Noun | 1. | tetralogy of Fallot - a congenital heart defect producing cyanosis; characterized by four symptoms: pulmonary stenosis and ventricular septal defect and malposition of the aorta over both ventricles and hypertrophy of the right ventricle pulmonary stenosis - abnormal narrowing of the opening into the pulmonary artery from the right ventricle syndrome - a pattern of symptoms indicative of some disease congenital heart defect - a birth defect involving the heart ventricular septal defect - a common congenital heart defect; an abnormal opening in the septum dividing the ventricles allows blood to pass directly from the left to the right ventricle; large openings may cause congestive heart failure |