|
| ||
|
|
||
Ablation Catheter (ablation + catheter)
Selected AbstractsCapsule Endoscopy in Examination of Esophagus for Lesions After Radiofrequency Catheter Ablation: A Potential Tool to Select Patients With Increased Risk of ComplicationsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2010LUIGI DI BIASE M.D. Capsule Endoscopy in Examination of Esophagus.,Background: Esophageal injury can result from left atrial radiofrequency ablation (RFA) therapy, with added concern because of its possible relationship to the development of atrial-esophageal (A-E) fistulas. Objective: Evaluate utility of esophageal capsule endoscopy to detect esophageal lesions as a complication of RFA therapy in the treatment of atrial fibrillation (AF). Methods: Consecutive patients with AF who underwent left atrial RFA therapy and received capsule endoscopy within 48 hours postablation. Video was reviewed by a single gastroenterologist. The medical records were also reviewed for symptoms immediately postablation and at the 3-month follow-up. Results: A total of 93 consecutive patients were included and 88 completed the study and were analyzed. The prevalence of esophageal lesions was 17% (15/88 patients). Nine percent (8/88) of these patients had lesions anatomically consistent with the location of the ablation catheter. Six patients with positive capsule findings had symptoms of chest pain (3/6, 50%), throat pain (2/6, 33%), nausea (1/6, 17%), and abdominal pain (1/6, 17%). An additional 24 patients were symptomatic postablation, but with normal capsule findings. All patients with identified lesions by capsule endoscopy received oral proton pump inhibitor therapy, and were instructed to contact the Cleveland Clinic in the event of worsening symptoms. No delayed complications were reported at the 3-month follow-up. Conclusion: This study supports the use of capsule endoscopy as a tool for the detection of esophageal injury post-RFA therapy. PillCam ESO is well tolerated and provides satisfactory images of the areas of interest in the esophagus without potential risk related to insufflation with regular esophagogastroduodenoscopy. (J Cardiovasc Electrophysiol, Vol. 21, pp. 839-844, August 2010) [source] Experience with the Hansen Robotic System for Atrial Fibrillation Ablation,Lessons Learned and Techniques Modified: Hansen in the Real WorldJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2009OUSSAMA M. WAZNI M.D. Introduction: The Hansen robotic system has only recently been used in the United States for catheter ablation procedures in humans. Atrial fibrillation (AF) ablation may be performed utilizing this system. We report our management of complications with early experience of this system. Methods and Results: All 71 patients in whom the system was utilized were included. In all patients, a 2-operator technique was to be employed; one operator manipulates the ablation catheter via the robot and the other manipulates the circular mapping and intracardiac echocardiogram catheters. There was no procedure-related mortality. All vascular complications occurred in the first 25 procedures performed. There were 6 intraoperative procedural-related complications. These included significant vascular complications (n = 4), one of whom required iliac vein stenting, and 2 cardiac tamponade (one related to a pop-phenomenon),successfully treated by pericardiocentesis. Early complications (n = 3) were 1 tamponade several hours post-procedure, 1 vascular complication, and 1 pericarditis. Late complications included 5 patients with severe pulmonary vein stenosis (all in first 27 patients) and 1 patient with gastroparesis. All complications were successfully managed without persistent morbidity and occurred earlier in our experience. This led to specific alterations in our vascular access and ablation techniques. These include the use of a longer 14 Fr sheath, through which the robotic sheath is more safely advanced. The choice of ablation catheter and titration of power, particularly when the catheter has a perpendicular orientation to the atrial wall, is also important. Conclusions: The suggested modifications may make the system easier to use with the potential to reduce complications. [source] First Experiences for Pulmonary Vein Isolation with the High-Density Mesh Ablator (HDMA): A Novel Mesh Electrode Catheter