What is restrictive cardiomyopathy?

Restrictive cardiomyopathy, or RCM, is a condition where the chambers of the heart become stiff over time. Though the heart is able to squeeze well, it is 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 tends to mostly affect older adults.

What causes restrictive cardiomyopathy?

Many different causes can lead to RCM. These are mostly other medical conditions. They include:

  • Amyloidosis, an abnormal buildup of protein in organs and tissues (the most common cause of RCM)
  • Hemochromatosis, a condition that occurs from an iron overload in the body
  • Sarcoidosis, a disease that causes scarring of the heart
  • Eosinophilic endomyocardial disease, a disease caused by certain tumors, lymphomas, or parasitic disease
  • Scleroderma, a disease that causes hardening of tissues in the body
  • Radiation of the heart, a condition that may occur during cancer 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 (may progress to shortness of breath when at rest)
  • Shortness of breath when lying flat
  • Fatigue
  • Swelling in the legs and other areas
  • Fainting
  • 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), to analyze the heart rhythm
  • Continuous portable ECG monitoring, to further analyze heart rhythms while you are away from the healthcare provider’s office
  • Chest X-ray, to see the heart anatomy
  • Blood tests, to help evaluate the type of RCM
  • Echocardiogram, to examine blood flow in the heart and heart motion
  • Exercise testing, to see how your heart performs during exercise
  • Cardiac MRI, to further look at heart anatomy and coronary arteries
  • Heart biopsy, to look at the heart in more detail
  • Cardiac catheterization with coronary angiography to look at the arteries (in special situations)

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. 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:

  • Diuretics (water pills) to reduce swelling
  • Medicine such as 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
  • Anticoagulants (blood thinners) to prevent blood clots
  • Medicine to help prevent abnormal heart rhythms
  • Lifestyle changes, such as cutting back on salt to reduce swelling

Your healthcare provider might also advise an implantable cardioverter-defibrillator (ICD). You may need this if you are at risk for heart rhythms that can cause sudden death. If your condition becomes very severe, you may need a heart transplant in the future.

What are the 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 of complications during pregnancy
  • Sudden cardiac death from a dangerous heart rhythm (rarely)

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 health care provider about what kinds of exercise are OK for you.
  • You might need other lifestyle changes, like losing weight, quitting smoking, or improving your diet. You may need to cut back on your intake of salt.
  • You may need to cut back your alcohol and caffeine intake. (These increase the risk of abnormal heart rhythms.)
  • Monitor your symptoms carefully. If you are gaining weight quickly, this might be a sign of increased swelling due to poor heart function.

When should I call my healthcare provider?

See a healthcare provider right away if you have severe symptoms like chest pain or severe shortness of breath. If your symptoms are gradually increasing, plan to see your healthcare provider soon.

Key points

RCM affects the heart muscle. The heart becomes stiffer and is unable to relax well. 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 healthcare provider regularly for monitoring. This is important even if you don’t have any symptoms.
  • Early stages of RCM may not require treatment. But, some people may need medications or procedures if symptoms are bothersome or heart function worsens. Tell your healthcare 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.

Action alert

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

  • 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 names of new medicines, treatments, or tests, and any new instructions your provider gives you.
  • 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.

Saint Luke's Cardiovascular Consultants

A leader in cardiac care, Saint Luke’s Cardiovascular Consultants treats patients throughout the Kansas City area and surrounding communities. Our medical team consists of both board-certified clinical cardiologists as well as physicians certified in specialty areas of cardiology including interventional cardiology, echocardiography, nuclear cardiology, preventive cardiology, and electrophysiology.