title: Ultra high-density multipolar mapping with double ventricular access: a novel technique for ablation of ventricular tachycardia.
abstract: Ultra High-Density Multipolar Mapping With Double Ventricular Access.
  
  
  BACKGROUND
  Analogous to the use of circular loop catheters to guide ablation around the pulmonary veins, it may be advantageous to use a multipolar catheter in the ventricle for rapid mapping and to guide ablation. We describe a technique using double access into the left ventricle for multipolar electroanatomic mapping and ablation of scar-mediated ventricular tachycardia (VT).
  
  
  METHODS
  Double access into the left ventricle was obtained via transseptal technique. Endocardial mapping was performed via the first transseptal sheath using a steerable duodecapolar catheter. Higher density mapping was performed in areas of dense scar (<0.5 mV) and border zone (0.5-1.5 mV). All late potentials (LPs) observed on the 20 poles were tagged and pacemapping was performed at these sites for comparison with the clinical or induced VT 12-lead template. If VT was hemodynamically tolerated, entrainment mapping was attempted at sites demonstrating diastolic activity. Ablation was performed through the second transseptal sheath with an open-irrigated catheter at target sites identified by LPs, pacemapping, and/or entrainment on the duodecapolar catheter.
  
  
  RESULTS
  Seventeen patients (88% ischemic cardiomyopathy) underwent electroanatomic mapping and ablation with double transseptal access. The mean number of endocardial mapping points was 819 ± 357 with an average mapping time of 31 ± 7 minutes. The mean number of VTs induced was 2.8 ± 1.6, mean cycle length 418 ms ± 101. LPs were seen in all patients during endocardial mapping with the duodecapolar catheter. Good (56%) and perfect (44%) pacemaps were seen in all patients when performed. Concealed entrainment, guided by the earliest diastolic activity seen on the duodecapolar catheter, was demonstrated in 4 patients (24%). Acute success was achieved in 94% of patients with complete success in 47% and partial success in 47%. The intermediate success rate (free of VT recurrence) was 69%, with an average follow-up of 8 ± 3 months.
  
  
  CONCLUSIONS
  Mapping and ablation of scar-mediated VT using a multipolar catheter results in ultra high-density delineation of the left ventricular substrate. A novel double ventricular access strategy has the potential to facilitate identification of LPs, pacemapping, and entrainment mapping.
authors.affiliation: UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, CA90095-1679, USA. rtung@mednet.ucla.edu
authors.forename: Roderick
authors.initials: R
authors.lastname: Tung
authors.forename: Shiro
authors.initials: S
authors.lastname: Nakahara
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Maccabelli
authors.forename: Eric
authors.initials: E
authors.lastname: Buch
authors.forename: Isaac
authors.initials: I
authors.lastname: Wiener
authors.forename: Noel G
authors.initials: NG
authors.lastname: Boyle
authors.forename: Corrado
authors.initials: C
authors.lastname: Carbucicchio
authors.forename: Paolo Della
authors.initials: PD
authors.lastname: Bella
authors.forename: Kalyanam
authors.initials: K
authors.lastname: Shivkumar
mesh_terms: D000368:Aged; D018780:Body Surface Potential Mapping / Q000295:instrumentation*; D017115:Catheter Ablation / Q000295:instrumentation*; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000601:surgery*; D016896:Treatment Outcome