Researchers have picked apart the mechanisms behind calcium-triggered heart arrhythmias, hoping soon to development new medications to fight their deadly occurrence.

There are many factors that can contribute to the development of heart arrhythmias. Stepping out of sync can cause the heart to beat irregularly leading to dizziness, fainting or even sudden arrhythmic death.

A common mechanism of cardiac arrhythmias is calcium overload in the heart, but the underlying cause of calcium-triggered arrhythmias has remained a mystery for decades.

Now, using a combination of molecular biology, electrophysiology, and genetically engineered mice, Canadian scientists 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.

Experiments using genetically-modified mice allowed the team to manipulate this sensor, and even prevent oncoming calcium-triggered arrhythmias.

“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," says Dr Wayne Chen, the study's senior author and University of Calgary researcher.

“These findings open a new chapter of calcium signalling and the discovery fosters the possibilities of new drug interventions.”