Tetralogy of Fallot is a birth defect of the heart consisting of four abnormalities that results in insufficiently oxygenated blood pumped to the body. At birth, infants may not show the signs of the cyanosis but later may develop episodes of bluish skin from crying or feeding called "Tet spells".
Review Date 2/23/2022
Updated by: Thomas S. Metkus, MD, Assistant Professor of Medicine and Surgery, Johns Hopkins University School of Medicine, Baltimore, MD. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.