What is cardiomyopathy?
Cardiomyopathy (cardio-my-op-a-thee) is a disease of the heart muscle that reduces the heart’s ability to pump oxygen-rich blood to the body. This can lead to heart failure.
Types
There are four types of cardiomyopathy. Treatment depends on the type you have and how serious it is.
1. Dilated (congestive) cardiomyopathy
This is the most common form of cardiomyopathy. It often occurs as a result of restricted blood flow to the heart muscles (cardiac ischemia). It weakens and thins the walls of the heart chambers.
The disease often starts in the left ventricle, which is the main pumping chamber of the heart. When the walls dilate and become thin, the inside of the chamber gets larger. The left ventricle beats with less force, so it pumps blood less effectively to the rest of your body. The problem can then spread to the heart’s right ventricle and the atria.
Dilated cardiomyopathy mostly affects middle-aged men. Causes include viral infection of the heart muscle, excessive alcohol consumption, cocaine and the abuse of antidepressant drugs. In rare cases it may be caused by pregnancy or connective tissue disorders such as rheumatoid arthritis. In most cases of dilated cardiomyopathy, the cause is unknown.
2. Hypertrophic cardiomyopathy (HCM)
HCM occurs because the heart's walls become thickened, which makes it harder for the heart to pump blood.
In obstructive hypertrophic cardiomyopathy the ventricle size remains normal, but thickening of the walls may block blood flow out of the ventricles. Sometimes the wall between the bottom chambers of the heart (the septum) also becomes enlarged and blocks blood flow out of the left ventricle.
HCM can lead to the development of abnormal heart rhythms (arrhythmias). In rare cases, some people with HCM may experience a cardiac arrest (also known as cardiopulmonary arrest) during vigorous physical activity.
HCM is usually an inherited disease caused by gene mutations, but sometimes the cause isn’t clear. Although it can develop at any age, HCM is usually more severe if diagnosed during childhood.
3. Restrictive cardiomyopathy
In this type of cardiomyopathy, the heart muscle becomes less elastic which prevents the heart from stretching properly. This limits the amount of blood that can fill the heart's chambers.
Restricted cardiomyopathy is a rare type of cardiomyopathy that affects older people most often. It can be caused by other diseases such as hemochromatosis, amyloidosis, sarcoidosis, connective tissue disorders or eosinophilic heart disease.
4. Arrhythmogenic right ventricular cardiomyopathy (ARVC) or Arrhythmogenic right ventricular dysplasia (ARVD)
ARVC/D is a rare type of cardiomyopathy. The right ventricular muscle is replaced by fat or scar tissue, which interferes with the normal heartbeat rhythm.
ARVC/D is a leading cause of sudden cardiac death among young people – particularly young athletes – but it can be present in people at any age and fitness level. ARVC/D is often caused by genetic mutations.
The most common symptoms of ARVC/D include palpitations, fainting, chest pain and a rapid, irregular heartbeat. Consult a doctor if you experience any of these symptoms, especially if someone in your immediate family has been diagnosed with ARVC/D.
Who is at risk?
The risk factors for cardiomyopathy are the conditions or habits that make it more likely that you will develop the disease. Some risk factors can be changed and others cannot.
Medical conditions that increase your chances of developing cardiomyopathy:
- coronary artery disease
- high blood pressure
- cancer treatments (chemotherapy and/or radiation)
- diabetes
- thyroid disease
- hemochromatosis (a disease in which the body stores excess iron)
- diseases and/or infections of the heart
Risk factors you cannot change:
- family history of cardiomyopathy, heart failure, cardiac arrest
Risk factors you can change:
Causes
The cause of cardiomyopathy is often unknown. Some contributing factors include:
- genetic conditions
- congenital heart disease
- damage to the heart because of a previous heart attack or infection
- chronic fast heart rate
- valvular heart disease
- long-standing high blood pressure
- unhealthy weight
- diabetes
- too much alcohol
- recreational drug use
- low intake of essential vitamins and minerals (such as thiamin)
- connective tissue disorders (such as rheumatoid arthritis)
- thyroid disease
- pregnancy complications
- some chemotherapy drugs and radiation treatment for cancer
Symptoms
In the early stages of cardiomyopathy, some people may not have any signs or symptoms. As the disease gets worse, you may experience:
- irregular or rapid heartbeats (heart palpitations)
- fainting
- light-headedness
- breathlessness during activity or while resting (from fluid building up in the lungs)
- irregular heartbeats
- swelling of the hands and feet
- bloating of the abdomen (from increased fluid)
- a cough when lying down
HCM and ARVC/D may cause:
- dizziness
- fainting
- heart murmurs
- chest pain
If you have one or more of these symptoms, see your doctor. Get immediate medical help if you experience chest pain, fainting or difficulty breathing.
Diagnosis
Your doctor will diagnose cardiomyopathy by doing a physical exam and assessing your:
- signs and symptoms
- medical history
- family history
- test results
Some of the tests used to diagnose cardiomyopathy are:
- angiography
- blood tests
- cardiac catheterization
- chest x-ray
- echocardiogram
- EKG/ECG (electrocardiogram)
- stress test (exercise electrocardiogram)
- MRI (cardiac magnetic resonance imaging)
- CT scan (cardiac computerized tomography)
- genetic testing
Treatment
The goal of cardiomyopathy treatment is to reduce your symptoms. Your treatment plan will depend on what type of cardiomyopathy you have, how serious it is and what symptoms you are experiencing. Your doctor will suggest medications, surgery, lifestyle changes or a combination of the three to manage your condition.
Medications
If you have an underlying medical condition causing cardiomyopathy, then it is important to treat the underlying disease.
If your healthcare team knows the cause of your cardiomyopathy, then it will be treated immediately with the appropriate medications. Medications include:
Surgery and other procedures
Surgery may be an option for you. A surgically implanted cardioverter defibrillator (ICD) may be necessary to manage heart rhythm problems. It can deliver an electric shock to control an abnormal rhythm. An implanted pacemaker may be recommended to coordinate the contractions between the left and right sides of your heart. In a small number of cases, a heart transplant may be necessary.
Lifestyle
If cardiomyopathy is properly treated and controlled, many people with the condition can manage with just a few changes to their normal lifestyle. Some people might need to make major adjustments to their lifestyle. If you are told to limit or avoid some sports or activities, there are other light-to-moderate physical activities that can help you to remain healthy and avoid other heart problems. It is important to talk to your cardiologist about how you can live a healthy, active lifestyle without risking further complications.
A dietitian can advise you about healthy eating. They can provide tips to manage your fluid and salt intake to help your heart.
Giving up alcohol completely is a good idea. Losing weight can also help relieve symptoms by reducing the burden on your heart.
Talk to your doctor about the lifestyle changes that will benefit you the most.
Complications
Cardiomyopathy may lead to other heart conditions.
- Heart failure – because the heart is not able to pump blood out of the heart effectively.
- Blood clots – that can form in the heart when blood is not pumped out effectively.
- Valve problems – because a bigger heart size can prevent the valves from closing properly.
- Cardiac arrest and sudden death – can be triggered by abnormal heart rhythms
