ADAM Health Encyclopedia

Cardiomyopathy

Definition

Cardiomyopathy is a weakening of the heart muscle or a change in heart muscle structure. It is often associated with inadequate heart pumping or other heart function problems.

Causes

Cardiomyopathy can be caused by:

• Alcoholism
• Celiac disease
• End-stage kidney disease
• Heart attacks
• Infections due to viruses
• Long-term, severe high blood pressure
• Nutritional deficiencies (particularly selenium, thiamine, and L-carnitine)
• Systemic lupus erythematosus

There are many different types of cardiomyopathy. This article provides a general overview. Please see the linked article for details on a specific type of cardiomyopathy.

Specific types of cardiomyopathy include:

• Alcoholic cardiomyopathy
• Dilated cardiomyopathy
• Hypertrophic cardiomyopathy
• Ischemic cardiomyopathy
• Peripartum cardiomyopathy (occurs during or in the first 5 months after pregnancy)
• Restrictive cardiomyopathy

Other types of cardiomyopathy include:

• Tachycardia mediated cardiomyopathy: This occurs in people who have an abnormally fast heart rate.
• Idiopathic cardiomyopathy: "Idiopathic" means that the cause is unknown.
• Hypertensive cardiomyopathy: Occurs in people who have high blood pressure for a long time, especially when it has gone untreated for years.
• Infectious cardiomyopathy: HIV, Lyme disease, Chagas disease, viral myocarditis, and other infections can cause this condition
• Toxic cardiomyopathy: Cocaine use and certain chemotherapy drugs can also cause dilated cardiomyopathy.

Symptoms

• Abdominal swelling
• Chest pain, or "angina" - sharp, continuous pressure in the middle of the chest; more common in ischemic cardiomyopathy
• Cough - may be caused by extra liquid building up in the lungs, secondary to heart failure
• Decreased alertness
• Difficulty concentrating
• Dizziness
• Fainting - especially after activity; temporary and brief loss of consciousness
• Fatigue -- decreasing ability to tolerate physical activity
• High blood pressure
• Light-headedness - especially after activity
• Loss of appetite
• Low amount of urine during daytime
• Need to urinate at night
• Palpitations - the sensation of feeling the heart beat
• Shortness of breath
  • Need for extra pillows to sleep - lying flat causes shortness of breath
  • Waking up at night with sudden shortness of breath
• Swelling of legs or ankles

Exams and Tests

The doctor may hear an irregular heartbeat or abnormal heart sounds and breath sounds when listening to the chest and lungs with a stethoscope.

A heart murmur may be detected if heart valve disease is also present.

There may also be other signs of heart failure.

The following tests may show decreased heart function and heart swelling:

• Coronary angiography
• Echocardiogram and ultrasound examination of the heart.
• Chest x-ray
• Chest CT scan
• MRI of chest
• ECG

Rarely, a heart biopsy performed during a heart catheterization may be needed to rule out other disorders.

The following lab tests may be ordered:

• Blood chemistries
• Cardiac enzymes, includingCPK isoenzymes and LDH isoenzymes
• Complete blood count
• Coronary risk profile
• Toxicology screen for cocaine

Treatment

While all types of cardiomyopathy can cause heart failure, each case requires specific strategies for recovery.

Treatment involves a combination of patient education, dietary changes, and medications.

Possible medications include:

• ACE-inhibitors and angiotensin receptor blockers (ARBs): These drugs have been shown to improve survival and reduce heart-related complications.
• Aldosterone blockers: These drugs help balance electrolytes in the body. Studies have shown that aldosterone blockers can improve survival in patients who have a heart attacked complicated by cardiomyopathy.
• Beta blockers: Beta blockers are widely used for congestive heart failure. They improve survival in patients with cardiomyopathy and are important parts of therapy. Beta blockers slow the heart rate.
• Diuretics: Often called "water pills," diuretics help relieve the fluid overloads in heart failure.
• Positive inotropic medications: These medicines help the heart contract. They include dopamine, dobutamine, and milrinone.
• Vasodilators: These drugs dilate blood vessels at several levels in the body, reducing the workload for the heart.

Other drugs that correct irregular heart rhythms and blood thinners may also be used.

Certain individuals with severely weak pumping function of the heart and severe heart failure may need a biventricular pacemaker. It works on the right and left chambers (ventricles) of the heart and keeps them pumping together. In very specific cases, this special pacemaker may also have a defibrillation function, which means it can quickly detect a life-threatening, rapid heartbeat and convert it back to normal. See: Defibrillation.

In severe cases, surgery may be performed to help the patient live longer until a donated heart is available. However, surgery does not cure the disease. Surgical procedures include:

• Left ventricular assist device (LVAD): LVADs are the most common type of heart pump. They help the left side of the heart push blood to the aorta, the body’s main blood vessel.
• Dynamic cardiomyoplasty: A procedure in which a flap created from a patient's chest muscle is trained to contract often and "wrapped around" the heart to help it contract.

Patients with advanced, severe heart failure need a heart transplant.

Outlook (Prognosis)

The outlook depends on many different things, including the severity of the heart problem, the cause of the cardiomyopathy, and how well you respond to treatment.

The disorder is chronic (long-term)and the condition may get worse very quickly.

Possible Complications

• Heart failure
• Irregular heart beat

When to Contact a Medical Professional

Go to the emergency room or call the local emergency number (such as 911) if symptoms of heart failure develop.

Hare JM. The dilated, restrictive, and infiltrative cardiomyopathies. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Libby: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. St. Louis, Mo: WB Saunders; 2007: chap 64.