More than 1.8 million people in Germany live with atrial fibrillation, and the increase in the population's life expectancy increases.
Because the flicker is usually the result of an aging heart.
Circulating electrical excitations arise in the scarred atria.
The atria beat chaotically and at breakneck speed, up to 600 times per minute instead of the usual 60 to 80 times.
Some patients would not notice anything from the fibrillation, says Andreas Götte, board member in the competence network for atrial fibrillation and cardiologist in Paderborn, “but some suffer quite a lot from the fibrillation attacks”. They feel their heart beating unpleasantly or racing, they can hardly breathe, they get dizzy and some are even scared to death. If the symptoms disturb, doctors recommend either medication - antiarrhythmics - or catheter ablation, in which the pathological foci of excitation in the atria are obliterated.
However, the drugs cause side effects, and the ablation, although rare, can lead to bleeding, injury, or other complications. Recently, Oklahoma researchers unveiled an alternative procedure that patients can use at home. The patient clamps a small clip on the tragus - on the cartilage in front of the ear opening - and stimulates a branch of the vagus nerve with the help of a device the size of a cell phone. The nerve belongs to the parasympathetic part of the autonomic nervous system. This probably plays a central role in the development of atrial fibrillation.
The idea is that with the stimulation via the parasympathetic vagus nerve, sympathetic nerve activities are suppressed centrally in the brain, so that the fibrillation does not even begin or is suppressed. The Oklahoma researchers examined 53 patients. 27 of them were asked to fix the clip to the tragus for one hour a day for six months and stimulate it with the device. The remaining 26 participants served as controls and clamped the clip to their earlobe - but their vagus nerve was not stimulated. At the start of the study, halfway through, and at the end, an electrocardiogram was recorded over two weeks to record times with atrial fibrillation episodes. In addition, the researchers measured inflammatory messengers such as TNF-alpha in the blood, because these are also said to be involved in the development of atrial fibrillation.
After six months, patients with the stimulation suffered from significantly fewer atrial fibrillation episodes.
The blood levels of TNF-alpha had also decreased.
The authors concluded that vagus nerve stimulation through the skin is an inexpensive and low-risk alternative for selected patients.
No more than a glimmer of hope
Heart specialist Götte is skeptical, however. The method is interesting, he says, but is still far from becoming a real alternative to drugs and ablation. The study was well structured with the placebo stimulation, but with 53 patients it was very small, so that the results have yet to be reproduced in larger studies. He also considers the two-week electrocardiogram to be insufficient, says Götte. “It would have been ideal if the heart rhythm had been recorded permanently over the entire six months, for example with a recorder implanted under the skin.” It could well be that a patient had atrial fibrillation of all times when it was not being measured.
Apart from that, the patients responded very differently to the stimulation.
Some had much fewer atrial fibrillation episodes afterwards, but others did not.
The Oklahoma researchers themselves admit that they have no biomarkers that can be used to predict which patient will benefit.
“As long as we don't know, the device has no place in the routine,” says Götte.
The approach is nothing more than a glimmer of hope, says Thomas Lüscher, cardiologist at Imperial College in London.
He is impressed that the stimulation through the skin works at all: “That worked almost too well in the study to be true.
Let's wait and see what further examinations show. ”In addition, the patients should not be under the illusion that they would be able to do without their blood thinners.
Blood thinners are said to reduce the risk of stroke. Patients with atrial fibrillation are more likely to get this because blood clots form more easily in their atria, which can get into the brain and block a vessel there. The medication has to be taken permanently and there is always a risk of bleeding if the dosage is incorrect. Doctors use a point system to calculate who needs blood thinners.
So far, antiarrhythmic drugs or catheter ablation have been recommended primarily to patients who clearly feel the fibrillation and suffer from it. However, there are indications that patients who do not feel its flickering could also benefit from the stimulation through the skin. An international research group now wants to investigate this in the large "East" study. Around 3000 patients are to be included. Half of them are treated classically for arrhythmias - regardless of whether they have noticeable symptoms or not. The rest only if they actually have complaints. After three years, the researchers look to see which group is better at preventing cardiovascular diseases and premature deaths. The researchers expect results in 2021. "If the treatment would also benefit symptom-free patients,the stimulation through the skin would be particularly interesting, ”says Lüscher.