The most common among the inherited heart diseases is a particular disease of the heart muscle known as hypertrophic cardiomyopathy - HCM. In hypertrophic cardiomyopathy heart muscle gets progressively thickened so that in some cases it obstructs the flow of blood from the left ventricle into the aorta (hypertrophic obstructive cardiomyopathy - HOCM). But in most cases there is no obstruction to the blood flow and it is called hypertrophic non obstructive cardiomyopathy (HNOCM). Some forms of heart muscle disease coming under the group of familial dilated cardiomyopathy are also inherited. In these cases, the heart muscle becomes weak and heart progressively enlarges and fails.
Another group of inherited disorders of the heart are inherited electrical disorders of the heart (cardiac ion channel disorders or cardiac channelopathies). This broad group has several disorders like long QT syndromes, short QT syndromes, Brugada syndrome and arrhythmogenic cardiomyopathy. These produce life threatening abnormalities of heart rhythm which can lead to sudden death.
Some of the birth defects of the heart (congenital heart disease) can also run in families. Some cases of atrial septal defects can be familial. Beyond these truly genetic disorders of the heart, the most common form of heart disease in adults due to disease of the blood vessels of the heart known as coronary artery disease also has a familial predisposition. Family history of premature coronary artery disease is an important non modifiable risk factor for heart attacks.