for Both Mapping and Radiofrequency Delivery in a Single UnitJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2009AXEL MEISSNER M.D. Background: Interventional therapy of atrial fibrillation (AF) is often associated with long examination and fluoroscopy times. The use of mapping catheters in addition to the ablation catheter requires multiple transseptal sheaths for left atrial access. Objectives: The purpose of this prospective study was to evaluate feasibility and safety of pulmonary vein (PV) isolation using the high-density mesh ablator (HDMA), a novel single, expandable electrode catheter for both mapping and radiofrequency (RF) delivery at the left atrium/PV junctions. Methods: Twenty-six patients with highly symptomatic paroxysmal AF (14, 53.8%) and persistent AF (12, 46.2%) were studied. Segmental PV isolation via the HDMA was performed using a customized pulsed RF energy delivery program (target temperature 55,60°C, power 70,100 W, 600,900 seconds RF application time/PV). Results: All 104 PVs in 26 patients could be ablated by the HDMA. Segmental PV isolation was achieved with a mean of 3.25 ± 1.4 RF applications for a mean of 603 ± 185 seconds. Entrance conduction block was obtained in 94.2% of all PV. The mean total procedure and fluoroscopy time was 159.0 ± 32 minutes and 33.5 ± 8.6 minutes, respectively. None of the patients experienced severe acute complications. After 3 months no PV stenosis was observed, and 85.6% and 41.6% of the patients with PAF and persistent AF, respectively, did not report symptomatic AF. Conclusions: In this first study of PV isolation using the HDMA, our findings suggest that this method is safe and yields good primary success rates. The HDMA simplifies AF ablation, favorably impacting procedure and fluoroscopy times. [source] Esophageal Luminal Temperature Measurement Underestimates Esophageal Tissue Temperature During Radiofrequency Ablation Within the Canine Left Atrium: Comparison Between 8 mm Tip and Open Irrigation CathetersJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2008JENNIFER E. CUMMINGS M.D. Introduction: Evaluation of luminal temperature during left atrial ablation is used clinically; however, luminal temperature does not necessarily reflect temperature within the esophageal wall and poses a risk of atrioesophageal fistula. This animal study evaluates luminal esophageal temperature and its relation to the temperature of the external esophageal tissue during left atrial lesions using the 8 mm solid tip and the open irrigated tip catheters (OIC). Methods and Results: A thermocouple was secured to the external surface of the esophagus at the level of the left atrium of the dogs. Luminal esophageal temperature was measured using a standard temperature probe. In four randomized dogs, lesions were placed using an 8 mm solid tip ablation catheter. In six randomized dogs, lesions were placed using the 3.5 mm OIC. The average peak esophageal tissue temperature when using the OIC was significantly higher than that of the 8 mm tip catheter (88.6°C ± 15.0°C vs. 62.3°C ± 12.5°C, P < 0.05). Both OIC and 8 mm tip catheter had significantly higher peak tissue temperatures than luminal temperatures (OIC: 88.6°C ± 15.0°C vs 39.7°C ± 0.82°C, P < 0.05) (8 mm: 62.3°C ± 12.5°C vs 39.0 ± 0.5°C, P < 0.05). Both catheters achieved peak temperatures faster in the tissue as compared to the lumen of the esophagus, although the tissue temperature peaked significantly faster for the OIC (OIC: 25 seconds vs 90 seconds, P < 0.05) (8 mm: 63 seconds vs 105 seconds, P < 0.05). Conclusion: Despite the significant difference in actual tissue temperatures, no significant difference was observed in luminal temperatures between the OIC and 8 mm tip catheter. [source] Validation of Three-Dimensional Cardiac Image Integration: Use of Integrated CT Image into Electroanatomic Mapping System to Perform Catheter Ablation of Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2006PETER M. KISTLER M.B.B.S., Ph.D. Introduction: Accurate visualization of the complex left atrial (LA) anatomy and the location of an ablation catheter within the chamber is important in the success and safety of ablation for atrial fibrillation (AF). We describe the integration of CT into an electroanatomic mapping (EAM) system and its validation in patients undergoing catheter ablation