The congenital heart block (CHB) is the heart block that is diagnosed in fetus (in utero) or within the first 28 days after birth (neonatal period), some studies also include the diagnosis during early childhood to the definition of CHB. It refers to the disorder in the electrical conduction system within the heart muscle, which leads to the failure in pumping the blood efficiently into the aorta and the pulmonary trunk. The result of CHB can be first, second, or third-degree (complete) atrioventricular block (a block in the atrioventricular node) in which no electric signals move from the atrium to the ventricles
The congenital heart block is a rare disease that affects around 1 child in every 15,000–20,000 births. However, its high mortality (which can be as high as 85% in some severe cases) makes the early diagnosis and intervention very important. CHB can be isolated, where the fetus does not suffer from any other problems, or it can be a result of other diseases either in the child or in the mother.
In most cases, the congenital heart block is associated with other diseases, and therefore, the symptoms vary a lot between patients. However, low heart rate is usually the main clinical presentation that leads to the diagnosis. Also, the treatment varies as well due to the associated diseases and it can be non-invasive (medications given to the pregnant woman or to the child), or a surgery in some cases when the CHB is resulted from anatomical disorders in the heart.