What doctors wish patients knew about atrial fibrillation

Every beat of the human heart carries life, rhythm and stability. But what happens when that rhythm falters? Atrial fibrillation (AFib) is a condition that disrupts this delicate balance, leaving millions of adults in the U.S. at risk for complications such as stroke and heart failure. Despite its growing prevalence, AFib remains underdiagnosed and misunderstood, often lurking silently before making its presence known. 

More than 5 million adults in the U.S. are living with AFib, and more than 12 million people are projected to have the condition by 2030. While AFib can affect anyone, it is more common among people of European descent. But Black people who have AFib are more likely to have serious complications such as stroke or heart failure, according to the American Heart Association. Meanwhile, about one-third of people with AFib don’t know they have it, which is why it is important to become familiar with the risk factors and follow up with your physician as needed. 

The AMA’s What Doctors Wish Patients Knew™ series gives physicians a platform to share what they want patients to understand about today’s health care headlines.

In this installment, Paari Dominic, MBBS, MPH, a cardiac electrophysiologist and associate professor of internal and cardiovascular medicine at University of Iowa Health Care, took time to discuss AFib and what patients need to know. 

University of Iowa Health Care is a member of the AMA Health System Program, which provides enterprise solutions to equip leadership, physicians and care teams with resources to help drive the future of medicine.

“Traditionally, we’ve always associated the left top chamber of the heart as being the primary driver of atrial fibrillation, where the electrical signals get confused and chaotic. This causes the upper chambers of the heart to beat at an astonishing rate of 300 to 400 beats per minute,” said Dr. Dominic, noting “that compares with a normal range of 60–100 heartbeats a minute. However, as our understanding of the condition evolves, research shows that both the left and right chambers contribute.”

Paari Dominic, MBBS, MPH

“Heart arrhythmias usually occur as a result of organized electrical dysfunction where electricity goes down one way, comes up another, and keeps going back and forth in a circle—called re-entry—creating fast heartbeats,” he explained. “Atrial fibrillation, however, is one of the few arrhythmias where the electrical activity is completely chaotic, spreading unpredictably throughout the upper chambers with no clear pattern or organization.”

Atrial fibrillation “causes the upper chambers of the heart to quiver instead of contracting properly. There are portions of the upper left and right chambers that require active contraction of the heart to empty the blood,” Dr. Dominic said. “Atrial fibrillation disrupts this process, and blood can stagnate, increasing the risk of clot formation. These clots can develop in the upper chambers of the heart and potentially lead to a stroke which is a major complication of AFib.”

Symptoms of AFib include “palpitations, shortness of breath, dizziness or lightheadedness and maybe some chest pressure,” Dr. Dominic said. But “the most common symptom of AFib—which is the most underappreciated symptom—is fatigue.” 

“A majority of my AFib patients often don’t feel palpitations, but they almost always have fatigue,” he said, noting that “not every patient will realize they have felt fatigue, but once they are back in normal rhythm, they can see the difference.”

“The younger you are, the less likely you are to develop AFib,” Dr. Dominic said, noting “the risk is minimal and less than 1% when you’re younger.”

“As you get older, if you look at the patient population of about 60 years old, the lifetime risk of developing AFib is almost one in four,” he said. “There is a high incidence of AFib as you get older, so it’s really age dependent.”

Age is a major risk factor for atrial fibrillation, but so is high blood pressure, which causes one in five cases of AFib.  

Additionally, “diabetes and other heart problems and structural problems such as blockages in your heart arteries or heart failure are also risk factors,” Dr. Dominic said. “If you have valve problems in the heart, that can be a risk factor too.”

Beyond those, “obesity and sleep apnea are also risk factors of AFib,” he said. “Lung conditions that reduce your oxygen content, as well as lifestyle habits like smoking and alcohol use, can also contribute by giving rise to the risk factors that cause atrial fibrillation.”

“There is a genetic component of atrial fibrillation in families. Not every atrial fibrillation is familial, though,” Dr. Dominic said. “Some of them happen due to random genetic variations or risk factors. But there is a subset of patients with familial atrial fibrillation which occurs due to known gene mutations.”

 “It’s difficult to say on a general basis. But on a case-by-case basis many of my patients have more than just atrial fibrillation. Some have a family history of multiple family members with heart failure, cardiac conditions and other heart diseases,” he said. 

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“When atrial fibrillation initially starts, it lasts for a few seconds to minutes before returning to a normal rhythm,” Dr. Dominic said. “The normal heart rhythm, otherwise called sinus rhythm, originates from the right top chamber of the heart, an area called the sinus node which regulates the heartbeat within the normal range of 60 to 100 beats per minute.”

“During AFib, the chaotic heart rhythm takes over, overwhelming the sinus node, so it can no longer regulate the heartbeat,” he added. “Once AFib stops, the sinus node takes over again and restores a normal heart rhythm.”

“As you progress in the disease process of atrial fibrillation, AFib gets longer and longer in duration and the intervening episodes of sinus rhythm become shorter and shorter,” Dr. Dominic explained. “Initially you may have AFib once a month, once a week. Then you start having it every day and it lasts longer.”

If episodes last less than one week and go away on their own, it is considered paroxysmal AFib, but “if your atrial fibrillation episodes persist for more than seven days, we call that persistent atrial fibrillation,” he said. “And if they continue for more than a year, we refer to it as longstanding persistent atrial fibrillation. These classifications help physicians understand where a patient is in the disease process, but they don’t represent different types of AFib—it’s all the same condition.”

The basic diagnostic test for atrial fibrillation is an electrocardiogram (ECG), which “can show if you have AFib,” Dr. Dominic said, noting “most physicians will have a suspicion of AFib when they feel the pulse or they hear the heart rhythm because they can see that there is irregularity in the pulse or heart beats.”

