Cardiomyopathy

Often the cause of the cardiomyopathy is unknown. In some people, however, it's the result of another condition (acquired) or passed on from a parent (inherited).

Contributing factors for acquired cardiomyopathy include:

• Long-term high blood pressure
• Heart tissue damage from a heart attack
• Chronic rapid heart rate
• Heart valve problems
• Metabolic disorders, such as obesity, thyroid disease or diabetes
• Nutritional deficiencies of essential vitamins or minerals, such as thiamin (vitamin B-1)
• Pregnancy complications
• Drinking too much alcohol over many years
• Use of cocaine, amphetamines or anabolic steroids
• Use of some chemotherapy drugs and radiation to treat cancer
• Certain infections, especially those that inflame the heart
• Iron buildup in your heart muscle (hemochromatosis)
• A condition that causes inflammation and can cause lumps of cells to grow in the heart and other organs (sarcoidosis)
• A disorder that causes the buildup of abnormal proteins (amyloidosis)
• Connective tissue disorders

Types of cardiomyopathy include:

• Dilated cardiomyopathy. In this type of cardiomyopathy, the pumping ability of your heart's main pumping chamber — the left ventricle — becomes enlarged (dilated) and can't effectively pump blood out of the heart.

  Although this type can affect people of all ages, it occurs most often in middle-aged people and is more likely to affect men. The most common cause is coronary artery disease or heart attack.

• Hypertrophic cardiomyopathy. This type involves abnormal thickening of your heart muscle, particularly affecting the muscle of your heart's main pumping chamber (left ventricle). The thickened heart muscle can make it harder for the heart to work properly.

  Hypertrophic cardiomyopathy can develop at any age, but the condition tends to be more severe if it becomes apparent during childhood. Most affected people have a family history of the disease, and some genetic mutations have been linked to hypertrophic cardiomyopathy.

• Restrictive cardiomyopathy. In this type, the heart muscle becomes rigid and less elastic, so it can't expand and fill with blood between heartbeats. This least common type of cardiomyopathy can occur at any age, but it most often affects older people.

  Restrictive cardiomyopathy can occur for no known reason (idiopathic), or it can by caused by a disease elsewhere in the body that affects the heart, such as when iron builds up in the heart muscle (hemochromatosis).

• Arrhythmogenic right ventricular dysplasia. In this rare type of cardiomyopathy, the muscle in the lower right heart chamber (right ventricle) is replaced by scar tissue, which can lead to heart rhythm problems. It's often caused by genetic mutations.

• Unclassified cardiomyopathy. Other types of cardiomyopathy fall into this category.

Risk factors

There are a number of factors that can increase your risk of cardiomyopathy, including:

• Family history of cardiomyopathy, heart failure and sudden cardiac arrest
• Long-term high blood pressure
• Conditions that affect the heart, including a past heart attack, coronary artery disease or an infection in the heart (ischemic cardiomyopathy)
• Obesity, which makes the heart work harder
• Long-term alcohol abuse
• Illicit drug use, such as cocaine, amphetamines and anabolic steroids
• Certain chemotherapy drugs and radiation therapy for cancer
• Certain diseases, such as diabetes, an under- or overactive thyroid gland, or a disorder that causes the body to store excess iron (hemochromatosis)
• Other conditions that affect the heart, such as a disorder that causes the buildup of abnormal proteins (amyloidosis), a disease that causes inflammation and can cause lumps of cells to grow in the heart and other organs (sarcoidosis), or connective tissue disorders

Complications

Cardiomyopathy can lead to other heart conditions, including:

• Heart failure. Your heart can't pump enough blood to meet your body's needs. Untreated, heart failure can be life-threatening.
• Blood clots. Because your heart can't pump effectively, blood clots might form in your heart. If clots enter your bloodstream, they can block the blood flow to other organs, including your heart and brain.
• Valve problems. Because cardiomyopathy causes the heart to enlarge, the heart valves might not close properly. This can lead to a backward flow of blood.
• Cardiac arrest and sudden death. Cardiomyopathy can lead to abnormal heart rhythms. These abnormal heart rhythms can result in fainting or, in some cases, sudden death if your heart stops beating effectively.

Prevention

In many cases, you can't prevent cardiomyopathy. Let your doctor know if you have a family history of the condition.

