Catheter-mediated electrical ablation of the posterior septum via the coronary sinus: electrophysiologic and histologic observations in XXXX .

@entity2293 @entity301 @entity235 @entity11233 @entity713 @entity11283 @entity453 @entity943 @entity204 @entity130
In a series of 12 @entity235 , the electrophysiologic and histologic effects of a single damped sine-wave shock delivered via standard electrocatheters to the region of the coronary sinus orifice were investigated. Six @entity235 received 200 J and six received 360 J of stored energy. The shock was delivered to two consecutive proximal poles of a standard quadripolar catheter positioned at the coronary sinus orifice and connected to the positive output (anode) of a defibrillator. A disc electrode positioned on the anterior chest wall served as the cathode (negative pole). During the shock, voltage and current were recorded. Electrophysiologic testing was done before and 4 weeks after the shock. At 4 weeks, animals were killed and serial sections of the atrioventricular groove and conduction system were performed. No significant long-term change in atrioventricular conduction, spontaneous or induced @entity943 was observed. However, transient @entity713 was seen in five and @entity11233 in six animals in the short term. No persistent electrocardiographic changes were observed, and no sudden @entity204 occurred. Microscopically, transmural @entity130 was inconstant and infrequent. However, transmural @entity130 at the level of the coronary sinus was produced over a 10 +/- 5 mm length with the 200 J shock and a 21 +/- 6 mm length with the 360 J shock. Neither @entity453 nor damage to the conduction system was seen and @entity2293 did not occur. However, localized intramural @entity301 (on the endocardial aspect only) was observed in each @entity235 , consistent with @entity11283 . With the present technique, @entity130 potentially capable of blocking the effects of accessory pathway conduction could be produced without other electrophysiologic alterations or complications. @entity130 (and therefore to any accessory pathway per se) is probably unlikely. @entity11283 may play a significant role in the @entity130 observed in this study.
