Imagine if all it took to treat the heart condition atrial fibrillation was clipping a small device to your ear for an hour a day?
That futuristic scenario could soon be a reality, according to a new study.
In a small, early trial, the researchers found the device – which emits a mild electric current – appears to be effective at controlling atrial fibrillation (a-fib) and was well-tolerated by patients.
“This was the first human study [on this treatment].
The research is still in its early phases, but the results are promising and warrant further studies,” said lead author Dr. Stavros Stavrakis. He’s an associate professor at the University of Oklahoma Health Sciences Center in Oklahoma City.
A-fib affects more than 33.5 million people worldwide.
What is atrial fibrillation?
Atrial fibrillation (say “AY-tree-uhl fih-bruh-LAY-shun”) is the most common type of irregular heartbeat (arrhythmia).
Normally, the heart beats in a strong, steady rhythm.
In atrial fibrillation, a problem with the heart’s electrical system causes the two upper parts of the heart, the atria, to quiver, or fibrillate.
The quivering upsets the normal rhythm between the atria and the lower parts of the heart, the ventricles. And the ventricles may beat fast and without a regular rhythm.
This is dangerous because if the heartbeat isn’t strong and steady, blood can collect, or pool, in the atria. And pooled blood is more likely to form clots. Clots can travel to the brain, block blood flow, and cause a stroke.
Atrial fibrillation can also lead to heart failure.
What causes atrial fibrillation?
Conditions that damage or strain the heart commonly cause atrial fibrillation. These include:
- High blood pressure.
- Coronary artery disease.
- Heart attack.
- Heart valve disease.
Other possible causes include:
- Other medical problems, such as heart failure, lung disease, pneumonia, or a high thyroid level.
- Heart surgery.
- Heavy alcohol use. This includes having more than 3 drinks a day over many years as well as drinking a large amount of alcohol at one time (binge drinking).
What are the symptoms?
Symptoms may include:
- Feeling dizzy or light-headed.
- Feeling out of breath.
- Feeling weak and tired.
- Feeling like the heart is fluttering, racing, or pounding (palpitations).
- Feeling like the heart is beating unevenly.
- Having chest pain (angina).
- Feeling anxious.
Sometimes atrial fibrillation doesn’t cause obvious symptoms.
If you have symptoms, see your doctor. Finding and treating atrial fibrillation right away can help you avoid serious problems.
The heart rhythm disorder causes the upper chambers in your heart to quiver at times.
That can cause blood to pool and possibly clot.
When the heart starts beating normally again, the clot may get pushed into the bloodstream where it can travel to the brain and cause a stroke, according to the American Heart Association (AHA).
Treatment includes lifestyle changes and medications to control the heart rate and rhythm and prevent blood clots.
Sometimes, procedures such as ablation (which destroys malfunctioning tissue) or surgery to implant a pacemaker are necessary to control a-fib, the AHA says.
Stavrakis and his team hoped to find a less invasive option, with fewer side effects.
The new treatment is called low-level transcutaneous electrical stimulation (LLTS).
It involves slight electrical stimulation to the vagus nerve through the ear.
The vagus nerve is part of the autonomic nervous symptom, which is responsible for body functions you don’t think about, like blood pressure, body temperature and heart rhythm.
The device is essentially a TENS (transcutaneous electrical nerve stimulation) unit with an ear clip.
TENS, a battery-operated device that delivers electrical impulses through electodes, has been used to help control pain by overriding pain signals in nerves, according to the Arthritis Foundation.
The TENS unit with the ear clip was initially designed to treat tinnitus, a condition that causes ringing in the ear.
In animal studies, stimulation of the vagus nerve via the ear could change the electrical properties of the heart in dogs, Stavrakis said. However, it’s not clear yet if that’s exactly how it works in people.
The treatment may change the electrical stimulation in the heart, or it may be that reduced inflammation may help, he said.
Stavrakis said he thinks this treatment is probably best for patients in the early stages of a-fib, though that hasn’t yet been tested.
The current study included patients with a-fib; 26 people (average age 65) were in the treatment group, and 27 (average age 68) were in the placebo group.
Both groups wore an ear clip attached to the TENS unit for an hour daily for six months. This was done at home, often while the patients did something else, like watching TV.
Heart rates were measured for two weeks continuously at the start of the study, at three months and again at six months.
After six months, the researchers found that atrial fibrillation was reduced by 85 percent in the active treatment group compared to the placebo group.
When the researchers looked at both the three- and six-month time points, atrial fibrillation was reduced by 75 percent compared to placebo.
Stavrakis said the researchers didn’t change any medications that people were on. About half were on drugs to control their heart rhythm, which he said was considered an add-on therapy.
Dr. John Osborne, a spokesperson for the American Heart Association, reviewed the study and said, “I’m very intrigued by the potential of this treatment.
It was easy, simple and probably very well-tolerated. It seems like it would be pretty inexpensive, too.”
He said the drugs for treating a-fib have side effects that can be intolerable to some, and procedures for the condition tend to be invasive.
“There’s a huge opportunity for other strategies to control a-fib,” he noted.
Osborne did point out the study’s limitations – patients came only from a single medical center and the study was quite small.
Still, he said the findings were impressive, and more study needs to be done.
Findings from the study are scheduled to be presented on Thursday at the Heart Rhythm Society meeting, in San Francisco. Research presented at meetings is typically viewed as preliminary until it’s been published in a peer-reviewed journal.
More information: Stavros Stavrakis, M.D., Ph.D., associate professor, University of Oklahoma Health Sciences Center, Oklahoma City; John A. Osborne, M.D., Ph.D., spokesperson, American Heart Association, and State of the Heart Cardiology, Dallas, Texas; May 9, 2019, presentation, Heart Rhythm Society meeting, San Francisco
The Heart Rhythm Society has more about atrial fibrilla