Cardiac Amyloidosis

Quick answer

What Is Cardiac Amyloidosis?

Cardiac amyloidosis is a buildup of an abnormal protein called amyloid in the heart muscle, which makes the heart walls thick and stiff. As a result, the heart has trouble filling with blood, and heart failure and rhythm problems can develop.

Sources

Signs That Need Urgent Help

Fainting or nearly fainting
A very slow heartbeat with weakness or severe dizziness
A very fast, pounding heartbeat with chest pain or shortness of breath
Severe shortness of breath at rest or being unable to lie flat
Swelling that increases quickly over a few days
Sudden facial drooping, arm weakness, or slurred speech

If these signs appear, go to the nearest emergency department right away or call Heart Attack Center 1500 258.

Urgency note: Cardiac amyloidosis keeps progressing if its cause is not treated, and it can lead to heart failure and rhythm problems. Specific treatments for the AL and ATTR types are more beneficial when started before the heart damage becomes advanced.

01 / Understanding the condition

About Cardiac Amyloidosis

Cardiac amyloidosis occurs when certain proteins misfold, form fibers called amyloid, and then deposit between the heart muscle cells. These deposits make the heart walls look thickened and become stiff, so the heart has difficulty expanding to fill with blood. As a result, the pressure inside the heart rises, and fluid easily builds up in the lungs and legs. The heart's electrical system is also often affected. Cardiac amyloidosis belongs to the group of diseases covered on the Infiltrative Cardiomyopathy page.

Two Main Types

Almost all cardiac amyloidosis comes from two types. The AL type occurs when plasma cells in the bone marrow produce abnormal immunoglobulin light chains. This type can progress quickly and often affects the kidneys, nerves, and other organs. The ATTR type comes from transthyretin, a protein made in the liver. Wild-type ATTR appears with age without a gene abnormality, usually in men over 65, whereas hereditary ATTR is caused by an inherited change in the TTR gene. Other types, such as AA amyloidosis due to long-standing inflammation, rarely affect the heart. Telling the AL and ATTR types apart is important because their treatments are very different.

More Common Than Once Thought

Cardiac amyloidosis was once considered very rare. Today, with bone scintigraphy and cardiac MRI, the disease is found more often, for example in some older adults with heart failure with preserved ejection fraction or with aortic stenosis. A study in Spain found wild-type ATTR in about 13 out of 100 hospitalized patients with heart failure with preserved ejection fraction and thickened heart walls.

Clues to Recognize

Doctors suspect amyloidosis when the heart walls are thick without severe hypertension, when blood pressure actually drops in someone who used to have hypertension, when the ECG voltage is low compared with the wall thickness, or when usual heart medicines are hard to tolerate. Clues outside the heart include carpal tunnel syndrome in both hands, narrowing of the spinal canal in the lower back, a ruptured tendon of the upper arm muscle (biceps), tingling in the feet, and protein leaking into the urine. In the AL type, an enlarged tongue or bruising around the eyes may also be found. Some of these clues appear years before heart symptoms.

02 / Understanding the condition

Symptoms to Recognize.

Common Symptoms

Shortness of breath with less and less activity over time
Swelling in the feet, legs, or abdomen
Tiring easily and a reduced ability to be active
Dizziness or nearly fainting when standing up
A heartbeat that feels pounding, irregular, or slow
Blood pressure dropping in someone who used to have hypertension
Tingling, numbness, or burning in the hands and feet
Diarrhea alternating with constipation, or weight loss

Symptoms in Older Adults

Wild-type ATTR is common in men over 65 and is often mistaken for ordinary heart failure due to age.

Shortness of breath and swelling that do not improve with usual heart failure medicines
A history of carpal tunnel syndrome in both hands, often years earlier
Lower back and leg pain from narrowing of the spinal canal
Getting dizzy easily after taking blood pressure medicines
A slow heartbeat or frequently nearly fainting

Not everyone has the same symptoms. If symptoms keep coming back or get worse, get checked.

03 / Understanding the condition

What Causes This Condition?

Abnormal immunoglobulin light chains from plasma cells in the bone marrow (AL amyloidosis)
Transthyretin that becomes unstable with aging, without a gene abnormality (wild-type ATTR)
An inherited change in the TTR gene that makes transthyretin prone to depositing (hereditary ATTR)
Plasma cell disorders such as monoclonal gammopathy or multiple myeloma that underlie the AL type
Long-standing inflammation over many years that produces amyloid A protein, although it rarely affects the heart

04 / Understanding the condition

Who Is at Higher Risk?

Age

Wild-type ATTR increases sharply after age 65. AL amyloidosis usually appears after age 50.

Genetic

Changes in the TTR gene are inherited in an autosomal dominant pattern, meaning each child of an affected person has a 50 percent chance of inheriting it. A family history of heart failure, peripheral nerve problems, or heart thickening should be shared with your doctor.

