Restrictive Cardiomyopathy: Symptoms, Causes, and Treatment

According to an article by Raffaello Ditaranto et al. in 2022, restrictive cardiomyopathy is the least common form of cardiomyopathy. It accounts for only 2.5% to 3% of all cases. Although rare, it is a complex muscle disorder that significantly impacts a person’s quality of life. 

Early diagnosis and a treatment plan can make all the difference in helping individuals regain their strength and mobility. But what is restrictive cardiomyopathy, and what are its causes? Continue reading to learn more about restrictive cardiomyopathy echo tests, symptoms, causes, and treatment. 

Restrictive cardiomyopathy (RCM) is also known as idiopathic restrictive cardiomyopathy or infiltrative cardiomyopathy. It is a heart condition characterised by stiffening of the muscles in the lower chambers (ventricles). 

The stiffness makes it challenging for the ventricles to fill with blood during the diastole or relaxation phase, reducing blood flow in the heart.

The severity and combination of symptoms for restrictive cardiomyopathy can vary from person to person. In the early stages, individuals may experience no symptoms. As the condition worsens, common signs and symptoms may include:

1. Shortness of Breath (Dyspnea): This is often the most noticeable symptom, especially during physical activity. It occurs due to the heart’s reduced ability to fill with blood when the muscles relax. This can lead to elevated pressure in the atria, causing fluid to build up in the lungs. As a result, individuals may experience congestion.
2. Fatigue: Individuals with restrictive cardiomyopathy may feel unusually tired or lethargic, even with minimal exertion. The heart cannot pump blood effectively to meet the body’s demands.
3. Swelling (oedema): Fluid retention, especially in the legs, ankles, feet, and abdomen, is a common symptom. The compromised heart function can lead to fluid buildup in the extremities.
4. Dizziness or Fainting: Inadequate blood flow to the brain can result in insufficient oxygen delivery. As a result, individuals may experience symptoms like fainting or dizziness. 
5. Irregular Heartbeats: The stiffness of the heart muscle can disrupt the normal electrical signals responsible for maintaining a regular rhythm.
6. Chest Pain: Some individuals may experience chest discomfort or angina. This is particularly true during physical activity or when the heart is under increased stress.

Restrictive cardiomyopathy pathophysiology involves changes in the heart muscle that restrict its ability to contract and relax effectively. Sometimes, restrictive cardiomyopathy is idiopathic, i.e., its exact cause is unknown. 

In other cases, several different causes, generally other health conditions, can result in RCM. These causes include:

Infiltrative Diseases: 

These are conditions that cause scarring of the heart muscle. They include:

1. Amyloidosis: This is the most common cause of restrictive cardiomyopathy. It is a condition when abnormal proteins accumulate in tissues and organs throughout the body, including the heart.
2. Hemochromatosis: A condition in which too much iron accumulates in the body. Excess iron can damage the heart muscle and lead to RCM.
3. Sarcoidosis: It is a disease that causes inflammation and the formation of granulomas (small lumps of tissue) in various organs, including the heart.
4. Eosinophilic Endomyocardial Disease: It is a rare cause of restrictive cardiomyopathy due to certain tumours, lymphomas, or parasitic diseases. 

Storage Diseases:

In these disorders, abnormal substances accumulate within the heart cells. Examples include: 

1. Gaucher Disease: The accumulation of harmful quantities of lipids (fatty compounds) throughout the body. 
2. Fabry Disease: An inherited disorder occurs due to the buildup of globotriaosylceramide (a type of fat) in the cells of the body. 
3. Glycogen Storage Disease (GSD): A rare inherited condition in which the body cannot properly use or store glycogen (a form of sugar). 

Connective Tissue Disorders:

These are a group of conditions affecting the structures supporting the body, including joints, skin, blood vessels, and organs. Connective tissue disorders that can cause RCM include:

1. Scleroderma: A disease that causes hardening and thickening of the skin and other tissues.
2. Systemic Lupus Erythematosus (SLE): An autoimmune disorder, i.e., the immune system mistakenly attacks healthy tissue. The disease can affect various body parts, including the heart.  

Radiation-Induced Heart Disease:

Radiation therapy for cancer can damage the heart tissues and blood vessels. This leads to scarring that results in increased stiffness of the heart muscle. As a result, the heart does not function properly, leading to RCM.

Rare Genetic Factors:

Restrictive cardiomyopathy can occur due to mutations in specific genes like TNNI3. They provide instructions for producing proteins like cardiac troponin I, found solely in the heart. Mutations in these genes produce defective proteins, impairing the heart’s ability to relax. This leads to inadequate ventricular filling and the development of restrictive cardiomyopathy. 

