Arrhythmias in patients with hypoplastic left heart syndrome

Background Mortality between stage I and II palliation for hypoplastic left heart syndrome (HLHS) has been associated with arrhythmias. The stage-related proportion, associations, and clinical impact of arrhythmias in patients with HLHS have not been evaluated. In addition, arrhythmia subtypes have not been described in this patient group. Methods We performed a retrospective analysis of all patients at Duke University Medical Center who received one or more palliative stages for HLHS from September 2000 to October 2008. Results Overall, 49 (57%) of 86 patients had 63 arrhythmias. The majority of arrhythmias occurred between stage I and II, with 44 (51%) of 86 patients manifesting a new arrhythmia. Arrhythmias occurring in this interval tended to be associated with a higher mortality compared with arrhythmias occurring after stage II (odds ratio = 3.2 [95% CI 0.84-12.0], P = .09). Overall mortality was similar in patients with and without arrhythmias ( P = .99). Supraventricular tachycardia was the most common arrhythmia (16/63; 25%), but persistent bradycardias (sinus node dysfunction or high-grade atrioventricular block) had the worst clinical outcome with 73% mortality (8/11). There was no association between arrhythmia occurrence and degree of tricuspid regurgitation, left ventricular hypertension, genetic syndrome, type of stage I operation, or need for extracorporeal membrane oxygenation. Conclusions A large proportion of patients with HLHS experience serious arrhythmias requiring therapy, especially between stage I and II. Persistent bradycardia following stage I is associated with a high mortality rate. Considering all arrhythmia patients, overall mortality was not different compared with the arrhythmia-free group.