Researchers at the University of Calgary say they have made a key discovery in heart arrhythmia.

It has been known for years that elevated levels of calcium in the heart can cause it to beat irregularly. However, no one knew what was raising the calcium levels — until now.

"This calcium sensor is responsible for calcium-triggered arrhythmia and we can actually show that when you manipulate the sensor in the mouse, or in mice, we can actually protect those mice completely from calcium-triggered arrhythmia," said Wayne Chen, a researcher at the Libin Cardiovascular Institute.

Heart arrhythmia can result in symptoms such as dizziness and fainting and can cause sudden death in severe cases.

Currently arrhythmia patients get a defibrillator implanted to regulate their heart rhythms.

Researchers are hoping their discovery will help develop medication to manipulate the sensor in a patient's body to prevent the problem before they need the defibrillator device.

Roughly 30,000 Canadians die every year from heart arrhythmia.