Carol Krucoff continues to live a normal life despite her heart condition. (Courtesy of Carol Krucoff )

Like the sun rising in the east and setting in the west, the steady beat of my heart is something I had counted on all my life — until one day in 2011, when my regular heart rhythm changed to chaos and I landed in the hospital with the first of dozens of episodes of atrial fibrillation.

The most common type of heart rhythm disturbance in the United States, atrial fibrillation — sometimes called AFib — is caused by a disorder in the heart’s electrical system that makes its upper two chambers, the atriums, contract fast and irregularly. When this happens, blood can pool in the atriums, where it may clot. If a clot travels to the brain, it can cause a stroke, which is why people with this disorder are often put on blood thinners.

While AFib itself is usually not life-threatening, it dramatically increases the risk of stroke if left untreated and can lead to other problems, including heart failure and chronic fatigue.

Some people with AFib don’t know they have it: The National Stroke Association estimates that one-third of Americans who have AFib are undiagnosed. But others are acutely aware when their heart rhythm shifts from steady to disorganized. For many people, being out of rhythm can be frightening, exhausting and sometimes disabling as their heart thumps wildly in their chest.

An alien in my rib cage

For me, going into AFib feels as if my heart suddenly leaps into a crazy dance — not the rapid, rhythmic gallop of vigorous exercise or strong emotion but a rough, unpredictable, messy romp, as if an alien has invaded my rib cage. More concerning than this weird sensation is the effect AFib has on my ability to do simple tasks. Walking up stairs leaves me breathless; prolonged standing makes me dizzy. This can trigger anxiety, which itself can trigger AFib.

A number of medical conditions are risk factors for AFib, including hypertension, heart disease and diabetes. It also can be related to alcohol and caffeine consumption, electrolyte imbalance and severe infection.

In my case, heart surgery in 2008 at age 54 to replace a congenitally abnormal aortic valve put me at increased risk. Age is also a risk factor, so as the population ages, AFib is becoming more common. The Centers for Disease Control and Prevention estimates that 9 percent of people 65 and older have the condition.

Like me, many people’s adventures in AFib start with occasional bouts that begin suddenly and stop on their own, which is classified as paroxysmal atrial fibrillation. I tried to figure out what was triggering my episodes — so I could perhaps make lifestyle changes that would keep my heart steady — and kept a detailed chart listing date and time of onset, plus duration. Throughout 2012, I experienced about two bouts a month, which typically lasted about 12 hours. Most episodes started in the middle of the night — often around 2 a.m., when I awoke to go to the bathroom. But I was uncertain whether I woke up, then went into AFib, or I first went into AFib during sleep, which woke me up.

Concern about waking up “fibbing” (as I began calling the experience) began to interfere with my ability to fall asleep. A nurse suggested that lying on the left side might trigger episodes, so my husband and I switched sides of the bed to make it more comfortable for me to sleep on my right side.

Stress is a known trigger, and while some episodes occurred after hectic days, others happened after easy days and for no apparent reason — and one even started while I was having a massage.

I developed strategies that allowed me to do almost everything I needed to do regardless of my heart’s rhythm. I rarely canceled an appointment or class because I was in AFib: I taught yoga and gave presentations with a chair nearby so I could sit if my racing heart made me lightheaded or tired. Although I usual prefer to take the stairs, in AFib I’d ride the elevator or climb stairs one flight at a time, resting after each flight to catch my breath.

Shock treatment

The frequency of my episodes increased to about five a month in 2013, then to nearly nine a month in 2014. I tried numerous medications to control them, but all were unsuccessful. By the fall of 2014, I was fibbing two or three times a week. That November, I went into AFib for more than a week, a condition classified as persistent atrial fibrillation, and my doctor put me on a blood thinner.

For the first time, I did not revert to normal rhythm on my own, so I was hospitalized for a cardioversion, a procedure that uses electrical current to shock the heart back into order. While the cardioversion got me back in to a normal rhythm, it did nothing to change the underlying structural problem that was causing the AFib. And so I was ready to try a more permanent — and invasive — solution called a cardiac ablation.

Done under general anesthesia, the procedure involved having catheters guided up through the veins in the groin to my heart, where radio-frequency energy was used to destroy heart tissue that had been disturbing the electrical flow. After that January 2015 ablation, I was doing so well that in June my doctors said I could stop taking blood thinners. But in August I awoke in the middle of the night “fibbing” again and was quickly hospitalized, put back on blood thinners and cardioverted back into rhythm.

That episode, though, was an unpleasant surprise: I’d hoped I was cured. But the sobering reality is that atrial fibrillation is almost always a chronic disease. My cardiologist hoped the single episode was just a blip, but six months later it happened again.

I scheduled a second ablation. I had been warned this might be necessary because the heart rhythm specialist had done the minimal amount necessary in the first, hoping that would be sufficient.

I’ve been in normal rhythm since that second procedure last May. Soon, I’ll have an imaging procedure to see how my heart has healed and whether I’ll need to stay on blood thinners, possibly for the rest of my life.

Like most medical procedures, cardiac ablation carries risks, including bleeding, infection and damage to blood vessels and the heart. For this reason, I chose an extremely experienced doctor to do it, and my hope of living life free from AFib was worth the potential risks to me.

Now when I feel the steady beat of my heart, I count it as a blessing I’ll never again take for granted. Because I know that everything can change in a heartbeat.

Krucoff is a yoga therapist at Duke Integrative Medicine in Durham, N.C., and co-author of “Relax Into Yoga for Seniors: A Six-Week Program for Strength, Balance, Flexibility and Pain Relief.”

What you need to know about blood thinners

Blood thinners are often an essential part of treatment for people with AFib because these drugs help prevent clots from forming and reduce the risk of stroke. But they have risks, including bleeding that can be hard to stop. The oldest and most widely prescribed anticoagulant is warfarin (Coumadin), which requires regular blood draws to measure clotting time and may required a person to limit the intake of certain foods and drugs that can increase or reduce clotting. Newer drug options, such as apixaban (Eliquis) and rivaroxaban (Xarelto), do not require frequent monitoring or a restricted diet, but are more expensive.