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Background: Data comparing remote magnetic catheter navigation (RMN) with manual catheter navigation (MCN) ablation of atrial fibrillation (AF) is lacking. The aim of the present prospective observational study was to compare the outcome of RMN versus (vs.) MCN ablation of AF with regards to AF recurrence. Methods: The study comprised 667 consecutive patients with a total of 939 procedures: 287 patients were ablated using RMN, 380 using MCN. Results: There was no significant difference between the groups at baseline. After 2.3 ± 2.3 years of follow‐up, 23% of the patients in the MCN group remained free of AF recurrence compared to 13% in the RMN group (p <.001). After analysis of 299 repeat ablations (133 MCN, 166 RMN) there was a significantly higher reconnection rate of pulmonary veins after RMN ablation p <.001). In multivariable Cox‐regression analysis, RMN ablation was an independent risk factor for AF recurrence besides age, persistent AF, number of isolated pulmonary veins, and left atrial diameter. Procedure time, radiofrequency application time and total number of ablation points were higher in the RMN group. Total fluoroscopy time and total fluoroscopy dose were significantly lower for RMN. Complication rates did not differ between groups (p =.842), although the incidence of significant pericardial effusion was higher in the MCN group (seven cases vs. three in RMN group). Conclusions: In our study the AF recurrence rate and pulmonary vein reconnection rate is higher after RMN ablation with a similar complication rate but reduced probability of pericardial effusion when compared to MCN. [ABSTRACT FROM AUTHOR]

Introduction: Ablation of pulmonary veins (PV) is an established therapeutic option for patients with symptomatic drug-refractory paroxysmal atrial fibrillation (AF). Radiofrequency (RF) is currently the most widespread energy source for PV ablation. Cryothermal energy applied with a cryoballoon technique as an alternative has recently evolved. Methods and Results: In a case-control setting, we compared 20 patients with paroxysmal AF who underwent their first PV ablation with the cryoballoon technique to 20 matched patients with conventional RF ablation. In the case of persistent electrical potentials after cryoballoon ablation, it was combined with ablation with a conventional cryocatheter. All patients performed daily event recording for 3 months after ablation procedure. Ablation parameters and success rate after 3 and 6 months were compared. In the cryoballoon group, the overall success rate was 55% (50% in the cryoballoon only group [14 patients] and 66% in the combination group [6 patients]), as opposed to the RF group with 45%. AF episode burden was lower after cryoballoon ablation. There was no significant difference between cryoballoon and RF ablation regarding procedure parameters. In the cryoballoon group, 3 phrenic nerve palsies occurred using the 23 mm balloon that resolved spontaneously. Conclusion: PV ablation with the cryoballoon technique is feasible and seems to have a similar success rate in comparison to RF ablation. Procedure- and fluoroscopy duration are not longer than in conventional RF ablation. [ABSTRACT FROM AUTHOR]

Background: Arrhythmia recurrence after atrial fibrillation (AF) ablation is often associated with pulmonary vein reconnection (PVR). We prospectively examined anatomical sites of both acute and chronic PVR. Methods: One hundred and fifty AF patients underwent PV wide encirclement and sites where immediate electrical isolation (EI) occurred were tagged using electroanatomic mapping/CT integration (Cartomerge™, Biosense Webster, Diamond Bar, CA, USA). After 30 minutes PVs were checked and acute PVR sites marked at reisolation. Chronic PVR sites were marked at the time of repeat procedures. Results: On the left, immediate EI sites were predominantly on the intervenous ridge (IVR) and PV-left atrial appendage (PV-LAA) ridge. On the right they were at the roof, IVR, and floor of the PVs. Ninety-eight of one hundred and fifty patients had PVs checked after >30 minutes. Thirty-two of ninety-eight had acute PVR. This was mostly on the IVR and PV-LAA ridge on the left (88%), and on the roof and IVR on the right (78%). At repeat procedure, 38/39 patients had chronic PVR, predominantly on the IVR (61%) and PV-LAA ridge (21%) on the left, and on the roof, IVR, and floor of the right PVs (79%). There was minimal acute or chronic PVR posteriorly. Acutely PVR occurred close to the immediate EI site 60% of the time, but only 30% of the time chronically. Conclusion: Acute and chronic PVR sites have a preferential distribution. This may be determined by anatomical and technical factors. Knowledge of immediate EI sites may be beneficial acutely, but with chronic PVR a careful survey is required. These findings may help target ablation, improving safety and success. [ABSTRACT FROM AUTHOR]

