Home About us Contact
|
Home About us Contact | ||
|
|
||
Atrial Foci (atrial + focus)
Selected AbstractsThe Different Mechanisms Between Late and Very Late Recurrences of Atrial Fibrillation in Patients Undergoing a Repeated Catheter AblationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2006MING-HSIUNG HSIEH M.D. Introduction: The mechanisms of late (<1 year after the ablation) and very late (>1 year after the ablation) recurrences of paroxysmal atrial fibrillation (AF) after catheter ablation have not been reported. Methods and Results: Fifty consecutive patients undergoing a repeated electrophysiologic study to investigate the recurrence of paroxysmal AF after the first ablation were included. Group 1 consisted of 12 patients with very late (26 ± 13 months) and group 2 consisted of 38 patients with late (3 ± 3 months) recurrence of paroxysmal AF. In the baseline study, group 1 had a lower incidence of AF foci from the pulmonary veins (PVs) (67% vs 92%, P = 0.048) and a higher incidence of AF foci from the right atrium (50% vs 13%, P = 0.014) than group 2. In the repeated study, group 1 had a higher incidence of AF foci from the right atrium (67% vs 3%, P < 0.001) and a lower incidence of AF foci from the left atrium (50% vs 97%, P < 0.001), including a lower incidence of AF foci from the PVs (50% vs 79%, P = 0.07) and from the left atrial free wall (0% vs 29%, P = 0.046) than group 2. Furthermore, most of these AF foci (64% of group 1, 65% of group 2) were from the previously targeted foci. Conclusion: The right atrial foci played an important role in the very late recurrence of AF, whereas the left atrial foci (the majority were PVs) were the major origin of the late recurrence of AF after the catheter ablation of paroxysmal AF. [source] Catheter Ablation of Chronic Atrial Fibrillation Targeting the Reinitiating TriggersJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2000MICHEL HAÏSSAGUERRE M.D. Trigger Ablation in Chronic AF. Introduction: We assessed the mode of reinitiation of atrial fibrillation (AF) after cardioversion and the efficacy of ablating these foci of reinitiation in patients with chronic AF. Methods and Results: Fifteen patients, 7 with structural heart disease, underwent mapping and catheter ablation of drug-resistant AF documented to he persistent for 5 ± 4 months. In all patients, cardioversion was followed by documentation of P on T atrial ectopy and early recurrence, which allowed mapping of the reinitiating trigger or the source of ectopy. Radiofrequency (RF) ablation was performed at pulmonary vein (PV) ostia using a target temperature of 50°C and a power limit of 30 to 40 W, with the endpoint being interruption of all local muscle conduction. A total of 32 arrhythmogenic PVs and 2 atrial foci (left septum and left appendage) were identified: 1, 2, and 3 or 4 PVs in 5, 3, and 6 patients. RF applications at the ostial perimeter resulted in progressively increasing delay, followed by abolition of PV potentials in 8, but potentials persisted in 6. A single ablation session was performed in 7 patients and 8 underwent two or three sessions because of recurrence of AF; ablation was directed at the same source due to recovery of local PV potential or at a different PV. No PV stenosis was noted either acutely or at repeated follow-up angiograms. Nine patients (60%) were in stable sinus rhythm without antiarrhythmic drugs at follow-up of 11 ± 8 months. Anticoagulants were interrupted in 7 patients. Conclusion: PVs are the dominant triggers reinitiating chronic AF in this patient population. Elimination of PV potentials by ostial RF applications results in stable sinus rhythm in 60%. A larger group and longer follow-up are needed to investigate further the role of trigger ablation in curative therapy for chronic AF. [source] Internal Atrial Defibrillation During Electrophysiological Studies and Focal Atrial Fibrillation Ablation ProceduresPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2001MARTIN R. KARCH KARCH, M.R., et al.: Internal Atrial Defibrillation During Electrophysiological Studies and Focal Atrial Fibrillation Ablation Procedures. Induction of sustained AF during electrophysiological studies requires electrical cardioversion to restore sinus rhythm for continuation of the electrophysiological study and mapping procedure. The study included 104 consecutive patients (age 59 ± 12 years, 74 men), who were in stable sinus rhythm at the beginning of the electrophysiological study, underwent internal atrial defibrillation (IAD) of AF (> 15 minutes) that was induced during electrophysiological study. In 21 patients, AF was regarded to be the clinical problem (group I), and in the remaining 83 patients other arrhythmias represented the primary target of the electrophysiological study (group II). A 7.5 Fr cardioversion catheter (EP Medical) equipped with a distal array was used and placed in the left pulmonary artery and a proximal array of the same size was located along the lateral right atrial wall. All patients were successfully cardioverted with a mean energy of 6.2 ± 4.0 J. In 18 (78%) of 21 group I patients and in 12 (14%) of 81 group II patients, AF recurred 3.7 ± 3.4 and 2.4 ± 1.4 times during electrophysiological study, respectively. The IAD shock did not suppress focal activity, thus the mapping of atrial foci responsible for AF could be continued even after several IADs. No IAD related complications occurred during the study. In conclusion, (1) IAD can be safely and successfully performed during electrophysiological study without using narcotic drugs or high electric energies; (2) IAD does not suppress focal activity; and (3) even if AF recurs frequently during the electrophysiological study, IAD can be performed several times without significant time delay. [source] Temperature-Sensitive Focal Atrial Tachycardia in the Left AtriumJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2000G. ANDRÉ NG M.B.CH.B., Ph.D. Temperature-Sensitive Focal Atrial Tachycardia. Temperature sensitivity has not been reported in focal atrial tachycardia. We describe a patient with a left atrial tachycardia whose tachycardia rate was affected by hot and cold drinks. The elTects were still evident after autonomic blockade. The arrhythmia focus was located at the entrance of the left upper pulmonary vein. Radiofrequency ablation was carried out, which proved to be difficult, but it was successful after several applications of energy, suggesting an epicardial location of the arrhytbmia focus. Sensitivity of atrial tachycardia rate to the temperature of food or drink ingested suggests a left atrial focus with a posterior and possibly epicardial location. [source] | ||||||||||