NEW YORK (Reuters Health) - Patients whose ventricular tachycardia--a rapid, abnormal heart rhythm--can be reproduced in the cardiac laboratory face a significantly higher risk of sudden death than patients whose ventricular tachycardia cannot be induced.

The finding may help to identify heart disease patients at greatest risk for sudden death or cardiac arrest.

Most sudden deaths and cardiac arrests in heart attack patients result from ventricular tachycardia or its more dangerous cousin, ventricular fibrillation.

A special form of cardiac evaluation called electrophysiologic (EP) testing can divide patients into two groups: those with an abnormal rhythm that can be induced by testing and those without such an abnormal heart rhythm. But whether this grouping accurately predicts outcomes has been controversial, according to Dr. Alfred E. Buxton, of the Rhode Island Hospital, in Providence, and associates from 85 study sites across the US and Canada.
　　
　　The group's study of more than 1,700 patients--353 with inducible abnormal rhythms and 1,397 without--may lay the controversy to rest. Their results are published in the June 29th issue of The New England Journal of Medicine.

Patients with inducible ventricular tachycardia had a 2-year rate of cardiac arrest or death from an abnormal rhythm of 18%, compared with 12% for patients without inducible ventricular tachycardia. Five-year rates were 32% and 24%, respectively, the authors report.

Overall death rates were also worse for patients with reproducible heart rhythm abnormalities. Two-year death rates were 28% for such patients, compared with 21% for patients without inducible abnormalities, the report indicates. Five-year death rates from all causes were 48% and 44%, respectively.

The authors conclude that EP testing can be used to determine which patients face a higher risk of cardiac arrest and death. Such patients might be candidates for more aggressive approaches to prevent or treat their abnormal rhythms.

　　(From Yahoo)