for AF. Methods and Results: Thirty patients (59.2 ± 8 years, 25 M) with paroxysmal (12) and persistent (18) AF underwent ablation using CT image integration into an electroanatomic mapping system. CT registration using the pulmonary veins as markers (landmark) was achieved with an error of 6.4 ± 2.8 mm with repeat registration required in two patients. Registration of the CT by best fit to a electroanatomic geometry (surface) was achieved with an error of 2.3 ± 0.4 mm. There was no significant difference in the regional LA registration error at superior (1.7 ± 0.7 mm), inferior (2.2 ± 1.4 mm), septal (1.7 ± 0.8 mm), and lateral (1.7 ± 0.7 mm, P = 0.13) sites. Cardiac rhythm at the time of CT did not have a significant effect on total or regional surface registration accuracy (mean total 2.5 ± 0.3 in AF patients vs 2.3 ± 0.5 in SR patients, P = 0.22). The integrated CT was used to guide the encirclement of the pulmonary veins (PV) in pairs with electrical isolation achieved by maintaining ablation along the ablation line in 58 of 60 PV pairs. Postprocedural PV angiography did not demonstrate significant stenosis. Conclusion: CT image integration into an EAM system was successfully performed in patients undergoing catheter ablation for AF. With a greater appreciation of the complex and variable nature of the PV and LA anatomy this new technology may improve the efficacy and safety of the procedure. [source] Real-Time Monitoring of Luminal Esophageal Temperature During Left Atrial Radiofrequency Catheter Ablation for Atrial Fibrillation: Observations About Esophageal Heating During Ablation at the Pulmonary Vein Ostia and Posterior Left AtriumJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2006CHRISTIAN PERZANOWSKI M.D. Introduction: Left atrial radiofrequency catheter ablation (RFA) is gaining acceptance as treatment for drug-refractory atrial fibrillation (AF). This therapy has been associated with esophageal injury and atrioesophageal fistula formation causing death. Methods: We describe 3 patients undergoing catheter ablation for AF during real-time monitoring of luminal esophageal temperature. Results: We observed heating of the esophagus during short duration low power RFA, at either the left or right pulmonary vein ostia. Cryoablation at the pulmonary vein ostium in one patient resulted in esophageal cooling. Furthermore, we observed that fluoroscopic localization of the ablation catheter at a site apparently distant from the esophagus is not adequate to assure avoidance of ablation-induced esophageal heating. Conclusions: Real-time monitoring of luminal esophageal position and temperature is feasible, enhances recognition of esophageal heating, and may add useful information beyond that provided by fluoroscopic assessment of esophageal position. There is a potential role for esophageal monitoring to help avoid thermal injury to the esophagus during catheter ablation for atrial fibrillation. [source] Cerebral Diffusion-Weighted Magnetic Resonance Imaging: A Tool to Monitor the Thrombogenicity of Left Atrial Catheter AblationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2006LARS LICKFETT M.D. Introduction: Cerebral embolism and stroke are feared complications of left atrial catheter ablation such as pulmonary vein (PV) ablation. In order to assess the thrombogenicity of left atrial catheter ablation, knowledge of both clinically evident as well as silent cerebral embolism is important. The aim of the current study was to examine the use of diffusion-weighted magnetic resonance imaging (DW-MRI) for detection of cerebral embolism, apparent as well as silent, caused by PV catheter ablation. Methods and Results: Twenty consecutive patients without structural heart disease undergoing lasso catheter-guided ostial PV ablation using an irrigated-tip ablation catheter were studied. Cerebral MRI including DW single-shot spin echo echoplanar, turbo fluid attenuated inversion recovery, and T2-weighted turbo spin echo sequences were performed the day after the ablation procedure. Ten patients also underwent preprocedure cerebral MRI. All ablation procedures were performed without acute complications. A mean of 3.2 ± 0.6 PVs were ablated per patient. No patient had neurological symptoms following the procedure. In 2 of 20 patients (10%), DW-MRI revealed new embolic lesions, which