An electrogram mapping approach was more effective than an anatomic approach in achieving complete block before cross-over (59% vs 19%, P<0.005) in patients with atrial flutter.
RCT (n=63)
Does an electrogram mapping approach improve the achievement of complete cavotricuspid isthmus block compared to an anatomic approach in patients with atrial flutter and incomplete block after initial ablation?
In patients with atrial flutter and incomplete block after initial ablation, an electrogram mapping approach is significantly more effective than an anatomic approach for achieving complete cavotricuspid isthmus block.
Absolute Event Rate: 59% vs 19%
p-value: p=<0.005
INTRODUCTION: The cavotricuspid isthmus can be ablated using an anatomic approach or an electrogram mapping approach in which sites at which there is a gap in the line of block are targeted. The aim of this study was to compare the anatomic and electrogram mapping approaches for creating a line of block in the cavotricuspid isthmus after an initial, unsuccessful anatomically directed ablation line. METHODS AND RESULTS: The subjects of this study were 63 patients with isthmus-dependent atrial flutter in whom a single series of contiguous applications of radiofrequency energy guided by fluoroscopy in the cavotricuspid isthmus did not result in complete block. The patients were randomly assigned to additional ablation on an anatomic basis (n = 31) or guided by single potentials or narrowly split double potentials during coronary sinus pacing (n = 32). After every 15 applications of radiofrequency energy, the alternate approach was used until complete block was achieved. Before cross-over, complete block was achieved in 6 patients (19%) with the anatomic approach compared with 19 patients (59%) with the electrogram mapping approach (P < 0.005). The electrogram mapping approach also was more effective than the anatomic approach in achieving complete isthmus block after the first cross-over (72% vs 23%, P < 0.005) and after the second cross-over (80% vs 42%, P < 0.05). CONCLUSION: When there is incomplete block after an initial series of applications of radiofrequency energy in the cavotricuspid isthmus, complete block is achieved more efficiently with an electrogram mapping approach than with an anatomic approach.
Tada et al. (Mon,) conducted a rct in Isthmus-dependent atrial flutter (n=63). Electrogram mapping approach vs. Anatomic approach was evaluated on Complete block before cross-over (p=<0.005). An electrogram mapping approach was more effective than an anatomic approach in achieving complete block before cross-over (59% vs 19%, P<0.005) in patients with atrial flutter.