Congenital heart defects are the most common inborn defects. There are different types of malformations of the heart and the great vessels. We are able to treat all of them at our Heart Center.

		Aortic stenosis (AS) An aortic stenosis means the significant narrowing of the left ventricular outflow tract, this is either caused by a thickened aortic valve or an underdeveloped aortic root. The stenosis may be below the aortic valve (sub valvular), at the level of (valvular) or above the aortic valve (supra valvular). The left chamber is pumping against an increased resistance and gets thickened( hypertrophic). The severity of the restriction defines the seriousness of the disease. Sub valvular and supra valvular aortic stenosis have to be corrected surgically, if this is necessary. Valvular aortic stenosis usually may be treated using a balloon catheter. At our institution we perform balloon valvuloplasty as soon as the instantaneous valvular gradient reaches 70 mm mercury.

		ASD - Atrial septal defect ASD means an inborn gap in the intra atrial septum. This defect causes a left to right shunt and over perfusion of the lungs. Small ASD´s show a high spontaneous occlusion rate during the first year of life. Depending on the size and the location of the defect it may be closed interventionally with a device or surgically with a pericardium patch. VSDs and ASDs together come to half of the congenital heart defects. An occlusion of an ASD with an umbrella is a routinely performed intervention and seems to be the treatment of choice for most of the atrial septal defects. Crucial for a successful interventional occlusion is the correct selection of suitable patients. Usually the correct position of the device is checked during the intervention using trans esophageal echo cardiography. The complication rate is approximately as high as that of the surgical occlusion.

		AV – Channel An AV - channel as a septal defect involving the AV - valves. The valve between the atria and the ventricles is a common AV - valve. Caused by the huge defect in the middle of the heart a big amount of oxygen saturated blood flows from the left to the rigt heart and then through the lungs. Because of the over perfusion of the lungs, the lung vessels get damaged and the pulmonary vascular resistance increases leading to pulmonary hypertension. The surgical repair of an AV - channel can be performed as long as the pulmonary hypertension is reversible. In our center we usually go for an early complete correction at the age of 3 months. With this strategy we get excellent results.

		Tetralogy of Fallot The Tetralogy of Fallot (TOF) is a complex defect leading to cyanosis. There are the following lesions: - a big ventricular septal defect - a significant narrowing of the right ventricular outflow tract (pulmonary stenosis) - malposition of the great vessels, with the aorta to far to the right overriding the VSD - equal pressure in the right and left chamber The right ventricle is pumping with high pressure against the narrowing of the pulmonary vessels and gets thicker (hypertrophic). A portion of the unsaturated blood is pressed into the aorta causing cyanosis. After birth the narrowing of the right outflow tract increases and a sufficient blood flow through the lungs is no more guaranteed. In modern pediatric heart centers Tetralogy of Fallot is early and completely corrected at the age of 8 - 12 weeks.

		HLHS - Hypoplastic Left Heart Syndrome With HLHS the whole left heart is under developed, so the perfusion of the body is at risk. In the fetus the right chamber does the perfusion of both circulations. After birth the atrial duct closes and so the system perfusion is no more guaranteed leading to a life threatening situation. A few years ago HLHS was always a lethal heart defect. Nowadays there are two therapeutic approaches: Heart transplant and the Norwood – Operation. At our center we perform the Norwood operation since 1997 successfully. This operation is a palliative intervention. After successful Norwood I - operation a cavopulmonary connection (Glenn anastomosis) at the age of 3-4 months is performed. At the age of 4 - 6 years the cavopulmonary anastomosis is completed with the Fontan operation.

		ISTHA – Aortic isthmus stenosis An aortic isthmus stenosis is a congenital defect of the great vessels. Just after the origin of the left subclavian artery from the aortic arch the arch is usually a little bit narrow. In case of aortic isthmus stenosis this constriction is severe leading to hypertrophy of the left heart chamber and to an increased blood pressure in the upper part The treatment of choice is to resect the stenosis and do an end-to-end-anastomosis. Balloon dilatation of the native aortic isthmus stenosis has not brought convincing results, so most of the centers have left this technique. But if there is any restenosis after surgery, balloon dilatation is the treatment of choice.

		PDA – Persistent Ductus arteriosus Botalli In the fetal circulation the arterial duct (Ductus arteriosus Botalli) is a normal and necessary short - cut between the pulmonary artery and the aorta.A few days after birth the duct closes spontaneously. If this closing is still missed a few weeks after birth, we call this a persistent ductus arteriosus (PDA). Children with a small PDA do not have any symptoms, but if the duct is big, frequent respiratory infections and even cardiac failure may occur. Because of the increased risk of acquiring an endocarditis all PDA´s persisting over more than two years should be closed. There are three different methods for closure: - surgery - endoscopic clipping - interventional closure with a coil or an umbrella The ideal method is chosen by the cardiologist depending on the size of the duct.

		PFO – Patent Foramen ovale The Foramen ovale is a natural and in fetal life necessary gap in the interatrial septum, which closes usually in the first year of life. If closure is incomplete it is called a persistent foramen ovale. A PFO has not any pathologic significance in childhood.

		Pulmonary valve stenosis In pulmonary valve stenosis a thickened pulmonary valve decreases blood flow from the right ventricle to the lungs. The cusps of the valve are usually thickend and do not open adequate. The right chamber is pumping against an increased resistance and gets thickened( hypertrophic). The severity of the restriction defines the seriousness of the disease. In case of minor stenosis there are not any symptoms. If the stenosis is severe even cyanosis may occur due to the diminished blood flow through the lungs. In our center we perform balloon valvuloplasty as soon as the instantaneous valvular gradient reaches 50 mm mercury.

		TGA – Transposition of the Great Arteries In TGA the aorta arises from the right and the pulmonary artery from the left ventricle. After birth the short - cuts between the left and the right heart close and there is no more communication between the systemic and the pulmonary circulation - this is a life threatening situation for the baby. For correction the arterial switch operation is usually performed in the first week of life.

		VSD – Ventricular septal defect A VSD is the most common heart defect. There is an inborn hole in the interventricular septum. As blood pressure is higher in the left than in the right chamber an amount of oxygen saturated blood flows from the left to the right heart with every heart beat ( left - to - right shunt ) and then through the lungs. The bigger the defect is, the more the lung is over perfused and this may cause damage of the lung vessels. It is an individual decision if and when the defect has to be closed. Huge defects with pulmonary hypertension must be closed within the first year, ideally within the first 6 months of life to prevent the lung vessels from damage.