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.
Keywords: ST-elevation myocardial infarction; complete atrioventricular block; high-degree atrioventricular block; pacemaker; sinoatrial node dysfunction.
© 2019 The Authors. Clinical Cardiology published by Wiley Periodicals, Inc.