Synonyms in the broadest sense
Congenital cyanotic heart defects with right-left shunt
Definition
The Fallot ́sche Tetralogy is a congenital heart defect. It is one of the most common cyanotic heart defects. Cyanotic means that the heart defect has a negative effect on the oxygen content of the blood.
The blood, which is pumped from the heart to the organs, therefore contains too little oxygen. This is noticeable in the color of the patient’s skin. This skin color is pale bluish.
Especially the lips appear blue discolored. This type of heart defect has a so-called right-left shunt. This means that there is a normally non-existent connection between the right and left heart.
General
The Fallot tetralogy combines different characteristics of a very specific congenital heart defect. This was first described in 1888 by Etienne-Louis Fallot as a heart defect with four different characteristics (Greek: tetra = four): First, the pulmonary artery, which pumps the blood from the heart into the lungs, is stenosed (constricted). The blood reaches the right heart from the body’s circulation with relatively low oxygen levels.
First it is pumped from the right atrium into the right chamber, then from there into the pulmonary artery. If this artery is now narrowed, not enough blood reaches the lungs to be loaded with oxygen again. In some cases, the pulmonary artery may be completely blocked.
In this case, the blood supply to the lungs takes place through a “duct” (ductus arteriosus) that remains in the child’s development and which connects the aorta with the pulmonary arteries in a quasi-regressive manner. Since this duct normally closes in the first days of life, it is kept open with medication. Furthermore, the tetralogy of Fallot is characterized by a defect of the cardiac septum, which normally separates the left from the right heart (medical term: septal defect).
The defect lies in the part of the wall that separates the ventricles from each other (medical term: ventricular septal defect). This is the right-left shunt mentioned above. The blood can now flow from the right heart directly into the left heart.
Thus it bypasses the path through the lungs and is not enriched with oxygen.
- Pulmonary stenosis (pulmonary artery occlusion)
- Right ventricular hypertrophy (thick muscle layer of the right ventricle)
- Ventricular septal defect (VSD) (hole in the heart septum)
- Crossing the aorta above the VSD
The so-called “riding aorta” (aorta is the main artery of the human body) is directly related to the wall defect: Since the septum “has a hole” in the area of the ventricles and the blood can now flow directly from the right chamber to the left chamber, this excess blood must also be pumped into the body via the main artery. This increased pressure causes the aorta to “ride” over the pulmonary arteries.
The increase in muscle volume (med. : hypertrophy) of the right chamber is related to the narrowed pulmonary arteries. More force must be applied to pump the blood through the smaller diameter of the vessel. Thus the muscle gains mass; comparable to any other muscle in the body that we train more.
- Main artery (aorta)
- Ventricle
- Coronary arteries
- Atrium (Atrium)
- Vena cava (vena cava)
- Carotid artery (carotid artery)
