Simultaneous atrial fibrillation and sinus rhythm in a heart transplant recipient: ablation guided by novel dispersion analysis: a case report

Background: Atrial fibrillation (AF) in heart transplant recipients poses significant challenges, especially in the context of complex post-surgical cardiac anatomy. This case report describes a rare phenomenon of simultaneous sinus rhythm (SR) and AF in distinct cardiac regions, with AF ablation guided by dispersion analysis using the VOLTA AF Explorer system. Case summary: A 60-year-old male with a history of bicaval orthotopic heart transplantation presented with symptomatic AF. During invasive electrophysiological mapping, AF spontaneously terminated in the donor heart while persisting in the residual atrial tissue of the recipient's heart, specifically the posterior left atrial wall. Dispersion analysis, an experimental AF mapping technique, was employed to identify the arrhythmogenic substrates sustaining AF in the donor and recipient atria. Using this information, targeted and effective radiofrequency ablation was performed on both regions of the left atrium. Discussion: This case highlights the unique challenges of managing AF in heart transplant recipients, particularly when dual rhythms occur in electrically separate regions of the atria. The application of dispersion analysis, though novel and currently supported by limited evidence in this patient population, provided critical insights that enabled precise ablation. The observation of simultaneous SR and AF during invasive mapping underscores the complex post-surgical anatomy characteristic of heart transplant recipients. Dispersion analysis-guided ablation was successfully performed in a patient with electrically distinct donor and recipient atria, each capable of independently sustaining AF. Further studies are warranted to assess the broader utility of this innovative approach in similar clinical scenarios.