Matters of the HEART

Atrial fibrillation topic of ‘Heart Talk’ program

The parts of a heart are shown. This organ, specifically atrial fibrillation, was the subject of a Wednesday talk, “Heart Talk with the Docs,” at the Holiday Inn in Marquette. (Journal file photo)

MARQUETTE — The heart, being the complex organ it is, sometimes doesn’t function properly depending on the circumstances.

One of those issues — atrial fibrillation — was the subject of a UP Health System “Heart Talk with the Docs” program Wednesday at the Holiday Inn.

Commonly known as A-fib, the condition is a rapid irregular heart rhythm involving the upper chambers of the heart, or the atria. It can happen in people with no other heart abnormalities, although conditions like high blood pressure and obesity can lead to the stiffening of the heart muscle.

Speaking about A-fib were Dr. Rudy Evonich and Dr. Michael Mellana, both UPHS cardiac electrophysiologists.

Some understanding of the condition was in order.

A diagram shows an episode of atrial fibrillation. (Photo courtesy of J. Heuser)

“The sinus node regulates the heart rate, much like a thermostat regulates the temperature in the room,” Evonich said. “A normal resting heart rate is 60 or 70 beats a minute, and the sinus node sets that rate for you.”

The sinus node, he said, “pays attention” to what a person is doing.

“It knows if you’re chasing the dog down the street or carrying groceries up the steps, that your muscles are using more oxygen and nutrients, and it increases the heart rate to meet that need,” Evonich said.

When a sinus node fires, he explained, it causes the atria to squeeze, which contributes to filling the lower chambers, or ventricles, which then pump the blood throughout the body.

With A-fib, instead of squeezing in a coordinated, orderly fashion, an atrium “quivers and shakes,” and with that comes consequences.

“When the upper chamber’s quivering rather than squeezing, it’s not filling the lower chamber the way it should, so the heart operates less efficiently as a pump, and in addition, the heartbeat tends to beat much faster, making the heart less efficient as a pump, and the cadence of the rhythm is off,” Evonich said.

All this, he noted, results in symptoms like palpitations, fatigue, shortness of breath and light-headedness.

Mellana talked about some of the triggers that can lead to A-fib.

He acknowledged the population is aging, but mentioned the obesity epidemic, which causes problems like sleep apnea, heart failure, hypertension and diabetes.

“Sleep apnea is a common trigger for atrial fibrillation,” Mellana said.

Since A-fib can lead to a premature death, treating it is important.

“If you maintain a normal rhythm, you’ll live longer,” Mellana said.

Options include a cryoballoon catheter ablation, he said, with people having this procedure needing to be on blood thinners — either Warfarin or one of the newer drugs.

He also prefers ablation over medications used to treat A-fib, with catheters having improved over the years.

“If you’re on the spectrum that responds, that’s good,” Mellana said of those medications. “If it doesn’t work, then we’ll do the ablation.”

Common heart rate-controlling medications include Digoxin, Lopressor, Metoprolol, Atenolol, Diltiazem and Verapamil. Common anti-arrhythmic medications include Amiodarone, Multaq, Sotalol, Propafenone, Flecainide and Dofetilide.

There’s another frightening dimension to A-fib.

Evonich said one-third of people with A-fib will have a stroke.

“Strokes due to atrial fibrillation are larger strokes,” Evonich said. “They’re more likely to be disabling strokes. They’re fatal strokes, and folks with atrial fibrillation who have a stroke are more likely to have another stroke.”

One in four people with A-fib who had a stroke die within a month, he said, and of those who survive, 30 percent are severely impaired and 70 percent are vocationally impaired, meaning they can’t return to work.

Some patients take Warfarin to thin their blood, he said.

“Monitoring is mandatory, so you have to have blood tests to assess how thick or thin your blood is to make sure that you’re protected against stroke and not at high risk for bleeding,” Evonich said.

Novel oral anticoagulants are easier to monitor than Warfarin, he said, but there is a higher risk of bleeding and are costly, and because of those factors, between 20 and 30 percent stop their medicines within two years.

Evonich also discussed the Watchman device, a plug that sits at the opening of the left atrial appendage and is considered safer than Warfarin in the long term. The appendage is sealed, which means clots can’t leave and cause a stroke, he said.

UPHS is taking part in the aMAZE Trial, the purpose of which is to determine whether the LARIAT procedure can be performed in patients with persistent or longstanding A-fib when done in addition to catheter ablation.

According to amazetrial.com, the LARIAT procedure is cleared by the U.S. Food and Drug Administration for use in general surgery to close soft tissue, but hasn’t been well-studied for closing the left atrial appendage in A-fib patients who also receive catheter ablation.

“We expect it’s going to reduce the recurrence risk for atrial fibrillation but also probably impact the stroke risk because the left atrial appendage is where 90 percent of the clots come from,” said Evonich, with those clots causing strokes in people with A-fib.

People who attended the presentation — some of whom have A-fib and others who know people with that condition — came for a variety of reasons. One audience member, Shirley Pum of Marquette, is a retired registered nurse.

“I like to keep up with what’s happening,” Pum said.

Christie Bleck can be reached at 906-228-2500, ext. 250. Her email address is cbleck@miningjournal.net.