Doctors find first drug to target atrial fibrillation

Scientists at the University Medical Center Hamburg-Eppendorf have discovered the first molecule for the targeted treatment of atrial fibrillation (a specific heart rhythm disorder). The study is published in the European Heart Journal .
In chronic atrial fibrillation, the influx of calcium ions into the cells of the heart muscle decreases. As a result, atrial contraction becomes chaotic and very frequent, which increases the risk of thrombosis and heart failure.
Normally, heart muscle cells die in the laboratory after a few hours. But in order to be able to adequately study them, they must live at least a few days. Scientists managed to extend the life of cells and study their behavior during arrhythmias. It turned out that a protein, phosphodiesterase 8B (PDE8B), is responsible for the violation of calcium flow. It accumulates during atrial fibrillation in the cells of the atria. Conventional anti-arrhythmia drugs target the entire heart, even if only the atria or only the ventricles are affected.
“Reduced calcium current is one of the characteristic features of chronic atrial fibrillation. But its causes remained unknown for decades, so scientists could not develop a therapy to combat this phenomenon, ”explained the author of the study.
Scientists have successfully tested a substance that slows down PDE8B in mice. It is currently undergoing clinical trials for dementia. The scientists now intend to test the drug on horses, which can also develop atrial fibrillation, making them unsuitable for racing.