Randomized comparison of anatomic and electrogram mapping approaches to ablation of typical atrial flutter.
BACKGROUND
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.


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).


CONCLUSIONS
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.
Department of Internal Medicine, University of Michigan, Ann Arbor 48109-0022, USA.
Hiroshi
H
Tada
Hakan
H
Oral
Mehmet
M
Ozaydin
Aman
A
Chugh
Christoph
C
Scharf
Sohail
S
Hassan
Radmira
R
Greenstein
Frank
F
Pelosi
Bradley P
BP
Knight
S Adam
SA
Strickberger
Fred
F
Morady
D001282:Atrial Flutter / Q000473:pathology / Q000601:surgery*; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014261:Tricuspid Valve / Q000033:anatomy & histology* / Q000601:surgery; D014682:Vena Cava, Inferior / Q000033:anatomy & histology* / Q000601:surgery