were located in the right periventricular white matter in one and in the left temporal lobe in the other patient. There was no statistically significant difference in age, history of hypertension, left atrial volume, and procedure duration between the 2 patients with and the 18 patients without cerebral embolism following AF ablation. Conclusion: This is the first study using highly sensitive DW-MRI of the brain to detect asymptomatic cerebral embolism after left atrial catheter ablation. Even small, clinically silent, embolic lesions can be demonstrated with this technique. DW-MRI can be used to monitor and compare the thrombogenicity of different AF ablation approaches. [source] Creating Continuous Linear Lesions in the Atria: A Comparison of the Multipolar Ablation Technique Versus the Conventional Drag-and-BurnJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2005WILBER W. SU M.D. Introduction: Catheter-based treatment of atrial fibrillation (AF) requires the isolation of the triggering foci as well as modification of the atria with substrate that sustains AF. The creation of linear lesions in the left atrium with standard radiofrequency ablative methods requires long procedural times with unpredictable results. Methods: The simultaneous delivery of phase-shifted radiofrequency energy from a multipolar catheter was compared to the conventional drag-and-burn technique for creating linear lesions in 10 dogs. Four atrial sites were targeted under intracardiac ultrasound and fluoroscopic guidance in each of 10 dogs. The conventional drag-and-burn technique or the multipolar phase-shifted ablation catheter was randomly applied for 60 seconds and compared. Results: Creating linear lesions using the simultaneous multipolar phase-shifted ablation catheter was on average 11.0 minutes faster (33.6 minutes vs 44.6 minutes, P < 0.01) than the drag-and-burn method. The fraction of the lesion length achieved using phase-shifted ablation compared to that intended was 23% greater (76% vs 53%, P < 0.01), and has less discontinuities (0.1 compared to 0.8 discontinuities/line, P < 0.003). There was no significant difference in either the lesion transmurality, or fluoroscopy times. Conclusion: The simultaneous delivery of phase-shifted, radiofrequency energy using a multipolar catheter is more effective and efficient in producing linear lesions than the traditional drag-and-burn technique. Using the multipolar ablative method to create linear lesions may be a useful technique in the treatment of patients with substrate-mediated atrial fibrillation. [source] Cooled Needle Catheter Ablation Creates Deeper and Wider Lesions Than Irrigated Tip Catheter AblationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2005ARAVINDA THIAGALINGAM F.R.A.C.P. Objectives: To design and test a catheter that could create deeper ablation lesions. Background: Endocardial radiofrequency (RF) ablation is unable to reliably create transmural ventricular lesions. We designed an intramural needle ablation catheter with an internally cooled 1.1-mm diameter straight needle that could be advanced up to 14 mm into the myocardium. The prototype catheter was compared with an irrigated tip ablation catheter. Methods: Ablation lesions were created under general anesthesia in 14 male sheep (weight 44 ± 7.3 kg) with fluoroscopic guidance. Each of the catheters was used to create two ablation lesions at randomly allocated positions within the left ventricle. The irrigation rate, target temperature, and maximum power were: 20 mL/min, 85°C, 50 W for the intramural needle catheter and 20 mL/min, 50°C, 50 W for the irrigated tip catheter, respectively. All ablations were performed for 2 minutes. After the last ablation, blue tetrazolium (12.5 mg/kg) was infused intravenously. The heart was removed via a left thoracotomy after monitoring the sheep for one hour. Results: There was no evidence of cardiac tamponade in any sheep. The intramural needle catheter lesions were significantly wider (10.9 ± 2.8 mm vs 10.1 ± 2.4 mm, P = 0.01), deeper (9.6 ± 2.0 mm vs 7.0 ± 1.3 mm, P = 0.01), and more likely to be transmural (38% vs 0%, P = 0.03). Conclusions: Cooled intramural needle ablation creates lesions that are significantly deeper and wider than endocardial RF ablation using an irrigated tip catheter in sheep hearts. This technology may