16.10 Pathologie

• Introduction
  
• Right cardiac obstruction (without shunt)
  • Pulmonary stenosis (PS)
  • Tricuspid stenosis
• Left cardiac obstruction (without shunt)
  • Aortic stenosis
  • Aortic insufficiency
  • Aortic isthmus stenosis (coarctatio aortae)
  • Interrupted aortic arch
  • Hypoplastic left cardiac syndrome
• Heart abnormality with left-right shunt (acyanotic)
  • Persisting ductus arteriosus (PDA)
  • Atrial septum defect (ASD)
  • Ventricle septum defect (VSD)
  • Atrioventricular septum defect
• Heart abnormality with right-left shunt (cyanotic)
  • Fallot's tetralogy
  • Pulmonary valve atresia
  • Tricuspid atresia
• Heart abnormality with false connections of the blood vessels
  • Transposition of the great vessels (TGA)
  • Double inlet ventricle
  • Complete pulmonary vein inlet errors
  • Truncus arteriosus communis

Introduction

The formation of the heart is a very complex process - errors can occur at every step in its development. They lead to congenital disorders that, due to an incidence of 1 in 1000 newborns, belong to the most frequent birth defects. Chromosomal aberrations are also very frequently associated with heart abnormalities. In the future, it will probably be possible to trace even more congenital malformations back to genetic predispositions when the processes that lead to heart formation are better understood at the molecular level.

In the clinic 4 very frequent heart abnormalities dominate. They make up more than half of the ones that are encountered. They are:

• VSD = ventricular septal defect (28%)
• ASD = atrial septal defect (11%)
• Pulmonary stenosis (9%)
• PDA= persisting ductus arteriosus (9%)

One can also subdivide congenital heart abnormalities according to location and hemodynamic effects. In case of an incomplete separation of the lungs and somatic circulation systems a shunt is formed. With each cardiac contraction the blood goes over from one circulation system to the other according to the different blood pressures in the two systems.

Cardiac abnormalities can thus be subdivided into the following three groupings:

• Anomalies without shunt
• Anomalies with left-right shunt (normally without cyanosis)
• Anomalies with right-left shunt (with cyanosis --> mixed blood)

Besides auscultation (with the stethoscope) echocardiography is the most frequently applied diagnostic method for clinical examinations. Cardiac catheter examinations are indicated in complex cardiac abnormalities and before operations.

Right cardiac obstruction (without shunt)

Obstructions, i.e. obstructions of the passages, can occur at various levels in the right side of the heart or in the pulmonary outflow path. Pure obstructions do not result in a mixing of the blood but a massive additional strain on the cardiac muscles because they have to pump against increased resistance.

Pulmonary stenosis (PS)

Isolated PS occurs with a frequency of 9% of all congenital cardiac abnormalities and, combined with other cardiac abnormalities, with a frequency of nearly 21%.

All forms lead to a hindrance of blood flow ejection from the right ventricle to the pulmonary artery. Depending on how big the stenosis is, a pressure stress and a compensatory hypertrophy of the right ventricle develop.

Tricuspid stenosis

IIt is corrected by a commissurotomy (expansion) of the valve opening rims.