You can help reduce your chance of cardiomyopathy and other types of heart disease by living a heart-healthy lifestyle and making lifestyle choices such as:

• Avoiding the use of alcohol or cocaine
• Controlling high blood pressure, high cholesterol and diabetes
• Eating a healthy diet
• Getting regular exercise
• Getting enough sleep
• Reducing your stress

Your doctor will conduct a physical examination, take a personal and family medical history, and ask when your symptoms occur — for example, whether exercise brings on your symptoms. If your doctor thinks you have cardiomyopathy, you might need to undergo several tests to confirm the diagnosis, including:

• Chest X-ray. An image of your heart will show whether it's enlarged.
• Echocardiogram. This uses sound waves to produce images of the heart, which show its size and its motions as it beats. This test checks your heart valves and helps your doctor determine the cause of your symptoms.
• Electrocardiogram (ECG). In this noninvasive test, electrode patches are attached to your skin to measure electrical impulses from your heart. An ECG can show disturbances in the electrical activity of your heart, which can detect abnormal heart rhythms and areas of injury.
• Treadmill stress test. Your heart rhythm, blood pressure and breathing are monitored while you walk on a treadmill. Your doctor might recommend this test to evaluate symptoms, determine your exercise capacity and determine if exercise provokes abnormal heart rhythms.

• Cardiac catheterization. A thin tube (catheter) is inserted into your groin and threaded through your blood vessels to your heart. Doctors might extract a small sample (biopsy) of your heart for analysis in the laboratory. Pressure within the chambers of your heart can be measured to see how forcefully blood pumps through your heart.

  Doctors might inject a dye into your blood vessels so that they show on X-rays (coronary angiogram). This test can be used to ensure there are no blockages in your blood vessels.

• Cardiac MRI. This test uses magnetic fields and radio waves to create images of your heart. Cardiac MRI might be used in addition to echocardiography, particularly if the images from your echocardiogram aren't helpful in making a diagnosis.
• Cardiac CT scan. You lie on a table inside a doughnut-shaped machine. An X-ray tube inside the machine rotates around your body and collects images of your heart and chest to assess the heart size and function and heart valves.

• Blood tests. Several blood tests might be done, including those to check your kidney, thyroid and liver function, and to measure your iron levels.

  One blood test can measure B-type natriuretic peptide (BNP), a protein produced in your heart. Your blood level of BNP might rise when your heart is in heart failure, a common complication of cardiomyopathy.

• Genetic testing or screening. Cardiomyopathy can be hereditary. Discuss genetic testing with your doctor. He or she might recommend family screening or genetic testing for your first-degree relatives — parents, siblings and children.

The goals of cardiomyopathy treatment are to manage your signs and symptoms, prevent your condition from worsening, and reduce your risk of complications. Treatment varies by which type of cardiomyopathy you have.

Medications

Your doctor might prescribe medications to improve your heart's pumping ability, improve blood flow, lower blood pressure, slow your heart rate, remove excess fluid from your body or keep blood clots from forming.

Be sure to discuss possible side effects with your doctor before taking any of these drugs.

Surgically implanted devices

Several types of devices can be placed in the heart to improve its function and relieve symptoms, including:

• Implantable cardioverter-defibrillator (ICD). This device monitors your heart rhythm and delivers electric shocks when needed to control abnormal heart rhythms. An ICD doesn't treat cardiomyopathy, but watches for and controls abnormal rhythms, a serious complication of the condition.
• Ventricular assist device (VAD). This helps blood circulate through your heart. VAD usually is considered after less-invasive approaches are unsuccessful. It can be used as a long-term treatment or as a short-term treatment while waiting for a heart transplant.
• Pacemaker. This small device placed under the skin in the chest or abdomen uses electrical impulses to control arrhythmias.

Nonsurgical procedures

Other procedures used to treat cardiomyopathy or arrhythmia include:

• Septal ablation. A small portion of the thickened heart muscle is destroyed by injecting alcohol through a long, thin tube (catheter) into the artery supplying blood to that area. This allows blood to flow through the area.
• Radiofrequency ablation. To treat abnormal heart rhythms, doctors guide long, flexible tubes (catheters) through your blood vessels to your heart. Electrodes at the catheter tips transmit energy to damage a small spot of abnormal heart tissue that is causing the abnormal heart rhythm.

Surgery

Types of surgery used to treat cardiomyopathy include:

• Septal myectomy. In this open-heart surgery, your surgeon removes part of the thickened heart muscle wall (septum) that separates the two bottom heart chambers (ventricles). Removing part of the heart muscle improves blood flow through the heart and reduces mitral valve regurgitation.

Lifestyle and home remedies

These lifestyle changes can help you manage cardiomyopathy:

• Quit smoking.
• Lose weight if you're overweight.
• Eat a healthy diet, including a variety of fruits and vegetables and whole grains.
• Reduce the amount of salt in your diet, and aim for less than 1,500 milligrams of sodium daily.
• Get modest exercise after discussing with your doctor the most appropriate program of physical activity.
• Eliminate or minimize the amount of alcohol you drink. Specific recommendations will depend on the type of cardiomyopathy you have.
• Try to manage your stress.
• Get enough sleep.
• Take all your medications as directed by your doctor.
• Go to your doctor for regular follow-up appointments.