Integration Of Electroanatomical Mapping Research Articles

Initial experience on cardiac magnetic resonance-aided VT ablation in South America.

Cardiac magnetic resonance (CMR) allowed to precisely identify the substrate in scar-related ventricular tachycardia (VT). New software has been developed to define the 3D scar and corridors to help VT ablation by integrating the scar and electroanatomical mapping (EAM). The objective of this study is to evaluate the results of VT ablation aided by the integration of EAM and CMR software processed scar. We selected patients that underwent VT ablation with the integration of EAM and CMR processed using ADAS software and imported to the CARTO system using VTK file format. From 2019 to 2021, eight patients (mean age 63 ± 4.4, 62.5% male; EF 47 ± 12%) underwent CMR-aided VT ablation. Mean procedural time was 281 ± 77min. There was of 9 ± 4.4 epicardial and 7.9 ± 4.3 endocardial bulls eye segments with at least 2g of border zone or core scar. In a median follow-up time of 532days (Q1: 284, Q3: 688), three patients (37.5%) presented VT recurrence, all three underwent a second procedure, with no VT recurrence on the follow-up. No patient died in the follow-up. CMR aided is ablation is feasible and effective in patients with scar related VT.

5209Stereotactic radioablation of ventricular tachycardia guided by direct integration of 3D electroanatomic mapping: development and validation of a new method

Abstract Background Stereotactic body radiotherapy (SBRT) has emerged as a promising bailout therapy for recurrent ventricular tachycardia (VT) in patients with failed radiofrequency catheter ablation. However, SBRT can function only if the ablation target is precisely identified. Purpose We sought to develop a novel method for direct integration of electroanatomic mapping (EAM) data to an SBRT work station for radioablation of VT. Methods Candidates for SBRT were patients with recurrent, drug-resistant VT who underwent ≥2 previous radiofrequency catheter ablations (CARTO 3, Biosense-Webster, Diamond Barr, CA) and continued to have inducible clinical VT or clinical recurrences of VT. At the end of the last catheter ablation, the operators performed additional EAM to obtain landmarks for image registration: aorta with the ostium of the left main coronary artery or left atrium with ostia of pulmonary veins. Correct position of the catheter at the landmark was verified by intra-cardiac echocardiography. VT substrate–defined by a combination of voltage mapping, pace mapping, and detection of local abnormal ventricular activity and/or late potentials was marked by custom tags as a target for SBRT. The CARTO maps were exported and converted to 3D shells with encoded EAM properties (VTK format). On the following day, the patients underwent contrast-enhanced computer tomography (CT) of the heart. Using 3D Slicer software 4.10 (slicer.org), the EAM-derived anatomical structures with the marked ablation target were projected onto CT images by landmark registration with manual correction. The CT study with the projected contours of the EAM-detected ablation target was imported as a DICOM-RT format into a stereotactic radiotherapy planning work station (Multiplan 3.5, Accuray, Sunnyvale, CA). SBRT was performed using a contemporary radiosurgery system with real-time motion tracking of the ablation target (CyberKnife 8.5, Accuray). The prescribed (X-ray) dose was 25 Gy during a single session. Results The proposed work-flow was verified in four patients with structural heart disease and drug-resistant VT who had 2–3 unsuccessful radiofrequency catheter ablations (all males; age: 68–78 years; left ventricular ejection fraction: 20–25%; ischemic/non-ischemic cardiomyopathy: 2/2). Integration of EAM data with CT was achieved in all patients. None of them experienced acute radiotoxicity after SBRT. At a follow-up checkup at one month, three of the patients remained arrhythmia-free. One patient experienced VT recurrence one day after SBRT, but no VTs recurred during the following month of follow-up. Figure 1 Conclusions This is the first report demonstrating the feasibility of SBRT of VT guided by direct integration of EAM. The proposed method is best suited as a bailout procedure for patients with previously failed catheter ablation. Acknowledgement/Funding M.S. was supported by ESC Research Fellowship 2018

A novel approach for left ventricular lead placement in cardiac resynchronization therapy: Intraprocedural integration of coronary venous electroanatomic mapping with delayed enhancement cardiac magnetic resonance imaging

