete AV block (CAVB) in ST-segment elevation myocardial infarction (STEMI) with various modalities of treatment and to examine the factors associated with early reversal of CAVB.

Methods: We prospectively assessed the STEMI patients complicated by CAVB. The mean time to reversal of CAVB was analyzed and compared according to the treatment received. Multivariate logistic regression analysis was performed to find the predictors of mortality.

Results: Of 3954 patients with STEMI, CAVB was present in 146(3.7%) patients. Inferior wall myocardial infarction (IWMI) was more commonly associated with CAVB than anterior wall myocardial infarction (AWMI) (74.7% vs 25.3%). The mean time to reversal of CAVB was 25.4 ± 35.5 h. It was significantly lower with the primary percutaneous coronary intervention (PCI) compared to thrombolysis (5.21 ± 10.54 vs 12.98 ± 17.14; p = 0.0001). Predictors of early reversal of CAVB were early presentation to hospital (<6 h) from symptom onset, presence of IWMI, any revascularization done, primary PCI performed in comparison to thrombolysis, and normal serum creatinine levels. The presence of older age, broader QRS complex, cardiogenic shock/heart failure, and elevated creatinine were independent predictors of mortality. The CAVB reverted in all the alive patients except one who required permanent pacemaker implantation.

Conclusion: CAVB is uncommon in STEMI and it recovers in a vast majority of surviving patients. The time to reversal of CAVB in STEMI is lower with primary PCI compared to thrombolysis. Outcomes are poor without revascularization in such patients.