Arrhythmia culprit caught in action

Using powerful X-rays, University of British Columbia researchers have reconstructed a crime scene too small for any microscope to observe – and caught the culprit of arrhythmia in action.

Characterized by the heart beating too fast, too slow or inconsistently, arrhythmias may cause a decrease of blood flow to the brain and body, resulting in heart palpitation, dizziness, fainting, or even death.

Presented today at the 2013 Annual Meeting of the American Association for the Advancement of Science (AAAS) in Boston, the 3D animated model reveals for the first time how gene mutations affect the crucial pathway in heart muscle cells that controls its rhythm.

"Our heart runs on calcium," says UBC molecular biologist Filip Van Petegem. "Every heart beat is preceded by calcium ions rushing into heart muscle cells."

"Then, a special protein opens the pathway for calcium to be released from compartments within these cells, and in turn initiates the contraction."

Mutations to the gene that forms this protein have been linked to arrhythmia and sudden cardiac deaths in otherwise healthy people.

"Reconstructing the pathway and its dynamic motion enabled us to see the process in action," says Van Petegem. "We found that the mutations destabilize the pathway's structure, causing calcium to be released prematurely.

"Finding a way to stabilize the pathway could prevent these deadly conditions and save lives."

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Brian Lin

brian.lin@ubc.ca
604-818-5685
University of British Columbia