Medical

Monoclonal gammopathy, multiple myeloma, and other plasma cell disorders increase the risk of the AL type. Uncontrolled long-standing inflammation can cause AA amyloidosis.

Other

Men develop wild-type ATTR far more often than women. The V122I gene variant is found more often in people of African descent.

Groups at Higher Risk

Older Men: Wild-type ATTR is found far more often in men over 65, often together with heart failure with preserved ejection fraction.
People with Heart Failure with Preserved Ejection Fraction: Some patients with thickened heart walls turn out to have undiagnosed ATTR, especially if they do not improve with usual treatment.
People with Plasma Cell Disorders: Monoclonal gammopathy and multiple myeloma can produce light chains that deposit as AL amyloid in the heart and kidneys.
Family Members of People with Hereditary ATTR: Children and siblings may inherit the TTR gene change, so they can have counseling and genetic testing.
Older Adults with Aortic Stenosis: ATTR is found in some older adults with severe aortic stenosis, including those about to have a valve replacement.

Having a risk factor does not mean a person will definitely develop this condition.

05 / Understanding the condition

How Is It Diagnosed?

Diagnosis starts with suspicion, usually from a combination of heart failure symptoms, echocardiography or ECG findings, and clues in other organs. The first step recommended by the 2021 ESC position statement is to test the blood and urine for monoclonal protein, because the AL type needs prompt treatment. If no monoclonal protein is found and bone scintigraphy shows strong uptake in the heart, ATTR can be confirmed without a biopsy. If monoclonal protein is found, a tissue biopsy is needed to confirm the amyloid type, and the patient is referred to a hematologist.

Cardiac MRI helps when the echocardiography results are not yet clear. Once ATTR is confirmed, TTR genetic testing is done to find out whether the disease is inherited. Severity is assessed from NT-proBNP, troponin, kidney function, and the ability to be active, as the basis for choosing treatment.

Echocardiography
Shows thickened walls, enlarged atria, and impaired filling. Measuring how the muscle deforms (strain) often reveals a characteristic pattern in which the tip of the heart is relatively spared.
Electrocardiogram (ECG)
Low voltage that does not match the wall thickness, a pattern resembling an old heart attack, conduction problems, or atrial fibrillation are clues.
Laboratory Tests
Free light chain tests plus electrophoresis and immunofixation of blood and urine proteins look for the monoclonal protein that marks the AL type. NT-proBNP and troponin are used to assess the stage of the disease.
Bone Scintigraphy (Bone Scan)
Strong uptake in the heart, when blood and urine tests find no monoclonal protein, can confirm ATTR without a biopsy.
Cardiac MRI
A characteristic contrast enhancement pattern and a high extracellular volume help distinguish amyloidosis from heart thickening due to other causes.
Endomyocardial Biopsy
Done when tests without an incision have not confirmed the diagnosis, or to confirm the AL type. Sometimes a biopsy of abdominal fat or another organ is enough.
Once ATTR is confirmed, TTR genetic testing distinguishes the wild-type form from the hereditary form and serves as the basis for testing family members.

06 / Understanding the condition

Treatment Options.

Treatment is decided by a doctor after an assessment. The categories below can help you follow the conversation with your doctor.

Transthyretin Stabilizers

Transthyretin stabilizer medicines keep the protein from breaking apart and depositing. In the ATTR-ACT trial, this class of medicine reduced deaths and hospitalizations in cardiac ATTR.

Transthyretin Production Suppressors

Medicines that suppress the production of transthyretin in the liver are used in hereditary ATTR with nerve problems, and studies are also evaluating their benefit when the heart is involved.

Chemotherapy for the AL Type

A hematologist gives chemotherapy to suppress the plasma cells that make the abnormal light chains. In selected patients, a stem cell transplant may be considered.

Tailored Heart Failure Treatment

Diuretics (water pills) are the mainstay for shortness of breath and swelling. Beta blockers, ACE inhibitors, and digoxin are used with caution or avoided because they can lower blood pressure or slow the heart rate too much.

Blood Thinners

Recommended for people with cardiac amyloidosis who have atrial fibrillation, regardless of the commonly used stroke risk scores.

Pacemakers and ICDs

A pacemaker is implanted if there is heart block or the heartbeat is too slow. An ICD is considered in selected patients who have had a dangerous ventricular rhythm.

Heart Transplant

An option for selected patients with advanced heart failure, once the underlying disease is under control.

Whether a test or therapy is suitable and available needs to be confirmed with your care team.

07 / Understanding the condition

Complications to Watch For.

Heart Failure

Stiff walls cause fluid to build up in the lungs and legs. This heart failure usually has a preserved ejection fraction, but the heart's pumping can weaken in later stages.

Atrial Fibrillation and Blood Clots

Enlarged atria make atrial fibrillation more likely. Clots can form in the atria even when the stroke risk by the commonly used scores appears low.

Heart Block and Slow Heartbeat

Amyloid in the heart's electrical system can slow or block conduction, so a pacemaker is needed.

