EP Lab Digest - December 2007 - (Page 6)

6 COVER STORY DECEMBER 2007 IMPROVED ANATOMICAL ORIENTATION Continued from cover As one of the premier heart centers in Germany, our institution performs catheter ablation with great frequency. Approximately 2,000 ablation cases per year are going to be performed in two EP labs, with an increasing number of those cases being AF patients. Threedimensional mapping, atrial chamber reconstruction and non-fluoroscopic catheter visualization are being used in most of these cases. In May 2007, we began using the EnSite™ System (St. Jude Medical, St. Paul, Minnesota) with the EnSite Fusion™ Registration Module. To date, our group has completed nearly 100 cases using this software. Although we have only recently become regular users of this system, the introduction of EnSite Fusion has had a very positive impact, and we now find it very easy to use. It provides us with a realistic understanding of individual patient anatomy, and facilitates the ablation procedure by enabling us to work entirely in the registered CT model without any additional chamber surface reconstruction.This accurate anatomical orientation is difficult to achieve with electroanatomical chamber reconstruction alone, where the resolution of the anatomical model is limited in regions with difficult catheter access. With the EnSite Fusion tool, we are able to achieve an accurate, quality registration in no more than 10 minutes, a fact which has definitely helped reduce our average procedure time. Christopher Piorkowski, MD. The Leipzig Heart Center Team (left to right): C. Henker, MD, M. Esato, MD, A. Bollmann, MD, PhD, R. Kronberg, S. Baumgärtner, C. Irmisch, C. Tilch, S. Less, T. Gaspar, MD, A. Arya, MD, C. Piorkowski, MD, G. Hindricks, MD, PhD. Registration of the CT Image into the Mapping System CT scans are performed on a 64-row spiral CT scanner and segmented prior to the procedure. For re-ablation cases, we use the initial CT scan from the index procedure. Segmentation is performed using the Verismo tool on the EnSite System. We begin all AF ablation procedures by placing patients in deep sedation, then inserting standard catheters in the coronary sinus (CS) and right ventricular apex (R VA). We then perform a single transseptal puncture using the Agilis™ NxT Steerable Sheath (St. Jude Medical). Once access is gained into the left atrium (LA), we begin IV heparin to achieve ACT of 250 ms. The sheath is continuously flushed. Initially, a 20-pole Optima™ spiral mapping catheter is inserted into the left atrium and optimized.The spiral catheter is used to access each pulmonary vein, using the synced CT image as anatomical guidance. Each vein is assessed for conduction, then the catheter is dragged out of the PV as points are taken through all 20 electrodes to create individual PV geometries. This is done for all veins, and afterwards the spiral catheter is removed and saved for later use (Figure 2). At this point the ablation catheter is Figure 1. Registered CT image and Figure 2. Sync view (LPO) of the landmark point ablation lesions on EnSite Fusion. at the inferior edge of the left lower PV. inserted.We utilize the Coolpath (Mtype, 4 mm irrigated tip) ablation catheter (St. Jude Medical). The catheter is inserted into the left lower PV and then slowly dragged out until it falls into the left atrial cavity. The inferior edge Figure 4. Additional registration points bring Figure 3. Initial registration step showing of the left lower the reconstructed surfaces into alignment with when reconstructed PV geometries and PV is taken as a the CT model (PA view). the CT image are brought together. landmark (“fiducial” or anchoring point) on the CT and real-time models. When this objective is Using this point, we then complete the achieved, we hide the initial registration of the CT anatomy into reconstructed PVs and the real-time model (Figure 3). remove unnecessary distal After this initial step, we improve the reg- parts of the CT PVs to istration by further aligning the CT PVs maintain image clarity. We with the reconstructed PV anatomies. then further improve our Beginning with the vein appearing furthest registration by placing the from the CT surface, we add in on average ablation catheter at the LA four registration points at corresponding roof and using it to conlocations between reconstructed PV anato- firm proximity to the CT Figure 5. Secondary registration step with most my and CT surfaces (Figure 4). Our objec- model (Figures 6A–C). If reconstructed PV anatomies lying inside the CT model (PA view). tive is that all reconstructed PVs appear we see a location with within the CT image (Figure 5). It is impor- inexact alignment (e.g., tant to keep in mind that points should be catheter is not at the CT surface), we add Our technique for CT image registration added so that the CT is brought towards the a landmark point pulling the CT image is based on the concept that the pulreconstructed PV anatomies at this phase. onto the catheter tip (this does not alter monary veins are the most stable anatomThe software allows adjustment of the regis- the CT model.) This is repeated at the ical structures in the heart. Therefore, we tration in either direction. basal posterior wall and the LA isthmus. See IMPROVED ANATOMICAL ORIENTATION page 8

Table of Contents Feed for the Digital Edition of EP Lab Digest - December 2007

EP Lab Digest - December 2007 Improved Anatomical Orientation During AF Catheter Ablation: Experience from Leipzig Heart Center One EP Lab’s Solution to the Administration of Deep Sedation Contents Letter from the Editor Spotlight Interview: Northeast Georgia Medical Center Emerging Technologies for the Electrophysiology Lab The Western Atrial Fibrillation Symposium About the PRECEDE-HF Trial: Interview with William T. Abraham, MD, FACP, FACC, FAHA Overview on Shire and the Discontinuation of Ethmozine®: After the Heart Rhythm Society Intervenes, the Company Changes its Decision Minimizing the Risk of Infection at Children’s Sibley Heart Center: Interview with Nicole Jarrell, RNC, MSN, and J. Renee Watson, RN, CIC Is There a Link Between Gasoline Vapors and Brugada Syndrome? Interview with Darko Kranjcec, MD and Hugues Abriel, MD, PhD New Feature! Pacemaker/ICD Puzzle Email Discussion Group Events Calendar Industry News and Products

EP Lab Digest - December 2007

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