Restrictive cardiomyopathy can happen to anyone, but some people may have a higher risk of the disease. However, having one or more of these factors does not mean that individuals will develop RCM. These risk factors include: 

1. Having a family history of cardiomyopathy, heart failure, and sudden cardiac arrest 
2. Heart conditions like coronary artery disease or a past heart attack 
3. Chronic high blood pressure 
4. Obesity 
5. Illicit drugs like cocaine, amphetamines, and anabolic steroids
6. Alcohol misuse
7. Treatment with chemotherapy or radiation  

There is no way to completely prevent restrictive cardiomyopathy (RCM), as various underlying medical conditions can cause it. However, there are ways to reduce the heart workload and the risk of developing RCM. These steps include: 

1. Maintaining a Healthy Weight: Achieving a healthy weight reduces the strain on the heart, easing its workload and promoting optimal functioning.
2. Controlling Other Medical Conditions: Effective management of blood pressure, blood cholesterol, and diabetes can prevent the progression of RCM. It reduces further damage to the heart muscle and minimises the risk of complications. 
3. Reducing Stress: Chronic stress can worsen cardiovascular conditions. Individuals with RCM should prioritise stress reduction through techniques like meditation, mindfulness, and relaxation exercises.
4. Taking the Medications as Prescribed: Adhering to prescribed medications helps manage symptoms and improve cardiac function.
5. Getting Regular Checkups With the Doctor: Regular medical checkups are essential for individuals with RCM. Monitoring the condition through blood tests and imaging studies allows for early detection of changes. This enables timely adjustments to the treatment plan.

The diagnosis of restrictive cardiomyopathy begins with a thorough physical examination. The doctor listens to the patient’s heartbeat and checks their blood pressure. They may order one or more of the following tests to confirm the diagnosis: 

1. Blood Tests: They are performed to look for elevated levels of certain biomarkers which indicate heart failure. These biomarkers include cardiac troponin, myoglobin, and B-type natriuretic peptide (BNP). 
2. Chest X-ray: The doctor may order this test to examine the size and structures of the heart. It produces a single, 2D image of these structures. 
3. Electrocardiogram (ECG): The test records the electrical activity of the heart. It helps identify irregular rhythms or patterns indicative of cardiomyopathy.
4. Echocardiogram (Echo): A restrictive cardiomyopathy echo test assesses whether the heart ventricles function as they should. It is one of the first tools used to diagnose a cardiac issue. 
5. Exercise Stress Test: It involves monitoring the heart’s response to physical exertion. The patient typically exercises on a treadmill or stationary bike while their heart rate, blood pressure, and electrocardiogram (ECG) are closely monitored. The test assesses how the heart performs under physical stress. 
6. Cardiac CT Scan: It provides detailed cross-sectional heart images. The test helps visualise the heart structure, including thickening and scarring of the heart muscle. 
7. Heart MRI: This imaging technique provides detailed heart images. Unlike X-rays, MRI produces multiple 3D images, allowing for a comprehensive assessment of the heart structure, function, and blood flow.
8. Heart PET Scan: This test with a radioactive tracer can help evaluate blood flow, metabolism, and inflammation in the heart. 
9. Right Heart Catheterisation: This is both a diagnostic and therapeutic procedure. The doctor threads a catheter through the right side of the heart. The test checks the pumping and pressure within the heart chambers. Increased pressure in the right atrium and ventricle helps diagnose the condition.  
10. Myocardial Biopsy: It involves taking a small tissue sample from the heart for microscopic examination. 
11. Genetic Testing: The test looks for gene mutations or abnormalities associated with cardiomyopathies. 

How to Prepare for the Doctor Consultation? 

Preparing for a doctor consultation for restrictive cardiomyopathy can help patients make the most of the visit. The following tips help individuals prepare: 

1. Compile medical history, including previous heart conditions, surgeries, or a family history of heart issues
2. List current medications and supplements, including their frequency and dosages
3. Note the experienced symptoms and their frequency 
4. Prepare a list of queries and questions for the doctor 
5. Bring a friend or a family member to the appointment 

What to Expect from the Doctor? 

During a consultation for restrictive cardiomyopathy, the doctor may ask various questions to gather information about symptoms, medical history, and lifestyle. Here are some questions patients might expect:

1. What symptoms are you experiencing?
2. When did you first notice these symptoms?
3. Have these symptoms changed over time? 
4. Does anything seem to improve or worsen these symptoms?
5. Have you been diagnosed with any heart conditions in the past?
6. Do you have a family history of heart disease or restrictive cardiomyopathy?
7. Are you currently taking any medications?
8. Do you smoke or consume alcohol? If yes, how frequently?
9. Have you noticed any changes in your ability to exercise?
10. Have you ever had heart-related procedures? 

Questions to Ask the Doctor

When consulting with a doctor about restrictive cardiomyopathy, patients must ask questions to understand their condition and make decisions. Here are some questions they might consider asking:

1. What might have caused my restrictive cardiomyopathy? 
2. What tests will be conducted to diagnose my condition?
3. What are the available restrictive cardiomyopathy treatment options?
4. Are there any potential side effects of these treatments?
5. Will I need surgery?
6. Are there any specific lifestyle changes I should consider to improve my heart health?
7. What symptoms should I look out for that indicate worsening of the condition?
8. Should I seek a second opinion from a specialist?

Patients should not hesitate to ask any other questions they may have. 

