@entity1162 and the antiarrhythmic efficacy of XXXX .

@entity1 @entity2643 @entity712 @entity1165 @entity17742 @entity1167 @entity1162
@entity2643 is an antiarrhythmic agent known to cause prolongation of action potential duration which is reflected in the electrocardiogram as a prolongation of the QT interval. @entity1162 in @entity1 dying suddenly was compared with that in @entity1 who remained alive to determine whether a difference existed between these two groups. The electrocardiogram and @entity2643 levels were evaluated in 33 @entity1 who presented with @entity1167 and symptomatic @entity1165 in whom no other antiarrhythmic agent was found effective in preventing induction of @entity1165 during electrophysiologic studies. There were 30 @entity1 and 3 @entity1 (mean age 52 +/- 10 years). Twenty-three are alive after a mean follow-up period of 12 +/- 7 months. Ten died: six suddenly, three of non-cardiac causes and one of @entity712 . Using a two-way analysis of variance, the percent change in QT, QTc, JT and JTc intervals before and after @entity2643 therapy was analyzed. Marked prolongation in the QT interval was present in @entity1 who remained alive with @entity2643 therapy. A significant difference in percent @entity1162 was seen between the latter @entity1 and those who died suddenly (p less than 0.005). No difference was observed in the percent change in QRS interval between the two groups. The levels of @entity2643 (2.5 versus 3.2 micrograms/ml) and its metabolite ( @entity17742 ) were not significantly different between the living @entity1 and those who died suddenly. These findings suggest that a prolongation of the QT interval may be a marker for the therapeutic antiarrhythmic effect of @entity2643 .
