Scientists solve sudden cardiac death mystery

August 1, 2014
Scientists solve sudden cardiac death mystery

(Medical Xpress)—Scientists have discovered the cause of sudden cardiac death in young children, for the first time making it possible to pinpoint a therapeutic target for future efforts in developing a cure.

Heart specialists at Cardiff found that incoherent communication between two vital proteins in heart cells was to blame for the previously inexplicable cause of death.

"A healthy and regular heartbeat is maintained by precise control of the calcium level in , but our experiments have identified a genetic flaw that invites chaos to this process," said team leader of the study, Professor Tony Lai from the School of Medicine's Sir Geraint Evans Wales Heart Research Institute (WHRI).

Dr Michail Nomikos, also from the School of Medicine and the study's lead author, explained why this biological equilibrium becomes unstable: "When calcium levels rise the heart contracts and when the calcium levels drop the heart muscle relaxes, similar to the upstroke and downstroke of a motor engine. The precise control of this movement relies on the direct physical interaction between a calcium channel protein ryanodine receptor (RyR), and a calcium-sensing protein called calmodulin."

"We discovered that a genetic mutation in calmodulin causes a loss of regular heart rhythm and produces ineffective communication between calmodulin and RyR. Our findings show that there is inadequate binding between these proteins due to the mutated calmodulin gene resulting in the loss of control of cell and thereby abnormal heart function.

"Abnormal changes in calcium levels disrupt the smooth cycling between cardiac contraction and relaxation that leads to irregular heartbeat and sudden death."

In the future, Professor Lai anticipates that finding a way to intervene in ensuring a stable interaction between calmodulin and RyR in the heart will give doctors a new weapon in the fight against .

Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation, said: "Keeping the heart's calcium levels under control is critical to maintaining a healthy rhythm.

"By showing how mutation could disrupt this and lead to sudden , the Cardiff team have provided new clues for how to treat the condition in the future.

"Uncovering genetic links like this is vital to help combat the devastating effects of inherited heart conditions. The BHF is urgently campaigning for more research to help find the undiscovered faulty genes putting people at greater risk of disease."

Explore further: Researchers solve puzzle of proteins linked to heart failure

Related Stories

Researchers solve puzzle of proteins linked to heart failure

February 22, 2012
Sudden cardiac death is a risk for patients with heart failure because the calcium inside their heart cells is not properly controlled and this can lead to an irregular heartbeat. New findings published in PLoS ONE, which ...

Researchers discover how heart arrhythmia occurs

January 19, 2014
Researchers have discovered the fundamental biology of calcium waves in relation to heart arrhythmias.

New target to stop cancer's spread discovered

January 30, 2013
Disrupting a key interaction between two types of proteins in cells inhibits the spread of cancerous cells, providing researchers with a new pathway toward developing cancer-fighting drugs, according to new findings by Georgia ...

Cause of heart arrhythmia discovered using X-rays at CLS

February 22, 2013
Using powerful X-rays at the Canadian Light Source synchrotron, scientists have reconstructed the scenario of heart arrhythmia in action, making critical progress towards preventing deadly conditions and saving lives.

Recommended for you

Could aggressive blood pressure treatments lead to kidney damage?

July 18, 2017
Aggressive combination treatments for high blood pressure that are intended to protect the kidneys may actually be damaging the organs, new research from the University of Virginia School of Medicine suggests.

Quantifying effectiveness of treatment for irregular heartbeat

July 17, 2017
In a small proof-of-concept study, researchers at Johns Hopkins report a complex mathematical method to measure electrical communications within the heart can successfully predict the effectiveness of catheter ablation, the ...

Concerns over side effects of statins stopping stroke survivors taking medication

July 17, 2017
Negative media coverage of the side effects associated with taking statins, and patients' own experiences of taking the drugs, are among the reasons cited by stroke survivors and their carers for stopping taking potentially ...

Study discovers anticoagulant drugs are being prescribed against safety advice

July 17, 2017
A study by researchers at the University of Birmingham has shown that GPs are prescribing anticoagulants to patients with an irregular heartbeat against official safety advice.

Protein may protect against heart attack

July 14, 2017
DDK3 could be used as a new therapy to stop the build-up of fatty material inside the arteries

Heart study finds faulty link between biomarkers and clinical outcomes

July 14, 2017
Surrogate endpoints (biomarkers), which are routinely used in clinical research to test new drugs, should not be trusted as the ultimate measure to approve new health interventions in cardiovascular medicine, according to ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.