Ventricular Rhythm Disorders

In advanced stages, fast rhythms from the ventricles can occur and cause fainting or cardiac arrest.

Kidney and Nerve Problems

Especially in the AL type and hereditary ATTR, amyloid also affects the kidneys and peripheral nerves, including the nerves that regulate blood pressure and digestion.

Bleeding Tendency

In the AL type, amyloid can bind clotting factor X and make blood vessels fragile, so bruising and bleeding happen easily, especially during procedures.

08 / Understanding the condition

What Can You Do?

Tell your doctor about any family history of amyloidosis, heart failure, or peripheral nerve problems
If you are diagnosed with monoclonal gammopathy, have regular monitoring with a hematologist
Weigh yourself every morning to spot fluid buildup early
Limit salt as your doctor advises to help prevent fluid buildup
Tell every doctor about your diagnosis before starting a new medicine
Avoid NSAID pain relievers without your doctor's advice because they can harm the kidneys
Get up slowly from sitting or lying down if you often feel dizzy
With hereditary ATTR, encourage close family members to talk with a doctor about genetic testing

09 / Understanding the condition

When Should You See a Doctor?

See a cardiologist if you have the following symptoms, especially if they come with nerve, kidney, or hand problems. If you faint, have a very slow heartbeat, or have severe shortness of breath at rest, go to the emergency room right away.

Shortness of breath, swelling, or fatigue that does not improve with heart failure treatment
Blood pressure dropping or frequent dizziness when standing, even though you used to have hypertension
Carpal tunnel syndrome in both hands along with heart symptoms
Being told your heart walls are thickened without severe hypertension
A diagnosis of monoclonal gammopathy or myeloma, followed by shortness of breath or swelling
A family member with hereditary ATTR

Don't Wait in an Emergency.

If symptoms are severe or come on suddenly, go to the nearest emergency department right away or call Heart Attack Center 1500 258, rather than waiting for an appointment.

10 / Common questions

Questions You May Have.

Frequently asked questions about cardiac amyloidosis.

Can cardiac amyloidosis be cured?

Amyloid deposits that have already formed usually cannot be removed yet, but the course of the disease can be slowed. In ATTR, transthyretin stabilizer medicines were shown to reduce deaths and hospitalizations in the ATTR-ACT trial. In the AL type, chemotherapy that successfully suppresses the plasma cells can stop new amyloid from forming, and organ function may partly improve. Results tend to be better when treatment begins before the heart damage is advanced.

How is cardiac amyloidosis different from ordinary heart failure?

The symptoms are similar: shortness of breath, swelling, and tiring easily. Clues that point to amyloidosis include thick heart walls without severe hypertension, blood pressure that actually drops, low ECG voltage, difficulty tolerating usual heart failure medicines, and carpal tunnel syndrome in both hands. The diagnosis is confirmed with blood and urine tests, bone scintigraphy, cardiac MRI, or a biopsy, not from echocardiography alone.

Does cardiac amyloidosis run in families?

It depends on the type. Hereditary ATTR is passed down in an autosomal dominant pattern, so each child of an affected person has a 50 percent chance of inheriting the TTR gene change. Close family members are encouraged to talk with a doctor about genetic testing even before they have symptoms, so monitoring can start earlier. In contrast, wild-type ATTR and the AL type are generally not passed directly to children.

Why do certain heart medicines need to be used with caution?

A stiff heart relies heavily on heart rate and filling pressure to maintain blood flow. Beta blockers, ACE inhibitors or ARBs, and some rhythm medicines can lower blood pressure or slow the heart rate too much, while digoxin needs to be used with great caution. That is why your doctor chooses and adjusts medicines carefully. Do not add, reduce, or stop medicines on your own, and tell your doctor if you often feel dizzy.

Can I still exercise?

Usually yes, with the intensity adjusted. Light to moderate activity such as walking helps maintain fitness and independence. Avoid strenuous or sudden exertion, especially if you often feel dizzy, have fainted before, or have a rhythm problem. Your doctor will set safe activity limits based on your test results, and supervised cardiac rehabilitation can be a safe way to get started.

Why is cardiac amyloidosis often diagnosed late?

Its symptoms resemble more common conditions, such as heart failure due to age, hypertension, or coronary artery disease. Clues outside the heart, such as carpal tunnel syndrome or tingling, often appear years earlier and are not linked to the heart. Today, with bone scintigraphy and cardiac MRI, the diagnosis is easier to make. If your heart failure does not improve with usual treatment, ask your doctor whether amyloidosis should be considered.

Sources and Medical Review

Translated from the Indonesian edition medically reviewed by dr. Suko Adiarto, Sp.JP(K), Ph.D. on September 15, 2026.

Sources as cited in the Indonesian edition.

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The information on this page is for educational purposes and does not replace medical consultation, diagnosis, or treatment. For any health concerns, please consult a doctor directly.

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