Dilated Cardiomyopathy

Basic Facts

  • Doctors use the term cardiomyopathy to describe a chronic disorder of the heart muscle’s function that reduces the amount of blood the heart is able to pump.
  • A weakened heart responds to a reduced output of blood by dilating, or enlarging, to hold more blood.
  • Although there are several types of cardiomyopathy, the most common form is dilated cardiomyopathy 
  • Dilated cardiomyopathy is a common cause of congestive heart failure, the name for a range of symptoms that accompany a weakened heart.

Dilated cardiomyopathy is a chronic disorder that occurs when the main pumping chamber of the heart (the left ventricle) dilates, meaning it stretches. Consequently, the inside of the chamber becomes larger. The heart no longer contracts normally and cannot pump blood very well. As the heart becomes weaker, heart failure can occur. 

 

 

Because the body compensates for dilated cardiomyopathy, the disease may have no symptoms initially. As the condition worsens, the heart may perform normally when a person is resting, but may cause symptoms during periods of exercise or psychological stress.

Dilated cardiomyopathy is a common cause of congestive heart failure, the symptoms of which are often the first indication that a person has cardiomyopathy. Symptoms of congestive heart failure include:

  • Dyspnea (shortness of breath),
  • Orthopnea (shortness of breath while lying down),
  • Edema (swelling of feet, ankles, legs, or abdomen),
  • Palpitations (awareness of one's own heartbeat),
  • Lung congestion, and
  • Fatigue.

 

Although most cases of dilated cardiomyopathy result from unknown causes, known causes include:

  • Myocarditis (inflammation of the heart’s walls usually caused by a virus),
  • Ischemia (lack of oxygen in the heart),
  • A previous heart attack,
  • Severe coronary heart disease,
  • Heart valve disease,
  • Chronic alcohol abuse,
  • Chemotherapy drugs,
  • High blood pressure, 
  • Arrhythmias (disturbances of the heart’s rhythm or rate), and
  • Autoimmune illnesses (such as lupus or rheumatoid arthritis).

 

A physician diagnoses dilated cardiomyopathy after a physical examination. He or she may check for shortness of breath during exercise and weakness. The physician may also hear rales, or wet crackles, through a stethoscope, indicating fluid in the lungs. 

To confirm the diagnosis, the physician may order tests, including:

  • Blood Tests
  • Chest X Ray
  • Echocardiography – This test uses sound waves to create a moving picture of the heart, showing its size and shape, as well as how the heart chambers and valves are working.
  • Electrocardiography (ECG) – This test records the electrical activity of the heart.
  • Cardiac Catheterization and Angiography - Cardiac catheterization involves the insertion of a thin tube called a catheter into an artery. During angiography, physicians inject dye through the catheter that allows them to study blood flow through the heart and blood vessels and look at the pumping function of the heart.
  • Stress test- a non-invasive way of looking for blockages in the heart arteries

The physician may prescribe congestive heart failure medications to control the symptoms of heart failure that can accompany dilated cardiomyopathy, including:

  • Angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), which dilate (widen) the blood vessels and help strengthen the heart muscle
  • Anticoagulants, which inhibit blood clot formation by preventing the clumping of platelets in the blood,
  • Beta-blockers, which lower blood pressure and heart rate, reducing the workload on the heart,
  • Digitalis, which regulates the heart's rate and rhythm and strengthens the force of heart contractions,
  • Diuretics, which reduce fluid retention, a common symptom of heart failure,
  • Nitrates, which causes blood vessels to dilate, and
  • Vasodilators, which relax the walls of the blood vessels, allowing more blood to flow through.

Patients with severe congestive heart failure that is associated with dilated cardiomyopathy may require a left ventricular heart assist device or even a heart transplant.

Lifestyle Changes

A physician may recommend that the patient first make lifestyle changes, including:

  • Quitting smoking
  • Eating to control high blood pressure
  • Eating to lower cholesterol
  • Exercising
  • Losing weight
  • Controlling diabetes  
  • Consume alcohol moderately