Chronic @entity6237 therapy selected by electrophysiology testing of intravenous XXXX .

@entity1 @entity2643 @entity712 @entity1165 @entity3794 @entity6237 @entity1167 @entity583 @entity1818
The utility of @entity6237 was evaluated in 93 @entity1 by means of electrophysiologic studies before and after intravenous @entity6237 administration to determine long-term efficacy. Twenty @entity1 had a prior history of at least one @entity1167 and 73 @entity1 had sustained @entity1165 ( @entity1165 ). The mean radionuclear ejection fraction was 32 +/- 5%. @entity6237 was evaluated in 93 @entity1 , with 44 @entity1 no longer having @entity1165 following @entity6237 (47% efficacy). @entity1818 was evaluated in 69 @entity1 ; 24 @entity1 had an adverse reaction to reaction to @entity1818 and 28 of the 69 @entity1 were protected on @entity1818 (40% efficacy). The mean serum concentration of @entity6237 achieved in the protected group was 298 +/- 36 ng/ml and 4.3 micrograms/ml for @entity1818 . Both @entity6237 and @entity1818 significantly prolonged refractoriness, lengthened QRS duration, while only @entity1818 increased the QT interval. All 93 @entity1 were discharged on antiarrhythmic therapy, 42 on @entity6237 , 27 on other antiarrhythmic therapy guided by electrophysiologic testing, and 24 on @entity2643 (when all other agents failed). Six of the 42 @entity1 on @entity6237 complained of adverse side effects, but none were severe enough to warrant stopping therapy. Of the 42 @entity1 on @entity6237 , four (9%) died suddenly over 18 +/- 4 months. Twenty-seven @entity1 were on other therapy; eight of these have died, three suddenly (11%), four with @entity583 , and one due to @entity712 . Twenty-four @entity1 started @entity2643 ; 11 have died, five (21%) suddenly, four of @entity712 , one of @entity3794 , and one with @entity583 .(ABSTRACT TRUNCATED AT 250 WORDS)
