Article Details

Background: Pacemaker syndrome is a recognized complication of atrioventricular (AV) dyssynchrony and may occur in patients with dual-chamber pacemakers following automatic mode changes associated with battery depletion.
Case Presentation: A 75-year-old woman with a dual-chamber pacemaker implanted for carotid sinus hypersensitivity presented with acute decompensated heart failure, acute kidney injury, and newly developed massive tricuspid regurgitation. Device interrogation revealed that the pacemaker had reached recommended replacement time (RRT), corresponding to the elective replacement indicator (ERI) state, resulting in automatic transition to ventricular-only pacing with loss of AV synchrony. Following generator replacement and restoration of dual-chamber pacing, the patient experienced rapid improvement in symptoms, renal function, and tricuspid regurgitation severity.
Discussion: This case demonstrates that ERI-associated loss of AV synchrony can precipitate acute heart failure, cardiorenal dysfunction, and reversible functional tricuspid regurgitation despite preserved ventricular systolic function. It underscores the importance of considering pacemaker syndrome in patients with implanted devices who present with otherwise unexplained clinical deterioration and highlights the value of prompt device interrogation.
Conclusion: Early recognition of ERI-associated pacemaker syndrome and timely generator replacement can restore AV synchrony and lead to rapid reversal of hemodynamic compromise and clinical recovery.

Keywords: Pacemaker syndrome; Dual-chamber pacemaker; Atrioventricular synchrony; Recommended replacement time (RRT); Tricuspid regurgitation; Acute decompensated heart failure; Acute kidney injury