Syncope Boosts Cardiac Arrest Risk in Long-QT Syndrome

Among adolescents with the hereditary condition, risk is reduced by treatment with β-blockers

TUESDAY, Sept. 12 (HealthDay News) -- In adolescents with hereditary long-QT syndrome (LQTS), the timing and frequency of syncope, gender and QTc interval are all risk factors that can play a role in sudden cardiac death, according to a study published in the Sept. 13 issue of the Journal of the American Medical Association.

Jenny B. Hobbs, M.D., of the University of Rochester Medical Center, Rochester, N.Y., and colleagues conducted a study of 2,772 patients from the International Long QT Syndrome Registry. Of these, 81 patients had aborted cardiac arrest, and 45 experienced sudden cardiac death. Of the 81 patients who experienced aborted cardiac arrest, nine subsequently had sudden cardiac death.

Those who had a syncope once or twice within the past two years were 12-18 times more likely to experience a life-threatening event than those with no syncope over the same time frame. In the former group, use of β-blockers reduced the risk by 64 percent. For those aged 13 to 20 years old there were no significant sex differences in terms of risk, but males aged 10 to 12 had a four times higher risk than females of cardiac arrest.

"This clinically oriented risk-stratification approach might serve as a useful guide for prophylactic treatment decisions to reduce the risk of sudden death in patients with LQTS during the high-risk teenage years," the authors wrote.

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