What is restrictive cardiomyopathy?

Restrictive cardiomyopathy (RCM) is a condition where the chambers of the heart become stiff over time. Though the heart is able to squeeze well, it's not able to relax between beats normally. This makes it harder for the heart to fill with blood. The blood backs up in the circulatory system. This can cause fluid to build up in the body, including the lungs, which leads to many of the symptoms of the condition. It also increases the pressure inside the ventricles, and the atria can become enlarged.

There is also an increased risk for irregular heart rhythms. Eventually, this disease makes the heart unable to pump as much blood out to the body as it normally would. Most people with RCM eventually develop heart failure. RCM is a fairly uncommon form of cardiomyopathy. It can affect people at any age.

What causes restrictive cardiomyopathy?

RCM can be acquired or inherited. Many different health conditions can lead to RCM. They include:

• Amyloidosis. This is an abnormal buildup of protein in organs and tissues. This is the most common cause of RCM.

• Hemochromatosis. This condition occurs from an iron overload in the heart and body.

• Sarcoidosis. This disease causes scarring of the heart.

• Eosinophilic endomyocardial disease. This is a disease caused by certain tumors, lymphomas, or parasitic diseases.

• Scleroderma. This disease causes hardening of tissues in the body.

• Radiation-induced heart disease. This condition may occur from cancer radiation treatment.

• Certain rare genetic conditions. You may have increased risk if you have a family member with RCM.

In some cases, the cause of RCM is not known.

What are the symptoms of restrictive cardiomyopathy?

In its early stages, RCM may not have any symptoms. These may worsen slowly or more quickly. Some symptoms include:

• Shortness of breath with exertion. This may progress to shortness of breath when at rest.

• Shortness of breath when lying flat.

• Fatigue

• Swelling in the legs and other areas

• Fainting during or after exertion

• Weakness or lightheadedness

• Cough

• Abnormal heart rhythms

How is restrictive cardiomyopathy diagnosed?

Your healthcare provider will take a careful medical history and do a thorough physical exam. Your healthcare provider may use one or more of these tests to help make the diagnosis:

• Electrocardiogram (ECG). This checks the heart rhythm.

• Continuous portable ECG monitoring. This looks at heart rhythms while you're away from the healthcare provider’s office.

• Chest X-ray. This looks at the heart size and anatomy.

• Blood tests. These help assess the type of RCM.

• Echocardiogram. This examines blood flow in the heart and how well the heart pumps blood to the body.

• Exercise testing. This is done to see how your heart does during exercise.

• Cardiac MRI. This further looks at heart anatomy and coronary arteries.

• Heart biopsy. This looks at a small tissue sample from the heart in more detail.

• Cardiac catheterization with coronary angiography. This looks at the arteries in special cases and also measures pressures within the heart.

How is restrictive cardiomyopathy treated?

The causes of RCM can be hard to treat. The treatment is often centered around the underlying cause. For example, chelation therapy or phlebotomy may help RCM caused by too much iron in the body. Chelation therapy uses drugs that bind to iron and removes it from the body. Phlebotomy removes some of the iron-loaded blood from the body through an IV line. A bone marrow transplant may be used to treat RCM caused by amyloidosis. It replaces cells that make the amyloid proteins.

Your healthcare provider may prescribe treatments to help reduce your symptoms, such as:

• Water pills (diuretics) to reduce swelling

• Medicine, such as heart-rate-lowering calcium channel blockers or beta-blockers, to reduce the heart’s workload and increase its efficiency

• Medicine, such as ACE inhibitors, to help the heart pump better

• Blood thinners (anticoagulants) to prevent blood clots if you have certain abnormal heart rhythms

• Medicine to help prevent abnormal heart rhythms

• Lifestyle changes, such as cutting back on salt to reduce swelling

• Heart transplant or left ventricular assist devices (LVAD). This may be considered in advanced cases.

What are possible complications of restrictive cardiomyopathy?

Some complications can occur from dilated cardiomyopathy, such as:

• Heart failure

• Stroke from a blood clot in the heart that travels to the brain

• Abnormal heart rhythms

• Increased risk for complications during pregnancy

• Sudden cardiac death from a dangerous heart rhythm (rare)

Your healthcare provider’s treatment plan will work to prevent these complications.

How do I manage restrictive cardiomyopathy?

Your healthcare provider may give you additional instructions about how to manage your RCM.

• Your healthcare provider may want to treat you for other heart conditions.

• Talk with your provider about what kinds of exercise are OK for you.

• • You may need to cut back on your intake of salt.

  • You may need to cut back on your alcohol and caffeine intake. (These can increase the risk of abnormal heart rhythms.)

• Monitor your symptoms carefully. If you're gaining weight quickly, this might be a sign of increased swelling due to poor heart function.

When should I call my healthcare provider?

Call 911 if you have severe symptoms like chest pain or severe shortness of breath. If your symptoms are gradually increasing, see your healthcare provider right away.

Key points about restrictive cardiomyopathy

• RCM affects the heart muscle, making it stiffer. It can make the heart unable to pump enough blood out to the body. It can also sometimes lead to dangerous heart rhythms.

• Follow your healthcare provider’s instructions carefully. Take all your medicines as prescribed.

• See your provider regularly for monitoring. This is important even if you don’t have any symptoms.

• Some people may need medicines or procedures if symptoms are bothersome or heart function gets worse. Tell your provider if you have severe symptoms or if your symptoms get worse.

• Other family members may need to be tested for RCM, especially if the cause of your disease is unknown.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are and when they should be reported.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions.