An automatic and accurate registration method for electro-anatomical map and CT surface.

Multisensor systems with optical 3D sensors are frequently employed to capture complete surface information by measuring workpieces from different views. During coarse and fine registration the resulting datasets are afterward transformed into one common coordinate system. Automatic fine registration methods are well established in dimensional metrology, whereas there is a deficit in automatic coarse registration methods. The advantage of a fully automatic registration procedure is twofold: it enables a fast and contact-free alignment and further a flexible application to datasets of any kind of optical 3D sensor. In this paper, an algorithm adapted for a robust automatic coarse registration is presented. The method was originally developed for the field of object reconstruction or localization. It is based on a segmentation of planes in the datasets to calculate the transformation parameters. The rotation is defined by the normals of three corresponding segmented planes of two overlapping datasets, while the translation is calculated via the intersection point of the segmented planes. First results have shown that the translation is strongly shape dependent: 3D data of objects with non-orthogonal planar flanks cannot be registered with the current method. In the novel supplement for the algorithm, the translation is additionally calculated via the distance between centroids of corresponding segmented planes, which results in more than one option for the transformation. A newly introduced measure considering the distance between the datasets after coarse registration evaluates the best possible transformation. Results of the robust automatic registration method are presented on the example of datasets taken from a cutting tool with a fringe-projection system and a focus-variation system. The successful application in dimensional metrology is proven with evaluations of shape parameters based on the registered datasets of a calibrated workpiece.

Automatic Registration between Real-Time Ultrasonography and Pre-Procedural Magnetic Resonance Images: A Prospective Comparison between Two Registration Methods by Liver Surface and Vessel and by Liver Surface Only

In this paper, we propose an automatic and accurate image registration method for the high resolution. Due to the strong distortion caused by the terrain relief in this kind of images, it cannot be resolved by one set of transformation coefficients for the whole image. So the method mainly consists of two parts: one part is the dense feature point matching, and the other is the faced based differential registration. The matching algorithm integrates the feature point matching, relaxation optimization technique, the Least Square Matching, the coarse-to-fine strategy, and it can provide hundreds of thousands of reliable and accurate control points. With the TIN, these points divide the image into a lot of small triangles. For each triangle, we can assume the local distortion is simple and can be depicted by the affine transformation function. Finally, faced based differential registration is performed to resample the slave image. Experiments have been carried out and satisfactory results have been obtained.

Veltmann C, Schimpf R, Steitner F, Hu D, Pfeiffer R, Borggrefe M, Wolpert C, Antzelevitch C. Electrocardiographic identification of SCN5A mutation carriers in a large European family. Europace Journal 2009, 11(Supplement 2), Abstract 34.Wijnmaalen AP, Van Der Geest RJ, Siebelink HJ, Kroft L, Bax JJ, Reiber JH, Schalij MJ, Zeppenfeld K. Integration of MRI derived 3D scar maps with electroanatomical mapping during catheter ablation of scar-related ventricular tachycardia late after myocardial infarction. Europace Journal 2009, 11(Supplement 2), Abstract 35.Algalarrondo VA, Dinanian SD, Juin CJ, Adams DA, Slama MS. Paroxystic AV block and prophylactic pacing in familial amyloid polyneuropathy. Europace Journal 2009, 11(Supplement 2), Abstract 36.# Electrocardiographic identification of SCN5A mutation carriers in a large European family {#article-title-2} Veltmann C, Schimpf R, Steitner F, Hu D, Pfeiffer R, Borggrefe M, Wolpert C, Antzelevitch C. Electrocardiographic identification of SCN5A mutation carriers in a large European family. Europace Journal 2009, 11(Supplement 2), Abstract 34.Wijnmaalen AP, Van Der Geest RJ, Siebelink HJ, Kroft L, Bax JJ, Reiber JH, Schalij MJ, Zeppenfeld K. Integration of MRI derived 3D scar maps with electroanatomical mapping during catheter ablation of scar-related ventricular tachycardia late after myocardial infarction. Europace Journal 2009, 11(Supplement 2), Abstract 35.Algalarrondo VA, Dinanian SD, Juin CJ, Adams DA, Slama MS. Paroxystic AV block and prophylactic pacing in familial amyloid polyneuropathy. Europace Journal 2009, 11(Supplement 2), Abstract 36.The loss-of-function SCN5A missense mutation E1784K leads to the Brugada and/or Long QT phenotype and to cardiac conduction disease. The aim of the present study was to perform a genotype-phenotype correlation in a large family with the E1784K mutation and to identify electrocardiographic markers capable of differentiating between mutation carriers and non-carriers. Methods: We screened a large 33-member European family. The work-up included the medical and family history (n=33), a baseline ECG (n=27), sodium blocker challenge (n=23) and genetic screening (n=27). Results: 27 members (28±15 years of age; 16 males, 11 females) were genotyped. In 17 of 27 patients (8 males, 9 females) a E1784K missense mutation was identified in SCN5A. Mutation carriers revealed significantly longer PR and QT intervals and QRS duration compared to non-carriers. (PQ: 195ms vs. 155ms, P<0.003; QT: 466ms vs. 415ms, P<0.0001, QRS: 100ms vs. 80ms; P<0.002). Using ROC analysis, QTc ≥ 445 ms was identified as a good predictor of a positive genotype (sensitivity 88%, specificity 100%). No patient showed a spontaneous Brugada type I ECG. 4 patients displayed a Brugada type II and III ECG. Out of 23 ajmaline tests 12 were positive, 8 negative und 3 were prematurely terminated due to QRS prolongation and premature ventricular contractions. All non-carriers revealed a negative ajmaline test (n=8). In 15 of 17 patients with positive genotype, ajmaline challenge was performed. 12 tests (80%) were positive and 3 tests were prematurely terminated. Conclusions: Our results indicate E1784K-SCN5A carriers have significantly longer PR, QT and QRS durations. 80% of mutation carriers and none of non-carriers display a Type I ST segment elevation characteristic of Brugada syndrome following challenge with sodium channel blockers. QTc interval ≥ 445 predicted the presence of the E1784K mutation. All non-carriers displayed normal ECG parameters. # Integration of MRI derived 3D scar maps with electroanatomical mapping during catheter ablation of scar-related ventricular tachycardia late after myocardial infarction {#article-title-3} Veltmann C, Schimpf R, Steitner F, Hu D, Pfeiffer R, Borggrefe M, Wolpert C, Antzelevitch C. Electrocardiographic identification of SCN5A mutation carriers in a large European family. Europace Journal 2009, 11(Supplement 2), Abstract 34.Wijnmaalen AP, Van Der Geest RJ, Siebelink HJ, Kroft L, Bax JJ, Reiber JH, Schalij MJ, Zeppenfeld K. Integration of MRI derived 3D scar maps with electroanatomical mapping during catheter ablation of scar-related ventricular tachycardia late after myocardial infarction. Europace Journal 2009, 11(Supplement 2), Abstract 35.Algalarrondo VA, Dinanian SD, Juin CJ, Adams DA, Slama MS. Paroxystic AV block and prophylactic pacing in familial amyloid polyneuropathy. Europace Journal 2009, 11(Supplement 2), Abstract 36.Background: The current used gold standard to guide substrate based ablation of scar-related ventricular tachycardia (VT) relies on electroanatomical endocardial and epicardial voltage mapping (EAM). Integration of the complex 3-dimensional (3D) scar geometry derived from contrast enhanced magnetic resonance imaging (CE-MRI) with EAM may provide supplementary substrate information. This study aimed to assess the feasibility of integrating CE-MRI derived data with EAM during radiofrequency catheter ablation (RFCA) of scar-related VT. Methods: 15 patients (14 male, 64±9yr) referred for RFCA of VT late after myocardial infarction underwent CE-MRI using a 1.5 T MRI system. Endocardial and epicardial contours of the CE-MRI were used to create 3D surface meshes of the left ventricle (LV), the aortic cusps and the left main (LM) origin. The vertices of the meshes were color coded based on the transmural extend of scar at a particular intramural location. Prior to ablation the MRI derived scar maps were imported into the CARTO-merge system. Bipolar endocardial EAM of the LV and aortic cusps were obtained and the LM location was marked. Areas with bipolar electrograms <1.5mV were defined as scar. Registration of the MRI derived scar maps and electroanatomical voltage maps was performed using the LM as landmark and the CARTO surface registration algorithm. Results: The average number of LV EAM points was 258±42. Merging of MRI derived scar data with voltage maps was successful in all patients with an average registration error of 3.8±0.6mm. There was a good agreement between regions of transmural scar defined by MRI and EAM. In 5 (33%) patients the subendocardial scar area identified by CE-MRI was larger than the scar area defined by EAM. Conclusions: Integration of MRI derived scar maps with EAM during VT ablation is feasible and accurate. CE-MRI derived scar maps identify intramural scar undetected by EAM and may provide important supplementary substrate information. # Paroxystic AV block and prophylactic pacing in familial amyloid polyneuropathy {#article-title-4} Veltmann C, Schimpf R, Steitner F, Hu D, Pfeiffer R, Borggrefe M, Wolpert C, Antzelevitch C. Electrocardiographic identification of SCN5A mutation carriers in a large European family. Europace Journal 2009, 11(Supplement 2), Abstract 34.Wijnmaalen AP, Van Der Geest RJ, Siebelink HJ, Kroft L, Bax JJ, Reiber JH, Schalij MJ, Zeppenfeld K. Integration of MRI derived 3D scar maps with electroanatomical mapping during catheter ablation of scar-related ventricular tachycardia late after myocardial infarction. Europace Journal 2009, 11(Supplement 2), Abstract 35.Algalarrondo VA, Dinanian SD, Juin CJ, Adams DA, Slama MS. Paroxystic AV block and prophylactic pacing in familial amyloid polyneuropathy. Europace Journal 2009, 11(Supplement 2), Abstract 36.Introduction: Familial amyloid polyneuropathy (FAP) is a dominantly inherited disease caused by mutated transthyretin. FAP cardiopathy is characterized by conduction disorders, denervation, and hypertrophic cardiomyopathy. Because of the risk of high degree atrioventricular (AV) block, prophylactic pacing can be suggested for high risk patients: in case of infra nodal AV block (HV interval > 70ms or between 60ms and 70ms with ECG abnormalities) or in case of unexplained syncope. By using pacing systems wich preserve physiological AV conduction, our purpose was to estimate prevalence of AV block and pacing dependance for high risk FAP patients. Methods: In a cohort of 29 FAP patients with conduction disorders leading to prophylactic pacing, we studied AV conduction using the AAI Safe R system (ELA medical). Datas were collected by using the Holter memories of pacemakers. Results: Patients were 50±15 years old and were followed during 13.7±11.9 months after pace maker insertion (12080 days cumulated). Before pace maker insertion, ECG was normal in 23% of cases. Electrophysiologic study showed 118±12ms for AH interval and 62±6ms for HV interval. Average percentage of ventricular pacing was 15±25%and 31±34% for atrial pacing. If 58% of patients (17/29) had less than 5% needs of ventricular pacing, we noted AV blocks episods for all patients but three (90%). Frequency of AV conduction disorders was 356±514 events per month (epm) and was distributed in 17±56 epm for type III AV block, 288±483 epm for type II AV block, 39±61epm for type I AV block and 1±4 for pauses. Percentage of ventricular pacing was positively correlated to frequency of AV block (R = 0.9, P<0.0001), to AH interval (R = 0.7, P = 0.003) and negatively to HV interval (R = -0.63, P = 0.007). During the study, sustained atrial arrhythmias occurred in two patients. No sustained ventricular arrhythmias were noted. Conclusion: Patients with FAP cardiopathy can present unpredictable paroxystic high degrees AV blocks. For patients with high risk of conduction disorders (HV interval >70ms, HV interval between 60ms and 70ms with ECG abnormalities or in case of unexplained syncope), prophylactic pacemaker insertion should be performed. Pacemaker features designed to promote spontaneous atrioventricular conduction allow a good AV conduction monitoring in FAP patients. Pre operative impairment of the nodal conduction is correlated to the rate of ventricular pacing with this stimulation mode.

Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Background Atrial voltage mapping and atrial cardiac magnetic resonance imaging are two contemporary methods for quantification of atrial fibrosis. However, the absence of a gold standard for measuring atrial fibrosis has precluded their direct comparison. Nevertheless, understanding the relative performance of voltage mapping and atrial late gadolinium enhancement for identification of atrial cardiomyopathy remains critical to correctly targeting clinical application of these techniques. Purpose To assess the relative performance of electroanatomic voltage mapping and atrial late gadolinium enhancement imaging using three surrogate markers chosen to distinguish pre-procedural utility (progression to recurrent atrial fibrillation following ablation) from potential utility for providing atrial fibrillation mechanistic insights (paroxysmal vs. persistent status of atrial fibrillation and relationship with co-morbidities associated with atrial fibrillation). Methods 123 patients underwent atrial late gadolinium enhancement imaging and electroanatomic voltage mapping prior to atrial fibrillation ablation. Atrial late gadolinium enhancement imaging was assessed with CEMRG software and electroanatomic voltage mapping processed with OpenEP software using previously published thresholds. Low voltage tissue was defined at (1) &amp;lt;0.5mV, (2) &amp;lt;1.17mV, and (3) &amp;lt;1.3mV. Atrial fibrosis using late gadolinium enhancement was defined using four thresholds (1) signal intensity &amp;gt;3.3 standard deviations above the blood pool mean; (2) image intensity ratio (IIR) 1.2x blood pool mean; (3) IIR 1.32x blood pool mean; and (4) IIR 0.97x blood pool mean. Results Patients with persistent atrial fibrillation and those with CHA2DS2VaSc &amp;gt;2 had increased low voltage area for each of the thresholds tested, but there was no increase in atrial late gadolinium enhancement area at any of the imaging thresholds tested. Increased atrial fibrosis using IIR&amp;gt;0.97 was independently associated with recurrence of atrial fibrillation (OR 1.05 (CI 1.01-1.09), p=0.009) in both univariate and multivariate analysis. Low voltage area &amp;lt;1.13mV and low voltage area &amp;lt;1.17mV were associated with increased risk of recurrence (OR 1.02 (CI 1.01-1.04), p=0.01, and OR 1.03 (CI 1.01-1.04), p=0.009) in univariate analysis but neither voltage threshold remained statistically significant in multivariate analysis controlling for clinical variables. Conclusion Increased fibrosis burden measured with atrial magnetic resonance imaging, but not with low voltage area, is independently associated with recurrence of atrial fibrillation following catheter ablation. However, increased low voltage area measured with electroanatomic mapping is associated with persistent atrial fibrillation status and CHADS2VaSc score. These findings support the use of magnetic resonance imaging for pre-procedure assessment and the use of electroanatomic mapping for intraprocedural mechanism-based assessment of atrial cardiomyopathy.

Introduction: The radiofrequency catheter ablation (RFCA) of ventricular arrhythmias (VAs) originating from the right ventricular outflow tract (RVOT) is a well-established therapy. Traditionally, RFCA is guided using electroanatomical 3D mapping systems involving manual catheter navigation within cardiac chambers. While effective, this approach may be time-consuming, and it carries a potential risk of cardiac wall perforation. Although the risk is low, it cannot be underestimated. Therefore, alternative mapping methods are sought to reduce procedural times and improve the overall efficiency of RVOT-VAs ablation. Aim: To evaluate the safety, feasibility, and efficacy of a universal RVOT 3D model implementation for the ablation of idiopathic RVOT-VAs. Methods: Consecutive patients undergoing VA ablation supported with a universal RVOT 3D model (3D-MODEL group) were included in the study. The RVOT universal model in this group was created by processing DICOM images for the improved segmentation of anatomical structures, followed by production using 3D printing technology. Patients who underwent classic endocardial electroanatomical mapping served as controls (EAM group). Results: A total of 228 patients were included in the study (143 women, age 50 ± 17 years): 149 in the 3D-MODEL group and 79 in the EAM group. The acute complete elimination of clinical VAs was achieved for 133 (89%) of patients in the 3D-MODEL group vs. 65 (82%) in the EAM group (p = 0.14). The procedural time was significantly shorter in the 3D-MODEL group compared to the EAM group (38 ± 14 min vs. 80 ± 39 min, p < 0.001). A significant difference was also observed in the radiofrequency time between the 3D-MODEL and EAM groups (251 ± 176 s vs. 503 ± 425 s, p < 0.001). No significant difference in fluoroscopy time was found between the groups (284 ± 167 s vs. 260 ± 327 s, p = 0.49). Two cases of cardiac tamponade occurred, both in patients from the EAM group. During follow-up, lasting 14 ± 10 months, 87% of patients in the 3D-MODEL group and 75% in the EAM group remained arrhythmia-free (p = 0.45). Conclusions: The use of universal RVOT 3D modeling is a feasible, safe, and effective alternative to classic electroanatomical mapping in the ablation of idiopathic RVOT-VAs.

