RIGHT VENTRICULAR REMODELING IN REPAIRED TETRALOGY OF FALLOT: MECHANISMS, ASSESSMENT METHODS AND PROGNOSTIC IMPLICATIONS

Abstract

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and surgical advances now allow most patients to reach adulthood. However, anatomical repair does not eliminate long-term cardiovascular risk: chronic pulmonary regurgitation, frequently related to transannular patch repair, imposes volume overload on the right ventricle (RV) and triggers a dynamic remodeling process characterized by dilatation, altered geometry, progressive systolic and diastolic dysfunction, abnormal ventricular interaction and arrhythmogenic substrate formation. This article aims to narratively review the pathophysiological mechanisms of RV remodeling in repaired TOF, the main imaging assessment methods — echocardiography with strain analysis and cardiovascular magnetic resonance (CMR) with T1 mapping and late gadolinium enhancement — and their prognostic implications regarding ventricular arrhythmias and sudden cardiac death risk. The review indicates that isolated volumetric parameters, such as RV end-diastolic volume, have limited predictive value when used alone, whereas myocardial deformation measures (RV global longitudinal and free-wall strain) and fibrosis markers (extracellular volume, native T1 and late gadolinium enhancement) add incremental prognostic value. Contemporary risk stratification should integrate volumetric, functional, strain and fibrosis data with electrophysiological parameters to better guide the optimal timing of pulmonary valve replacement and reduce the risk of arrhythmic events and sudden death in this growing adult congenital heart disease population.