Preliminary human experience using a novel robotic catheter remote control

Session 32 The remaining 71 study pts (53%) underwent catheter ablation. This was successful in 58 (82%) pts. During FU, 30 (52%) of the 58 successfully treated pts had recurrences after a median of 20 months (range 13-24). RVOT-T were similar in morphology to those treated previously in 33% and different in 67% of cases. Conclusions: Decennial FU in pts with RVOT-T is excellent. AA drug is effective in half of the pts and therapy discontinuation is possible in 50% of them. Therefore, primary drug therapy should be considered in pts with RVOT-T. Catheter ablation is an effective option in this setting. However, late recurrences with similar or different morphology may arise in half of the pts after successful treatment.

ABSTRACT SESSION 32: CATHETER ABLATION V: New Techniques and Approaches Friday, May 6, 2005 10:45 a.m.–12:15 p.m. AB32-1 PRELIMINARY HUMAN EXPERIENCE USING A NOVEL ROBOTIC CATHETER REMOTE CONTROL Nassir F. Marrouche, MD, Johannes Brachmann, MD, Oussama M. Wazni, MD, Volker Shibgilla, Salwa Beheiry, RN, Jens Guenther, MD and Andrea Natale, MD. Cleveland Clinic Foundation, Cleveland, OH, Klinikum Coburg, Coburg, Germany and Pacific Heart Centers, San Francisco, CA. We evaluated the safety and efficacy of a novel robotic catheter with remote control (RCC) in humans. Methods and Results: The RCC (Hansen Medical) and steerable guide catheter and sheath (Hansen Medical) were evaluated in 7 patients (3 women, mean age 65⫾20 years) presenting for mapping and/or ablation of atrial arrhythmia. In all patients 3D reconstruction of the right atrial chamber anatomy was performed with the CARTO system and using the RCC. In all 7 patients mapping was performed successfully. The mean fluoroscopy and procedure times were 14.5⫾4.4 (range 10-20 minutes) and 88⫾11 minutes (range 70-101 minutes), respectively. In addition 2 of these patients mapping of the left atrium was performed and all 4 PVs were accessed. In 3 patients the RCCS was used in conjunction with the 3D mapping system CARTO not only to map but also to ablate the existing arrhythmia. In the 2 patients with SVT, AVNRT was defined as their clinical arrhythmia and successful modification of the slow pathway was performed using the RCCS (mean fluoroscopy and procedure times were 38⫾9 and 199⫾2 minutes, respectively; 76⫾8 CARTO points). A right atriatomy scar was identified in the patient presenting with incisional flutter and an ablation line was drawn between the scar and lateral aspect of the tricuspid annulus leading to the termination of the tachycardia (fluoroscopy time 45 minutes, procedure time 145 minutes, 110 CARTO mapping points). No acute complications were detected. At 4 months follow-up all patients were arrhythmia free and did not experience complications. In Conclusion: The preliminary human experience suggest that mapping and ablation using this novel robotic catheter with remote control system is feasible. AB32-2 EFFECTS OF ELIMINATING COMPLEX ELECTROGRAMS BY RADIOFREQUENCY CATHETER ABLATION ON SPECTRAL CHARACTERISTICS OF ATRIAL FIBRILLATION Kristina Lemola, MD, Michael Ting, MS, Priya Gupta, MS, Jeffrey N. Anker, PhD, Claudio Munhoz, MD, Abhilash Patangay, MS, Kamala Tamirisa, MD, Eric Good, DO, Jihn Han, MD, Scott Reich, MD, David Tschopp, MD, Petar Igic, MD, Darryl Elmouchi, MD, Aman Chugh, MD, Frank Pelosi, Jr., MD, *Fred Morady, MD and *Hakan Oral, MD. University of Michigan, Ann Arbor, MI and LSA Chemistry and Applied Physics, University of Michigan, Ann Arbor, MI.

