Congenital heart defects

In 1892, Sir William Osler wrote in "The Principles and Practise of Medicine" that congenital heart disease "has only a limited clinical interest, as it is for the most part incompatible with life" (Kasper 2015).

Fortunately, the achievements of the last century, especially the last 60 years, have completely changed this picture, so that over 90% of affected children now live to adulthood (Kasper 2015).

Cardiopulmonary bypass surgery has been possible since the 1950s (Bouma 2017).

A congenital heart defect (AHF) is a hereditary malformation of the heart or the great vessels.

AHFs are divided into:

• I. Acyanotic vitia
  • Obstruction of valves or large vessels such as in:
    • aortic valve stenosis
    • Aortic isthmus stenosis
    • Pulmonary stenosis (Herold 2023)
  • Primary left-right shunt such as in:
    • Atrial septal defect
    • Ventricular septal defect
    • Atrioventricular septal defect
    • Partial pulmonary vein malformation
    • Persistent ductus arteriosus botalli
    • Aortopulmonary window (Herold 2023)

• II Cyanotic vitia
  • Right-left shunt
    • Truncus arteriosus
    • Tetralogy of Fallot
    • Tricuspid atresia
    • Transposition of the great vessels
    • Pulmonary atresia
    • Total pulmonary vein malformation and others (Herold 2023)

A further classification includes simple, moderate and complex AHF:

• Simple AHF

Individual lesions are present, e.g. a shunt or a valve malformation (Kasper 2015)

• Moderately severe AHF

In moderate AHF, there are two or more simple defects (Kasper 2023).

• Complex defects

These consist of components of an intermediate defect as well as a more complex cardiac and vascular anatomy (Kasper 2023).

The right ventricular defects include:

- Pulmonary valve stenosis

- Tetralogy of Fallot

- Pulmonary atresia with ventricular septal defect

- Pulmonary atresia with intact ventricular septum and critical pulmonary stenosis

- Pulmonary stenosis

- Tricuspid atresia

- Ebstein anomaly

- Double outlet right ventricle (Blum 2016)

The left ventricles include:

- Aortic valve stenosis

- Aortic valve insufficiency

- Interrupted aortic arch and critical aortic isthmus stenosis

- Non-critical aortic coarctation stenosis

- Mitral valve stenosis

- Mitral valve insufficiency (Blum 2016)

The most common birth defects are cardiovascular in nature (Kasper 2015). Today, a malformation of the heart or large vessels is found in around 1% of all live births (Herold 2023).

Up to 60 % of cardiac malformations are simple malformations (Blum 2016), while around 25 % of those affected have critical AHF (Singh 2021). Malformations of the heart valves affect < 15 % (Blum 2016).

The number of adults with AHF living in Germany is estimated at 203,000 - 304,000 (Schmaltz 2013).

AHF usually develop at a very early stage of pregnancy, i.e. in the 5th - 8th week of pregnancy. Multifactorial causes such as environmental influences, genetics, infections (e.g. rubella), alcohol, drugs, various medications, etc. are suspected.

Chromosomal abnormalities such as trisomy 21, Marfan syndrome, Turner-Noonan syndrome (Herold 2023) and Williams-Beuren syndrome (Yuan 2017) are also frequently associated with AHF.

Similarly, mothers with pregestational diabetes mellitus have a significantly increased risk of all phenotypes of congenital heart defects for their child (Maduro 2022).

Up to 400 different genes are associated with the pathogenesis of congenital heart defects (Williams 2019).

The symptoms depend on the respective heart defect and can consist of:

- Weak drinking in the infant

- Weight stagnation

- Sweating on the head when drinking

- tachypnea

- Hepatomegaly

- Edema (Blum 2016)

- syncope

- very rarely sudden cardiac death (Hoffmann 2014)

Up to 50 - 60 % of critical AHF can be diagnosed prenatally using ultrasound (Singh 2021).

Postnatal diagnostics include auscultation, ECG, chest X-ray and measurement of oxygen saturation as well as non-invasive imaging such as echocardiography, cardiac MRI and angio-CT. Invasive diagnostics include cardiac catheterization (Blum 2016).

Shunts can be assessed well by echocardiography, otherwise shunts and most congenital heart diseases can be optimally assessed by CMR (Kasper 2015).

In the surgical treatment of AHF, a distinction is made between corrective and palliative procedures:

- Corrective surgery:

In a corrective procedure, normal function is restored and maintained, life expectancy is normalized and no further medical or surgical interventions are required.

Examples include surgery for e.g. an ASD (atrial septal defect) and a PDA (patent ductus arteriosus botalli) (Herold 2023).

- Palliative surgery:

Surgical palliative surgery can be, for example, the creation of an aortopulmonary shunt, surgery for pulmonary atresia with ventricular septal defect and aortopulmonary collaterals, implantation of conduits, heart transplantation, lung transplantation or a heart-lung transplantation (Herold 2023).

The previously high mortality rate for AHF has been significantly reduced in recent decades. In the meantime, > 90 % of those affected reach adulthood (Herold 2023).

In addition to gynecological monitoring, pregnant women with congenital heart defects should always be monitored by a cardiologist at the same time (Kasper 2015).

Follow-up care

Almost all patients with a congenital heart defect require lifelong cardiological care, ideally with an additional qualification in "EMAH" = "adults with congenital heart defects". A distinction is made between the treatment of:

• 1. secondary condition:
  • This is defined as anatomical and hemodynamic changes

due to the surgical procedure that were unavoidable at the time of surgery (Herold 2023)

• 2. residual condition: This refers to postoperative anatomical and hemodynamic changes,
  • which partly existed due to the malformation
  • have developed as a result of the AHF
  • Abnormalities that could not be corrected or were not corrected due to a high risk (Herold 2023)

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