How AFib Can Lead to Stroke and What You Can Do About It (video/podcast)

Many things can affect your heart rate, such as excitement, fear, anxiety or exercise. However, more than 10 million adults in the United States experience a random abnormal heartbeat due to a condition called atrial fibrillation (AFib). In addition to causing uncomfortable symptoms, AFib can significantly increase the risk of stroke and other heart problems.

San Diego Health host Susan Taylor talks with Nicholas Olson, MD, a cardiologist at Scripps Clinic Anderson Medical Pavilion in La Jolla, about how AFib increases stroke risk and the new treatments that are making it easier to manage.

Your heart has two upper chambers called the atria and two lower chambers called the ventricles. Normally, electrical signals travel through the heart in an organized pattern, allowing the chambers to contract in sequence and pump blood efficiently.

With atrial fibrillation, these electrical signals become chaotic. Instead of beating in a steady rhythm, the upper chambers quiver rapidly, often causing the heart to beat faster than 100 beats per minute. This abnormal heart rhythm is called arrhythmia.

AFib rarely has a single cause; instead, several factors often work together to increase a person's risk. Common risk factors include:

• Aging
• Family history or genetics
• High blood pressure
• Diabetes
• Heart valve disease
• Obesity
• Sleep apnea

People with multiple risk factors are more likely to develop AFib over time.

Atrial fibrillation symptoms vary widely from person to person. Some people notice dramatic symptoms, while others have few or none.

“Sometimes it’s palpitations or a racing heart sensation, but other times it’s just fatigue or low energy,” Dr. Olson says. “Some people describe it as a hunger for air.”

AFib can also come and go, a pattern known as paroxysmal AFib. Episodes may last minutes, hours or longer before the heart returns to a normal rhythm.

“Not every episode of shortness of breath or heart palpitations means you have AFib,” Dr. Olson notes. “However, any new or unexplained symptoms deserve medical attention, especially if you have risk factors or a family history of the condition.”

When the upper chambers of the heart aren’t contracting correctly, blood can pool inside the heart and form clots. If one of those clots breaks loose and travels to the brain, it can block blood flow and cause a stroke. Over time, untreated AFib may also increase the risk of heart failure and dementia.

Because of these risks, early diagnosis and treatment are important, even if symptoms seem mild.

Diagnosing AFib requires recording the heart’s electrical activity. Sometimes a simple electrocardiogram (EKG) in your doctor’s office is enough. However, because AFib can come and go, your physician may recommend wearing a portable heart monitor for several days or weeks to capture an abnormal rhythm.

Treatment focuses on two main goals: preventing stroke and controlling the abnormal heart rhythm.

Blood-thinning medications are often the first line of treatment to help prevent clots and reduce stroke risk. Because these can cause side effects like excessive or prolonged bleeding, nosebleeds or increased bruising, some people can’t tolerate them.

If blood thinners are not an option, your physician may recommend a left atrial appendage closure. This minimally invasive procedure helps prevent blood clots from forming in the heart.

The abnormal rhythm itself can often be treated with medications or with a catheter ablation, a minimally invasive procedure that uses extreme cold or heat to destroy the heart tissue that triggers the erratic signals.

In catheter ablation, the physician inserts a thin catheter through a vein in the leg and carefully guides it into the heart. Once in position, the catheter delivers energy that targets the heart tissue responsible for triggering AFib. Often, this can fix the abnormal rhythm but has a slight risk of damage to the surrounding tissues. The procedure takes several hours and may require an overnight stay in the hospital.

The newest AFib ablation procedure, pulsed field ablation (PFA), is a faster and more precise atrial fibrillation treatment. Unlike older ablation techniques that relied on heat or cold, pulsed field ablation uses electrical energy designed to selectively treat heart tissue while minimizing injury to nearby tissues. It usually requires an hour or less and most patients go home the same day. Patients can perform light activities within the first few days, with most returning to usual activities within a week.

“Pulsed field ablation is a really revolutionary new tool,” Dr. Olson says. “It doesn’t cause any inflammation, it’s very efficient and it’s very safe.”

Dr. Olson notes that Scripps participated in the clinical trials that helped demonstrate the effectiveness of this technology and now performs PFA as the primary approach for AFib ablation.

“AFib has always been a very challenging medical condition to treat,” he says. “Now we have a new tool that allows us to put a tiny tube up into the heart, find your AFib, fix it, and you’re out the door two hours later. I think that’s absolutely incredible.”