be useful in treating ventricular tachycardia resistant to conventional ablation techniques. [source] Detection of Inadvertent Catheter Movement into a Pulmonary Vein During Radiofrequency Catheter Ablation by Real-Time Impedance MonitoringJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2004PETER CHEUNG M.D. Introduction: During radiofrequency ablation to encircle or isolate the pulmonary veins (PVs), applications of radiofrequency energy within a PV may result in stenosis. The aim of this study was to determine whether monitoring of real-time impedance facilitates detection of inadvertent catheter movement into a PV. Methods and Results: In 30 consecutive patients (mean age 53 ± 11 years) who underwent a left atrial ablation procedure, the three-dimensional geometry of the left atrium, the PVs, and their ostia were reconstructed using an electroanatomic mapping system. The PV ostia were identified based on venography, changes in electrogram morphology, and manual and fluoroscopic feedback as the catheter was withdrawn from the PV into the left atrium. Real-time impedance was measured at the ostium, inside the PV at approximately 1 and 3 cm from the ostium, in the left atrial appendage, and at the posterior left atrial wall. There was an impedance gradient from the distal PV (127 ± 30 ,) to the proximal PV (108 ± 15 ,) to the ostium (98 ± 11 ,) in each PV (P < 0.01). There was no significant impedance difference between the ostial and left atrial sites. During applications of radiofrequency energy, movement of the ablation catheter into a PV was accurately detected in 80% of the cases (20) when there was an abrupt increase of ,4 , in real-time impedance. Conclusion: There is a significant impedance gradient from the distal PV to the left atrium. Continuous monitoring of the real-time impedance facilitates detection of inadvertent catheter movement into a PV during applications of radiofrequency energy. (J Cardiovasc Electrophysiol, Vol. 15, pp. 1-5, June 2004) [source] Randomized Comparison of Bipolar versus Unipolar Plus Bipolar Recordings During Segmental Ostial Ablation of Pulmonary VeinsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2002HIROSHI TADA M.D. Unipolar vs Bipolar Electrograms.Introduction: Segmental ostial ablation to isolate pulmonary veins is guided by pulmonary vein potentials. The aim of this prospective randomized study was to compare the utility of unipolar plus bipolar electrograms versus only bipolar electrograms as a guide for segmental ablation to isolate the pulmonary veins in patients with atrial fibrillation. Methods and Results: Isolation of the left superior, right superior, and left inferior pulmonary veins was attempted in 44 patients (35 men and 9 women; mean age 54 ± 10 years) with paroxysmal atrial fibrillation. A decapolar Lasso catheter was positioned in the pulmonary veins, near the ostium, and a conventional ablation catheter was used for segmental ablation aimed at elimination of all pulmonary vein potentials. One hundred fourteen pulmonary veins were randomly assigned for ostial ablation guided by either bipolar or unipolar plus bipolar recordings. Electrical isolation was achieved in 51 (96%) of 53 pulmonary veins randomized to the bipolar approach, and 57 (93%) of 61 pulmonary veins randomized to the unipolar plus bipolar approach (P = 0.7). In the unipolar plus bipolar group, the total duration of radiofrequency energy needed to achieve isolation, 5.5 ± 2.8 minutes/vein, was significant shorter than in the bipolar group, 7.6 ± 4.1 minutes/vein (P < 0.01). Mean procedure and fluoroscopy durations per vein were 19% to 28% shorter in the unipolar plus bipolar group. Conclusion: Segmental ostial ablation to isolate the pulmonary veins can be achieved more efficiently and with less radiofrequency energy when guided by both unipolar and bipolar recordings than by bipolar recordings alone. [source] Three-Dimensional Catheter Positioning During Radiofrequency Ablation in Patients: First Application of a Real-Time Position Management SystemJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2000NATASJA M.S. DE GROOT M.D. Three-Dimensional Reai-Time Position Management. Introduction: Precise localization of target sites for radiofrequency catheter ablation (RFCA) of arrhythmias is hampered by the relative inaccuracy of X-ray localization