Catheter ablation of atrial fibrillation (AF) is complicated by cerebral emboli resulting in acute ischemia. Recently, cerebral ischemic microlesions have been identified with diffusion-weighted ...magnet resonance imaging (MRI).
The clinical course and longer-term characteristics of these lesions are not known and were investigated in this study.
Of 86 patients, 33 (38%) had new asymptomatic cerebral lesions documented on MRI after catheter ablation for AF; 14 of these 33 (42%) underwent repeat MRI at different time intervals (2 weeks to 1 year) during follow-up, and clinical symptoms as well as size and number of residual lesions were documented.
In postablation cerebral MRI, 50 new lesions were identified (3.6 lesions/patient) in 14 patients. No patient presented any neurological symptoms. Distribution of the lesions was predominantly in the left hemisphere (60%) and the cerebellum (26%); 52% of the lesions were small (≤3 mm maximum diameter), 42% were medium (4 to 10 mm) and 3 lesions (6%) had a maximum diameter >10 mm. Follow-up MRI after a median of 3 months revealed 3 residual lesions in 3 of 14 patients corresponding to the large acute postablation lesions (>10 mm). The remaining 47 of 50 (94%) of the small or medium-sized lesions were not detectable at follow-up evaluation.
Most asymptomatic cerebral lesions observed acutely after AF ablation procedures were ≤10 mm in diameter. 94% of all lesions healed without scarring at follow-up >2 weeks after ablation. The larger acute lesions produced chronic glial scars. Neither chronic nor acute lesions were associated with neurological symptoms.
Objectives We compared the safety of different devices by screening for subclinical intracranial embolic events after pulmonary vein isolation with either conventional irrigated radiofrequency (RF) ...or cryoballoon or multielectrode phased RF pulmonary vein ablation catheter (PVAC). Background New devices specifically designed to facilitate pulmonary vein isolation procedures have recently been introduced. Methods This prospective, observational, multicenter study included patients with symptomatic atrial fibrillation referred for pulmonary vein isolation. Ablation was performed using 1 of the 3 catheters. Strict periprocedural anticoagulation, with intravenous heparin during ablation to achieve an activated clotting time >300 s, was ensured in all patients. Cerebral magnetic resonance imaging was performed before and after ablation. Results Seventy-four patients were included in the study: 27 in the irrigated RF group, 23 in the cryoballoon group, and 24 in the PVAC group. Total procedure times were 198 ± 50 min, 174 ± 35 min, and 124 ± 32 min, respectively (p < 0.001 for PVAC vs. irrigated RF and cryoballoon). Findings on neurological examination were normal in all patients before and after ablation. Post-procedure magnetic resonance imaging detected a single new embolic lesion in 2 of 27 patients in the irrigated RF group (7.4%) and in 1 of 23 in the cryoballoon group (4.3%). However, in the PVAC group 9 of 24 patients (37.5%) demonstrated 2.7 ± 1.3 new lesions each (p = 0.003 for the presence of new embolic events among the 3 groups). Conclusions The PVAC is associated with a significantly higher incidence of subclinical intracranial embolic events. Further study of the causes and significance of these emboli is required to determine the safety of the PVAC.
Summary Background Catheter ablation is increasingly used to manage atrial fibrillation, but arrhythmia recurrences are common. Adenosine might identify pulmonary veins at risk of reconnection by ...unmasking dormant conduction, and thereby guide additional ablation to improve arrhythmia-free survival. We assessed whether adenosine-guided pulmonary vein isolation could prevent arrhythmia recurrence in patients undergoing radiofrequency catheter ablation for paroxysmal atrial fibrillation. Methods We did this randomised trial at 18 hospitals in Australia, Europe, and North America. We enrolled patients aged older than 18 years who had had at least three symptomatic atrial fibrillation episodes in the past 6 months, and for whom treatment with an antiarrhythmic drug failed. After pulmonary vein isolation, intravenous adenosine was administered. If dormant conduction was present, patients were randomly assigned (1:1) to additional adenosine-guided ablation to abolish dormant conduction or to no further ablation. If no dormant conduction was revealed, randomly selected patients were included in a registry. Patients were masked to treatment allocation and outcomes were assessed by a masked adjudicating committee. Patients were followed up for 1 year. The primary outcome was time to symptomatic atrial tachyarrhythmia after a single procedure in the intention-to-treat population. The trial is registered with ClinicalTrials.gov , number NCT01058980. Findings Adenosine unmasked dormant pulmonary vein conduction in 284 (53%) of 534 patients. 102 (69·4%) of 147 patients with additional adenosine-guided ablation were free from symptomatic atrial tachyarrhythmia compared with 58 (42·3%) of 137 patients with no further ablation, corresponding to an absolute risk reduction of 27·1% (95% CI 15·9–38·2; p<0·0001) and a hazard ratio of 0·44 (95% CI 0·31–0·64; p<0·0001). Of 115 patients without dormant pulmonary vein conduction, 64 (55·7%) remained free from symptomatic atrial tachyarrhythmia (p=0·0191 vs dormant conduction with no further ablation). Occurrences of serious adverse events were similar in each group. One death (massive stroke) was deemed probably related to ablation in a patient included in the registry. Interpretation Adenosine testing to identify and target dormant pulmonary vein conduction during catheter ablation of atrial fibrillation is a safe and highly effective strategy to improve arrhythmia-free survival in patients with paroxysmal atrial fibrillation. This approach should be considered for incorporation into routine clinical practice. Funding Canadian Institutes of Health Research, St Jude Medical, Biosense-Webster, and M Lachapelle (Montreal Heart Institute Foundation).