Image integration of three-dimensional (3D) reconstructions of left atrial (LA) and pulmonary vein (PV) anatomy into electroanatomical mapping (EAM) plays a major role in atrial fibrillation (AF) ablation. Point-by-point EAM is commonly used for registration of imported LA and PV anatomy. We aimed to assess the accuracy of intraprocedural rotational angiography-based LA imaging registered by spatial reconstruction of intracardiac echocardiography (ICE) in patients undergoing AF ablation. Twenty-two patients (11 males, 66 ± 12 years) were studied. Reconstructions of LA and PVs based on rotational angiography were registered by a second 3D reconstruction based on ICE. In a second step, EAM points were added to ICE 3D reconstructions. A 3D image of the LA and PVs was reconstructed in all patients by both imaging modalities. Rotational angiography and ICE-based LA 3D reconstructions took 11.5 ± 5.2 and 20.4 ± 11.2 min, respectively. A total of 17 ± 6 two-dimensional ICE fans were used for spatial reconstruction of ICE. The deviation between the two 3D shells was 2.6 ± 0.5 mm. Integration of 78 ± 58 EAM points into ICE 3D reconstruction did not significantly reduce the deviation to rotational angiography-based reconstructions (2.7 ± 0.6 mm). All PVs were isolated successfully. Intraprocedural 3D reconstruction of LA and PVs for ablation of AF is feasible based on both rotational angiography and ICE. LA reconstructions based on rotational angiography can accurately be registered using 3D ICE shells. Additional EAM does not enhance accuracy. Therefore, registration of rotational angiography-based 3D reconstructions by 3D reconstructions from ICE seems to be an alternative technique to support AF ablation.

Catheter ablation (CA) with guidance using fluoroscopy and electroanatomic mapping (EAM) is the standard and most effective treatment for atrioventricular accessory pathways (AP). However, data on fluoroscopy-free CA with AP remains limited. This study evaluated the feasibility of performing CA without fluoroscopy guidance, using only EAM, in patients with right-sided AP. We retrospectively included 100 consecutive patients with pre-excitation in ECG who underwent CA for right-sided AP. All procedures were performed using EAM. The primary outcome was the feasibility of performing the AP CA without the use of fluoroscopy. Secondary outcomes included the acute and long-term success rate, complications, and procedure time. In 74 patients, the procedure was completed without fluoroscopy (ZF-EAM group), while 26 patients required fluoroscopy during the procedure (F-EAM group). Acute procedural success was achieved in 91% of patients overall, with a higher rate in the ZF-EAM group (72 of 74; 97%) compared to the F-EAM group (19 of 26; 73%) (P <0.001). After follow-up, long-term recurrence was observed in 6 of 72 patients (8.3%) in the ZF-EAM group and none of the 19 patients (0%) in the F-EAM group (P = 0.34). The procedure duration was shorter in the ZF-EAM group (median 1.3 hours [0.9-1.8]) compared to the F-EAM group (median 1.8 hours [1.3-2.6]; P = 0.007). No major complications occurred in either group. CA of right-sided AP, guided entirely by EAM without the use of fluoroscopy, is feasible in most cases. This approach was associated with high efficacy and safety, and it may reduce procedure times.