procedures. This study evaluated the efficacy of a three-dimensional (3D) real-time position management system in guiding RFCA procedures in patients. Methods and Results: Patients (n = 30, age 59 ± 20 years) referred for ablation of either atrial flutter (n = 10), ventricular tachycardia (n = 15), or accessory pathways (n = 5) were studied. The real-time position management system uses ultrasound ranging techniques to track the position of an ablation catheter relative to two multitransducer reference catheters, positioned in the right atrium or coronary sinus and the right ventricle. Each catheter contains three or four ultrasound transducers. The distance between the transducer(s) is determined hy calculating the time necessary for an ultrasound pulse to reach other transducers, assuming the speed of sound in blood is 1,550 m/sec. The proximal His bundle was marked at the beginning and the end of the procedure as an electrical landmark to verify reproducibility. After identification of target sites, the position of each lesion created with the ablation catheter was marked. Successful ahlation was achieved in 94% of the patients. The distance between the location of the proximal His hundle as marked at the beginning and at the end of the procedure was 2.0 ± 1.2 mm (range 1.5 to 3.5). Conclusion: The new 3D real-time position management system facilitated RFCA procedures as it allowed accurate and reproducible 3D tracking of the mapping and ablation catheter. [source] Nonfluoroscopic Three-Dimensional Mapping for Arrhythmia Ablation: Tool or Toy?JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2000APICHAI KHONGPHATTHANAYOTHIN M.D. Arrhythmia Ahlation with Nonfluoroscopic 3D Mapping. Introduction: Conventional mapping and ablation rely on fluoroscopy, which can result in imprecise positioning of the ablation catheter and long fluoroscopic exposure times. We evaluated a nonfluoroscopic three-dimensional mapping system, termed CARTO, and compared the results of ablation using this technique with those of conventional mapping. Methods and Results: We compared the results of 88 arrhythmia ablations (79 patients) using CARTO with 100 ablations (94 patients) using the conventional technique. The ablations were separated into four groups: (1) AV nodal reentrant tachycardia (AVNRT); (2) atrial tachycardia/flutter; (3) ventricular tacbycardia (VT); and (4) bypass tract tachycardia. We compared the success rate, complications, and fluoroscopy and procedure times. Tbe ablation outcomes were excellent and comparable in all four types of the arrhythmias between the two techniques. Major complications included one cardiac tamponade in each group and one second-degree AV block in the conventional group. Fluoroscopy time was shorter using the CARTO technique: 10 ± 7 versus 27 ± 15 minutes for AVNRT (P < 0.01), 18 ± 17 versus 44 ± 23 minutes for atrial tachycardia and flutter (P < 0.01), 15 ± 12 versus 34 ± 31 minutes for VT (P < 0.05), and 21 ± 14 versus 53 ± 32 minutes for bypass tract tachycardia (P < 0.01). Procedure times were similar except for the bypass tract patients, wbich was shorter in the CARTO group, 4 ± 1.3 versus 5.5 ± 2.5 hours (P < 0.01). Conclusion: The electroanatomic three-dimensional mapping technique reduced fluoroscopy time and resulted in excellent outcome without increasing the procedure time. [source] Catheter Ablation for Paroxysmal Atrial Fibrillation: A Randomized Comparison between Multielectrode Catheter and Point-by-Point AblationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2010ALAN BULAVA M.D., Ph.D. Introduction:,Catheter ablation for paroxysmal atrial fibrillation is widely used for patients with drug-refractory paroxysms of arrhythmia. Recently, novel technologies have been introduced to the market that aim to simplify and shorten the procedure. Aim:,To compare the clinical outcome of pulmonary vein (PV) isolation using a multipolar circular ablation catheter (PVAC group), with point-by-point PV isolation using an irrigated-tip ablation catheter and the CARTO mapping system (CARTO group; CARTO, Biosense Webster, Diamond Bar, CA, USA). Methods:,Patients with documented PAF were randomized to undergo PV isolation using PVAC or CARTO. Atrial fibrillation (AF) recurrences were documented by serial 7-day Holter monitoring. Results:,One hundred and two