Cardiac Amyloidosis
What is Cardiac Amyloidosis?
Cardiac amyloidosis is a rare condition where abnormal proteins called amyloid build up in your heart tissue. These protein deposits make your heart walls thick and stiff. When your heart becomes stiff, it cannot relax and fill with blood properly between beats.
Think of your heart muscle like a sponge that needs to squeeze and then relax. In cardiac amyloidosis, the amyloid deposits make that sponge more like a hard brick. Your heart struggles to pump blood efficiently throughout your body. This can lead to heart failure if not diagnosed and treated early.
There are different types of cardiac amyloidosis based on which protein is building up. The two most common types are AL amyloidosis and ATTR amyloidosis. Each type has different causes and requires different treatment approaches. Early detection through specialized testing is essential for better outcomes.
Symptoms
- Shortness of breath, especially when lying down or during physical activity
- Severe fatigue and weakness that limits daily activities
- Swelling in the legs, ankles, and feet
- Irregular heartbeat or heart palpitations
- Chest discomfort or pressure
- Dizziness or feeling lightheaded when standing up
- Unintended weight loss
- Numbness or tingling in the hands and feet
- Difficulty swallowing
- Purple discoloration around the eyes or on the skin
Some people may have mild symptoms early on that they dismiss as normal aging or being out of shape. Cardiac amyloidosis often goes undiagnosed for months or years because symptoms develop gradually. This is why specialized testing is important if you have unexplained heart failure symptoms.
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Causes and risk factors
Cardiac amyloidosis happens when abnormal proteins misfold and stick together to form amyloid fibers. These fibers deposit in your heart tissue over time. In AL amyloidosis, the problem starts with plasma cells in your bone marrow that produce abnormal antibody proteins. In ATTR amyloidosis, the liver produces an abnormal version of a protein called transthyretin, or you inherit a genetic mutation that causes this problem.
Risk factors include being over 60 years old, having a family history of amyloidosis, being male, and having African ancestry for certain genetic types. People with multiple myeloma or other plasma cell disorders have higher risk for AL amyloidosis. Wild-type ATTR amyloidosis typically affects older adults without a genetic mutation. Hereditary ATTR runs in families and can affect people at younger ages.
How it's diagnosed
Diagnosing cardiac amyloidosis requires specialized testing beyond routine blood work. Your doctor will start with an echocardiogram, which uses sound waves to create images of your heart. An electrocardiogram checks your heart's electrical activity. Blood tests like B Type Natriuretic Peptide can show elevated levels that indicate your heart is under stress, though this test alone cannot diagnose cardiac amyloidosis.
More specialized tests include cardiac MRI scans and nuclear imaging studies that can identify amyloid deposits. Your doctor may order blood and urine tests to check for abnormal proteins. A tissue biopsy, where a small sample of heart or fat tissue is examined under a microscope, can confirm the diagnosis and identify which type of amyloidosis you have. Genetic testing may be recommended if hereditary ATTR is suspected. Talk to your doctor about which specialized tests are right for your situation.
Treatment options
- Medications that target the abnormal protein production, depending on the type of amyloidosis
- Chemotherapy drugs for AL amyloidosis to reduce abnormal plasma cells
- Newer medications called TTR stabilizers that prevent transthyretin from breaking apart in ATTR amyloidosis
- Gene-silencing therapies that reduce production of abnormal transthyretin protein
- Diuretics to reduce fluid buildup and swelling
- Medications to manage irregular heart rhythms
- Low-sodium diet to help control fluid retention
- Limiting alcohol and caffeine intake
- Gentle exercise as tolerated, with guidance from your care team
- Heart transplant or stem cell transplant in select cases
- Regular monitoring with your cardiologist and amyloidosis specialist
Frequently asked questions
AL amyloidosis is caused by abnormal plasma cells in your bone marrow making defective antibody proteins. ATTR amyloidosis is caused by abnormal transthyretin protein made by your liver or inherited through genetic mutations. Each type requires different treatments, so identifying which type you have is essential for proper care.
Cardiac amyloidosis is considered rare, but experts believe it is underdiagnosed. Wild-type ATTR may affect up to 13% of people over 80 with heart failure. As awareness grows and diagnostic testing improves, doctors are identifying more cases. Many people are diagnosed only after years of unexplained heart failure symptoms.
Blood tests alone cannot diagnose cardiac amyloidosis, but they provide important clues. B Type Natriuretic Peptide levels are often elevated when your heart is stressed by amyloid deposits. Your doctor may also order blood tests to look for abnormal proteins or genetic markers. Definitive diagnosis requires imaging studies and often a tissue biopsy.
Some types of cardiac amyloidosis are hereditary, while others are not. Hereditary ATTR amyloidosis is passed down through families due to genetic mutations. AL amyloidosis and wild-type ATTR are not inherited. If you have a family history of amyloidosis or unexplained heart failure, genetic testing may be recommended.
Life expectancy varies greatly depending on the type of amyloidosis, how early it is diagnosed, and how you respond to treatment. Untreated AL amyloidosis historically had poor outcomes, but newer treatments have improved survival significantly. ATTR amyloidosis with new targeted therapies can allow people to live for many years with good quality of life. Early diagnosis and treatment are key to better outcomes.
Cardiac amyloidosis cannot be fully cured in most cases, but treatments can slow or stop disease progression. For AL amyloidosis, eliminating the abnormal plasma cells can stop new amyloid formation, and existing deposits may even shrink. New medications for ATTR amyloidosis can stabilize the protein or reduce its production. The goal is to manage the condition and maintain quality of life.
Disease progression varies by type and individual factors. AL amyloidosis can progress rapidly if untreated, sometimes over months. ATTR amyloidosis typically progresses more slowly over years. Early diagnosis and treatment can significantly slow progression and improve outcomes. Regular monitoring with your specialist helps track disease activity and adjust treatment as needed.
Treatment typically involves a team approach with multiple specialists. A cardiologist manages your heart function and symptoms. A hematologist or oncologist treats AL amyloidosis involving plasma cells. Amyloidosis specialists at dedicated centers have expertise in the latest diagnostic techniques and treatments. Your primary care doctor coordinates overall care and helps manage other health conditions.
Lifestyle changes support medical treatment but cannot reverse amyloid deposits. A low-sodium diet helps control fluid buildup and reduces strain on your heart. Gentle, regular exercise as tolerated can help maintain strength and function. Avoiding alcohol and staying hydrated are important. These changes work best alongside medical treatments prescribed by your doctor.
Talk to your doctor about testing if you have heart failure with certain features. These include thickened heart walls on imaging, low ECG voltages despite thick walls, or symptoms that do not respond well to standard heart failure treatment. Being over 60, having neuropathy symptoms, or having a family history of amyloidosis also warrant discussion about specialized testing.