Fly Well: Rhythm of my heart

Atrial fibrillation has multiple causes, including hypertension, heart attack, valve disease, or heart inflammation. Diabetes also is linked to heart disease encompassing atrial fibrillation. Alcohol, amphetamines, cocaine, electrolyte imbalance, or thyroid disease can present with AFib, which may resolve after treating the primary cause. Genetic predisposition, aging, hypothermia, pneumonia, lung cancer or blood clots, anemia, and kidney disease are also associated.

To be rock and roll music, it has to have a backbeat; you just can’t lose it. Same thing for the heart. Each heartbeat initiates with electrical impulses that flow through heart muscle, inducing synchronized cardiac contractions. AFib affects up to 6.1 million Americans, about a quarter of whom develop atrial fibrillation after age 40. More commonly seen in men and Caucasians, atrial fibrillation may be transitory, sporadic, or persistent. Nearly 90 percent of patients with atrial fibrillation have no symptoms, but one may experience palpitations, breathlessness, fatigue, dizziness, fainting, and chest pain. If disordered contractions interfere with pumping, heart failure develops, causing ankle swelling, cough, gasping when lying flat, and other problems. Atrial fibrillation allows blood to remain in the heart where it clots—commonly in the left atrial appendage (LAA)—and can then travel to the brain, causing stroke or even death.

Resting pulse is rapid at up to 110 to 140 beats a minute, with a characteristic “irregularly irregular” rhythm. With overactive thyroid disease—another suspect in atrial fibrillation—swollen neck, bulging eyes, thin hair, and other signs are present. With heart failure, there may be abnormal findings in limbs, chest, neck, or abdomen.

Electrocardiography (ECG) measures electrical activity. In atrial fibrillation it shows a typical pattern and also reveals evidence of prior heart attacks. Echocardiography uses sound waves to image valve movements, heart wall function, and to locate blood clots. A six-minute walk test helps define baseline performance and then is used to monitor treatment efficacy. If diagnosis is uncertain, such as when atrial fibrillation comes and goes, one might wear a Holter monitor to record electrical activity over the course of 24 hours.

Having confirmed atrial fibrillation is to blame, doctors perform a risk assessment to guide treatment. The famous Framingham heart study showed even short-term atrial fibrillation can cause problems years later, so regular review is merited.

Because atrial fibrillation and blood clots are associated, one treatment goal is to “thin” blood with an anticoagulant; aspirin and Coumadin (brand name for warfarin) are most common. Coumadin is administered orally, and frequent blood tests measure a clotting ratio called international normalized ratio (INR). This must be kept close to 2.5; higher and dangerous bleeding may ensue, too low and “thicker” blood may clot, leading to a stroke. The FAA allows pilots to take Coumadin with a tightly controlled INR and detailed report. Other drugs have similar anticoagulant effects (rivaroxaban, apixaban, edoxaban, and dabigatran) and are allowed as part of the required evaluation for special issuance.

In patients who have clinical indications for blood thinning, but have high risk for bleeding, minimally invasive techniques to isolate the LAA are considered, employing the Watchman implant.

Heart rate is controlled with digoxin, beta blockers, calcium channel blockers, or amiodarone—all allowed by the FAA. If all are exhausted, a permanent pacemaker may be required.

Rhythm control medications allowed by the FAA with a detailed cardiac evaluation include propafenone, flecainide, amiodarone, and sotalol; dofetilide is not allowed. Some patients are resistant or intolerant to medications. In those cases, a precise electrical shock, known as cardioversion, or minimally invasive techniques to stop the aberrant heart impulses may be offered.

Most patients lead a full life with atrial fibrillation. Hopefully the aforementioned explains why the FAA takes this seriously, but atrial fibrillation does not have to mean the end of your flying days. If diagnosed, self-ground until you’re stable and ready to submit records to the FAA for special issuance consideration.

Another rocker, Huey Lewis, sang, “the heart of rock and roll is still beating.” Enjoy Rod and Huey, and also listen metaphorically to keep your rhythm session on the beat.AOPA

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