Hypertrophic Cardiomyopathy: Heart Disease Due to Genetic Disorders

Hypertrophic cardiomyopathy, also called idiopathic cardiomyopathy, is an inherited or acquired disorder of the heart muscle. In hypertrophic cardiomyopathy, the muscle in the left ventricle of the heart becomes swollen and enlarged, preventing proper blood flow through the heart.

 

Hypertrophic cardiomyopathy is most often hereditary—a rare genetic disorder that can affect men and women of all ages. In the hereditary form of the disease, children are born with genetic mutations affecting the heart muscle. Almost seventy percent of diagnosed cases of hypertrophic cardiomyopathy have a family history of the disease.

Some symptoms like dizziness, shortness of breath, or chest pain may appear in both adults and children, but symptoms are not always present with hypertrophic cardiomyopathy. Arrhythmias, or irregular heartbeats, are common symptoms that are not always detected but they can be life-threatening. Young people may die a sudden death after strenuous exercise without ever knowing they had hypertrophic cardiomyopathy.

The goals of treatment in hypertrophic cardiomyopathy are to control symptoms and minimize complications. Drug therapy includes the use of beta blockers, calcium channel blockers and anti-arrhythmics. Severe cases may require cardiac surgery.

Beta and Calcium Channel Blockers: The most common treatments are either beta blockers or calcium channel blockers. Calcium channel blocking agents decreasethe movement of calcium into the cells of the heart and blood vessels,relaxing blood vessels, increasing the supply of blood and oxygen to the hearttoreduce its workload. These drugs help to reduce the "workload" of the heart and improve blood flow to the heart muscle. Beta blockers make the heart pump slower and allow the chambers in the heart to fill up more completely.

Anti-Arrhythmics and Amiodarone: A drug called amiodarone is sometimes used to prevent arrhythmias in hypertrophic cardiomyopathy. Some evidence suggests that the use of amiodarone may prevent the arrhythmias associated with sudden death.

Surgical Procedures: Some patients do not respond positively to treatment with drugs. A septal myotomy or a myomectomy involves the surgical removal of hypertrophic tissue in an attempt to restore the normal shape of the heart. These procedures can be performed on patients who have experienced no relief of symptoms with other therapies. Some patients may benefit from the placement of a permanent pacemaker to help the heart maintain a normal rhythm.

Prognosis is variable. Patients with hypertrophic cardiomyopathy are discouraged from excessive physical exertion. Certain strenuous exercises, including team sports, are demanding enough to bring on arrhythmias and can result in sudden death.

Resources

American Heart Association (updated 2004). Cardiomyopathy.

Beers, M.H. & Berkow, R. (ed). Cardiomyopathy. The Merck Manual of Diagnosis and Therapy, 17th Edition. Merck Research Laboratories, NJ, 1999.

Fauci, A., Braunwald, E., Isselbacher, K., Wilson, J., Martin, J., Kasper, D., Hauser, S. & Longo, D. (ed). Harrison's Principles of Internal Medicine, 14th Edition. McGraw-Hill, New York, 1998.

National Library of Medicine. (updated 2004). Hypertrophic cardiomyopathy. MedlinePlus Medical Encyclopedia.