title: Multipolar endocardial mapping of the right heart using a basket catheter: acute and chronic animal studies.
abstract: The development of catheter-based ablative techniques for primary atrial and ventricular arrhythmias is likely to be assisted by improved techniques for systematic endocardial activation sequence mapping. RA mapping using a multielectrode basket catheter has been shown to be feasible with minimal acute toxicity in a prior study. The objectives of the current study are to investigate: (1) the utility of the basket catheter for mapping RV activation; and (2) the evolution of acute endocardial lesions produced by basket catheter use in both the RA and RV over 4-8 weeks time. A flexible, 5-spoke basket catheter bearing 25 electrode pairs was placed in the RA (n = 9) or the RV (n = 13) in 22 juvenile sheep (22-56 kg). The catheter was deployed for 0.1-4.1 hr (RA) and 0.3-3.9 hr (RV). In 20 of these 22 animals, 32 recordings were made of filtered (30-250 Hz) bipolar electrograms and surface ECG. Electrograms were timed and used to construct activation sequences based on a schematic of catheter geometry. Hearts were examined either acutely (4 RA and 9 RV studies) or 4-8 weeks after the procedure (5 RA and 4 RV studies). One animal undergoing RA placement had an air embolism resulting in cardiac arrest immediately prior to basket placement; all other animals were stable during placement. RA electrograms of sufficient quality to determine activation time were recorded from 82% of pairs in RA maps, and RV electrograms from 89% of pairs in RV maps. Mean activation sequence duration in RV was 16 ms versus 47 ms in RA (P < 0.0001), making construction of RV maps more difficult. Acute postmortem studies of RV placement revealed a silent apical RV puncture in one animal. Superficial abrasion or ecchymosis of RV endocardium and/or tricuspid valve were noted in six animals. Postmortem exams in both RA and RV chronic studies showed healed endocardial lesions, with only superficial scarring. Rapid RV activation mapping using a basket catheter is feasible, but requires precision recording techniques. Endocardial abrasions produced in lambs both by RA and RV placement of the catheter are healed in < 4-8 weeks, with trivial residua. The multielectrode basket catheter may be applicable to the mapping of tachycardias originating in or involving the right ventricle.
authors.affiliation: Department of Cardiology, Children's Hospital, Boston, MA 02115, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Triedman
authors.forename: K J
authors.initials: KJ
authors.lastname: Jenkins
authors.forename: S D
authors.initials: SD
authors.lastname: Colan
authors.forename: R
authors.initials: R
authors.lastname: Van Praagh
authors.forename: J E
authors.initials: JE
authors.lastname: Lock
authors.forename: E P
authors.initials: EP
authors.lastname: Walsh
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000601:surgery; D016280:Atrial Function, Right; D018780:Body Surface Potential Mapping / Q000009:adverse effects / Q000295:instrumentation*; D006328:Cardiac Catheterization / Q000009:adverse effects / Q000295:instrumentation*; D017115:Catheter Ablation / Q000295:instrumentation; D002921:Cicatrix / Q000209:etiology; D004438:Ecchymosis / Q000209:etiology; D004562:Electrocardiography; D004566:Electrodes / Q000009:adverse effects; D004618:Embolism, Air / Q000209:etiology; D004699:Endocardium / Q000293:injuries / Q000502:physiology*; D004867:Equipment Design; D005240:Feasibility Studies; D006323:Heart Arrest / Q000209:etiology; D012756:Sheep; D012815:Signal Processing, Computer-Assisted; D017180:Tachycardia, Ventricular / Q000175:diagnosis; D014261:Tricuspid Valve / Q000293:injuries; D016278:Ventricular Function, Right; D014945:Wound Healing