Aims Atrial and ventricular tachyarrhythmias are common among patients with adult congenital heart disease (ACHD) and can impair quality of life and prognosis. Catheter ablation is often the main treatment option in this population, despite anatomical hurdles. Substrate mapping findings have not been thoroughly investigated as predictors of arrhythmia recurrence success and cardiovascular clinical outcome after ablation. We sought to determine the prognostic value of myocardial scar and chamber enlargement detected at electroanatomical mapping in ACHD patients undergoing catheter ablation of tachyarrhythmias. Methods and results Consecutive ACHD patients undergoing catheter ablation of atrial and ventricular tachycardias using different electroanatomical mapping systems were retrospectively identified from a hospital-based database. Scar extent detected at the electroanatomical mapping, as well as the total mapped area, was calculated. Arrhythmia recurrence, hospitalization for cardiovascular (CV) reasons, and a combined endpoint (arrhythmia recurrence and/or CV hospitalization) were evaluated during the follow-up. The relationship between the aforementioned electroanatomical findings and the patients’ outcome was assessed. Twenty patients (12 male, 60%; mean age 40 ± 11 years) undergoing atrial (n = 14; 70%) or ventricular (n = 6; 30%) tachyarrhythmia were included. Acute procedural success (arrhythmia termination and/or no reinduction) was achieved in all the patients. At a mean follow-up of 171 ± 135 weeks, eight patients (40%) had arrhythmia recurrence (4/6 in the ventricular tachycardia group, 67%, 4/14 in the atrial tachycardia group, 28%). Patients with arrhythmia recurrence had a more extensive bipolar scar (P = 0.029) and a larger total mapped area (P = 0.03) than patients without recurrence, and so did the patients with the composite endpoint (P = 0.029 and P = 0.03, respectively). Patients with subsequent CV hospitalization had a larger total mapped area than patients without CV hospitalization (P = 0.017). The presence of a bipolar scar ≥22.95 cm2 predicted arrhythmia relapse (0.039) at the multivariate analysis. Conclusions Patients with ACHD show a high recurrence rate after catheter ablation, especially for ventricular tachycardias. A large bipolar scar at the electroanatomical mapping and total mapped area predict arrhythmia recurrence, likely due to the presence of more extensive reentry circuits. A large total mapped area, which may reflect a greater disease severity, predicts both arrhythmia recurrence and CV hospitalizations. Early referral of ACHD patients for catheter ablation may be a sound strategy in order to perform the procedure in the setting of less advanced heart disease.

Since the introduction of atrial fibrillation (AF) ablation in the 1990s, the procedure has continuously evolved, with gradual improvements in outcomes and safety. Recent technological advancements include the introduction of contact force catheters and high-resolution electroanatomical mapping systems, while imaging modalities including transesophageal echocardiography and fluoroscopy have become integral parts of AF ablation procedures. Further, intraprocedural intracardiac echocardiography and the integration of cardiac magnetic resonance and computed tomography images with electroanatomical mapping have shown promise to improve procedural outcomes by reducing radiation exposure and procedural times. However, available data on procedural utility and the reduction in AF recurrence rates associated with these modalities are mixed. This review therefore aims to discuss the current common imaging modalities used in AF ablation and their potential impact on outcomes. In particular, imaging is discussed with respect to the important information it offers before, during, and after the procedure. Perspectives on the future of imaging in AF ablation are also shared.

During percutaneous puncture procedure, breath holding is subjectively controlled by patients, and it is difficult to ensure consistent tumour position between the preoperative CT scanning phase and the intraoperative puncture phase. In addition, the manual registration process is time-consuming and has low accuracy. We have proposed an automatic registration method using optical markers and a tumour breath-holding position estimation model based on the support vector regression algorithm. A robot system and a tumour respiratory motion simulation platform are built to perform puncture tests under different breath-holding states. The experimental results show that automatic registration has higher accuracy than manual registration, and with the tumour breath-holding position estimation model, the targeting accuracy of puncture under inconsistent breath-holding conditions is greatly improved. The proposed automatic registration and tumour breath-holding position estimation model can improve the accuracy and efficiency of puncture under inconsistent breath-holding conditions.

