Anti-La\SSB autoantibody
This antibody attacks the ribonucleoprotein La48 on the surface of the fetal cardiomyocytes, the links between this autoantibody and autoimmune CHB are less strong than the anti-Ro autoantibody and it usually accompanies it in the majority of cases.Although the autoimmune CHB has a relatively high mortality and morbidity rates, the chance of kids from -mothers positive to anti-Ro\SSA and/or anti-La\SSB antibodies- to suffer from CHB is only around 1-5%, which suggests the existence of other factors to influence the disease such as genetic and environmental factors. Other autoantibodies
Several autoantibodies were suggested to have links with the autoimmune CHB, mainly the ones associated with the different autoimmune diseases that are common among women (such as the antibodies associated with Systemic lupus erythematosus (SLE), Rheumatoid arthritis, Progressive systemic sclerosis (PSS), and Mixed connective tissue disease). However, the role of these autoantibodies was not studied comprehensively.Also, some antigens of the fetal heart tissue (apart from the "Ro" and the "La") were studied, but no clear link with the autoimmune CHB was proven. Congenital cardiac structural abnormalities
The presence of a cardiac structural abnormality is a major determination of the outcome of CHB. Its existence affects the conduction system of the heart and increases the mortality rate and the need for pace-maker implantation.The cardiac structural diseases that are usually associated with the congenital heart block include the left atrial isomerism with or without atrioventricular septal defect.
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 ventriclesThe 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.