Cardiac arrhythmia Effective therapy for atrial fibrillation

Excellent study opens up new treatment options for cardiac arrhythmias

Up to two million people in Germany suffer from atrial fibrillation, the most common cardiac arrhythmia. The symptoms are often characterized by irregularities in the heartbeat such as heart stuttering and palpitations. Also, the sufferers tend to increased blood clots, which is why the risk of having a stroke is increased. A German research team has taken a closer look at the causes of this disease in a recent study. From the new findings, the physicians could derive a new therapeutic approach for treatment of atrial fibrillation and heart failure.

The possibilities of drug treatment of atrial fibrillation is currently still very manageable and there is a great interest in new treatment options. In many cases, atrial fibrillation is associated with other heart disease and may be a possible cause of chronic heart failure (heart failure). Central element of the study was the exact investigation of the so-called two-domain k2 potassium channel K2P3.1 or TASK-1 called short, which plays a crucial role in cardiac arrhythmias. The study was awarded the August Wilhelm and Lieselotte Becht Research Award 2017 and published in the journal "European Heart Journal".

New findings in the study of cardiac arrhythmias open up new therapeutic approaches against atrial fibrillation and heart failure. (Image: Sonja Calovini / fotolia.com)

Cases of atrial fibrillation increase annually

The experts assume an annual increase in new cases of atrial fibrillation. Likewise, the number of diagnoses of chronic heart failure is growing. In 2016 alone, over 455,000 cases had to be hospitalized. Findings in research on this topic have not yet been exhausted and there are currently only limited effective drug treatment options for atrial fibrillation. "The interest of the heart medicine in new approaches for the treatment of atrial fibrillation in connection with the chronic systolic heart failure is therefore great", explains Prof. Dr. med. med. Hellmut Oelert, Chairman of the Scientific Advisory Board of the German Foundation for Heart Research (DSHF).

A new promising approach

The research team around PD Dr. med. Constanze Schmidt was able to establish an association between the TASK-1 potassium channel in the heart and the atrial fibrillation and to develop a promising approach for the development of new cardiac rhythm medications. The study is based on data from 175 patients with varying degrees of left ventricular pumping function. According to the researchers, the TASK-1 potassium channel plays a key role in the development of so-called action potentials in the cells of the heart muscle.

Increased TASK-1 currents lead to atrial fibrillation

The action potential describes a short-term change in the electrical state of excitation within those muscle cells that play an important role in the movement of the heart chambers. The researchers found that in patients with chronic atrial fibrillation, the TASK-1 potassium channel is significantly increased. According to the scientists, this results in a significant increase in cardiac muscle cells, which in turn leads to a significant reduction of the action potential on the anterior chamber level.

Basis for new therapies

"If one interrupts the increased TASK-1 currents, the action potential duration normalizes to values ​​of patients without atrial fibrillation," says Constanze Schmidt in a press release on the study results. This action potential reduction is the decisive basis for the development of atrial fibrillation. Conversely, the mechanism behaves in the heart muscle cells of heart failure patients. A low TASK-1 level with a decrease in the TASK-1 current is associated with an extension of the action potential duration.

Meaning for the heart medicine

These patterns provide an approach to the profile of action of new pharmacological therapies and treatment options. "We now know that atrial fibrillation and chronic heart failure are independent primary factors for the regulation of this TASK-1 potassium channel," explains Schmidt. Other secondary factors influencing the potassium channel include male gender, elevated body mass index over 27, and whether the patient is a smoker or not.

"Thanks to these findings, we can more specifically target rhythm drugs to the regulation of the TASK-1 potassium channel to treat heart disease. This represents a new therapeutic approach for individualized antiarrhythmic therapy, "sums up Schmidt. (Vb)