Comparison of Right Ventricular Stroke Work for Tetralogy Patient and Normal Subject

Tetralogy of Fallot (TOF), also called blue-baby syndrome is one of the most common congenital heart defects in children after infancy and is estimated to account for 10% of all congenital heart defects [3]. TOF consists of four interrelated lesions: i) ventricular septal defect ii) Pulmonary stenosis iii) Right ventricular (RV) hypertrophy and (iv) Overriding Aorta [3]. TOF has been successfully repaired for several decades (Fig. 1). There are now an estimated 100,000 adult “repaired TOF” patients in the United States alone. As a result, long-term sequelae of the disease and repair have become important clinical issue. Specifically, residual pulmonary valve insufficiency (PI) is one such accepted and often unavoidable sequela. PI, when severe, abnormally alters the RV loading conditions, thereby triggering RV hypertrophy and dilatation. In turn, RV dilatation can evolve into irreversible RV myocardial contractile dysfunction, and has been related to sudden death in many “repaired TOF” patients. To normalize RV loading conditions, pulmonary valve replacement is often necessary and should be performed prior to the onset of irreversible RV myocardial damage.