Atrial septal defect

The atrial septal (ASD ) or atrial septal defect is a hole in the septum between the two atria of the heart. He is the third most common congenital cardiac malformation with approximately 7.5 % of all congenital heart defects. An ASD also occurs, except the singular forms described here, in conjunction with other heart defects, and is then to evaluate different in its impact.

• 2.1 auscultation
• 2.2 ultrasound

Molding

• Open or persistent foramen ovale
• Ostium secundum

The ASD occurs in four versions:

Patent foramen ovale

The simplest form of Atriumseptumdefektes is the persistent foramen ovale ( PFO). The foramen ovale is a door -like connection between the atria of the heart that allows blood crossing from the right ( pulmonary circulation ) to the left ( systemic circulation ) in fetal ( prenatal ) circuit. Since the lung is not ventilated and is therefore not relevant with blood, the blood flows through the foramen ovale into the left atrium and through the ductus arteriosus (or even a D. arteriosus ) from the pulmonary artery into the aorta.

The foramen ovale normally closes in the first few days or weeks. Otherwise, one speaks of a persistent ( persistent, ongoing ) foramen ovale ( PFO). Children are not affected and treatment is usually not necessary. Rarely, however, to a paradoxical embolism, in which a blood clot passes through the hole and, for example, can cause a stroke.

After the first signs in 1996 now several studies have shown an association between patent foramen ovale and migraine arise. With 60-80 percent of migraine patients with aura to find these heart malformation. An artificial closure of the foramen ovale by an inserted by cardiac catheter technique umbrella ( Occluder ) can be in one of two cases the migraine disappear.

Secundum type

The most common form is the atrial septal defect from secundum, also known as ASD II. The hole is located in the middle and on the size of flow due to the pressure difference in the chambers of the heart, a more or less large quantity of blood from the left to right, back to the pulmonary circulation. This defect can be in many cases closed by the insertion of a closure system with the cardiac catheterization: a ' Doppelschirmchen ' or a self-centering metal frame made ​​of nitinol ( Amplatzer system) is introduced through the catheter into the hole where it develops. After overgrowth with endocardium ( endocardial ) the hole is permanently sealed. The prerequisite is that the hole is not too large, centrally located and has smooth edges. If these conditions are not met, the hole must be closed surgically.

Endocarditis is not recommended for ASD II. Pulmonary hypertension ( pulmonary hypertension ) through the shunt is not expected in the first decades of life, because of the difference in pressure in the atria is not very significant. This heart defect is sometimes diagnosed only in adolescents or advanced adulthood. It has been shown that patients with age often get significant discomfort from a certain Shuntgröße. Therefore, significant ASD II now mostly closed, even if the patients feel comfortable.

A due to other malformations nachgeburtlich unlocked retarded foramen ovale is classified in hemodynamic relevance as ASD II.

Ostium primum type

The next common form is the ostium primum defect -, also called ASD I. The hole is in the lower portion of the atrial septum, extends to the valve plane approach and is often associated with a malfunction of the mitral valve ( between the left atrium and left ventricle = ventricle ) associated rarely with a malfunction of the tricuspid valve ( between the right atrium and right ventricle ). It is based on this heart defect inhibition of Endokardkissenbildung. A cardiac catheterization or transesophageal echocardiography ( " sip echo " ) prior to surgery is rarely necessary. This defect is always closed surgically with a patch of plastic or body tissue. If a frequently occurring mild Mitralklappenfehlfunktion found after surgery, an increased risk of endocarditis must be considered further.

Sinus venosus type

A very rare form of ASD is the sinus venosus defect. It is located in the upper portion of the atrial septum and in about 90 % of the cases one or more fehleinmündende into the right atrium or the superior vena cava pulmonary veins are detected. Therefore a transesophageal echocardiography or cardiac catheterization before surgery is almost always necessary. Also, this defect is surgically closed with a patch and the pulmonary vein / s transposed so that normal blood flow is ensured in the left atrium. As with many defects in the atrium area occurs in the long term more likely to arrhythmia.

Diagnostics

Auscultation

On physical examination falls within the scope of auscultation on a splitting of the second heart sound, which is fixed, ie does not change during the inhalation and exhalation. Additionally you'll find a soft systolic murmur in the second left ICR ( intercostal space ), which is due to the relative narrowing of the pulmonary valve into existence; by the relative narrowness of the tricuspid valve, it can also lead to the lower sternum stressed diastolic come.

Ultrasound

Gold standard for detection is the transesophageal ultrasound examination with a non- respirable contrast agent. Sometimes can be detected through the opening with a low blood flow color Doppler echocardiography.

Therapy

For small defects, a spontaneous reduction or self- closing to wait. However, if there is an enlargement of the right heart, a closure of the defect in infancy should be done (3 to 4 years ). Even in childhood, the operation can be done minimally invasively through a lateral opening of the chest nowadays. In young girls, this approach has proven to be cosmetically cheap and very well accepted.

If the defect in the center of the atrial septum, a closure can now be performed with a Doppelschirmchen at 70 % of patients. This is used as part of a cardiac catheterization procedure. The implementation can be done in the majority of cases under transesophageal echokardiografischer control. In individual cases, angiographic representation is required.

For very large or unfavorably located defects surgery using the heart -lung machine must be carried out. Depending on the size of the defect is closed by direct suture or with a patch from the patient's own pericardium tissue.

Risks

Although nowadays a diagnosis of ASD is closed usually, this malformation is a fundamental risk to the affected dar. Since smaller ASD remain partially unnoticed (even with normal ultrasound examinations ), occur for example in supposedly healthy divers despite compliance with all precautions diving accidents since the filtering function of the lung by the ASD remains incomplete, which otherwise prevents an embolism in the systemic circulation.