Tetralogy of Fallot

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect, with an incidence of 32.6 per 100, 000live births. The embryologic theory supports Van Praagh et al.‘s hypothesis that the primary morphologic abnormality in TOF is an underdeveloped subpulmonary infundibulum. Genetic syndromes in the absence of abnormal pulmonary artery architecture have not been shown to be an independent risk factor for mortality in TOF repair, but they may affect perioperative outcomes. The recurrence rate also depends upon associated syndromes and genetic or environmental factors. The physiology in TOF is determined by the combination of the ventricular septal defect and the degree of pulmonary stenosis. In repaired TOF patients, echocardiography allows for serial assessment of right and left ventricle size and function and pulmonary regurgitation. Additional modalities such as magnetic resonance imaging are essential in decision-making for pulmonary valve replacement.