Early ATTR-CM symptoms: What to watch for
Fact-checked by Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed heart condition with symptoms that resemble several other disorders. Knowing how to identify early ATTR-CM symptoms can help ensure an accurate and timely diagnosis and better treatment.
In ATTR-CM, transthyretin (TTR) — a protein that helps transport certain hormones throughout the body — takes on an abnormal structure due to genetic or age-related factors.
This abnormal TTR protein forms clumps, called amyloid deposits, that accumulate primarily in the heart, damaging it and eventually causing symptoms of heart failure.
ATTR-CM is a progressive disease, meaning it gets worse over time as amyloid deposits increasingly build up. Reaching an early ATTR-CM diagnosis is crucial so treatment can begin before irreversible damage occurs.
Why early ATTR-CM symptoms are often overlooked
While an early diagnosis is key to successful treatment, it can be a challenging process. There are a number of reasons why the early signs of ATTR-CM are often overlooked:
- cardiac symptoms are nonspecific and may resemble those of other heart conditions or of generally poor health
- symptoms may be subtle or absent altogether, especially early in the disease course
- early symptoms can occur outside the heart, so they might be mistaken for noncardiac problems
Together, these factors can contribute to delayed or missed diagnoses. In particular, the nonspecificity of early heart disease symptoms can make it difficult to distinguish ATTR-CM from other types of cardiac amyloidosis — an umbrella term for heart disease related to amyloid deposits.
Understanding the early signs of cardiac amyloidosis can help you avoid overlooking important symptoms and advocate for timely and appropriate diagnostic testing.
Early heart-related symptoms to watch for
Symptoms of amyloidosis in the heart are similar to the general signs of heart failure. While these symptoms can at first be very subtle, some things to watch out for include:
- shortness of breath
- fatigue
- coughing or wheezing, especially when lying down
- irregular or fast heart rate
- difficulty exercising
- swelling in the legs, ankles, or feet
Unexplained fatigue and shortness of breath, even with little or no activity, are often among the early heart failure symptoms in ATTR-CM, with other symptoms emerging later.
People with ATTR-CM commonly experience heart failure with preserved ejection fraction (HFpEF), a type of heart failure in which the heart muscle is too stiff to relax between heartbeats, but can still pump blood out to the body at a normal rate. HFpEF and amyloidosis often occur together because amyloid deposits contribute to heart muscle stiffening.
Early heart rhythm and blood pressure changes
At diagnosis, 40% to 60% of people with ATTR-CM have atrial fibrillation (AFib), a heart rhythm problem in which the heart’s upper chambers beat irregularly and don’t pump blood as efficiently as they should. This can increase the risk of complications such as stroke and heart failure.
People with ATTR-CM often feel unwell from AFib, with possible symptoms including shortness of breath, fluttering or rapid heartbeat (palpitations), dizziness or lightheadedness, and low blood pressure, known as hypotension. People with ATTR-CM often cannot tolerate standard heart failure medications.
Many other conditions that cause heart failure symptoms are associated with high blood pressure. If individuals with heart failure symptoms have low or normal blood pressure and haven’t tolerated heart failure medications well, it may be a sign they should talk with a doctor about ATTR-CM testing.
The role of routine heart tests
Echocardiography (echo) and electrocardiography (ECG) are two common types of heart tests that can help identify AFib, HFpEF, or other signs that something is wrong with your heart.
If you have a family history of ATTR-CM or a known disease-related genetic mutation, your doctor might regularly order these tests to monitor your heart health. This can help reach an early ATTR-CM diagnosis even before symptoms are obvious.
If you don’t have known risk factors but you think you might be experiencing heart symptoms related to ATTR-CM, it’s a good idea to talk with your doctor about whether an echo or ECG makes sense for you.
Early noncardiac symptoms that may signal ATTR-CM
While ATTR-CM mainly affects the heart, amyloid deposits can also accumulate elsewhere, including in and around nerves or connective tissues. A number of the early and subtle symptoms of ATTR-CM affect these other tissues. These may include:
- carpal tunnel syndrome: characterized by symptoms such as pain, tingling, numbness, and weakness in the hand and wrist
- spinal stenosis: a narrowing of the space within the spinal canal, causing back pain and numbness
- biceps tendon rupture: a tear in the tendons of the upper arm
- peripheral neuropathy: nerve damage outside of the brain and spinal cord, which can cause pain, tingling, and other abnormal sensations
Carpal tunnel syndrome and ATTR-CM have a particularly strong link. Often, people with ATTR-CM have a history of carpal tunnel syndrome, which precedes the ATTR-CM diagnosis by five to 10 years. As such, experts consider carpal tunnel a red flag for ATTR-CM, particularly if it occurs in both wrists.
ATTR-CM is closely related to transthyretin amyloidosis with polyneuropathy (ATTR-PN), a condition in which amyloid deposits mainly cause peripheral nerve damage. Many people with ATTR-CM also experience these nerve-related symptoms to some degree.
Steps to take if you notice early symptoms
If you notice any early warning signs of ATTR-CM — particularly if multiple red flags are present — the first step is to let a healthcare provider know.
It’s also a good idea to track your symptoms, and note what seems to trigger their onset and how long they take to resolve. This can help you give your healthcare providers a full picture of your condition.
The more information they have, the better equipped your doctors will be to identify red flag symptom patterns and make a speedy diagnosis. Keeping a detailed symptom log also empowers you to self-advocate for appropriate testing and specialist referrals.
When to get checked for possible ATTR-CM
Any unexpected heart or nervous system symptoms could be a possible reason for ATTR-CM testing, so it’s important to report them to a healthcare provider.
If you don’t already have a cardiologist, a primary care doctor can work with you to determine if there is a risk of ATTR-CM or another heart issue and provide a referral to an experienced specialist for diagnostic testing as appropriate.
For people with a family history of hereditary ATTR-CM, genetic testing for disease-causing mutations may be appropriate even without symptoms present. In these cases, a genetic counselor will work with you to help you understand your risk, the symptoms to look out for, and the implications of genetic testing results.
Amyloidosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
