Assessment of anatomical parts of the right ventricle in patients after tetralogy of Fallot repair

Objectives. The objective of the study was to investigate the influence of the main right ventricular (RV) anatomical components on global RV function by using CMRI after tetralogy of Fallot (TOF) repair based on various surgical approaches. Materials and Methods. A total of 52 asymptomatic, clinically stable patients (28 boys and 24 girls) aged 7.5 (5.5; 9.5) years were retrospectively examined after TOF repair to assess RV dysfunction in the Pediatric Cardiac Surgery Department of the Novosibirsk Research Institute of Circulation Pathology n.a. acad. E.N. Meshalkin. All patients were divided into 2 groups depending on surgery technique of TOF repair: transannular plasty (group 1, 26 pts) or TOF repair with pulmonary annulus preservation (group 2, 26 pts). Results. Right ventricular ejection fraction for the entire ventricle and for its parts was significantly higher in group 2 whereas RV end diastolic volume (EDV) for the entire ventricle and for its parts and stroke volume (SV) were significantly higher in group 1. Pulmonary regurgitation was also higher in group 1: 36.7 (32; 44) versus 13.2 (3; 14) (p>0.01). Odds ratio for pulmonary regurgitation was lower in group 2 in comparison with group 1: OR (95% confidence interval, CI) 0.19 (0.04-0.72), р=0.02. Conclusions. Right ventricular function after TOF repair depends on the type of right ventricular outflow tract (RVOT) reconstruction. Through separate functional analysis of the anatomical RV components, this study demonstrated that the global RV function is decreased in patients after transannular plasty. Long-term RV dysfunction in group with transannular plasty was associated with significant pulmonary regurgitation and the presence of large akinetic RVOT region involving the sinus part in the contraction.