Indian-led study finds clues to sudden death of healthy peopleMarch 23rd, 2009 - 12:34 pm ICT by IANS
New York, March 23 (IANS) An Indian-born, Kolkata-educated scientist at Johns Hopkins University and his fellow researchers have found an answer to sudden death of healthy people, including athletes.
Describing it as sudden cardiac death, they say it is caused by abrupt stopping of the heart due to an abnormality in its electrical impulses.
In a study published in Nature Genetics, Aravinda Chakravarti of Johns Hopkins University School of Medicine and fellow scientists say that in such cases, the heartbeat becomes very irregular - either very fast or very slow - leading to fatal results.
They say their research has linked sudden cardiac death to congenital problems with the heart.
One such congenital problem is called ‘long QT syndrome’ (LQTS). People with this problem are prone to have either a prolonged or shortened QT interval - which is the time it takes for the heart to contract and then get ready for the next beat.
Scientists say when people with this syndrome suddenly become stressed or undertake strenuous physical activity, their heart simply snaps as it is not able to speed up properly.
This results in sudden cardiac death, they say. In their ground-breaking research, Chakravarti and colleagues have identified 10 common variants of genes that modify the QT interval or heart beat. As part of their research, they used DNA samples previously collected for epidemiological studies to analyse the genomes of 15,842 individuals whose QT intervals had been measured by electrocardiogram.
Calling it a major breakthrough in heart biology, Chakravarti said: “The reason people die from this cardiovascular disorder is because we know nothing about the antecedents.”
“It’s like a truck barrelling down a slope: there’s no way to stop it. The only way out is to understand the science of this in a deep, meaningful way. If we know, we can begin to intervene.”
The professor added: “I have no doubt, absolutely no doubt, that everything we discovered will have clinical benefit, but what I can’t tell you is when, I can’t tell you how.”
Till now, Chakravarti said, identifying who has “long QT syndrome” has been difficult because people exhibit no sign of the disorder till their heart suddenly stops beating.
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