“The problem with the ECG is that if someone is having paroxysmal atrial fibrillation, where the AFib comes only once in two weeks and spontaneously resolves, a 10 second ECG at their doctor’s office may be completely normal,” he said. “For that reason, oftentimes we will give continuous ECG monitoring for either a 48-hour period or two weeks or sometimes we even implant a small chip called a loop recorder underneath the skin that can detect AFib over the next three years.”

“Nowadays, a very common way patients present to us with AFib is when their watch alerts them that they have AFib, even when they don’t feel the symptoms of AFib” Dr. Dominic said. 

AFib can be detected by “any kind of heart-rate measuring device such as an Apple Watch, Fitbit or KardiaMobile, which is a personal ECG device that looks like a small rectangular strip and can be bought on Amazon,” he explained. These devices are “pretty reliable. The detection algorithms in KardiaMobile, especially, have a high sensitivity and specificity for detecting AFib.”

“In patients who have AFib, there are ways to evaluate how much AFib someone is having over a 24-hour period, if the Apple Watch is set up appropriately,” Dr. Dominic said, noting “you have to set up AFib history in your health app on the Apple Watch separately to turn on AFib monitoring.”

It is important to note, though, that if you have symptoms or your Apple Watch notes you’re in AFib, it is important to speak with your doctor. 

“We know that AFib increases the risk of stroke, and therefore, if AFib goes undetected for a long time, a stroke may be your first symptom,” Dr. Dominic said. “When a stroke occurs in patients with AFib, it’s typically much more severe than strokes caused by blockages in the neck or brain arteries, where the strokes tend to be smaller.

“This is probably because the clots that cause stroke in AFib comes from the heart, and therefore can be larger.  When these clots travel to the brain, they may occlude a major vessel and the resultant stroke can be major,” he added. 

“If we intervene sooner in patients with AFib, their outcomes improve significantly,” Dr. Dominic said, noting “recent studies have shown that pursuing a strategy to maintain a normal rhythm in patients with AFib within a year of detection produces better outcomes.”

Because of that evidence, “we’re focused on detecting AFib as early as possible,” he said. “The latest AFib guidelines define a subpopulation of patients at high risk of developing the condition. These subjects already have significant structural or electrical changes in their hearts which can predispose them to AFib and therefore can benefit from heightened surveillance. So, you don’t have to have AFib to be monitored in a health care setting.” 

“We are picking up patients who will develop AFib in the future and then start following them, making sure we monitor them closely so by the time they get AFib, they’re already in the system and we can address the issues sooner,” said Dr. Dominic.

“When you have AFib, your top chambers are going at 400 beats a minute, which drives the bottom chamber to go fast as well,” Dr. Dominic said. “In the past, we primarily followed a strategy called rate-control, where we left the patient in AFib. We focused on ensuring their heart’s lower chambers didn’t beat too quickly and worked to prevent a stroke by giving them blood thinners. 

“The other side of it is called rhythm control, where we do everything within our capacity to keep patients in normal rhythm, or put them back into normal rhythm. That includes medications called antiarrhythmic drugs,” he added. These medications prevent and treat a heart rhythm that is too fast or irregular. This includes sodium channel blockers, beta blockers, potassium channel blockers or calcium channel blockers. Most antiarrhythmic medications are taken by mouth over a long period of time for lasting treatment. Some are also delivered intravenously.

Additionally, cardioversion can be used “to reset their hearts back into normal rhythm,” he said, “or as a final option, we can use catheters or small flexible tubes that traverse through the veins, starting from the groin and moving up into the heart. These are used to perform a procedure called ablation, which restores a normal rhythm.”

“That whole arm of treatment is called rhythm-control strategy, where we keep people in normal rhythm. These patients require blood thinners if they are at a certain calculated risk of having a stroke to prevent strokes,” Dr. Dominic said. “We’re giving everybody with AFib and symptoms a chance to get back to normal rhythm.” 

“There is no cure for AFib at the moment. While we’ve developed ways to keep AFib at bay through many of the strategies discussed, it’s not a curable disease,” Dr. Dominic said. “However, after a first-time ablation procedure, about 70% of patients will remain in normal rhythm for at least the next five years or so.”

“With a second ablation, the chances of being in normal rhythm improve even further,” he said. “However, patients can still experience breakthrough atrial fibrillation, even after several years.nThis is why even after successful treatment, and a return to normal rhythm, we recommend continuing blood thinner therapy.” 

“As much as possible, we want to keep atrial fibrillation in the paroxysmal stage and never let patients progress to persistent atrial fibrillation where they remain in AFib all the time,” Dr. Dominic said. “Recent data shows that when the disease progresses to persistent atrial fibrillation, the outcomes are worse.”

“Treating sleep apnea may not take away atrial fibrillation completely, but it might actually help with the progression of atrial fibrillation,” Dr. Dominic said. “Treating obesity is the same.  Losing 10% of the body weight in obese patients, can significantly reduce occurrence and severity of AFib.”

Additionally, “treating blood pressure and eating healthy is important,” he said. “These are lifestyle modifications that we always teach our atrial filbrillation patients, but they often need to be put in place in conjunction with the other therapies.”

“Lifestyle modifications by themselves help, but they’re not the only thing that we should be pursuing,” Dr. Dominic emphasized.

“Anything that increases your heart rate, including caffeine from coffee or energy drinks,” said Dr. Dominic, “can trigger atrial fibrillation in patients with AFib.

“So, if you have already been diagnosed with atrial fibrillation, it may be good to limit caffeine and other stimulants that raise your heart rate,” he added.