Arrhythmias in patients with hypoplastic left heart syndrome

Abstract

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. Also, 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 hypoplastic left heart syndrome from September 2000 to October 2008. Results Overall, 49/86 (57%) patients had 63 arrhythmias. The majority of arrhythmias occurred between stage I and II with 44/86 (51%) patients manifesting a new arrhythmia. Arrhythmias occurring in this interval tended to be associated with a higher mortality compared to arrhythmias occurring after stage II, OR = 3.2 [95%CI 0.84, 12.0] (p=0.09). Overall, mortality was similar in patients with and without arrhythmias (p=0.99). 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 (ECMO). Conclusions A large proportion of patients with HLHS experience serious arrhythmias requiring therapy, especially between stages 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 to the arrhythmia free group.

Tachyarrhythmia Following Norwood Operation

“…In fact, 8 (28.5%) of 28 patients surviving to hospital discharge required no long-term antiarrhythmic treatment. 1 Ventricular tachyarrhythmias were observed in four patients in this study. Use of the right ventricle to pulmonary artery conduit is associated with a theoretical risk of a ventricular arrhythmia associated with the ventricular incision.…”

“…The majority are reported to occur within the immediate postoperative period. [1][2][3]10 The onset of arrhythmia following the Norwood procedure in our series occurred after ten days in 45% (n ¼ 15) of our patients. This finding was unexpected, as potentially dysrhythmic substrates including metabolic acidosis, electrolyte abnormalities, recent ischemic insult from cardiopulmonary bypass, and vasoactive medication use are most extreme in the first 72 hours after Norwood surgery.…”

“…1 Although the evaluation of bradycardia after Norwood was not one of the goals of this study, review revealed only one patient with long-term postoperative heart block requiring a pacemaker, who subsequently died.…”

Development and impact of arrhythmias after the Norwood procedure: A report from the Pediatric Heart Network

“…21 Before the SVR study, 1 single-center study examined the impact of atrioventricular block after surgery for single-ventricle congenital heart disease. In the 5 of 86 subjects who developed second- or third-degree atrioventricular block after the Norwood operation, Trivedi and colleagues 22 found a significant association of atrioventricular block with mortality, with none of the 5 subjects surviving to the stage II procedure. In our study, atrioventricular block was associated with decreased transplant-free survival in the Kaplan–Meier analysis and the unadjusted Cox proportional-hazards regression analysis, but this finding did not meet significance ( P = .098) in the adjusted Cox proportional-hazards regression analysis.…”

Current Therapy for Hypoplastic Left Heart Syndrome and Related Single Ventricle Lesions

“…It does not seem at this stage that the higher severity of this condition is related to the intrinsic inability of a single right ventricle to support a Fontan circulation for several decades, but rather to the fact that patients with HLHS tend to have a higher incidence of decreased ventricular function and atrioventricular valve regurgitation, and have a higher propensity of developing arrhythmias [60,74–76]. Because patients with HLHS have clearly a higher burden of disease, it is likely that some difference will appear in the future in the survival rate of these patients compared to the remaining Fontan population.…”