The name Tetralogy of Fallot comes from Mr. Etienne Louis Arthur Fallot, who made, in 1888, a fine description of the morphological alterations of the entity, which he called at first malaide bleue (blue disease).
It is a disease that is usually diagnosed at the moment of birth or during the first year of life , but it is not surprising that it is detected in adulthood, if the defects are not serious and the symptoms are subtle.
More than seven decades have passed since the first person in the world with TF underwent a surgical intervention , which was successful, palliative of the disease (a 15-month-old girl).
Produces 4 types of heart defects
Tetralogy of Fallot (TF) is the best known and most treated congenital heart disease , which includes the following four heart defects :
- Interventricular septal defect (VSD: interventricular communication): “hole” in the central wall of the heart that separates both ventricles , the two lower chambers of the organ, where the poorly oxygenated blood that reaches the heart is mixed abnormally with the richly oxygenated blood coming out of it.
- Thrust of the aorta artery : the aorta artery, which under normal conditions emanates from the left ventricle and carries oxygenated blood to the rest of the body’s organs, is “riding” at the exit of both ventricles and then collects low-oxygenated blood from the right ventricle. mixing it with the oxygen from the left.
- Obstruction in the right ventricular outflow tract (infundibular-pulmonary valve-pulmonary artery stenosis): narrowing of the pulmonary valve, the area below the valve, or the pulmonary artery.
- Right ventricular hypertrophy : thickening of the muscular wall of the right ventricle to be able to counteract the increase in pressures at the outlet of the same.
As in most congenital heart diseases, the causes of TF are not exactly known, and the majority of cases present as sporadic cases . However, specific genetic alterations (eg chromosome 22) associated with the disease have been suggested.
Symptoms of Tetralogy of Fallot
The determining factor for the appearance of the greatest number of symptoms is the degree of pulmonary obstruction. When the obstruction is severe and a duct called “ductus arteriosus” has closed after birth, the manifestations of hypoxia (lack of oxygen) and acidosis (acidification of the blood) appear already in the first hours or days of life.
A systolic heart murmur may be heard and cyanosis (bluish tinge) may be seen to the skin. Syncope (fainting spells) and sudden hypoxic attacks may occur , accompanied by severe abrupt cyanosis.
Signs such as weight loss, irritability, fatigue with meals, etc. can also be observed.
The definitive diagnosis is given by echocardiography (Gold Standard test), so the collaboration of the pediatric cardiologist is obviously essential.
Echocardiography is based on the use of sound waves that bounce off the organs and are projected as images of them on a television screen. The chest X-ray will show the typical “clog-shaped heart”.
For cases without significant residual lesions or arrhythmias, an annual medical check-up with clinical, electrical (ECG), radiological and echocardiographic evaluation is recommended .
It is surgical . The trend, over the years, has evolved towards the performance of the surgical intervention that involves the total definitive correction at younger ages.
The treatment of arrhythmias consists of the administration of antiarrhythmics and / or surgical ablation . However, a considerable number of patients will require surgical implantation of a defibrillator.
Prognosis and life expectancy
- The best survival and outcome data are obtained when total surgical correction is performed in the age range of 3 to 11 months of age .
- At present it is possible to speak of very high long-term survival rates (fifth decade of life) in those cases that underwent surgical correction and that with a normal quality of life in many cases.
- As complications and main causes of death in adult life are arrhythmias (sustained ventricular tachycardias) and sudden death (6% of cases).
What you should know…
- It is the best known and most treated congenital heart disease. The incidence of congenital heart disease can be estimated at 8-10 cases per 1,000 newborns, and TF accounts for 3.5% of all cases (approx. 1 case per 3000-4000 live newborns).
- It is a disease that is usually diagnosed at the moment of birth or during the first year of life, but it is not surprising that it is detected in adulthood, if the defects are not serious and the symptoms are subtle.
- The best survival and outcome data are obtained when total surgical correction is performed in the age range of 3 to 11 months of age.