Introduction: Long-term outcome of radiofrequency ablation (RFA) for atrial fibrillation (AF) is difficult to assess. This study sought to evaluate various aspects of very long-term follow-up (FU) by the properties of an implantable device. Methods: Fourteen patients with an implanted pacemaker device (Medtronic AT500) were selected for RFA, due to drug-refractory and highly symptomatic AF despite antibradycardic pacing. Results: With a mean FU of 41.4 ± 15.1 months, we could achieve continuous monitoring for more than 400,000 hours after RFA. Based on symptomatic episodes, simulated 24-hour, 48-hour, or 7-day Holter, 57% to 71% of the patients were classified as RFA responders. With permanent FU provided by the implanted device, 43% of the patients exhibited a positive treatment effect and only 21% had no tachyarrhythmic episode at all in long-term FU. With a mean of 1.7 ± 0.7 RFA per subject, atrial tachyarrhythmia burden (ATB) was significantly reduced from a median of 3.6 to 0.3 hours per day (P < 0.001). Two out of 14 patients developed AF recurrences after a tachyarrhythmia-free period of more than 12 months. Conclusion: Continuous monitoring provided by an implantable device is able to detect significantly more AF episodes than routine FU. ATB is decreased significantly by (repeated) RFA over a very long-term FU. AF may reoccur very late after long-lasting (>1 year) episode-free intervals. A subgroup of patients with drug-aggravated bradycardia in brady-tachy syndrome might be considered for PV isolation rather than pacemaker implantation. [ABSTRACT FROM AUTHOR]

Atrial premature depolarizations (APDs) triggering atrial fibrillation (AF) originate from mainly the pulmonary veins (PVs), but, in some cases, atrial ectopic beats (AEBs) triggering AF originate from the right atrium (RA) or the superior vena cava. Accurate identification of the origin of APDs in the PVs by means of RA and coronary sinus mapping is difficult. Purpose: The aim of this study was to identify the origin of AEBs triggering AF before transseptal catheterization. Electrode catheters were placed in the posteroseptal RA (PSRA), right pulmonary artery (RPA), left pulmonary artery (LPA), and esophagus in 10 patients with paroxysmal AF. We analyzed endocardial electrograms from the PSRA, RPA and LPA, and epicardial electrograms from the esophagus. The origin of the AEBs in the PVs was determined before PV ablation by mapping 4 PVs simultaneously. Four AEBs originated from the left superior PV (LSPV), 2 from the left inferior PV (LIPV), 4 from the right superior PV (RSPV), 2 from the RA or superior vena cava. In AEBs originating from the RA, the PSRA activation was the earliest and it proceeded in a cranial to caudal direction. In AEBs originating from the RUPV, RPA was the earliest. The esophageal activation sequence was in a cranial to caudal direction. In AEBs from the LSPV, LPA was the earliest and the esophageal activation sequence proceeded in a cranial to caudal direction. In AEDs from LIPV, LPA was the earliest, and the esophageal activation sequence was nearly simultaneous. Atrial activation sequences from the PSRA, RPA, LPA, and esophageal catheters can accurately identify the location of the initiating foci of AF before a transseptal procedure. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

Thrombus on Transseptal Sheath. Background:Transseptal (TS) catheterization is used for left atrial (LA) ablation procedures and a major risk is thromboembolism. The purpose of this study was to assess (1) the value of intracardiac ultrasound (ICUS) monitoring during LA ablation procedures, and (2) a new technique to reduce the risk of thrombus formation.Methods and Results:One hundred and eighty consecutive patients underwent TS catheterization under ICUS guidance with two sheaths for atrial fibrillation ablation and one for other LA procedures. Group I included the initial 90 patients in whom TS sheaths were flushed with a standard 2 U/cc concentration of heparin; group II consisted of the next 90 patients in whom sheaths were flushed with 1,000 U/cc concentration. All patients received bolus and infusion of heparin to maintain ACT between 250–300 seconds. ICUS was monitored throughout. In group I, echodense material at the tip of the sheath consistent with thrombus was observed on ICUS in 8 of 90 patients (9%) within 5–15 minutes of entering the LA. In group II, only 1 of 90 patient (1%) demonstrated thrombus (P<0.001). There were no significant clinical differences in group I patients with and without thrombus. In all nine patients, the clot was removed with vigorous aspiration. No patients suffered a neurological event.Conclusion:Thrombus formation on TS sheath, detected by ICUS, may be more common than expected despite adequate anticoagulation. Using a higher concentration of heparin for the TS system before deployment reduced the risk. The thrombus was retrieved with aspiration without the need to abort the procedure.(J Cardiovasc Electrophysiol, Vol. 16, pp. 1-5, June 2005) [ABSTRACT FROM AUTHOR]

