Outcomes of Patients With Arrhythmia During Single‐Ventricle Palliation

OBJECTIVES: This study evaluates the short- and long-term outcomes of patients with single-ventricle morphology with arrhythmias prior to Fontan surgery, assessing the association between early arrhythmias and subsequent clinical outcomes. BACKGROUND: Staged surgical palliation for single-ventricle physiology involves complex operations with a high incidence of arrhythmias. The optimal duration of antiarrhythmic medication use and its impact on surgical outcomes and long-term prognosis remain unclear. METHODS: A single-center retrospective analysis was conducted on patients treated between August 2011 and January 2024. Patients with single-ventricle physiology undergoing staged surgical palliation with documented arrhythmias were selected for detailed analysis. Data on patient characteristics, arrhythmia type, antiarrhythmic medication use, and outcomes were collected and analyzed. RESULTS: The study included 109 patients, predominantly male, with hypoplastic left heart syndrome being the most common morphology. Arrhythmias were primarily encountered during Stage 1 admission (97%), with no initial arrhythmia occurrence during interstage times. Pre-Fontan electrophysiology studies showed inducible tachycardia in 33% of patients. The need for ablation was seen in conjunction with heterotaxy syndrome and patients with longer duration and complexity of tachycardia prior to Fontan. Overall survival to Fontan was poor, with significant mortality at each stage of palliation. Subsequent post-Fontan arrhythmia was rare and there was no recurrence of patients undergoing ablation. CONCLUSION: Early arrhythmias are common in single-ventricle patients undergoing staged palliation and this cohort is associated with significant morbidity and mortality. Pre-Fontan electrophysiology studies and ablation may improve outcomes, particularly in high-risk cohorts, highlighting the need for tailored arrhythmia monitoring and management strategies. CONDENSED ABSTRACT: This study evaluates the outcomes of patients with single-ventricle physiology and arrhythmias occurring before Fontan surgery, examining the relationship between early arrhythmias and clinical outcomes. Conducted as a single-center retrospective analysis from August 2011 to January 2024, it includes 109 patients with hypoplastic left heart syndrome. Arrhythmias were common during Stage 1 admission (97%). Pre-Fontan electrophysiology studies showed inducible tachycardia in 33% of patients, with ablation needed in those with heterotaxy syndrome and complex tachycardia. Survival to Fontan was poor, with significant mortality at each stage. Tailored arrhythmia monitoring and management strategies are essential.