Contemporary practice pattern of permanent pacing for conduction disorders in inferior ST‐elevation myocardial infarction

BACKGROUND: Currently, there is no clear consensus regarding the optimal waiting period before permanent pacemaker implantation in patients with conduction disorders following an inferior myocardial infarction. HYPOTHESIS: We aimed to elucidate the contemporary practice pattern of pacing, especially the timing of pacemaker implantation, for sinoatrial node and atrioventricular (AV) conduction disorders following an inferior ST‐elevation myocardial infarction (STEMI). METHODS: Using the National Inpatient Sample database from 2010 to 2014, we identified patients with a primary diagnosis of inferior STEMI. Primary conduction disorders were classified into: (a) high‐degree AV block (HDAVB) consisting of complete AV block or Mobitz‐type II second‐degree AV block, (b) sinoatrial node dysfunction (SND), and (c) no major conduction disorders. RESULTS: Among 66 961 patients, 2706 patients (4.0%) had HDAVB, which mostly consisted of complete AV block (2594 patients). SND was observed in 393 patients (0.6%). Among the 2706 patients with HDAVB, 267 patients (9.9%) underwent permanent pacemaker. In patients with HDAVB, more than one‐third (34.9%) of permanent pacemakers were placed within 72 hours after admission. The median interval from admission to permanent pacemaker implantation was 3 days (interquartile range; 2‐5 days) for HDAVB vs 4 days (3‐6 days) for SND (P < .001). HDAVB was associated with increased in‐hospital mortality, whereas SND was not. CONCLUSIONS: In patients who developed HDAVB following an inferior STEMI, only one in 10 patients underwent permanent pacemaker implantation. Despite its highly reversible nature, permanent pacemakers were implanted relatively early.