Repaired Tetralogy of Fallot: Have We Understood the Right Timing of PVR?

Abstract

Despite many advances in surgical repair during the past few decades, the majority of tetralogy of Fallot patients continue to experience residual hemodynamic and electrophysiological abnormalities. The actual issue, which has yet to be solved, is understanding how this disease evolves in each individual patient and, as a result, who is truly at risk of sudden death, as well as the proper timing of pulmonary valve replacement (PVR). Our responsibility should be to select the most appropriate time for each patient, going above and beyond imaging criteria used up to now to make such a clinically crucial decision. Despite several studies on timing, indications, procedures, and outcomes of PVR, there is still much uncertainty about whether PVR reduces arrhythmia burden or improves survival in these patients and how to appropriately manage this population. This review summarizes the most recent research on the evolution of repaired tetralogy of Fallot (from adolescence onwards) and risk factor variables that may favor or delay PVR.

Keywords: PVR; pulmonary insufficiency; tetralogy of Fallot.

Figure 2

The parameters to be considered in repaired ToF. CMR = cardiac magnetic resonance; CPET = cardiopulmonary exercise test; ECV = extracellular volume fraction; EST = exercise stress test; EP = electrophysiological study; LV = left ventricle; RV = right ventricle. ECG: (A). Inferior fragmentation (black arrows) in a patient with QRS < 120 msec. (B). Anterior fragmentation (black arrows) in another patient with presence of right bundle branch block.

Figure 1

Adapted from [7]. Legend: LV = left ventricle; LVEDVI = left ventricular end diastolic volume indexed for BSA; PR = pulmonary regurgitation; RV = right ventricle; RVEDVI = right ventricular end-diastolic volume indexed for BSA; RVESVI = right ventricle end-systolic volume indexed for BSA; RVSP = right ventricle systolic pressure; right ventricle outflow obstruction. TOF, tetralogy of Fallot. Symptoms may include dyspnea, chest pain, and/or exercise intolerance referable to PR or otherwise unexplained.