Here's why your heart keeps going out of rhythm after therapy

Ablation procedures may not always fix a patient's abnormal heart rhythm completely and now, a recent study has found as to why it is so.

Researchers from the Intermountain Medical Center Heart Institute in Salt Lake City have found that certain molecules are associated with the recurrence of atrial fibrillation in some patients after therapy.

These molecules, known as circulating microRNA, have the promise of becoming screening tools to help determine which patients will benefit from various therapies, the team found.

Circulating microRNA refers to microRNA that has spilled out of the cell into the blood and can be measured. MicroRNA is the name given to small, very stable non-coding RNA molecules that are involved in gene regulation.

 

Researchers used a series of blood markers to identify those patients whose ablations worked the first time. They compared 85 patients who had successful ablations with 55 patients whose atrial fibrillation recurred within a year.

The microRNA particles studied can impact inflammation, fibrosis, and the heart's electrical activity. Because RNA molecules are so small and stable, they can be detected in circulating biological fluids like saliva and blood.

The researchers found low levels of three microRNA molecules, designated as 21, 150, and 328, in patients whose atrial fibrillation came back after ablation. Those molecules have already been associated with ablation's atrial scarring, called remodeling and adverse electrical healing.

"Our genetic makeup is important in how we respond and heal from procedures," said senior investigator T. Jared Bunch. "MicroRNA particles are a direct result of our genetic make-up. As we try to identify treatments that are tailored to an individual person, microRNA has the promise to help us determine who may be a better candidate for ablation versus other therapies."

Researchers hope the study findings will help doctors determine which treatments are more likely to work for different patients with atrial fibrillation, including those who wouldn't benefit from ablation, which is expensive and carries some risks.

Results of the study have been presented at the American College of Cardiology's Scientific Session.