Sinus rhythm mapping in healed experimental XXXX : contrasting activation patterns for inducing ventricular tachycardia versus fibrillation.

@entity162 @entity1165 @entity235 @entity583 @entity943
The inducibility of @entity1165 ( @entity1165 ) and fibrillation (VF) is variable in healed @entity583 ( @entity583 ) in the @entity235 . To better understand the electrophysiologic basis for these @entity943 , @entity583 was produced in @entity235 by ligating the left anterior descending artery. One week later, epicardial mapping was performed with the @entity235 in sinus rhythm using a hand-held bipolar electrode. Transmural mapping was performed with the @entity235 in sinus rhythm with 4 pairs of @entity162 mounted on a #14 needle. @entity943 were induced by the S1S2S3 technique or 3- to 5-beat burst pacing at twice diastolic threshold. Only VF could be induced in 11 @entity235 , while sustained @entity1165 was induced in 6 @entity235 . Significantly more marked and more extensive delay in activation was seen both in the epicardium and transmurally in @entity235 with @entity1165 than in @entity235 with VF. In addition, @entity235 with @entity1165 had morphologic evidence of a large transmural @entity583 , whereas @entity235 with VF had only a @entity583 . It is concluded that inducible sustained @entity1165 in the @entity235 is usually associated with a large transmural @entity583 and an activation sequence in sinus rhythm characterized by an extensive area of marked delay in activation. This activation pattern in sinus rhythm presumably is necessary to provide the underlying electrophysiologic milieu for sustained reentry.
