title: A new methodology for atrial flutter ablation by direct visualization of cavotricuspid conduction with voltage gradient mapping: a comparison to standard techniques.
abstract: OBJECTIVE
  To demonstrate that critical conduction within the cavotricuspid isthmus (CTI) can be directly visualized by voltage gradient mapping and facilitate efficient ablation compared to standard techniques.
  
  
  RESULTS
  Group 1 (1 operator, n = 11) ablated based upon contact voltage measurements and voltage gradient mapping. Ablation targeted low-voltage bridges (LVBs) within the CTI. Repeat maps were obtained following ablation. Group 2 (operators 2, 3, and 4 n = 35) utilized electroanatomic navigation and ablated by the creation of linear lesions from the tricuspid valve to the inferior vena cava. Demonstration of bidirectional block (BDB) was required in both groups. LVB were associated with CTI conduction in all Group A patients. LVB ablation terminated flutter, or created BDB. Following ablation, CTI voltage connections were absent in all patients. Compared with Group B, Group A had less radiofrequency (RF) lesions to atrial flutter (AFL) termination (P = 0.001), less total RF lesions (P = 0.0001), and less total RF time (P = 0.001). Group 1 had no recurrent AFL whereas Group 2 had three recurrences. (follow-up median of 231 ± 181 days).
  
  
  CONCLUSIONS
  (i) Voltage gradient mapping visualized regions of critical CTI conduction, (ii) ablation of LVB terminated AFL and resulted in BDB, (iii) repeat mapping confirmed the absence of trans-isthmus voltage, and (iv) Compared with standard ablation, voltage gradient mapping decreases total RF lesions, lesions to AFL termination, and total RF time. Use of voltage gradient mapping can facilitate successful AFL ablation.
authors: Iowa Heart Center, 411 Laurel Street, Des Moines, IA 50314, USA. sbailin@iowaheart.com
authors: Steven J
authors: SJ
authors: Bailin
authors: William Ben
authors: WB
authors: Johnson
authors: Pitayadet
authors: P
authors: Jumrussirikul
authors: Denise
authors: D
authors: Sorentino
authors: Robert
authors: R
authors: West
mesh_terms: D000200:Action Potentials; D000368:Aged; D000704:Analysis of Variance; D001282:Atrial Flutter / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012008:Recurrence; D013997:Time Factors; D016896:Treatment Outcome; D014261:Tricuspid Valve / Q000503:physiopathology*; D014682:Vena Cava, Inferior / Q000503:physiopathology*
keywords: Atrial flutter; Catheter ablation; Voltage gradient mapping