There are nearly 20,000 proteins present throughout the body, but one protein, in particular, can cause problems when it accumulates in various areas of the body — especially the heart.
Amyloidosis (am-uh-loi-doh-sis) is a rare disease that occurs when abnormal proteins called amyloid fibrils build up in organs or tissues of the body — leading to dysfunction or damage. While it’s fairly uncommon, many cardiologists believe amyloidosis may not be as rare as it’s considered — but its wide range of seemingly unrelated symptoms can make it difficult to identify and diagnose.
When amyloid fibrils build up in the heart, it’s known as cardiac amyloidosis. Cardiovascular problems that can occur due to amyloidosis include congestive heart failure, rhythm disorders, such as atrial fibrillation and heart valve diseases, including aortic stenosis, among others. Common symptoms caused by these conditions could include the following:
- Fatigue
- Shortness of breath
- Exercise intolerance
- Heart palpitations
- Fainting or swelling of the lower extremities or abdomen
However, when these proteins build up in other areas of the body, amyloidosis may present in other ways — including carpal tunnel syndrome, enlargement of the tongue, lower back pain caused by spinal stenosis, neuropathy or numbness of the hands and feet, gastrointestinal symptoms, among numerous other health problems. This makes it important to talk to your doctor about any medical symptoms you’re having — even if you don’t think they’re related to the heart.
“While amyloidosis is categorized as rare, what we’re learning is that it’s actually very underrecognized and under-diagnosed — particularly as a common cause of heart failure,” shares Dr. Kishan Parikh, WakeMed Heart & Vascular – Advanced Heart Failure. “Creating more awareness around these conditions can help patients and providers work together to arrive at more timely diagnoses for those with amyloidosis — which can lead to greater quality of life, longevity and overall health.”
Types of Cardiac Amyloidosis
There are numerous types of cardiac amyloidosis — and they are not all created equally. Some are hereditary; while others have no genetic link.
Here’s a quick overview of the most common types:
Light chain amyloidosis, also known as AL amyloidosis, most often affects people between the ages of 50 and 80 and is more prevalent in males. It’s a bone marrow disorder that occurs when certain proteins (light chain proteins) are misfolded and, therefore, get hung up or accumulate in various organs throughout the body, including the heart.
Transthyretin amyloidosis, also known as ATTR amyloidosis, is when a protein made by the liver (transthyretin) gets overproduced and, therefore, accumulates in tissues, such as the heart and nerves. There are two subtypes — hereditary ATTR, which is caused by a genetic mutation and may occur in younger adults (ages 50 and up); and wild-type ATTR, which is seen more often in adults age 70 and older. Because ATTR amyloidosis may affect the nerves, it’s sometimes seen with other neurological symptoms, such as carpal tunnel syndrome, lumbar spine problems and difficulty swallowing. It is even associated with bicep tendon ruptures. These non-cardiac symptoms may occur years before any heart-related symptoms occur.
There are several additional rare types of cardiac amyloidosis, including those associated with dialysis, certain blood cancers and more.