Carpal tunnel and stiff heart syndrome: Is there a connection?

Carpal tunnel syndrome may be linked to heart disease due to some shared underlying factors.

Many of us spend hours at a time on our laptops or smartphones. But the repetitive movements of constant typing or swiping can cause carpal tunnel syndrome (CTS), a common condition that affects the hands and wrists. On its own, CTS can lead to permanent nerve damage. But there's also an association between carpal tunnel and heart disease that people may not be aware of. If you have carpal tunnel syndrome, it's important to keep a close eye on your heart health.

What is carpal tunnel syndrome?

Carpal tunnel syndrome is an orthopedic condition that causes numbness, pain and tingling in the fingers, hands and wrists. It occurs when the median nerve is squeezed or compressed. The median nerve travels through the carpal tunnel, a narrow passageway in the wrist. Carpal tunnel syndrome may get worse over time and can lead to loss of sensation or weakness in the fingers if left untreated.

Although anyone can get carpal tunnel syndrome, people who perform repetitive motions with their hands and wrists are at an increased risk. Injuries and other health conditions such as diabetes or rheumatoid arthritis can also increase the risk of carpal tunnel.

What is the link between carpal tunnel and heart disease?

A recent study found that people with carpal tunnel syndrome are three times more likely to develop cardiac amyloidosis compared to those without CTS. Cardiac amyloidosis, also known as amyloid heart disease or "stiff heart syndrome," occurs when amyloid, a type of protein, builds up in the heart muscle. This makes it harder for the heart to work properly, which can eventually lead to heart failure.

Cardiac amyloidosis may also cause irregular heart rhythms (arrhythmias), including atrial fibrillation. Some people develop cardiac amyloidosis later in life, often as a result of another disease, while others inherit it genetically.

Research has also found that carpal tunnel is common in people with amyloidosis. Patients with transthyretin amyloidosis (ATTR), a rare and progressive type of amyloidosis, often have more severe carpal tunnel when diagnosed. Another study found that surgery for carpal tunnel in both arms often predates cardiac amyloidosis.

How carpal tunnel symptoms can affect heart disease

Although carpal tunnel syndrome and heart disease may not seem related, they do share some underlying factors.

Chronic inflammation from conditions such as diabetes and rheumatoid arthritis can lead to swelling in the wrist that narrows the carpal tunnel. Swelling compresses the median nerve and causes symptoms such as pain and tingling.

Chronic inflammation can lead to plaque buildup — or atherosclerosis — in the artery walls, which can lead to heart attack and stroke. It can also cause oxidative stress, an imbalance between free radicals and antioxidants in the body. Free radicals are unstable atoms that can damage cells, including those in the heart and blood vessels.

Metabolic syndrome — also called insulin resistance syndrome — is a group of conditions that occur together and increase the risk of heart disease, stroke, type 2 diabetes and other health problems. Metabolic syndrome can occur if you have three or more of the following conditions:

• Abdominal obesity
• High blood pressure
• High blood sugar levels
• High blood triglycerides
• Low HDL cholesterol

Previous research has also found that carpal tunnel syndrome is more severe in people with metabolic syndrome than those without it, and that metabolic syndrome is three times more common in people with CTS.

Keep an eye on your heart health

If you've been diagnosed with carpal tunnel syndrome, it's important to monitor your heart health for irregularities or risk factors that may develop. If you have heart disease or are at risk for it, managing the underlying factors can help reduce your risk or symptoms. It's important to control your blood pressure and blood sugar levels, manage cholesterol and reduce inflammation.

The Centers for Disease Control (CDC) recommends:

• Eat a healthy diet: Limit your alcohol consumption and avoid foods that are high in saturated and trans fat, cholesterol, sodium and sugar, such as highly-processed foods. Eating these foods regularly can contribute to heart disease, high cholesterol, high blood pressure and blood sugar levels and diabetes. Instead, eat more fruits, vegetables and whole grains.
• Get regular physical activity: Overweight or obese individuals put extra stress on their heart and blood vessels and typically have a higher risk for heart disease. The Surgeon General recommends two hours and 30 minutes of moderate-intensity exercise every week for adults.
• Get enough sleep: Chronic sleep disturbance can activate an inflammatory response in the body, and sustained inflammation can put you at risk for cardiovascular disease, high blood pressure and diabetes.
• Quit smoking: Smoking tobacco greatly increases your risk for heart disease. If you need help quitting, talk to your doctor about creating a cessation plan.

While carpal tunnel syndrome isn't a direct sign of heart disease, persistent swelling in the fingers and wrists could suggest amyloidosis. Irregular heartbeat together with carpal tunnel symptoms should be evaluated by a healthcare provider.