What is dilated cardiomyopathy?

Cardiomyopathy is a disease of the heart muscle (myocardium). As the disease progresses, the heart loses its ability to pump blood through the body and maintain a normal rhythm. As a result, you could develop heart failure, arrhythmias or heart valve problems.

Dilated cardiomyopathy is a cardiac condition where the heart’s left ventricle (the main pumping chamber of the heart) is enlarged or weakened, which decreases the amount of blood the heart can pump. As the disease progresses, it can impact other heart chambers.

Causes of dilated cardiomyopathy

Dilated cardiomyopathy can be passed down from your parents or caused by other outside factors such as:

  • Alcoholism
  • Diabetes
  • Thyroid disease
  • Severe coronary artery disease
  • Heart valve abnormalities
  • Drugs that cause damage to the heart
  • Viral infections to the heart

Risk factors for dilated cardiomyopathy

Risk factors for developing dilated cardiomyopathy include:

  • Ethnicity — African Americans are more likely to develop dilated cardiomyopathy than Caucasians.
  • Gender — men are more likely to develop dilated cardiomyopathy than women.
  • Genetic predisposition — if you have family members who have had cardiomyopathy, heart failure or sudden cardiac arrest, you have a higher probability of developing dilated cardiomyopathy. Genetic testing may be an option for patients who have family members with this condition.
  • Related cardiac conditions — if you have other conditions, such as coronary heart disease or a previous heart attack, you are more likely to develop dilated cardiomyopathy.
  • Excessive alcohol consumption — heavy alcohol consumption, regardless of beverage, can lead to dilation in the left ventricle.

Symptoms of dilated cardiomyopathy

Many people who have dilated cardiomyopathy do not have any symptoms, while others have severe symptoms that worsen as the disease progresses.

Symptoms include:

  • Shortness of breath
  • Fatigue
  • Swelling in the legs, knees or feet
  • Weight gain
  • Fainting
  • Palpitations
  • Dizziness or lightheadedness
  • Blood clots
  • Chest pain or pressure
  • Sudden death

Diagnosis of dilated cardiomyopathy

Dilated cardiomyopathy is diagnosed in a physical exam with your cardiologist. Your doctor will take a full medical history, evaluate your symptoms and perform a full physical exam. When necessary, he or she will order additional testing such as:

  • Blood tests — can determine if you have a condition that caused dilated cardiomyopathy such as an infection or a metabolic disorder.
  • Electrocardiogram (ECG or EKG) — can record electrical heart signals.
  • Chest x-ray — to check your heart and lungs for abnormalities in the heart’s size or structure or amount of fluid around the lungs, your doctor may order a chest x-ray.
  • Echocardiogram — uses sound waves to produce images of the heart and indicate if the left ventricle is enlarged; it is the primary diagnostic tool for diagnosing dilated cardiomyopathy.
  • Exercise stress test — measure your heart rate and oxygen use.
  • Cardiac catheterization — measures pressure in the heart and collect samples of muscle tissue to check for damage by inserting a narrow tube into your heart through a blood vessel in your arm, groin or neck.
  • CT (Computed tomography) or MRI (Magnetic resonance imaging) scans — can determine the size and function of your heart’s pumping chambers.
  • Myocardial biopsy (heart biopsy) — a test where a tissue sample is taken from the heart and examined under the microscope.

Treatments for dilated cardiomyopathy

Treatment goals are to decrease the size of the heart as well as eliminate substances in the blood that have caused the heart to enlarge.


Your doctor may prescribe medications to treat dilated cardiomyopathy. Beta-blockers, ACE inhibitors and diuretics are drugs used to manage heart failure. Blood thinners are prescribed to prevent blood clots.

If you have severe dilated cardiomyopathy, you may need more advanced treatments such as:

Cardiac pacemaker

A cardiac resynchronization biventricular pacemaker can improve the heart’s ability to contract more forcefully by stimulating the left and right ventricles.

Implantable cardioverter defibrillator (ICD)

ICDs are recommended for patients with severe dilated cardiomyopathy who are at risk for sudden cardiac death or life-threatening arrhythmias. An ICD continuously monitors the heart, and when it detects an abnormal heart rhythm, it will shock the heart muscle back into normal rhythm.

Implantable ventricular assist device (VAD)

A ventricular assist device is an implantable mechanical heart pump that is used to increase the supply of blood flow through the body. A VAD is indicated when a patient’s heart ventricle is weakened and unable to adequately pump blood through the body.

VADs can be used in a variety of situations including:

  • Temporary treatment to sustain the heart function while a patient is waiting for a heart transplant.
  • Temporary treatment as your heart heals and strengthens to effectively pump on its own.
  • Long-term treatment for heart failure if your heart is not strong enough for a heart transplant.

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