HERWEG, B., et al.: Treatment of Sustained Left Atrial Tachycardia by Ostial Pulmonary Vein Isolation. This report describes two patients with sustained regular left atrial tachycardias originating from multiple pulmonary veins in the absence of clinical evidence of atrial fibrillation. The tachycardias were eliminated by activation map-guided pulmonary vein isolation. Stable sustained regular pulmonary vein tachycardias unassociated with atrial fibrillation are uncommon, and they belong to the spectrum of pulmonary vein arrhythmias that include the more common paroxysmal and unstable tachycardias engendering atrial fibrillation. (PACE 2004; 27:1153–1157) [ABSTRACT FROM AUTHOR]

Superior PV Versus Four-PV Ablation for AF. Introduction: Isolation of all pulmonary veins (PV) is advocated for treatment of paroxysmal atrial fibrillation (PAF). However, the superior PVs are responsible for most AF triggers, whereas the inferior PVs carry the higher risk for ablation-induced ostial stenosis. The aim of this study was to compare a superior PV isolation approach with isolation of all PVs for treatment of PAF. Methods and Results: Fifty-two patients with PAF were randomized to either left superior pulmonary vein (LSPV) isolation followed by additional isolation of the right superior pulmonary vein (RSPV) in case of AF recurrence (group A, n = 27) or isolation of all four PVs followed by a repeat procedure in case of recurrence (group B, n = 25). At 1-year follow-up, 11 patients (41%) in group A and 8 patients (32%) in group B had AF relapse (P = 0.55). No significant differences in AF relapse were detected between groups at 3 and 12 months (log rank = 0.36, P = 0.54) and by Cox proportional hazards model analysis (P = 0.62). Nonsignificant PV stenosis was detected in two patients from group B. Total radiofrequency energy delivery and fluoroscopy and procedure times were lower in group A: 8.9 ± 1.4 minutes vs 25.6 ± 3.7 minutes (P < 0.001), 22.2 ± 6.8 minutes vs 62 ± 10.3 minutes (P < 0.001), and 131.8 ± 26.5 minutes vs 222.2 ± 32.3 minutes (P < 0.001), respectively. Conclusion. A staged superior PVs isolation approach confers equal success rates but with reduced radiofrequency energy delivery and fluoroscopy and procedure times compared to isolation of all PVs at the initial ablation attempt. (J Cardiovasc Electrophysiol, Vol. 15, pp. 1-5, June 2004) [ABSTRACT FROM AUTHOR]

Detection of Pulmonary Vein Potentials in Human. Introduction: Pulmonary vein (PV) isolation may cure paroxysmal atrial fibrillation (PAF); however, identification of PV potentials may be difficult in sinus rhythm. Studies have suggested that atrial pacing may improve the identification of PV potentials. Methods and Results: In 25 consecutive patients who underwent PV isolation for PAF, the results of pacing from the distal PV, distal and proximal coronary sinus, and high right atrium compared to sinus rhythm were analyzed to determine the most effective pacing site for identification of PV potentials. The percentage of confirmed PV potentials and the longest interval between atrial and PV potentials in each PV were compared during differential site pacing and sinus rhythm. PV potentials were confirmed in 63 (82%) of 77 PVs that could be mapped during the complete pacing protocol and during sinus rhythm. Distal PV pacing identified significantly more PV potentials (left upper pulmonary vein [LUPV] 100%, left lower pulmonary vein [LLPV] 84%, right upper pulmonary vein [RUPV] 80%, right lower pulmonary vein [RLPV] 53%) compared to other pacing sites and sinus rhythm. Among atrial pacing sites, those ipsilateral to the PV being mapped were the most effective for identifying PV potentials. The intervals between atrial and PV potentials were significantly longer during distal PV pacing than pacing at other sites (LUPV 81.6 ± 26.2 ms, LLPV 61.4 ± 26.1 ms, RUPV 59.7 ± 33.2 ms, RLPV 39.7 ± 26.7 ms). Conclusion: (1) Distal PV pacing was most effective for identifying PV potentials. (2) The interval between atrial and PV potentials was longest during distal PV pacing. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1311-1318, December 2003) [ABSTRACT FROM AUTHOR]