Placing the left ventricular (LV) lead at a site of late electrical activation remote from scar is desired to improve cardiac resynchronization therapy (CRT) response. The purpose of this study was to integrate coronary venous electroanatomic mapping (EAM) with delayed enhancement cardiac magnetic resonance (DE-CMR) enabling LV lead guidance to the latest activated vein remote from scar. Eighteen CRT candidates with focal scar on DE-CMR were prospectively included. DE-CMR images were semi-automatically analyzed. Coronary venous EAM was performed intraprocedurally and integrated with DE-CMR to guide LV lead placement in real time. Image integration accuracy and electrogram parameters were evaluated offline. Integration of EAM and DE-CMR was achieved using 8.9 ± 2.8 anatomic landmarks and with accuracy of 4.7 ± 1.1 mm (mean ± SD). Maximal electrical delay ranged between 72 and 197ms (57%-113% of QRS duration) and was heterogeneously located among individuals. In 12 patients, the latest activated vein was located outside scar, and placing the LV lead in the latest activated vein remote from scar was accomplished in 10 patients and prohibited in 2 patients. In the other 6 patients, the latest activated vein was located in scar, and targeting alternative veins was considered. Unipolar voltages were on average lower in scar compared to nonscar (6.71 ± 3.45 mV vs 8.18 ± 4.02 mV [median ± interquartile range), P <.001) but correlated weakly with DE-CMR scar extent (R -0.161, P <.001) and varied widely among individual patients. Integration of coronary venous EAM with DE-CMR can be used during CRT implantation to guide LV lead placement to the latest activated vein remote from scar, possibly improving CRT.

Feasibility of Transseptal Puncture Using a Nonfluoroscopic Catheter Tracking System.

Radiation exposure in the electrophysiology lab is a major occupational hazard to the electrophysiologists. A catheter localization system (MediGuide Technology, St. Jude Medical Inc., St. Paul, MN, USA) allows the integration of electroanatomical mapping and x-ray imaging, and has been shown to be effective in reducing radiation exposure during several electrophysiological procedures. We intended to evaluate the feasibility of this catheter tracking system to guide transseptal (TS) access. The feasibility of performing TS puncture with MediGuide (MDG) was assessed in a prospective observational study in 16 patients undergoing radiofrequency ablation for atrial fibrillation. These patients were compared to 16 matched patients undergoing similar procedures during the same time frame using conventional approach. There were no differences in mean age, gender distribution, and body mass index between the two groups. Total duration of fluoroscopic exposure during TS puncture was compared between the two groups. All patients underwent successful TS puncture. Fluoroscopy time for double TS puncture using the MDG system was significantly lower than the control group (0.48 ± 0.17 minutes vs. 5.9 ± 0.65 minutes; P < 0.0001). No major complications occurred during the procedures in either group. TS puncture can be successfully performed using MDG, and results in significant reduction in radiation exposure.

Poor negative remodeling of left atrium after catheter ablation for nonparoxysmal atrial fibrillation is a risk of very late recurrence

Purpose: It has been reported that some patients receiving catheter ablation for atrial fibrillation (AF) suffer from very late recurrence (VLR; initial recurrence >12 months after AF ablation), but its pathophysiology has not been fully elucidated. To evaluate it, we analyzed the left atrial function of nonparoxysmal AF patients who underwent catheter ablation by multi-detector computed tomography (MDCT). Methods: We retrospectively evaluated 56 patients who underwent initial ablation for drug-refractory persistent or longstanding persistent AF in our institute and had no AF recurrence in the initial year after ablation. We followed them for average 1.9±0.8 years and divided them into 2 groups based on the presence or absence of VLR (VLR-group, and NR-group, respectively). All patients were submitted to 128-slice MDCT scan before and 3 months after ablation for electroanatomic mapping integration, pulmonary veins anatomy delineation, and estimated LA volume (LAV) including maximum LAV during cardiac cycle (maxLAV) and LA emptying fraction (LAEF). Then, we compared them between groups. Results: Out of 56 study subjects, 6 patients experienced VLR. There was no significant difference between the groups in the preoperative LAEF (NR-group vs. VLR-group, 20±13% vs. 22±11%, P = 0.74), and preoperative maxLAV (80±28 mL vs. 72±28 mL, P = 0.45). Postoperative maxLAV tended to be larger in VLR patients than in NR patients (60±20 mL vs. 71±30 mL, P = 0.18). The reduction rate of maxLAV was significantly better in NR patients than in VLR patients (-22±19% vs. +2.0±28%, P = 0.002). Higher reduction rate of maxLAV was associated with lower risk of VLR. (Hazard ratio = 0.96, P = 0.04). Conclusions: Poor negative remodeling after ablation to non-paroxysmal AF is a risk factor of VLR. This data indicated that LA negative remodeling by maintaining sinus rhythm acts an important role to maintain sinus rhythm after ablation for nonparoxysmal AF.

