Cardiomyopathy

Types of cardiomyopathy

The main types of cardiomyopathy include dilated cardiomyopathy, hypertrophic cardiomyopathy and restrictive cardiomyopathy.

Dilated cardiomyopathy

With dilated cardiomyopathy, the pumping ability of the heart's left ventricle becomes enlarged or dilated so it can't effectively pump blood out of the heart.

Although it can affect people of all ages, it most commonly occurs in middle-aged people and is more likely to affect men. The most common cause is coronary artery disease or heart attack. However, it can also be caused by genetic defects.

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy involves abnormal thickening of your heart muscle, which makes it harder for the heart to work. It mostly affects the muscle of the heart's main pumping chamber (left ventricle).

Hypertrophic cardiomyopathy can develop at any age, but the condition tends to be more severe if it occurs during childhood. Most people with this type of cardiomyopathy have a family history of the disease. 

Restrictive cardiomyopathy

In this type, the heart muscle becomes stiff and less flexible, so it can't expand and fill with blood between heartbeats. This is the least common type of cardiomyopathy and can occur at any age, although is more common the the older age group.

Restrictive cardiomyopathy can occur for no known reason (idiopathic), or it can be caused by a disease elsewhere in the body that affects the heart.

Symptoms

Often early stages of cardiomyopathy have no signs or symptoms how ever as the condition progresses symptoms include:

• Breathlessness with activity or even at rest
• Swelling of the legs, ankles and feet
• Bloating of the abdomen due to fluid buildup
• Cough while lying down
• Difficulty lying flat to sleep
• Fatigue
• Heartbeats that feel rapid, pounding or fluttering
• Chest discomfort or pressure
• Dizziness, lightheadedness and fainting

What causes cardiomyopathy?

Unfortunately, often the cause is unknown. In some people it is secondary to another condition (acquired) or inherited from a parent. Some conditions and behaviours which can lead to cardiomyopathy include:

• Long-term high blood pressure
• Heart tissue damage from a heart attack
• Long-term raised heart rate
• Heart valve problems
• COVID-19 infection
• Certain infections, especially those that cause inflammation of the heart
• Metabolic disorders, such as obesity, thyroid disease or diabetes
• Lack of essential vitamins or minerals in your diet, such as thiamin (vitamin B-1)
• Pregnancy complications
• Iron buildup in your heart muscle (haemochromatosis)
• The growth of tiny lumps of inflammatory cells (granulomas) in any part of your body, including your heart and lungs (sarcoidosis)
• The buildup of abnormal proteins in the organs (amyloidosis)
• Connective tissue disorders
• Excessive alcohol intake over many years
• Use of some recreational drugs e.g. cocaine
• Use of some chemotherapy drugs and radiation to treat cancer

Treatments

The goal of treatment is to manage the symptoms, prevent the condition from worsening and reduce the risk of complications associated with cardiomyopathies. Treatments can include:

• Medications - which can help improve the heart's ability to pump blood, improve blood flow, reduce blood pressure and heart rate and prevent blood clots
• Surgery - it is possible to insert a device into the heart to help improve the heart function such as an implantable cardioverter-defibrillator (ICD), ventricular assist device (VAD) or a pacemaker. Extreme cases may require open heart surgery such as a septal myectomy or a heart transplant to treat cardiomyopathy.