Cardiac Amyloidosis

Cardiac amyloidosis is a buildup of misshapen proteins in your heart. It’s a leading cause of restrictive cardiomyopathy.

Abnormal proteins build up in your heart muscle. They make the walls of your heart thicken. These changes force your heart to work harder to pump enough blood through your body. The extra effort can weaken and damage your heart. It eventually can lead to heart failure.

If you have cardiac amyloidosis, there’s a good chance you have amyloid buildup in other areas of your body, too. But buildups in your heart tend to cause the most severe health problems. The good news is that recent therapies have improved outcomes for people with this condition.

Types of cardiac amyloidosis

The two most common types of amyloidosis that can affect your heart are:

• Light-chain amyloidosis (AL): The abnormal proteins come from your bone marrow.
• Transthyretin amyloidosis (ATTR): The abnormal proteins come from your liver. There are two subtypes of ATTR: hereditary (variant) and wild-type.

Symptoms of cardiac amyloidosis

Cardiac amyloidosis is a condition that gets progressively worse. It can lead to heart failure symptoms that become more severe with time. They include:

• Shortness of breath when you’re active or at rest
• Swelling in your belly and legs
• Fatigue for several days
• Heart palpitations during your normal routine

Amyloid can build up elsewhere in your body. So, you may have other symptoms, like peripheral neuropathy (tingling or numbness in your hands or feet) or dysautonomia (lightheadedness, dizziness, low blood pressure with changes in position).

Cardiac amyloidosis causes

The cause depends on the type of amyloidosis you have. Bone marrow disorders cause AL amyloidosis. A change in the transthyretin (TTR) gene or aging-related changes cause ATTR.

Complications of this condition

Cardiac amyloidosis changes your heart’s structure, and it can disrupt its electrical system. Complications include:

• Arrhythmias, like atrial fibrillation (AFib), bradycardia and ventricular tachycardia
• Bundle branch block
• Cardiorenal syndrome
• Heart failure
• Restrictive cardiomyopathy
• Stroke

How doctors diagnose this condition

Healthcare providers diagnose cardiac amyloidosis through various tests. Cardiac amyloidosis is part of a systemic (whole-body) disease. So, providers look at the big picture. In addition to zooming in on your heart, they step back and look for symptoms elsewhere.

Your provider may first suspect this condition based on your symptoms, medical history and physical exam findings. They’ll then use several tests to confirm it or rule it out.

Tests may include:

• Blood and urine tests to check for amyloid proteins and markers of heart function
• Electrocardiogram (EKG) to check your heart’s electrical activity
• Echocardiogram with strain to look for thickened heart muscle
• Cardiac MRI to distinguish cardiac amyloidosis from other causes of cardiomyopathy
• Nuclear imaging tests, including “amyloid” scans, to check for amyloid protein buildup in your heart
• Biopsy to check for amyloids in your heart or elsewhere
• Genetic testing to check for genetic changes as the cause of amyloidosis

Cardiac amyloidosis red flags

Your healthcare provider will look for “red flags” that point to cardiac amyloidosis. In addition to heart failure symptoms, they include:

• Atrial fibrillation (AFib)
• Thickness in the wall of your left ventricle
• Conduction system disease
• Elevated cardiac biomarkers
• High levels of protein in your pee
• History of carpal tunnel syndrome
• Lumbar spinal stenosis
• Peripheral or autonomic neuropathy
• Prior shoulder surgery
• Hip or knee replacement

How is cardiac amyloidosis treated?

Treatment depends on the type of amyloidosis. In general, there are three main groups of treatments:

• Amyloid-specific medications to slow or stop the production of abnormal proteins
• Treatments that manage your symptoms
• Organ transplantation to replace an organ that amyloidosis damaged

Currently, there’s no cure for cardiac amyloidosis. But early diagnosis and treatment can help limit long-term damage to your heart.

Researchers are currently studying other medications that target the underlying causes of cardiac amyloidosis. Ask your healthcare provider if you can join a clinical trial.

When should I see my healthcare provider?

You should see your healthcare provider regularly if you have cardiac amyloidosis. You may need frequent appointments to monitor the condition and get treatment.

Ask your providers which symptoms are warning signs that you need emergency care. Share this information with your loved ones so they can get help for you if needed.

What can I expect if I have this condition?

How cardiac amyloidosis will affect you depends on many factors, including:

• The type of amyloidosis
• Your age
• How long you had the disease before you got a diagnosis
• How quickly you begin treatment
• Other health conditions you have, including complications from amyloidosis

The outlook (prognosis) is generally worse in light-chain amyloidosis due to how quickly it progresses. ATTR has a slower — but still significant — course. Regardless of the type, cardiac amyloidosis is the leading cause of death in people with amyloidosis.

Your healthcare provider can give you a better idea of what to expect. In general, the sooner you receive treatment, the better your outlook and life expectancy.