Explanation of the term: The medical term ventricle refers to the two chambers of the heart. Septum refers to the cardiac septum. The term defect denotes a fault, in this case the hole in the cardiac septum.
A distinction is made between three defects according to their anatomical location:
- Membranous ventricular septal defect: Most common form of defect in the ventricular septum. The hole manifests itself in the membranous upper part of the septum.
- Perimembranous ventricular septal defect: The hole is located in the membranous and muscular part of the septum.
- Muscular ventricular septal defect: Defect in the myocardial part of the septum. It often has several holes.
The main task of the heart is to pump deoxygenated blood from the body through the lungs. The blood then returns to the heart enriched with oxygen. From the left ventricle, it is pumped back into the body's circulation.
The pressure in the left ventricle is higher than the pressure in the right ventricle, which is responsible for the pulmonary circulation.
A ventricular septal defect means that there is a connection between the two chambers of the heart. As a result, oxygen-rich blood flows from the left ventricle back into the right ventricle. This blood is then pumped together with the deoxygenated blood from the systemic circulation into the pulmonary circulation.
The reversal of the blood flow is also known under the medical term Eisenmenger reaction. The process places a heavy strain on the pulmonary vascular system, the ventricles and the entire heart.

Schematic representation of the human circulatory system © LuckySoul | AdobeStock
The extent of the strain depends on the size of the defect in the ventricular septum. If the hole is very small, there are usually no symptoms.
If the defect is larger, babies suffer from shortness of breath and rapid breathing. The children find drinking difficult as an additional physical burden and they start to sweat. The newborns also lag behind in their general development. This is mainly reflected in the fact that they hardly gain any weight.
There is also an increased susceptibility to infectious diseases, particularly of the respiratory tract. If left untreated, the chronic lack of oxygen causes
- blue discolored finger and toe tips and
- a blue discoloration of the tongue
in children.
The congenital heart defect is usually due to a defect in the genetic material. The growth of the heart chambers is faulty due to maldevelopment of the embryo.
This can be caused by an infection during pregnancy, such as
Other possible causes include harmful substances consumed during pregnancy, such as
In most cases, however, no specific causes can be identified.
There are various methods available to the pediatrician or pediatric cardiologist for diagnosis:
- Listening: With the help of a stethoscope, changes in heart sounds can already be detected in babies
- Ultrasound examination: A special form of ultrasound, echocardiography, shows the blood flow of the heart
- ECG: The ECG is used to record the cardiac currents and the strain on the heart
- X-ray: X-rays of the chest allow the size and position of the heart to be assessed
If these diagnostic methods cannot detect the holes with sufficient accuracy, further, even more precise examinations are necessary. These include magnetic resonance imaging (MRI ) and cardiac catheterization.
Oxygen saturation monitoring is also necessary to check how much oxygen is getting into the blood.
Smaller ventricular septal defects often close by themselves in the first few years of life. If the defect becomes medium to large in size, surgery is unavoidable. The operation should then be performed as early as possible.
The child should not be exposed to any major physical stress until the operation. Until then, the doctor can also initiate treatment with medication. This makes the heart's work easier and reduces the child's symptoms.
The operation cannot be performed on a beating heart. The heart must be stopped for this. The patient is therefore connected to a heart-lung machine. This takes over the function of the heart for the duration of the operation. It enriches the blood with oxygen and pumps it into the body.
First, the surgeon opens the chest and the right atrium. He then treats the hole in the cardiac septum through the heart valve between the right atrium and the right ventricle.
The hole is either sutured or covered with a plastic patch. For smaller defects, the hole can be closed with an umbrella using a catheter. The umbrella is inserted through the inguinal vein to the corresponding point in the heart.
After the operation, the patient is monitored in an intensive care unit.
Thanks to highly developed medicine, there are hardly any complications today. The child feels better just a few days after the operation. He or she can breathe normally again and quickly makes up for weight deficits. In older children, light sporting activity can be beneficial for the course of recovery in consultation with the doctor.
The child is not subject to any physical restrictions for the rest of its life. The operation enables a normal
- quality of life,
- career choice or
- pregnancy.
The child's life expectancy does not differ from that of people with a healthy heart. Nevertheless, lifelong check-ups of the heart function, especially of the heart chambers, are necessary.