There is no standardised treatment for restrictive cardiomyopathy. The treatment aims to manage symptoms, improve heart function, and address underlying causes when possible. Treatment approaches to reduce the severity of the condition include: 

Non-Surgical Treatment of Restrictive Cardiomyopathy 

Several non-surgical treatments are available to manage restrictive cardiomyopathy. They enhance the quality of life for individuals with this condition. These treatments include: 

Medications:

The medical specialist may prescribe the following medications: 

1. Diuretics (water pills) to reduce fluid buildup and swelling 
2. Beta-blockers, calcium channel blockers, or antiarrhythmics to treat heartbeat irregularities and reduce workload 
3. ACE inhibitors to help the heart pump blood better 
4. Anticoagulants (blood thinners) to prevent blood clots 

Lifestyle Changes:

Patients are advised to make certain lifestyle modifications to manage fluid retention and improve cardiovascular health. These changes include:

1. Following a heart-healthy diet 
2. Limiting salt intake
3. Quitting smoking
4. Engaging in regular exercise
   
   

Treating Underlying Conditions:

If an underlying disease causes RCM, the treatment involves alleviating symptoms of that primary condition. These may include the following: 

1. Corticosteroids to treat inflammation caused by conditions like sarcoidosis
2. Therapeutic phlebotomy (blood removal) for hemochromatosis 
3. Medications for certain types of amyloidosis

Implantable Devices:

In advanced cases of restrictive cardiomyopathy, doctors may recommend implantable devices to regulate heart rhythm and prevent cardiac arrest. These devices include: 

1. Implantable cardioverter-defibrillators (ICD)
2. Pacemakers
3. Surgical Treatment for restrictive cardiomyopathy

In severe cases where the heart function is significantly impaired, surgery may be the last option. Surgical treatment available for restrictive cardiomyopathy includes: 

Heart Transplant:

It is a life-saving option where the damaged heart is replaced with a healthy donor organ. The following is the cost of a heart transplant in India: 

Please Note: The selection of restrictive cardiomyopathy treatment is based on the patient’s condition and the treating doctor’s opinion. 

Complications of Restrictive Cardiomyopathy 

Restrictive cardiomyopathy can lead to several complications, affecting various aspects of cardiovascular health and overall well-being. Common complications associated with RCM include:

1. Heart Failure: As the ability of the heart to pump efficiently is compromised, heart failure may occur. 
2. Stroke: Reduced blood flow can lead to the formation of blood clots. These clots can travel to other body parts, resulting in stroke. 
3. Arrhythmias: The stiffness of the heart muscle can disrupt normal electrical signals. This increases the risk of arrhythmias (irregular heartbeat). 
4. Higher Risk of Complications for Pregnant Women: The added strain on the cardiovascular system can cause an increased risk of complications during pregnancy. These complications may include heart failure, arrhythmia, or foetal issues. 
5. Sudden Cardiac Death: In rare instances, individuals with restrictive cardiomyopathy may be at risk of sudden cardiac death due to dangerous heart rhythms.

When to See a Doctor?

Individuals should consult their doctor immediately if they experience worsening symptoms suggestive of heart or cardiovascular issues. These symptoms include: 

1. Severe shortness of breath 
2. Chest pain 
3. Fainting 

Diet for Restrictive Cardiomyopathy 

There is no specific diet for restrictive cardiomyopathy. However, adopting a heart-healthy diet can be beneficial in managing symptoms and supporting cardiovascular health. The following are some general dietary guidelines that individuals with restrictive cardiomyopathy may consider:

Low-Sodium Diet:

A high sodium intake can cause fluid retention and increase the risk of swelling. Moreover, it leads to high blood pressure. Therefore, individuals should avoid processed foods, canned foods, and other foods high in salt.

Heart-Healthy Fats:

Eat foods low in saturated and trans fat. Sources for healthy fats include:

1. Beans
2. Lean meats
3. Fish Poultry without skin
4. Fat-free or low-fat milk and other milk products

Whole Grains:

It is advised to limit refined grains and choose whole grains instead. They help decrease the risk of cardiovascular disease. Examples of whole grains include: 

1. Brown rice
2. Oats
3. Whole grain bread
4. Whole grain pasta

Fruits and Vegetables:

Eat various fruits and vegetables rich in vitamins, minerals, and antioxidants. These components contribute to overall heart health. Examples include: 

1. Apples 
2. Blueberries
3. Oranges
4. Broccoli
5. Spinach and other leafy greens
6. Pepper 
7. Tomato 

Limit Added Sugar:

Minimise the intake of foods and beverages high in added sugars. These include soda, energy drinks, candies, and desserts.

Restrictive cardiomyopathy poses complex challenges to cardiovascular health, marked by the stiffening of the heart muscle and potential complications. Effective management strategies like surgical intervention can significantly improve symptoms. Early diagnosis and regular monitoring are essential for optimising outcomes for restrictive cardiomyopathy.

If you have any more questions regarding restrictive cardiomyopathy, the team at HexaHealth can answer them. We will help you connect with top doctors and cardiologists for effective treatment. From diagnostic tests like restrictive cardiomyopathy echo and ECG to undergoing treatment, our team will guide you at every step. Get in touch with us TODAY! 

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