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Cardiomyopathy

Cardiomyopathy refers to diseases of the heart muscle.

PubMed Health Glossary
(Source: NIH - National Heart, Lung, and Blood Institute)

About Cardiomyopathy

Cardiomyopathy (KAR-de-o-mi-OP-ah-thee) refers to diseases of the heart muscle. These diseases have many causes, signs and symptoms, and treatments.

In cardiomyopathy, the heart muscle becomes enlarged, thick, or rigid. In rare cases, the muscle tissue in the heart is replaced with scar tissue.

As cardiomyopathy worsens, the heart becomes weaker. It's less able to pump blood through the body and maintain a normal electrical rhythm. This can lead to heart failure or irregular heartbeats called arrhythmias (ah-RITH-me-ahs). In turn, heart failure can cause fluid to build up in the lungs, ankles, feet, legs, or abdomen.

The weakening of the heart also can cause other complications, such as heart valve problems.

Overview

The main types of cardiomyopathy are:

  • Dilated cardiomyopathy
  • Hypertrophic (hi-per-TROF-ik) cardiomyopathy
  • Restrictive cardiomyopathy
  • Arrhythmogenic (ah-rith-mo-JEN-ik) right ventricular...

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What works? Research summarized

Evidence reviews

Genetic testing for predisposition to inherited hypertrophic cardiomyopathy

Bibliographic details: Lefevre F.  Genetic testing for predisposition to inherited hypertrophic cardiomyopathy. Chicago, IL, USA: Blue Cross and Blue Shield Association, Technology Evaluation Center. Assessment Program; 24,11. 201021114064

Interventions for treating pregnant women or new mothers with heart failure of unknown cause (peripartum cardiomyopathy)

Very rarely, some women suffer from heart failure (without any known cause) in late pregnancy or as a new mother. The heart muscle becomes large and weakened, and is unable to pump blood properly round the body. This affects the lungs, liver, and other body systems. Symptoms include: difficulty in breathing, shortness of breath, the heart racing or skipping beats. There can also be chest pain, swelling, and excessive weight gain during the last month of pregnancy. Women need to be cared for in intensive care wards. Labour is often medically induced earlier than normal if the problem arises late in pregnancy. These babies then suffer the problems of being born too early (prematurely). This review looked at interventions which might reduce harm for women with this condition The interventions included drugs, heart or blood monitoring, supportive therapies and heart transplants. We found only one pilot study, involving 20 women with heart failure after giving birth, that looked at bromocriptine given over a period of eight weeks. There were not enough data to provide a clear answer on the number of mothers dying, but the drug looked promising. Biochemical measurements were also made. Women need to be informed that the drug stops the production of breastmilk, making breastfeeding impossible. We found no trials on other possible interventions. Large trials are needed to decide the best treatment for these women and their babies.

Pacing for drug‐refractory or drug‐intolerant Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic disease with an autosomal‐dominant inheritance, which can cause obstruction in the left ventricle outflow tract. This obstruction can lead to a variety of symptoms like dyspnoea, chest pain, syncope and palpitations. The prevalence of HCM in the general population, as determined from echocardiographic studies in the United States, Japan, and China, has ranged from 0.16 to 0.29 percent. Treatment options for HCM ranges from drugs to surgery with each having its own limitations. Active cardiac pacing was suggested as a treatment option in some trials. We conducted this review to assess the available evidence on the effects of active pacing in drug‐refractory or drug‐intolerant HCM patients. Five studies (reported in 10 papers) were found to be relevant. However, three of the five studies provided un‐usable data. Thus data from only two studies (reported in seven papers) with 105 participants was included for this review. There was insufficient data to compare results on all‐cause mortality, cost effectiveness, exercise capacity, Quality of life and Peak O2 consumption. There was no difference in exercise capacity when comparing active pacing versus placebo pacing. However left ventricular outflow tract obstruction decreased significantly in the active pacing group compared to placebo. New York Heart Association functional class increased in the active pacing group compared to the placebo group and this was also observed when comparing active pacing versus trancoronary ablation of septal hypertrophy. Interpretation of these data needs to be cautious because existing data is derived from small trials at high risk of bias, which concentrate on physiological measures. Their results are inconclusive. Further large and high quality trials with more appropriate outcomes are warranted.

