Heart, section through the middle
Heart, section through the middle
Heart, front view
Heart, front view

Cardiomyopathy

Definition:
Cardiomyopathy is a weakening of the heart muscle (myocardium), which usually causes inadequate heart pumping.

Causes, incidence, and risk factors:

Cardiomyopathy can be caused by viral infections; heart attacks; alcoholism; long-term, severe hypertension (high blood pressure); or for other reasons not yet known.

Specific types of cardiomyopathy include:

  • Ischemic Cardiomyopathy: This is caused by heart attacks, which leave scars in the heart muscle (myocardium). The affected myocardium is then unable to contribute to the heart pumping function. The larger the scars (or the more numerous the heart attacks), the higher the chance there is of developing ischemic cardiomyopathy.
  • Idiopathic Cardiomyopathy: The term "idiopathic" means that the cause is unknown. Usually, this term refers to dilated cardiomyopathy.
  • Dilated Cardiomyopathy: This is a global, usually idiopathic myocardial disorder characterized by a marked enlargement and inadequate function of the left ventricle. It may affect young people.
  • Hypertrophic Cardiomyopathy: This is a disproportionate growth of the left ventricle muscle. Sometimes, the right ventricle is also affected. In up to 70% of cases, there is a family history of this condition.
  • Alcoholic Cardiomyopathy: This is a type of dilated cardiomyopathy that usually begins about 10 years after sustained, heavy alcohol consumption. It can occur with both typical signs of heart failure, as well as with atrial fibrillation or other heart rhythm problems.
  • Peripartum Cardiomyopathy: This is a dilated cardiomyopathy appearing in women during the last trimester of pregnancy, or after childbirth.
  • Restrictive Cardiomyopathy: This is a disorder affecting the diastolic (when the heart muscle is relaxing between contractions) function of the heart. The heart cannot relax adequately after each contraction (systole), and thus it cannot be adequately filled with blood. Examples of restrictive cardiomyopathy are amyloidosis and sarcoidosis.

Cardiomyopathy is not common, but can be severely disabling or fatal. Extreme cardiomyopathy with heart failure may require a heart transplant.

Symptoms:

Additional symptoms that may occur:

Signs and tests:

Examination may reveal an irregular heartbeat. Heart sounds and breath sounds may be abnormal. Additionally, there may be other signs of heart failure.

Decreased heart function and heart enlargement may appear in these tests:

  • Coronary Angiography: This is the study of the coronary arteries (the vessels providing blood to the heart muscle). The angiography is done by introducing a small tube through the artery in the groin area and advancing it to the heart, then injecting an X-ray dye to visualize the coronary arteries.
  • Echocardiogram and ultrasound examination of the heart.
  • Chest X-ray.
  • Chest CT scan.
  • MRI of chest.
  • ECG: May show enlargement, evidence of a previous heart attack, ischemic changes (abnormalities seen with a lack of blood flow to the heart), arrhythmias (abnormal heart rhythms) or other abnormalities.
  • Rarely, a heart biopsy may be needed to rule out other disorders.

Certain lab tests may be used to rule out other disorders and to assess the condition of the heart:

  • CBC (Complete Blood Count). Red and white blood cells are counted, as well as platelets.
  • Coronary Risk Profile: The patient's risk factors for coronary disease are evaluated. Risk factors include, but are not limited to, cigarette smoking, lipid profile (particularly cholesterol level), high blood pressure, diabetes, alcoholism, and physical inactivity.
  • Blood Chemistries: CBC, lipid profile (cholesterol test), and cardiac enzymes.
  • Cardiac Enzymes: (CPK isoenzymes, CK-MB, LDH isoenzymes).

Treatment:

While all types of cardiomyopathy can cause heart failure, each case requires specific strategies for recovery. Heart failure is treated with a vigorous blend of patient education, dietary changes, and medications.

Possible medications include:

  • Positive inotropic agents: These chemicals help the heart contract. The main agent of this category is digoxin. In-hospital options include dopamine, dobutamine, and milrinone.
  • Diuretics: Often called "water pills," diuretics help relieve the fluid overloads in heart failure.
  • Vasodilators: These drugs dilate blood vessels at several levels in the body, reducing the workload for the heart.
  • ACE-inhibitors and Beta blockers: These treatments act as vasodilators while helping to preserve the normal architecture of the heart muscle
  • Other drugs: Angiotensin II receptor blockers, antiarrhythmic drugs, and blood thinners.

Another technique which can be used is biventricular pacing. In this treatment, a pacemaker lead (i.e., cable) is inserted in each ventricle to help the heart contract better.

In severe cases, surgical procedures, which can be implemented to sustain life until a transplant donor becomes available, can help but do not cure the disease. They include:

  • Left Ventricular Assist Device (LVAD): Treatment provides mechanical circulatory support.
  • Dynamic Cardiomyoplasty: A procedure in which a skeletal muscle flap, created from a patient's thoracic muscle, is trained to contract often and "wrapped around" the heart to help it contract.

Advanced, severe heart failure requires heart transplantation.

Expectations (prognosis):

The outcome varies. The disorder is chronic and the condition may deteriorate rapidly.

Complications:
Calling your health care provider:
Go to the emergency room or call the local emergency number (such as 911) if symptoms indicating heart failure may be present, or if chest pain is present and not relieved by rest or medication.

Review Date: 5/25/2002
Reviewed By: Seth Keller, M.D., Division of Cardiology, Yale New Haven Medical Center, New Haven, CT. Review provided by VeriMed Healthcare Network.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2003 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.