patients (mean age 58 ± 11 years, 68 men) were included in the study. The patients had comparable baseline clinical characteristics, including left atrial dimensions and left ventricular ejection fraction, in both study arms (PVAC: n = 51 and CARTO: n = 51). Total procedural and fluoroscopic times were significantly shorter in the PVAC group (107 ± 31 minutes vs 208 ± 46 minutes, P < 0.0001 and 16 ± 5 minutes vs 28 ± 8 minutes, P < 0.0001, respectively). The AF recurrence was documented in 23% and 29% of patients in the PVAC and CARTO groups, respectively (P = 0.8), during the mean follow-up of 200 ± 13 days. No serious complications were noted in both study groups. Conclusions:,Clinical success rates of PV isolation are similar when using multipolar circular PV ablation catheter and point-by-point ablation with a three-dimensional (3D) navigation system in patients with PAF, and results in shorter procedural and fluoroscopic times with a comparable safety profile. (PACE 2010; 33:1039,1046) [source] Cavotricuspid Isthmus Ablation with Large-Tip Gold Alloy Versus Platinum-Iridium-Tip Electrode CathetersPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2009ATTILA KARDOS M.D., Ph.D. Background: Gold has excellent electrical conductive properties and creates deeper and wider lesions than platinum-iridium during radiofrequency (RF) ablation in vitro. We tested the maximum voltage-guided technique (MVGT) of cavotricuspid isthmus (CTI) ablation using two 8-mm tip catheters containing gold (group G) or platinum-iridium (group PI). Methods: We enrolled 31 patients who underwent CTI ablation. In group G (n = 15) CTI ablation was performed with a gold-tip ablation catheter, while in group PI (n = 16) a platinum-iridium tip was used. Ablation was guided by CTI potentials with the highest amplitude until achievement of bidirectional block (BIB). If BIB was not achieved after 10 RF applications, RF was delivered via a 3.5-mm irrigated-tip catheter. Success rate, procedure duration, duration of fluoroscopic exposure, and number of RF applications were measured. Results: BIB was achieved in all patients in group G, while in group PI an irrigated tip was used in four patients (0% vs 25%, P < 0.001). These four patients required a total of 21 additional RF applications (5.25 ± 2.22). Procedure time (56.4 ± 12 vs 73.1 ± 15 minutes P < 0.05) and fluoroscopic explosure (4.9 ± 2.3 vs 7.1 ± 3.8 minutes, P < 0.01) were shorter in group G than in group PI. Mean number of RF applications was lower (4.6 ± 1.9 vs 6.6 ± 3.1 P < 0.001) and total RF duration shorter (280 ± 117 vs 480 ± 310 seconds) in group G than in group PI. No difference was observed in the number of recurrences at a 6 month-follow up (1 in group G vs 1 in group PI). Conclusion: Using the MVGT of CTI ablation, gold-tip catheters were associated with shorter procedural and fluoroscopic times, and fewer RF applications. [source] Segmental Pulmonary Vein Ablation: Success Rates with and without Exclusion of Areas Adjacent to the EsophagusPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 6 2008KLAUS KETTERING M.D. Background: Catheter ablation has become the first line of therapy in patients with symptomatic recurrent, drug-refractory atrial fibrillation (AF). The occurrence of an atrioesophageal fistula is a rare but serious complication after AF-ablation procedures. This risk is even present during segmental pulmonary vein (PV) ablation procedures because the esophagus does frequently have a very close anatomical relationship to the right or left PV ostia. The aim of the present study was to analyze whether the exclusion of areas adjacent to the esophagus does have a significant effect on the success rates after segmental pulmonary vein ablation procedures. Methods: Forty-three consecutive patients with symptomatic paroxysmal AF were enrolled in this study. In all patients, a segmental PV ablation procedure was performed. The procedures were facilitated by a 3D real-time visualization of the circumferential mapping catheter placed in the pulmonary veins using the NavXÔ system (St. Jude Medical, St. Paul, MN, USA; open irrigated tip ablation catheter; 43°C; 30 W). In 21 patients, a complete ostial PV isolation was attempted regardless of the anatomical relationship between the ablation sites and the esophagus (group A). In the remaining 22 