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Ablation Techniques (ablation + techniques)
Selected AbstractsEpicardial Mapping and Ablation Techniques to Control Ventricular TachycardiaJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2005EDUARDO SOSA M.D. First page of article [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] The Mechanisms of Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2006PENG-SHENG CHEN M.D. In this article we have reviewed the mechanisms of atrial fibrillation (AF) with special emphasis on the thoracic veins. Based on a number of features, the thoracic veins are highly arrhythmogenic. The pulmonary vein (PV)-left atrial (LA) junction has discontinuous myocardial fibers separated by fibrotic tissues. The PV muscle sleeve is highly anisotropic. The vein of Marshall (VOM) in humans has multiple small muscle bundles separated by fibrosis and fat. Insulated muscle fibers can promote reentrant excitation, automaticity, and triggered activity. The PV muscle sleeves contain periodic acid-Schiff (PAS)-positive large pale cells that are morphologically reminiscent of Purkinje cells. These special cells could be the sources of focal discharge. Antiarrhythmic drugs have significant effects on PV muscle sleeves both at baseline and during AF. Both class I and III drugs have effects on wavefront traveling from PV to LA and from LA to PV. Separating the thoracic veins and the LA with ablation techniques also prevents PV-LA interaction. By reducing PV-LA interaction, pharmacological therapy and PV isolation reduce the activation rate in PV, intracellular calcium accumulation, and triggered activity. Therefore, thoracic vein isolation is an important technique in AF control. We conclude that thoracic veins are important in the generation and maintenance of AF. [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] Long-Term Follow-Up After Radiofrequency Catheter Ablation of Ventricular Tachycardia: A Successful Approach?JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2002ALIDA E. BORGER VAN DER BURG M.D. RF Catheter Ablation of VT.Introduction: Radiofrequency ablation (RFCA) of ventricular tachycardia (VT) is a potential curative treatment modality. We evaluated the results of RFCA in patients with VT. Methods and Results: One hundred fifty-one consecutive patients (122 men and 29 women; age 57 ± 16 years) with drug-refractory VT were treated. Underlying heart disease was ischemic heart disease in 89 (59%), arrhythmogenic right ventricular cardiomyopathy (ARVC) in 32 (21%), and idiopathic VT in 30 (20%; left ventricle in 9 [30%]; right ventricle in 21 [70%]). Ablation was performed using standard ablation techniques. Three hundred six different VTs were treated (cycle length 334 ± 87 msec, 2.0 ± 1.4 VTs per patient). Procedural success (noninducibility of VT after RFCA) was achieved in 126 (83%) patients (70 ischemic heart disease [79%]; 28 ARVC [88%]; 27 idiopathic VT [93%]). Procedure-related complications (< 48 hours) occurred in 11 (7%) patients: death 3 (2.0%), cerebrovascular accident 2 (1.3%), complete heart block 4 (2.6%), and pericardial effusion 3 (2.0%). Thirty-three (22%) patients received an implantable cardioverter defibrillator (because of hemodynamic unstable VT, failure of the procedure, or aborted sudden death). During follow-up (34 ± 11 months), VT recurrences occurred in 38 (26%) patients (recurrence rate: 19% in successfully ablated patients and 64% in nonsuccessfully ablated patients; P < 0.001). During follow-up, 12 (8%) patients died (heart failure 8, unknown cause 1, noncardiac cause 3). Conclusion: RFCA of VT can be performed with a high degree of success (83%). The long-term outcome of successfully ablated patients is promising, with a 75% relative risk reduction compared with nonsuccessfully ablated patients. During follow-up, only one patient died suddenly, supporting a selective ICD placement approach in patients with hemodynamically stable VT. [source] Percutaneous ablation procedures in cirrhotic patients with hepatocellular carcinoma submitted to liver transplantation: Assessment of efficacy at explant analysis and of safety for tumor recurrenceLIVER TRANSPLANTATION, Issue 9 2005Maurizio Pompili Aims of this retrospective study were to analyze the efficacy and safety of percutaneous ethanol injection (PEI) and radiofrequency ablation (RFA) in cirrhotic patients with hepatocellular carcinoma (HCC) submitted to orthotopic liver transplantation (OLT). We studied 40 patients undergoing OLT in whom 46 HCC nodules had been treated with PEI (13 nodules), RFA (30 nodules), or PEI+RFA (3 nodules). Child-Turcotte-Pugh class was A in 18 cases, B in 18, and C in 4. The mean waiting time for OLT was 9.5 months. The effectiveness of ablation techniques was evaluated by histological examination of the explanted livers. Complete necrosis was found in 19 nodules (41.3%), partial or absent necrosis in 27 nodules (58.7%). Among the 30 nodules treated by RFA, 14 were completely necrotic (46.7%) and 16 demonstrated partial necrosis (53.3%). Considering the 13 neoplasms undergoing PEI, 3 nodules showed complete necrosis (23.1%), 6 partial necrosis (46.1%), and 4 absent necrosis (30.8%). The rate of complete necrosis was 53.1% for nodules smaller than 3 cm and 14.3% for larger lesions (P = 0.033) but increased to 61.9% when considering only the lesions smaller than 3 cm treated by RFA. During the follow up, HCC recurred in 3 patients treated by PEI. No cases of HCC recurrence at the abdominal wall level were recorded. Percutaneous ablation procedures are effective treatments in cirrhotic patients with HCC submitted to OLT and are not associated to an increased risk of tumor recurrence. RFA provides complete necrosis in most nodules smaller than 3 cm, and appears to be the best treatment option in these cases. (Liver Transpl 2005;11:1117,1126.) [source] Non-surgical treatment of hepatocellular carcinomaALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2002A. M. Alsowmely Primary hepatocellular cancer is a disease with a poor prognosis for which there is little consensus on treatment and a paucity of comparative trials. The coexistence of cancer with cirrhosis complicates treatment, and also confers a high risk for the development of further tumours. Surgery, either by hepatic resection or orthotopic liver transplantation, is only a feasible option in a minority of patients. This article surveys the non-surgical approaches to the treatment of hepatocellular cancers,local ablation techniques, arterial embolization with and without chemotherapy, conventional chemotherapy and hormonal modulation, and targeted and external irradiation. [source] | ||||||||||