LAUSR

Cardiac resynchronization therapy (CRT) has become a treatment of choice in patients with chronic heart failure (HF). About 25% of patients with systemic right ventricle (SRV) progress to symptomatic HF, which may be refractory to drug therapy and is commonly associated with significant morbidity and mortality. For these reasons, CRT has been emerging as an effective treatment strategy for patients with SRV failure and electrocardiographic signs of ventricular dyssynchrony. Few studies have reported the acute and long - term effects of CRT in SRV subjects, with different findings. Our study aimed to describe the experience with CRT in SRV patients in a single tertiary centre. Assess the long term efficacy of CRT in patient with SRV All consecutive SRV patients who underwent CRT implantation and/or upgrading between 1994 and 2018 at our tertiary centre were included. Clinical and echocardiographic parameters before and after CRT implantation were collected and analyzed. A total of 21 patients (mean age 47.8±14.8 years, 13 M) were implanted with CRT-P (12, 57%) or CRT-D (9,43%) during the study period. 90% of patients showed an anatomy of congenitally corrected transposition of the great arteries (CCTGA), whereas 9.5% underwent Mustard procedure for transposition of the great arteries (TGA). Among CCTGAs, 11 (52.5%) subjects underwent previous surgical procedures, including implant of a conduit between the left ventricle (LV) and the pulmonary artery (PA) in 8 (38%) patients, tricuspid valve repair in 2 (9.5%) and surgical closure of atrial septal defect in 1 (5%). Before CRT implant/upgrading, 10 (48%) patients had a moderate to severe reduction in the SRV ejection fraction (EF) and 7 (33%) had a moderate to severe tricuspid regurgitation (TR). Overall, 15 (71%) patients referred a NYHA II or III. After a median follow up of 57 months (IQR 35–83), 43% of patients showed an improvement in their functional status, which was associated with an improvement of SRV EF and TR only in 22% and 33% of these patients. On the contrary, no patient reported a worsening in NYHA class, while SRV EF decreased in 28.5% and the grade of TR worsen in 23.8% of patients. CRT is emerging as an effective treatment for SRV dysfunction. However, criteria for implantation are not well defined and the deterioration of SRV function related to subpulmonary univentricular pacing should be considered. Moreover, TR did not improve in this study, suggesting that concurrent tricuspid valve interventions may be necessary in patients with severe TR and may facilitate the improvement in RV function achieved with CRT. Proper planning, tertiary expertise and international collaborations are all paramount in this field.