Cardiomyopathies

The term cardiomyopathy refers to diseases of the heart muscle. These diseases have a variety of causes, symptoms, and treatments. Cardiomyopathy occurs when the heart muscle becomes either weak and enlarged or abnormally rigid and thick. In rare situations, fat replaces the heart muscle resulting in life-threatening rhythm abnormalities.

The four main types of cardiomyopathy are:

1. Dilated cardiomyopathy
2. Restrictive Cardiomyopathy
3. Hypertrophic cardiomyopathy
4. Arrhythmogenic right ventricular dysplasia (ARVD)

A Cardiomyopathy can have a specific cause, though many times the cause is unknown and referred to as idiopathic. The common causes include conditions that can damage the heart such as a heart attack, poorly-controlled high blood pressure, valvular heart disease, and viral infections. Other times, cardiomyopathies are caused by a gene mutation and run in families. A Cardiomyopathy can affect people of all ages, but certain age groups are more susceptible to certain types. After a diagnosis has been made, there are many treatment options to consider and therefore, a cardiologist should be involved early in your medical care. With the appropriate treatment, symptoms and complications can be reduced and life expectancy prolonged.

Types of Cardiomyopathies

Dilated Cardiomyopathy

A dilated cardiomyopathy is the most common form of cardiomyopathy. There are many causes of dilated cardiomyopathy including: coronary artery disease, valvular heart disease, congenital heart disease, poorly-controlled high blood pressure, familial causes, viral infections, parasitic infections (Chagas disease), excessive alcohol consumption, illicit drugs use (including cocaine and amphetamines), chemotherapy drugs (such Adriamycin), complications during the last month of pregnancy or within 5 months of birth (peripartum cardiomyopathy) and idiopathic. As the heart dilates and becomes weak, the heart has a more difficult time pumping blood forward. Symptoms arise from inability to get sufficient blood forward but also from blood backing up. When there is insufficient forward flow, patients may feel lightheaded, tired, weak, and short of breath. On the other hand, when blood backs up, patients may develop shortness of breath, difficulty sleeping, abdominal pain, and swelling of the legs and feet.

Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy occurs when the heart muscle thickens abnormally. This type of cardiomyopathy can affect people of any age and is a significant cause of sudden death in athletes and children and young adults.

Hypertrophic cardiomyopathy can be obstructive or non-obstructive:

• In hypertrophic obstructive cardiomyopathy (HOCM), the muscular wall that divides the left and right sides of the heart thickens and bulges into the left ventricle. As blood is squeezed out of the heart, this bulge can partially block the flow of blood, making the heart work much harder unnecessarily. Obstructive hypertrophic cardiomyopathy also can affect the heart's mitral valve, causing blood to leak backward through the valve.

• In non-obstructive hypertrophic cardiomyopathy, the thickened heart muscle does not block the flow of blood out of the ventricle. The entire ventricle may become equally thick (symmetric ventricular hypertrophy) or may only affect the tip of the heart (apical hypertrophy).

In both types of hypertrophic cardiomyopathy, the thickened muscle makes the heart abnormally stiff as well as reduces the amount of blood that can fill the left ventricle. The result is increased pressure in the ventricles and the blood vessels of the lungs. The abnormalities of the heart muscle may also increase the risk of developing arrhythmias.

While some patients with hypertrophic cardiomyopathy have no symptoms and may lead a normal life, others can have severe symptoms or life threatening arrhythmias and suffer sudden death. Because many of these patients have an inherited gene mutation, a patient’s family history is very important as is the need sometimes to screen other family members by echocardiography.

Restrictive Cardiomyopathy

Restrictive cardiomyopathy tends to mostly affect older adults. As the normal heart muscle is infiltrated or replaced with abnormal tissue, the heart becomes stiff and cannot relax normally. As the disease process worsens, heart failure and arrhythmias may occur. Some of the diseases that can cause restrictive cardiomyopathy include hemochromatosis, sarcoidosis, amyloidosis, and connective tissue disorders. Other times, scarring after surgery, radiation treatments or infections may be a cause. Lastly, restrictive cardiomyopathy can occur for no known reason.

Arrhythmogenic Right Ventricular Dysplasia

Arrhythmogenic right ventricular dysplasia (ARVD) is an uncommon type of cardiomyopathy. ARVD develops when the muscle tissue in the right ventricle is replaced by fat and scar tissue. The main consequence is the development of dangerous arrhythmias. ARVD usually develops in teens or young adults and is often the cause of sudden cardiac death in young athletes. ARVD is thought to be an inherited disease.

What are the signs and symptoms of a Cardiomyopathy?

Some people with cardiomyopathy never have symptoms especially in the early stages of the disease. As cardiomyopathy progresses patients may develop fatigue, weakness, lightheadedness, chest pain, shortness of breath, difficulty sleeping flat, swelling in the legs/feet or abdomen, and fainting.

How can we diagnose if you have a Cardiomyopathy?

1. A patient’s symptoms, medical history, family history of cardiomyopathy, heart failure, or sudden cardiac arrest are very important to making the diagnosis.
2. The physical exam may have clues of heart failure as well as there being evidence of abnormal murmurs (heart sounds).
3. Appropriate diagnostic testing which may include an electrocardiogram (ECG), chest x-ray, echocardiogram, stress testing, cardiac catheterization, and cardiac CT/MRI can help in making the correct diagnosis (Please see our Services section for further descriptions of some of these modalities).

What are the goals of treatment?

1. Control symptoms so that the person can live as best as possible.
2. Manage any conditions that cause or contribute to the cardiomyopathy.
3. Stop the disease from getting worse if possible.
4. Reduce complications and the chance of sudden cardiac death.
5. Educate and discuss if family counseling is needed in addition to screening of immediate family members if a genetic component is suspected.

Specific types of treatment

Treatments for cardiomyopathy can include lifestyle changes, medicines, non-surgical procedures, and surgery.

Lifestyle changes
After being diagnosed with a cardiomyopathy, it is very important to discuss with your cardiologist how this will change your lifestyle.

Medicines
A number of medications may be used to treat a cardiomyopathy, both to improve symptoms but also to prolong one’s life and decrease risk of complications. Some of these medications include: Beta-blockers, diuretics, Angiotensin-converting enzyme (ACE) inhibitors, digoxin, anticoagulants, and anti-arrhythmics.

AICD/BIV
An automated implantable cardioverter defibrillator (AICD) may be implanted in people who are at high risk of life-threatening arrhythmia or sudden death or who have already suffered from “sudden cardiac death” or cardiac arrest. The Biventricular pacemaker (BiV) may be used in certain patients to improve heart failure symptoms.

Alcohol Septal Ablation & Surgical Septal Myectomy
In this procedure for HOCM, alcohol is injected into to the thickened area of heart muscle by catheter to shrink the heart muscle to normal size or the thickened tissue is surgically removed.

Surgically implanted devices
In very ill cardiac patients, a left ventricular assist device (LVAD) can help pump blood to rest of the body. The LVAD can be used as a long-term therapy or as a short-term treatment for people who are waiting for a heart transplant.

Heart transplant
As a last resort in specially selected patients, a person's diseased heart can be replaced with a healthy heart from a person who has recently died. At only certain hospitals is this an option, and INOVA Fairfax Hospital is a well known, closely located heart transplant center.