An automatic 3D point cloud registration method based on regional curvature maps

Aim AF is the most common arrhythmia in clinical practice and associated with an increased long-term risk of stroke, heart failure, and all-cause mortality. Catheter ablation of AF is relatively new modality to convert AF to sinus rhythm. This study was aimed to elaborate efficacy of catheter ablation in mixed type of AF. Methods Thirty patients (age of 52 ± 8 yo) comprised of 19 paroxysmal and 11 chronic AF underwent radiofrequency catheter ablation guided by electroanatomical CARTO™ mapping system. We used step wise ablation approach with circumferential pulmonary vein isolation (PVI) as a cornerstone. Additional ablation comprised of roof line, mitral isthmus line, complex fractionated atrial electrogram (CFAE), septal line and coronary sinus ablation was done respectively if indicated. All patients were followed up to 1 year for AF recurrence. Results Circumferential PVI was successfully performed in all patients but one. Average follow up period was 11.5 months. More than 80% of all patients remain in sinus rhythm at the end of follow period which 62% of them were free from any anti-arrhythmic drug. No major complication in all patients series. Conclusion Radiofrequency ablation guided with electroanatomical mapping is effective and safe in mixed type of AF. (Med J Indones 2009;19:172-8)

Three-dimensional electroanatomic mapping (EAM) systems reduce radiation exposure when radio frequency catheter ablation (RFCA) procedures are performed by well-trained senior operators. Given the steep learning curve associated with complex RFCA, trainees and their mentors must rely on multiple imaging modalities to maximize safety and success, which might increase procedure and fluoroscopy times. The objective of the present study is to determine if 3-D EAM (CARTO and ESI-NavX) improves procedural outcomes (fluoroscopy time, radio frequency time, procedure duration, complication, and success rates) during CA procedures as compared to fluoroscopically guided conventional mapping alone in an academic teaching hospital. We analyzed a total of 1070 consecutive RFCA procedures over an 8-year period for fluoroscopic time stratified by ablation target and mapping system. Multivariate logistic regression and adjusted odds ratios were calculated for each variable. No statistically significant differences in acute success rates were noted between conventional and 3-D mapping cases [CARTO (p = 0.68) or ESI-NavX (p = 0.20)]. Moreover, complication rates were also not significantly different between CARTO (p = 0.23) and ESI-NavX (p = 0.53) when compared to conventional mapping. Procedure, radio frequency, and fluoroscopy times were significantly longer with CARTO and ESI-NavX versus conventional mapping [fluoroscopy time: CARTO, 28.3min; ESI, 28.5min; and conventional, 24.3min; p < 0.001)]. The use of 3-D EAM systems during teaching cases significantly increases radiation exposure when compared with conventional mapping. These findings suggest a need to develop alternative training strategies that enhance confidence and safety during catheter manipulation and allow for reduced fluoroscopy and procedure times during RFCA.

Radiotherapy is a major treatment for head and neck cancer. Currently, computed tomography (CT) is utilized to delineate the target area and make radiotherapy plans. Compared with CT images, magnetic resonance (MR) images have excellent soft tissue contrast, which can distinguish normal surrounding tissues. It is necessary to register MR and CT images since it helps physicists to improve the accuracy of radiotherapy plans. Most of the current registrations require manual intervention to select regions of interest, which increases the workload of doctors and the time of registration to a certain extent. In this paper, an automatic registration method is proposed to delineate the regions of interest. Herein, surface meshes are extracted from the CT and MR images and utilized to perform the surface matching, then the regions of interest are extracted automatically by calculating the overlapped regions between the surface mesh of the surface-aligned MR images and CT images. Furthermore, a multi-level resolution registration mechanism is utilized to improve the registration speed. Surface matching is performed using low-resolution images to obtain transformation parameters as initial parameters for rigid registration followed by deformable registration. The experiments demonstrate that our proposed method performs better in the registration speed and accuracy over the conventional methods of delineating regions of interest manually.