patients, the esophagus was marked by a stomach tube and areas adjacent to the esophagus were excluded from the ablation procedure (group B). After discharge, patients were scheduled for repeated visits at the arrhythmia clinic at 1, 3, and 6 months after the ablation procedure. Results: The segmental pulmonary vein ablation procedure could be performed as planned in all patients. In group A, all pulmonary veins could be isolated successfully in 14 out of 21 patients (67%). A mean number of 3.7 pulmonary veins (SD ± 0.5 PVs) were isolated per patient. The main reasons for an incomplete PV isolation were: small diameter of the PVs, side branches close to the ostium, or poorly accessible PV ostia. In group B, all PVs could be isolated successfully in only 12 out of 22 patients (55%; P = 0.54). A mean number of 3.2 PVs (SD ± 0.9 PVs) were isolated per patient (P = 0.05). This was mostly due to a close anatomical relationship to the esophagus. The ablation strategy had to be modified in 16/22 patients in group B because of a close anatomical relationship between the left (n = 10) or right (n = 6) PV ostia and the esophagus. After 3 months, the percentage of patients free from an AF recurrence was not significantly different between the two groups (90% vs 95%; P = 0.61). After 6 months, there was no significant difference between the success rates either (81% vs 82%; P = 1.0). There were no major complications in both groups. Conclusions: The exclusion of areas adjacent to the esophagus results in a moderately higher percentage of incompletely isolated PVs. However, it does not have a significant effect on the AF recurrence rate during short-term and mid-term follow-up. [source] Atrial Linear Lesions: Feasibility Using CryoablationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2006KLAUS KETTERING Background: Long linear lesions are created in the left atrium to modify the atrial substrate, thereby curing atrial fibrillation. The creation of long linear left atrial lesions using radiofrequency (RF) ablation is time consuming and difficult. Furthermore, it might result in significant complications. Cryoablation might overcome some of the disadvantages of RF ablation. Therefore, the aim of our study was to assess whether the creation of a long linear lesion is possible using cryotherapy. Methods: A right atrial septal linear lesion was created in six pigs (median weight: 50 kg; range: 40,60 kg). The ablation procedure was performed with a 7-F Freezor cryocatheter. The nonfluoroscopic mapping system LocaLisa was used as a navigation tool. At each point, freezing was maintained at the lowest attainable temperature (,75°C) for 4 minutes. The CARTO system was used for the evaluation of the linear lesions. Furthermore, all animals were sacrificed immediately after the ablation procedure and a postmortem examination of the lesions was performed. Additionally, an analysis of the amplitudes of the intracardiac electrograms registered via the ablation catheter was performed before and after the ablation procedure. Results: A right atrial septal linear lesion could be created successfully in all six pigs. For the performance of this ablation line, a median number of 16 cryoapplications (range, 11,26) was necessary. The amplitudes of the intracardiac electrograms registered via the ablation catheter decreased significantly after ablation. The CARTO bipolar voltage map revealed very low potentials along the ablation line and showed a sharply demarcated ablation area at the septum in all pigs. Further analysis of the CARTO map revealed an incomplete conduction block in all cases. Most of the pigs had a small gap close to the fossa ovalis. The postmortem examination of 2,3,5-triphenyl-tetrazolium chloride-stained specimens showed sharply demarcated lesions without any ulcerations. There were no major complications during the procedure. Conclusions: The creation of long linear lesions using cryoablation is feasible and safe. Lesion characteristics are different and more favorable than those created by RF. However, the aim of creating a transmural lesion and a complete conduction block remains an unsolved problem even with current cryoablation techniques. Nevertheless, growing experience and technical improvements might overcome some of the current limitations of this new technique. [source] | ||||||||||