2009 Volume 73 Issue 3 Pages 444-450
Background: The electrophysiological characteristics of the Marshall potential is important in ligament of Marshall (LOM) ablation. Methods and Results: Marshall potential was recorded under sinus rhythm and left atrial appendage (LAA) pacing and in the first randomly selected 5 dogs (Group 1), LOM ablation was performed. Histological examination was performed in the remaining 10 dogs, which were subdivided according to the results (Groups 2, 3). During LAA pacing in Group 2, the AM interval was prolonged or shortened, whereas in Group 3 it was prolonged (125±9 vs 80±6 ms, P=0.043, when the pacing rate =350) (126±9 vs 80±6 ms, P=0.0442, when the pacing rate =450). The Marshall potential was separated from the atrial electrogram by LAA pacing in Groups 2 and 3. There was no significant difference in the AM interval during sinus rhythm and right atrial appendage pacing. Conclusions: Marshall potential has different forms on electrograms, including a prolonged AM interval, which presents with LAA pacing. This finding might be useful in LOM ablation. (Circ J 2009; 73: 444 - 450)
