A landmark international study has identified a genetic variation that may predispose people to double the risk of sudden cardiac arrest, a heart disorder that is fatal in about 95 percent of cases. This is the first genome-wide study of significance for sudden cardiac arrest. Because of the size of the study, its results can likely be applied to the general population.
Unlike heart attacks, which are typically caused by clogged arteries reducing blood flow to the heart, sudden cardiac arrest is the result of defective electrical impulses. With little or no warning, the disorder usually causes virtually instantaneous death. Every year, nearly 300,000 people in the U.S. and up to 5 million worldwide die from sudden cardiac arrest.
“We are starting to unravel the mystery of what causes sudden cardiac arrest and determine how to prevent it,” says the study’s senior author, Sumeet S. Chugh, MD, associate director of the Cedars-Sinai Heart Institute and a specialist in cardiac electrophysiology. “If we wait until someone has a sudden cardiac arrest, it is usually too late for treatment. That is why knowing who is genetically susceptible is so important.”