Cardiac resynchronisation therapy for failing single ventricle physiology

Abstract OBJECTIVES We aimed to evaluate the mid-term outcomes of cardiac resynchronisation therapy in patients with single ventricle, heart failure, and ventricular dyssynchrony, which leads to heart failure and poor outcomes. METHODS We retrospectively reviewed patients with single ventricle who underwent cardiac resynchronisation therapy at our institution between 2010 and 2024. Dyssynchrony was defined as QRS duration ≥130 ms and qualitative mechanical dyssynchrony between the main and rudimentary ventricles assessed by echocardiography and cine-angiography. Cardiac resynchronisation therapy indications were based on acute haemodynamic studies (shortened QRS duration and increased peak dP/dt). The patients were divided into Groups G (cardiac resynchronisation therapy after bidirectional Glenn) and F (after Fontan completion). Haemodynamic parameters, NYHA class, brain natriuretic peptide, survival, Fontan completion rate, and hepatic function were analysed. RESULTS Group G included nine, and Group F included 11 patients. One year after cardiac resynchronisation therapy, the systemic ventricular ejection fraction improved in Groups G (30–40%, p = 0.006) and F (30–53%, p = 0.001), with corresponding increases in cardiac index and NYHA class. The median follow-up was 6.7 years (Group G) and 7.6 years (Group F). The 5-year survival rates were 89% and 82%, respectively. The Fontan completion rate was 76% at 5 years in Group G. In Group F, brain natriuretic peptide levels improved, hepatic function remained stable, and no protein-losing enteropathy was reported. CONCLUSIONS Cardiac resynchronisation therapy improved systemic ventricular function and heart failure symptoms. Cardiac resynchronisation therapy might be a viable therapeutic option for patients with single ventricle, ventricular dyssynchrony, and heart failure.