Faulty gene can trigger fatal cardiac arrests
The heart has a regular electrical impulse that causes it to beat and pump blood around the body, but if this is interrupted it causes an abnormal heartbeat, known as an arrhythmia.
These dangerous heart rhythms can cause sudden cardiac arrests in seemingly healthy young people, and can cause deaths.
More than 1,500 Scots died in 2013 after suffering such a cardiac arrest, including talented footballer Jamie Skinner, 13, who had a fatal cardiac arrest on an Edinburgh pitch.
Experts from Manchester University, funded by the British Heart Foundation (BHF), will present research to the British Cardiovascular Society (BCS) Conference today, which has found that a faulty calcium channel in heart cells can lead to a rare but potentially fatal heart condition called CPVT (catecholaminergic polymorphic ventricular tachycardia).
The channel should open and shut to let calcium regularly into the heart cells, kicking off the required electrical impulse for the heart to beat.
During exercise, adrenaline is released which increases the amount of calcium stored in the cells. But when someone has the faulty gene, this channel can stay open for too long, making it leaky and flooding the heart cells with calcium. This in turn causes the fatal arrhythmia.
Professor David Eisner, from Manchester University, who led the research, said: “People who are prone to sudden arrhythmias often die young.
“Survivors may have an internal defibrillator fitted at a young age, to shock their heart back into a regular heartbeat if needed, but the device does not last forever and needs replacing as the child or young person grows.
“A better understanding of what goes wrong inside the heart during an arrhythmia is crucial to finding the genes that can cause abnormal heart rhythms, and developing better treatments for people at risk of the tragedy of sudden cardiac death.”
Clinicians from the team are working with the families of those who have died from sudden arrhythmic death syndrome (SADS) to determine if they are also at risk.
As the gene is inherited, the team wants to know if everyone with the faulty gene develops an arrhythmia or if there are other genes involved.
Professor Jeremy Pearson, associate medical director at the BHF, said: “Exercise is a vital part of maintaining a healthy heart and for the vast majority of people, it should be part of their daily routine but, for some people, exercise can trigger an underlying condition that they didn’t know they had.
“We know that screening doesn’t find everyone with the genes that can make them prone to sudden cardiac death and we urgently need more research to understand the causes of these rare, but potentially fatal, arrhythmias.”