Cardiomyopathy
Cardiomyopathy is disease in which the heart muscle becomes weakened, stretched, or has another structural problem. It often contributes to the heart's inability to pump or function well.
Many people with cardiomyopathy have heart failure.
The interior of the heart is composed of valves, chambers, and associated vessels.
The external structures of the heart include the ventricles, atria, arteries and veins. Arteries carry blood away from the heart while veins carry blood into the heart. The vessels colored blue indicate the transport of blood with relatively low content of oxygen and high content of carbon dioxide. The vessels colored red indicate the transport of blood with relatively high content of oxygen and low content of carbon dioxide.
Dilated cardiomyopathy involves enlargement of the heart muscle and is the most common type of cardiomyopathy. The heart muscle is weakened and cannot pump blood efficiently. Decreased heart function affects the lungs, liver, and other body systems.
Hypertrophic cardiomyopathy is the thickening of the muscles that make up the heart. The thickening may interfere with the normal functioning of the heart by narrowing the outflow of the ventricle; reducing the ability of the heart to relax and fill with blood during the relaxation phase; or reducing the ability of the valves of the heart to function properly. Any situation that increases the contraction or rate of contraction of the heart muscle can worsen these symptoms.
Peripartum cardiomyopathy is a rare disorder in which a weakened heart is diagnosed within the last month of pregnancy or within 5 months after delivery, without other identifiable causes for dysfunction of the heart. The heart muscle becomes enlarged and weakened and cannot pump blood efficiently. Decreased heart function affects the lungs, liver, and other body systems.
Cardiomyopathy, also known as myocardiopathy, is a condition that includes diseases of the heart muscle, resulting in abnormal heart function. It is a progressive impairment of the structure and function of the muscular walls of the heart chambers, and is distinguished from heart muscle impairment caused by hypertension, coronary atherosclerosis, valvular dysfunction, or abnormalities of the pericardium. Cardiomyopathy may be caused by many disorders, or it may be idiopathic (of unknown cause). The main types of cardiomyopathies are dilated, hypertrophic, and restrictive. Cardiomyopathies often cause symptoms of heart failure. Some cardiomyopathies may also cause chest pain, fainting, arrhythmia, or sudden death. Treatment of cardiomyopathies, in addition to lifestyle changes, includes drug therapy with beta-blockers, diuretics, anticoagulants and antiarrhythmics, surgical intervention, pacemaker therapy, and in high-risk patients, implantable cardioverter defibrillator to prevent sudden cardiac death. Cardiac transplantation is an option for patients who do not respond to any of these treatment options.
Causes
There are many types of cardiomyopathy, with different causes. Some of the more common ones are:
- Dilated cardiomyopathy (also called idiopathic dilated cardiomyopathy if there is no known cause) is a condition in which the heart becomes weak and the chambers get large. As a result, the heart cannot pump enough blood out to the body. It can be caused by many medical problems.
- Hypertrophic cardiomyopathy (HCM) is a condition in which the heart muscle becomes thick. This makes it harder for blood to leave the heart. This type of cardiomyopathy is most often passed down through families.
- Ischemic cardiomyopathy is caused by a narrowing of the arteries that supply the heart with blood. It makes the heart walls thin so they do not pump well.
- Restrictive cardiomyopathy is a group of disorders. The heart chambers are unable to fill with blood because the heart muscle is stiff. The most common causes of this type of cardiomyopathy are amyloidosis and scarring of the heart from an unknown cause.
- Peripartum cardiomyopathy occurs during pregnancy or in the first 5 months afterward.
Treatment
When possible, the cause of cardiomyopathy is treated. Medicines and lifestyle changes are often needed to treat the symptoms of heart failure, angina and abnormal heart rhythms.
Procedures or surgeries may also be used, including:
- A defibrillator that sends an electrical pulse to stop life-threatening abnormal heart rhythms
- A pacemaker that treats a slow heart rate or helps the heart beat in a more coordinated fashion
- Coronary artery bypass (CABG) surgery or angioplasty that may improve blood flow to the damaged or weakened heart muscle
- Heart transplant that may be tried when all other treatments have failed
Partially and fully implantable mechanical heart pumps have been developed. These may be used for very severe cases. However, not all people need this advanced treatment.
Outlook (Prognosis)
The outlook depends on many different things, including:
- Cause and type of cardiomyopathy
- The severity of the heart problem
- How long the problem has been present
- How well the condition responds to treatment
Heart failure is most often a long-term (chronic) illness. It may get worse over time. Some people develop severe heart failure. In this case, medicines, surgery, and other treatments may no longer help.
People with certain types of cardiomyopathy are at risk for dangerous heart rhythm problems.
References
Hershberger RE. The dilated, restrictive, and infiltrative cardiomyopathies. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 52.
Heidenreich PA, Bozkurt B, Aguilar D, et al. 2022 AHA/ACC/HFSA guideline for the management of heart failure: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol. 2022;79(17):e263-e421. PMID: 35379503
McKenna WJ, Elliott PM. Diseases of the myocardium and endocardium. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 54.
McMurray JJV, Pfeffer MA. Heart failure: management and prognosis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 53.
Rogers JG, O'Connor CM. Heart failure: pathophysiology and diagnosis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 52.
Version Info
Last reviewed on: 5/8/2022
Reviewed by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
