If the baby is not cyanotic, then it is sometimes referred to as a "pink tet". Other symptoms include a heart murmur which may range from almost imperceptible to very loud, difficulty in feeding, failure to gain weight, retarded growth and physical development, labored breathing (dyspnea) on exertion, clubbing of the fingers and toes, and polycythemia. The baby may turn blue with breastfeeding or crying.Those born with tetralogy of Fallot are more likely to experience psychiatric disorders such as attention deficit hyperactivity disorder (ADHD) in later life, potentially due to underlying genetic changes that predispose to both conditions. Tet spells
Infants and children with unrepaired tetralogy of Fallot may develop "tet spells". These are acute hypoxia spells, characterized by shortness of breath, cyanosis, agitation, and loss of consciousness. : 200  This may be initiated by any event – such as anxiety, pain, dehydration, or fever – leading to decreased oxygen saturation or that causes decreased systemic vascular resistance, which in turn leads to increased shunting through the ventricular septal defect. Typically, these spells decrease in frequency after the first four years of life.Clinically, tet spells are characterized by a sudden, marked increase in cyanosis followed by syncope. : 200 Older children will often squat instinctively during a tet spell. This increases systemic vascular resistance and allows for a temporary reversal of the shunt. It increases pressure on the left side of the heart, decreasing the right to left shunt, thus decreasing the amount of deoxygenated blood entering the systemic circulation.
This patient, who was 16 months old, was initially thought to have asthma, though an autopsy postmortem revealed a cardiac malformation with no ductus arteriosus or ligamentum arteriosum, indicating that the child may have died from TOF. Another 13-year-old patient was reported by Scottish physician William Hunter in 1782. Hunter described the patient, along with three others, as suffering from cyanosis after a posthumous examination in 1774.Other cases, such as those presented by Pulteney (1785), Abernethy (1793), Bell (1797), Dorsey (1812), and Farre (1814) also contributed to modern understandings of TOF. The first reported case of TOF was in America at the University of Pennsylvania in 1816, with more cases being reported by Peacock (1858 and 1869), Widman (1881), and finally Fallot (1888), after whom the condition is named. Fallot was the first to elegantly describe the four key features that differentiate it from other cyanotic cardiac conditions, and was prominent in the disqualification of a patent foramen ovale as a fifth feature. Fallot initially referred to it as "La maladie bleue", which is French for "the blue disease" or "cyanose cardiaque", translating to "cardiac cyanosis".The first surgical repair was carried out in 1944 at Johns Hopkins. The procedure was conducted by surgeon Alfred Blalock and cardiologist Helen B. Taussig, with Vivien Thomas also providing substantial contributions and listed as an assistant. This first surgery was depicted in the film Something the Lord Made. It was actually Helen Taussig who convinced Alfred Blalock that the shunt was going to work.