Factors affecting error in integration of electroanatomic mapping with CT and MR imaging during catheter ablation of atrial fibrillation

Integration of 3-D electroanatomic mapping with Computed Tomographic (CT) and Magnetic Resonance (MR) imaging is gaining acceptance to facilitate catheter ablation of atrial fibrillation. This is critically dependent on accurate integration of electroanatomic maps with CT or MR images. We sought to examine the effect of patient- and technique-related factors on integration accuracy of electroanatomic mapping with CT and MR imaging of the left atrium. Sixty-one patients undergoing catheter-based atrial fibrillation (AF) ablation procedures were included. All patients underwent cardiac CT (n = 11) or MR (n = 50) imaging, and image integration with real-time electroanatomic mapping of the aorta and left atrium (LA). CARTO-Merge software (Biosense-Webster) was used to calculate the overall average accuracy of integration of electroanatomic points with the CT and MR-derived reconstructions of the LA and aorta. There was a significant correlation between LA size assessed by electroanatomic mapping (112 +/- 31 ml) and average integration error (1.9 +/- 0.6 mm) (r = 0.46, p = 0.0003). There was also greater integration error for patients with LA volume >/= 110 ml (n = 31) versus < 110 ml (n = 30) (p = 0.004). In contrast, there was no significant association between average integration error and paroxysmal versus persistent AF, left ventricular ejection fraction, days from imaging to electroanatomic mapping, or images derived from CT versus MR. Patients with larger LA volume may be prone to greater error during integration of electroanatomic mapping with CT and MR imaging. Strategies to reduce integration error may therefore be especially useful in patients with large LA volume.

The impact of respiration on left atrial and pulmonary venous anatomy: Implications for image-guided intervention

Image-guided intervention using pre-acquired CT/MR 3-dimensional images is an emerging strategy for atrial fibrillation (AF) ablation but may be limited by its use of static images to depict dynamic physiology. The effect of biologic factors such as respiration on the left atrial-pulmonary venous (LA-PV) anatomy is not well understood but is likely to have important implications. Conventional CT/MR imaging is performed during an inspiratory breath-hold, while electroanatomical mapping (EAM) during "quiet" breathing approximates an expiratory breath-hold. This study examined the effects of respiration on LA-PV anatomy and the error introduced by respiration on the integration of EAM with 3D MR imaging. Pre-procedural MRI angiography was performed at both end-expiration (EXP) and end-inspiration (INSP) in 20 patients undergoing AF catheter ablation. 3D INSP and EXP surface reconstructions of the LA-PVs were compared. In selected pts, EAM data acquired during the ablation procedure (n=7) were integrated with the 3D MRI datasets. Qualitative assessment of the INSP and EXP 3D images revealed splaying of the PVs and reduction in PV caliber of the right-sided PVs during held inspiration. After aligning these two datasets, the average surface-to-surface distance calculated by region ranged from 1.99mm (right middle PV) to 3.79mm (left superior PV). Registration of the EAM to the MRI models was better for the EXP dataset (2.30+/-0.73mm) than the INSP dataset (3.03+/-0.57mm; p=0.004). There are significant changes in LA-PV anatomy with respiration. MR images acquired during standard held inspiration may introduce unnecessary errors in registration during image-guided intervention.

941 Integration of electroanatomic mapping and multidetector computed tomography as a guide for atrial fibrillation catheter ablation

941 Integration of electroanatomic mapping and multidetector computed tomography as a guide for atrial fibrillation catheter ablation

941 Integration of electroanatomic mapping and multidetector computed tomography as a guide for atrial fibrillation catheter ablation

941 Integration of electroanatomic mapping and multidetector computed tomography as a guide for atrial fibrillation catheter ablation

Injection of bone marrow-derived cells into a porcine myocardial infarction model guided by integration of electroanatomical mapping and magnetic reasonance imaging

Injection of bone marrow-derived cells into a porcine myocardial infarction model guided by integration of electroanatomical mapping and magnetic reasonance imaging