Congenital Heart Disease Support Group

Congenital heart disease is heart disease in the newborn, and includes congenital heart defects, congenital arrythmias, cardiomyopathies, and hypertrophic cardiomyopathy (HCM). Congenital heart disease, which is also referred to as CHD, is a defect of the heart that exists primarily at birth. CHD can describe a wide variety of different abnormalities affecting the heart. CHD occurs when the heart or blood vessels near the heart does not develop properly before birth. Therefore, the heart does not pump because it is not completely developed. Also the blood flow is obstructed in the heart of the vessels nearby, causing an abnormal flow of blood through the heart. Blood flow obstructions put a strain on the heart muscle causing the heart to work harder and beat faster. Abnormal blood flow usually occurs when there is a hole in the walls of the heart and may be an abnormal connection between two arteries outside the heart.

CHD has many diverse causes. Some factors are environmental, such as chemicals, drugs, or infection. However, the bulk of CHD is thought to be genetic in nature. Infections such as German measles (i.e. rubella) can produce CHD. Women with diabetes and phenylketonuria are at high risk for their children to be born with this disease. Other causes include the mother's excessive intake of alcohol and illegal drugs while pregnant. There are many genetic conditions which can be a factor in causing CHD, such as DiGeorge syndrome (22q11 deletion syndrome), Holt-Oram syndrome, and Alagille syndrome. Although these factors are known causes of CHD, most are currently unknown. Therefore, most cases of CHD are unknown.

Mild congenital heart diseases may not be observed or occur until adulthood. The physician or provider will find this through a series of questions in an examination. Echocardiography and cardiac magnetic resonance(MRI) are used to confirm CHD when signs or symptoms occur in the physical examination. An echocardiograph displays images of the heart and the sound waves it makes. It also finds abnormal rhythms or defects of the heart present with CHD. Fetal echocardiography is used to diagnose CHD in utero after 20 weeks of pregnancy. An ultrasound may be used to determine the defects in pregnant women. Cardiac MRI scans and uses magnetic fields and radio waves to determine these defects but is not always necessary in dianosing CHD. A chest x-ray may also be issued to look at the anatomical position of the heart and lungs. A Cat Scan(CT) can also be used to visualize CHD. All of these tests are ways to diagnose CHD by a physician.

Hypertrophic cardiomyopathy, or HCM, is a disease of the myocardium (the muscle of the heart) in which a portion of the myocardium is hypertrophied (thickened) without any obvious cause. Though perhaps most famous as a leading cause of sudden cardiac death in young athletes2 HCM's more important significance is as a cause of sudden unexpected cardiac death in any age group and as a cause of disabling cardiac symptoms.

A cardiomyopathy is any disease that primarily affects the muscle of the heart. In HCM, the normal alignment of muscle cells is disrupted, a phenomenon known as myocardial disarray. HCM also causes disruptions of the electrical functions of the heart. HCM is believed to be due to a mutation in one of many genes that results in a mutated myosin heavy chain, one of the components of the myocyte (the muscle cell of the heart). Depending on the degree of obstruction of the outflow of blood from the left ventricle of the heart, HCM can be defined as obstructive or non-obstructive.

HCM is also known as idiopathic hypertrophic subaortic stenosis (IHSS) and hypertrophic obstructive cardiomyopathy (HOCM). A non-obstructive variant of HCM is apical hypertrophic cardiomyopathy 3, which is also known as nonobstructive hypertrophic cardiomyopathy and Japanese variant hypertrophic cardiomyopathy (since the first cases described were all in individuals of Japanese descent).