UTILIZATION OF 3-D MAPPING FOR SUCCESSFUL ABLATION OF TYPICAL ATRIAL FLUTTER



Hakan Paydak, M.D., University of Arkansas for Medical Sciences, Little Rock, AR, USA

Objectives: Achieving bidirectional isthmus block (BIB) along the cavo-tricuspid isthmus (CTI) is crucial for successful atrial flutter (AFL) ablation and also to prevent recurrence. BIB can be demonstrated by utilizing intra-cardiac electro grams while pacing on both sides of the presumed isthmus block. 3-D mapping is a complementary tool for testing of BIB.

Background: Typical AFL is defined by CTI dependent counterclockwise or clockwise macro-reentry involving the right atrium. Catheter ablation carries high procedural success rate and creation of BIB along the CTI predicts long-term success. Isolated unidirectional isthmus block may rarely occur during AFL ablation. Utilization of 3-D mapping is an important tool to demonstrate absence of BIB and to prove BIB after further ablation.

Methods: Between July 2009 and March 2017, 105 AFL ablations were done at our institution. I herein report utilization of 3-D mappjng in these procedures.

Results: We had 100% success rate and 1 recurrence in 105 AFL ablations. We demonstrated persistence of BIB with 3-D mapping in 102 patients. Although we demonstrated unidirectional medial to lateral isthmus block in 3 patients; lateral to medial conduction remained intact in these patients. Further radiofrequency applications were delivered lateral to the first ablation line, while pacing the low right atrial free wall. 3-dimensional mapping confirmed achievement of BIB.

Conclusions: Even with successful termination of AFL during ablation, meticulous testing by pacing medial and lateral to the line of block should be done to confirm BIB. 3-D mapping is a great complementary tool to prove BIB.