Electrophysiological Sequelae Following Cardiac Surgery in Heterotaxy Syndrome

Abstract

Background: Cardiac conduction system abnormalities often associated with heterotaxy syndrome predispose affected patients to a variety of cardiac arrhythmias. Although surgical palliation has contributed to improved survival, the burden of postoperative arrhythmia remains a critical concern. In the current study, electrophysiological outcomes were reviewed and risk factors for arrhythmia were identified in patients undergoing cardiac surgery for heterotaxy

Methods: A retrospective analysis of 33 patients with heterotaxy syndrome who underwent cardiac surgery at a single tertiary center was conducted. Main outcomes included the incidence of postoperative abnormal heart rhythm, defined as new-onset heart block, tachyarrhythmia, or nodal rhythm, and overall mortality. Risk factors for abnormal rhythm and mortality were examined using logistic regression and Cox proportional hazards modeling, respectively. The Kaplan-Meier method was used to estimate survival.

Results: The cohort had a median age of 28 months (IQR: 14-58) at the time of surgery. Right isomerism was predominant (75.8%). Most patients (87.9%) were palliated via a single ventricle pathway. Preoperatively, 87.9% of patients had a normal ECG. Postoperatively, the incidence of abnormal heart rhythm was 24.2% (12.1% heart block, 12.1% tachyarrhythmia). Over a median follow-up of 54 months (IQR: 27-90), overall mortality was 18.18%. Kaplan-Meier analysis revealed survival rates of 88% at 3 years and 74% at 10 years. Univariable analysis identified that left isomerism (OR 14.88, p=0.019) and absent inferior vena cava (IVC) (OR 7.00, p=0.033) were significantly associated with developing postoperative arrhythmia. Older age at the time of analysis was significantly associated with improved survival (HR 0.89, p=0.025).

Conclusion: Patients with heterotaxy syndrome undergoing cardiac surgery face a substantial risk of postoperative arrhythmia. Left isomerism and absent IVC are significantly associated with postoperative arrhythmias. Older age at surgery was associated with improved survival. These findings emphasize the importance of comprehensive electrophysiological evaluation and risk factor assessment in managing heterotaxy syndrome patients.