Set of four congenital cardiac defects involving an opening in the wall that should separate the right and left ventricles (ventricular septal defect), allowing the aorta to receive venous as well as arterial blood: including stenosis of the pulmonary artery, hypertrophy of the right ventricle, and displacement of the aorta. Right ventricular hypertrophy is the fourth part of the tetralogy, although it may also be a consequence of the other defects.