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Summaries for consumers

Interventions for treating pregnant women or new mothers with heart failure of unknown cause (peripartum cardiomyopathy)

Very rarely, some women suffer from heart failure (without any known cause) in late pregnancy or as a new mother. The heart muscle becomes large and weakened, and is unable to pump blood properly round the body. This affects the lungs, liver, and other body systems. Symptoms include: difficulty in breathing, shortness of breath, the heart racing or skipping beats. There can also be chest pain, swelling, and excessive weight gain during the last month of pregnancy. Women need to be cared for in intensive care wards. Labour is often medically induced earlier than normal if the problem arises late in pregnancy. These babies then suffer the problems of being born too early (prematurely). This review looked at interventions which might reduce harm for women with this condition The interventions included drugs, heart or blood monitoring, supportive therapies and heart transplants. We found only one pilot study, involving 20 women with heart failure after giving birth, that looked at bromocriptine given over a period of eight weeks. There were not enough data to provide a clear answer on the number of mothers dying, but the drug looked promising. Biochemical measurements were also made. Women need to be informed that the drug stops the production of breastmilk, making breastfeeding impossible. We found no trials on other possible interventions. Large trials are needed to decide the best treatment for these women and their babies.

Pacing for drug‐refractory or drug‐intolerant Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic disease with an autosomal‐dominant inheritance, which can cause obstruction in the left ventricle outflow tract. This obstruction can lead to a variety of symptoms like dyspnoea, chest pain, syncope and palpitations. The prevalence of HCM in the general population, as determined from echocardiographic studies in the United States, Japan, and China, has ranged from 0.16 to 0.29 percent. Treatment options for HCM ranges from drugs to surgery with each having its own limitations. Active cardiac pacing was suggested as a treatment option in some trials. We conducted this review to assess the available evidence on the effects of active pacing in drug‐refractory or drug‐intolerant HCM patients. Five studies (reported in 10 papers) were found to be relevant. However, three of the five studies provided un‐usable data. Thus data from only two studies (reported in seven papers) with 105 participants was included for this review. There was insufficient data to compare results on all‐cause mortality, cost effectiveness, exercise capacity, Quality of life and Peak O2 consumption. There was no difference in exercise capacity when comparing active pacing versus placebo pacing. However left ventricular outflow tract obstruction decreased significantly in the active pacing group compared to placebo. New York Heart Association functional class increased in the active pacing group compared to the placebo group and this was also observed when comparing active pacing versus trancoronary ablation of septal hypertrophy. Interpretation of these data needs to be cautious because existing data is derived from small trials at high risk of bias, which concentrate on physiological measures. Their results are inconclusive. Further large and high quality trials with more appropriate outcomes are warranted.

Pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy

Named in honor of the Brazilian physician Carlos Chagas, Chagas disease is caused by the Trypanosoma cruzi parasite which needs humans for the start of its life cycle. It is common in Latin and Central America and leads to Chagas cardiomyopathy (heart muscle disease), and is an important cause of heart failure. The number of people infected with Chagas disease has been estimated to be about 10 to 12 million worldwide, and around 20% to 30% of individuals infected with Trypanosoma cruzi will develop symptomatic heart disease at some point during their lives.

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Terms to know

Arrhythmia (Cardiac Arrhythmia)
An arrhythmia is a problem with the rate or rhythm of the heartbeat. During an arrhythmia, the heart can beat too fast, too slow, or with an irregular rhythm.
Blood
A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.
Heart
The hollow, muscular organ that maintains the circulation of the blood.
Heart Failure
A chronic condition in which the heart cannot pump blood properly.
Heart Valves (Cardiac Valves)
Any of the four heart valves that regulate the flow of blood through the chambers of the heart.
Muscles
Muscles function to produce force and motion. They are primarily responsible for maintaining and changing posture, locomotion, as well as movement of internal organs, such as the contraction of the heart and the movement of food through the digestive system.
Myocardium
The muscular substance of the heart; the middle of the three layers forming the outer wall of the human heart.

More about Cardiomyopathy

Photo of an adult

Also called: Myocardial diseases, Myocardiopathy

Other terms to know: See all 7
Arrhythmia (Cardiac Arrhythmia), Blood, Heart

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