JACC: Case Reports (Jul 2025)

Worsening Heart Failure From Decreased Atrioventricular Synchronization Rate of a Leadless Pacemaker

  • Kazuku Ishihara, MD,
  • Takenori Ikoma, MD,
  • Makoto Sano, MD,
  • Terumori Satoh, MD,
  • Keisuke Iguchi, MD,
  • Atsushi Sakamoto, MD,
  • Kenichiro Suwa, MD,
  • Yoshihisa Naruse, MD,
  • Hayato Ohtani, MD,
  • Yuichiro Maekawa, MD

DOI
https://doi.org/10.1016/j.jaccas.2025.103862
Journal volume & issue
Vol. 30, no. 17
p. 103862

Abstract

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Background: Atrioventricular synchronous pacing with a leadless pacemaker is a therapy used in patients with atrioventricular block. However, atrial oversensing may cause an increase in heart rate, with resulting atrioventricular dyssynchrony. Case Summary: A 90-year-old woman, who was treated with a leadless pacemaker 2 years earlier for a complete atrioventricular block, developed congestive heart failure. The electrocardiogram revealed an increase in heart rate with atrioventricular dyssynchronous pacing and a decrease in atrioventricular synchronization rate. A manual atrial mechanical test indicated dyssynchronized atrioventricular pacing secondary to atrial mechanical oversensing. Discussion: This case of heart failure exacerbation resulted from 1) the increase in heart rate with atrioventricular dyssynchrony caused by atrial mechanical oversensing and 2) the dyssynchronous pacing resulting from pacing-induced cardiomyopathy. Take-Home Messages: Atrioventricular synchronization can vary with changes in cardiac structure and hemodynamics. It is important to assess atrioventricular synchrony repeatedly in electrocardiograms or rate histograms in the device.

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