Atrial Fibrillation With No Symptoms Is a Silent Killer

In less time than it takes to tie your shoelaces, someone living the United States will have a stroke. This means that every 40 seconds, a person has a stroke, and that accounts for nearly 800,000 strokes each year, according to the Centers for Disease Control and Prevention. While many people are familiar with stroke risk factors, such as stress, smoking, lack of physical activity and heart disease, there is a hidden condition that puts many people at risk: asymptomatic atrial fibrillation.

Credit: Adobe Stock

This is a type of atrial fibrillation (AF), or irregular heartbeat, that has no symptoms and, therefore, can be a silent killer. Scientists estimate that as many as 40 percent of people who have AF have the asymptomatic version.

Left unrecognized, the consequences of untreated asymptomatic AF are huge. People who have it are five times more likely to have a stroke than those who have symptomatic AF, according to the American Heart Association. But perhaps the worst part is that many people who have asymptomatic AF never find out — until it’s too late.

“If a person doesn’t have any symptoms, the only way you can find out if they have atrial fibrillation is by examining them,” says Dr. Richard Ammar, a cardiologist at Texas Health Allen. “But what many people realize is that many people usually have symptoms of atrial fibrillation before they develop asymptomatic AF — such as shortness of breath, palpitations, funny heartbeats, fatigue.”

Dr. Tulika Jain, a cardiologist at Texas Health Dallas and Cardiology and Interventional Vascular Associates, says in addition to being completely silent, AF symptoms can come and go. This also makes it harder for patients to notice symptoms or for doctors to detect an irregular heartbeat if the heart rate and rhythm register as normal during an exam.

Because asymptomatic AF can be difficult to catch, experts say it’s important that people learn about the risk factors and conditions that can cause atrial fibrillation. The risk factors include:

• Age; according to the National Stroke Association, AF tends to be more common in people over age 60
• Diabetes
• High blood pressure
• Coronary artery disease
• Valvular heart disease (conditions in which a heart valve does not properly close and some blood flows backwards into a previous chamber)
• Obesity
• Sleep apnea
• AF runs in your family
• Lung disease
• Kidney disease
• Congestive heart failure

Regarding that last risk factor, not only does congestive heart failure increase your risk of developing AF, but atrial fibrillation can also cause congestive heart failure.

Jain says several other conditions and situations can trigger AF, including stress, an overactive thyroid, surgery and drinking a lot of alcohol.

Technology can sometimes aid in diagnosing hidden AF, but experts say that many of the apps designed for mobile devices are not quite as reliable as they should be. In other cases, user error (such as sudden movements) may give inaccurate readings that unnecessarily frighten patients.

“Concerned patients wind up in the (emergency room) thinking they have AF when it’s actually a false positive,” Ammar warns. “But this may be more of a problem with home-based AF monitoring apps.”

Jain believes technology can help catch asymptomatic AF in some patients. For example, in a Swedish study, researchers had 7,173 participants who were 75 use a heart rhythm monitor over a three-week period. They found that 3 percent of these participants had atrial fibrillation.

Another study that monitored people over 65 who had pacemakers or defibrillators detected asymptomatic AF in 10 percent of participants after three months of monitoring. That number jumped to roughly 35 percent after a follow-up period of 2 1/2 years.

Cardiologist Dr. Nina Asrani, who practices at Texas Health Fort Worth and Consultants in Cardiology, says the steps to help prevent atrial fibrillation are similar to those for maintaining a strong, healthy heart. They are:

• Eating a healthful diet
• Getting regular exercise
• Avoiding smoking
• Limiting caffeine
• Avoiding or limiting alcohol intake
• If appropriate, taking medications for high blood pressure according to a doctor’s instructions
• Following doctor’s instructions for managing sleep apnea

Asymptomatic AF can seem scary, but armed with the combination of knowing the symptoms, risk factors and triggers, you should have the information you need to start a conversation with your doctor.

For more information about atrial fibrillation, visit the American Heart Association or National Stroke Association websites, or download this National Stroke Association fact sheet.