How heart arrhythmias occur

Researchers have found the underlying mechanism of the calcium-triggered arrhythmias.

The study findings outlines the discovery of this fundamental physiological process that researchers hope will one day help design molecularly tailored medications that correct the pathophysiology.

While many factors contribute to the development of arrhythmias, including genetics, scientists know that a common mechanism of cardiac arrhythmias is calcium overload in the heart, i.e. calcium-triggered arrhythmias that can lead to sudden death.

Using a combination of molecular biology, electrophysiology, and genetically engineering mice, scientists at the University of Calgary's and Alberta Health Services' Libin Cardiovascular Institute of Alberta (Libin Institute)have discovered that a calcium-sensing-gate in the cardiac calcium release channel (ryanodine receptor) is responsible for initiation of calcium waves and calcium-triggered arrhythmias.

Utilizing a genetically modified mouse model they were able to manipulate the sensor and completely prevented calcium-triggered arrhythmias.

SR Wayne Chen, PhD, the study's senior author and University of Calgary- Libin Institute researcher, said that the calcium-sensing- gate mechanism discovered here is an entirely novel concept with potential to shift our general understanding of ion channel gating, cardiac arrhythmogenesis, and the treatment of calcium-triggered arrhythmias.

The findings have been published in the journal Nature Medicine.