Prognosis
Untreated, tetralogy of Fallot rapidly results in progressive right ventricular hypertrophy due to the increased resistance caused by narrowing of the pulmonary trunk. : 199  This progresses to heart failure which begins in the right ventricle and often leads to left heart failure and dilated cardiomyopathy. Mortality rate depends on the severity of the tetralogy of Fallot. If left untreated, TOF carries a 35% mortality rate in the first year of life, and a 50% mortality rate in the first three years of life. Patients with untreated TOF rarely progress to adulthood.Patients who have undergone total surgical repair of tetralogy of Fallot have improved hemodynamics and often have good to excellent cardiac function after the operation with some to no exercise intolerance (New York Heart Association Class I-II). Long-term outcome is usually excellent for most patients, however residual post-surgical defects such as pulmonary regurgitation, pulmonary artery stenosis, residual VSD, right ventricular dysfunction, right ventricular outflow tract obstruction may affect life expectancy and increase the need for reoperation. : 205 Cardiovascular and cerebrovascular complications in patients with repaired CHD such as TOF occur earlier in life compared to healthy subjects. Chronic pulmonary regurgitation and right ventricular dilation and dysfunction is also common.Within 30 years after correction, 50% of patients will require reoperation. The most common cause of reoperation is a leaky pulmonary valve (pulmonary valve insufficiency). This is usually corrected with a procedure called pulmonary valve replacement. : 136 One common prognostic factor with TOF is the development of ischemia reperfusion injury.
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.