S63 Background: Left atrial (LA) sites where complex electrograms (EGM), characterized by fractionation, short cycle length, and/or continuous electrical activity, are recorded have been targeted to eliminate atrial fibrillation (AF). There have been no studies on whether EGM-guided ablation (EGMRF) has any effect on the frequency content of AF. The purpose of this study was to determine the effects of elimination of complex EGM within the LA on spectral characteristics of AF. Methods: EGM-RF was performed in 28 pat (mean age⫽58⫾9 y) with paroxysmal (18) or chronic AF (10). AF was induced by rapid atrial pacing. Complex EGM within the LA were targeted without creating any circular or linear lesions, using an 8 mm-tip ablation catheter and an electroanatomic mapping system. The endpoint of ablation was termination and noninducibility of AF (no episode of AF (⬎60 sec) with 5 induction attempts). Bipolar EGMs recorded from the coronary sinus catheter before and after EGM-RF during AF were analyzed by fast Fourier Transformation to determine the fundamental frequency (FF) (⫽ frequency of rotors) and Full band Width at Half Max Amplitude (FWHM). To quantitatively analyze the complexity of the EGM, the carrier frequency (CF), and its FWHM were determined before and after EGM-RF. Results: A mean of 39 ⫾ 15 LA sites were ablated. FF decreased significantly from 5.3 ⫾ 1.4 Hz before, to 3.7 ⫾ 1.2 Hz after EGM-RF (P⬍0.001). The frequency of oscillation of the rotors (FWHM of FF curve) was lower after, 0.46 ⫾ 0.28Hz, than before EGM-RF 0.6 ⫾ 0.27Hz; (P⫽0.11). EGM-RF also resulted in a significant decrease in the mean FWHM of the CF curve, representing the oscillatory component, fibrillatory conduction of LA tissue, 31.3 ⫾ 13.2 Hz vs. 45.7 ⫾ 11.8 Hz, P⫽0.02. Conclusions: Ablation of complex electrograms within the LA results in modification of the LA electrophysiologic substrate as manifest by a decrease in the FF of the rotors and in the extent of fibrillatory conduction. Whether alteration of spectral characteristics of AF is associated with an improvement in clinical outcomes remains to be determined in long-term follow-up studies. AB32-3 HIGH INTENSITY FOCUSED ULTRASOUND FOR PULMONARY VEIN ANTRUM ISOLATION - FIRST CLINICAL EXPERIENCE WITH A NOVEL STEERABLE BALLOON CATHETER Matthias Antz, MD, Sabine Ernst, MD, Feifan Ouyang, MD, Boris Schmidt, MD, Peter Falk, MD and Karl-Heinz Kuck, MD. Allgemeines Krankenhaus St. Georg, Hamburg, Germany. High intensity focused ultrasound (HIFU) applied via a balloon catheter (ProRhythm™) is a novel technology for pulmonary vein (PV) isolation. The catheter is designed as a fluid filled balloon catheter with an integrated ultrasound transducer and a dorsally attached parabolic CO2 balloon to focus a 25 mm ring of ultrasound energy forward to the balloon. Until recently, catheter manipulation was restricted to an over-the wire technique. This excluded accessibility of the right inferior PV (RIPV) and led to extensive procedure and fluoroscopy times. The purpose of this study was to describe the first clinical experience with the steerable HIFU balloon catheter. Methods: 6 pts (2 female), mean age 61 ⫹/- 2 years, with paroxysmal AF were studied. Double transseptal puncture was performed for left atrial insertion of a Lasso catheter and the 14 F HIFU balloon catheter. After PV angiography the balloon catheter was positioned at the PV antrum. Sonication was performed with 45 Watts applied for 60 seconds. After HIFU application the lasso catheter was reinserted in the PV to detect eventual persistence of PV spikes. Additional PV angiographies were performed at the end of the procedure to assess occurrence of PV stenosis. Results: The catheter was navigated to all PV ostia (6 right superior PV, 6 RIPV, 4 left superior PV, 4 left inferior PV and 2 left common ostia). All 22 PV antrums were sonicated with a median of 5.5 (range 2-23) applications. In 20/22 PV complete electrical isolation was achieved. Only partial antrum isolation was achieved in 1 RIPV and in 1 left common PV, in the latter due to a 30% narrowing of its lower branch. Mean procedure time was 285 ⫹/- 15 min, mean fluoroscopy time was 67 ⫹/- 5 min. Conclusion: The novel steerable HIFU-balloon catheter markedly im-