Surgical repair of tetralogy of Fallot (TOF) may be followed by various conditions and residual findings, early postoperatively or late during follow-up. Most of these conditions affect the right ventricular outflow tract and the pulmonary arteries and thus, indirectly, the right ventricle.This paper discusses the role of the right ventricle during the natural history of repaired TOF. The different imaging methods used to assess the function of the right ventricle in relation to this congenital heart disease are highlighted. Particular attention is focused on the volume overloaded right ventricle, as this condition is nowadays a subject of intense discussion, particularly regarding the appropriate timing for pulmonary valve replacement. The most recent literature on this topic is briefly reviewed. In summary, preservation of right ventricular function and prevention of right ventricular arrhythmias are crucial for these patients' survival and outcome.
Key words: right ventricle; tetralogy of Fallot; pulmonary regurgitation
IntroductionTetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, occurring in 0.04-0.08% of all liveborns [1, 2]. The main feature of TOF is a ventricular septum defect with anterior deviation of the outlet septum, leading to infundibular subpulmonary stenosis and placing the aorta in an overriding position; in addition, valvular pulmonary stenosis with possible hypoplasia of the main pulmonary artery and its side branches occurs, together with hypertrophy of the right ventricle (RV) ( fig. 1).Besides closing the ventricular septal defect, surgical repair consists of reconstruction of the right ventricular outflow tract (RVOT). RVOT reconstruction can be performed by various surgical techniques, some resulting in residual RVOT obstruction (commissurotomy) and others completely relieving the obstruction at the price of causing pulmonary regurgitation (transannular patch). Thus the surgical technique used usually determines the postoperative findings and eventually the patients' long-term outcome. However, the surgical technique providing the best outcome for the patients has not yet been defined, and the type of repair is chiefly determined by the personal strategy of the operating surgeon in each individual centre. Surgical repair can be performed during the first months of life, ideally at the age of 3 to 4 months, with low perioperative mortality. Long-term mortality was studied by Nollert et al., who reported a 20-year survival rate of 94% [3]. Nevertheless, the survival curve seems to deteriorate after 25 years post TOF repair [3], and significant residual findings may occur resulting in significant morbidity during follow-up. Similarly, Oechslin et al. reported a cumulative percentage of reinterventions required in TOF patients [4]. The most common indications for reintervention consisted of lesions affecting the (RVOT 75%), including severe pulmonary regurgitation, conduit failure and RVOT obstruction. Due to their anatomical location, all these findings may ev...