BACKGROUND: The Mustard operation is a complex atrial rerouting performed in @entity1 with @entity3886 ( @entity3886 ). Cavotricuspid isthmus (CTI)-dependent @entity956 ( @entity956 ) is an important problem in these @entity1 . While catheter ablation (CA) is successful, three-dimensional (3D) mapping is necessary to prove block at the CTI. 3D mapping, however, requires baffle puncture. We tested a simplified concept to prove @entity616 after CA for @entity956 in Mustard @entity1 . METHODS: During electrophysiology study, catheters were placed in the high and low systemic venous atrium (HSVA and LSVA) and in the low pulmonary venous atrium (LPVA). LPVA and then LSVA were paced while recording in the HSVA and the alternate site. While pacing from one low site, the time taken to activate the other low site and the HSVA was compared before and after successful ablation. RESULTS: Three @entity1 with Mustard operation and @entity956 underwent successful CA. Involvement of the CTI in @entity956 was proved by entrainment mapping. @entity956 was terminated during ablation and no longer inducible after ablation in all. LSVA pacing showed LPVA activation preceded HSVA activation preablation and activation pattern reversal after ablation. Likewise, LPVA pacing showed LSVA activation preceding HSVA preablation with reversal after ablation. CONCLUSION: This study provides a simple method to demonstrate bidirectional block at the CTI in @entity1 with CTI-based @entity956 after Mustard operation for @entity3886 .

Simplified demonstration of cavotricuspid XXXX after catheter ablation in @entity1 after Mustard's operation.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity3886 :: ('MESH:D014188', 'Disease') :: ['transposition of the great arteries', 'TGA'] @entity956 :: ('MESH:D001282', 'Disease') :: ['atrial flutter', 'AFL'] @entity616 :: ('MESH:D006327', 'Disease') :: ['isthmus block']
@entity616 :: (MESH:D006327,Disease) :: ['isthmus block']