Objectives Our purpose was to evaluate the efficacy of antiarrhythmic drugs (AADs) in recurrent ventricular fibrillation (VF) associated with inferolateral early repolarization pattern on the ...electrocardiogram. Background Although an implantable cardioverter-defibrillator is the treatment of choice, additional AADs may be necessary to prevent frequent episodes of VF and reduce implantable cardioverter-defibrillator shock burden or as a lifesaving therapy in electrical storms. Methods From a multicenter cohort of 122 patients (90 male subjects, age 37 ± 12 years) with idiopathic VF and early repolarization abnormality in the inferolateral leads, we selected all patients with more than 3 episodes of VF (multiple) including those with electrical storms (≥3 VF in 24 h). The choice of AAD was decided by individual physicians. Follow-up data were obtained for all patients using monitoring with implantable defibrillator. Successful oral AAD was defined as elimination of all recurrences of VF with a minimal follow-up period of 12 months. Results Multiple episodes of VF were observed in 33 (27%) patients. Electrical storms (34 ± 47 episodes) occurred in 16 and were unresponsive to beta-blockers (11 of 11), lidocaine/mexiletine (9 of 9), and verapamil (3 of 3), while amiodarone was partially effective (3 of 10). In contrast, isoproterenol infusion immediately suppressed electrical storms in 7 of 7 patients. Over a follow-up of 69 ± 58 months, oral AADs were poorly effective in preventing recurrent VF: beta-blockers (2 of 16), verapamil (0 of 4), mexiletine (0 of 4), amiodarone (1 of 7), and class 1C AADs (2 of 9). Quinidine was successful in 9 of 9 patients, decreasing recurrent VF from 33 ± 35 episodes to nil for 25 ± 18 months. In addition, quinidine restored a normal electrocardiogram. Conclusions Multiple recurrences of VF occurred in 27% of patients with early repolarization abnormality and may be life threatening. Isoproterenol in acute cases and quinidine in chronic cases are effective AADs.
Experimental data suggest that use of cryoablation in pulmonary vein isolation (PVI) is associated with less cell damage and less thrombus formation compared to radiofrequency (RF) energy.
The ...purpose of this study was to test the hypothesis that cryoablation significantly reduces markers of cell damage, platelet activation, and inflammation in patients undergoing PVI for treatment of atrial fibrillation (AF).
Sixty patients with symptomatic drug-resistant AF (age 56 ± 9 years, 48 males, 38 with paroxysmal AF) were randomly assigned to undergo PVI using either an open irrigated-tip RF catheter or a cryoballoon. Markers of cell damage (high-sensitive troponin T hs-TnT, microparticles), platelet activation (platelet reactivity by aggregometry, expression of platelet surface proteins P-selectin and activated glycoprotein GP IIb/IIIa), and inflammatory response (high-sensitive C-reactive protein hs-CRP) were determined before and up to 48 hours after the procedure.
PVI resulted in a significant rise in hs-TnT, microparticles, markers of platelet activation, and hs-CRP over time, with distinct temporal patterns for each parameter. However, after Bonferroni correction for repeated measurements, no significant differences were noted in these parameters between patients treated with cryoablation or RF energy. Procedural time was significantly shorter in patients treated with cryoballoon (177 ± 30 minutes vs 200 ± 46 minutes, P = .03), with no differences in fluoroscopic time, periprocedural complications, or success rate.
Cryoablation and RF energy result in a comparable rise of markers of cell damage, platelet activation and inflammatory response. The data do not support the concept of an improved safety profile for cryoablation in PVI.
Abstract Background Pulmonary vein (PV) isolation (PVI) has emerged as an effective therapy for paroxysmal atrial fibrillation (AF). However, AF recurs in up to 50% of patients, generally because of ...recovery of PV conduction. Adenosine given during the initial procedure may reveal dormant PV conduction, thereby identifying the need for additional ablation, leading to improved outcomes. The Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination (ADVICE) study is a prospective multicentre randomized trial assessing the impact of adenosine-guided PVI in preventing AF recurrences. Methods Patients undergoing a first PVI procedure for paroxysmal AF will be recruited. After standard PVI is completed, all patients will receive intravenous adenosine in an attempt to unmask dormant conduction. If dormant conduction is elicited, patients will be randomized to no further ablation (control group) or additional adenosine-guided ablation until dormant conduction is abolished. If no dormant conduction is revealed, randomly selected patients will be followed in a registry. The primary outcome is time to first documented symptomatic AF recurrence. Assuming that dormant conduction is present in 50% of patients post PVI and symptomatic AF recurs in 45% of controls, 244 patients with dormant conduction will be required to obtain > 90% power to detect a difference of 20%. Thus, a total of 488 patients will be enrolled and followed for 12 months. Conclusion The ADVICE trial will assess whether a PVI strategy incorporating elimination of dormant conduction unmasked by intravenous adenosine will decrease the rate of recurrent symptomatic AF compared with standard PVI.
Recent data have shown a high incidence of the early repolarization pattern confined in inferolateral leads in patients with idiopathic ventricular fibrillation.
The purpose of the present study was ...to investigate the prevalence and the prognostic significance of the early repolarization pattern in inferolateral leads in patients with Brugada syndrome.
Clinical, genetic, and electrophysiologic data from 290 individuals (223 males, mean age 48.3 +/- 14.2 years) with a spontaneous or drug-induced type 1 electrocardiogram (ECG) pattern of Brugada syndrome and structurally normal hearts were analyzed. Twelve-lead ECGs were evaluated for the presence of early repolarization pattern, which was defined as J-point elevation of at least 0.1 mV from baseline in at least two inferior or lateral leads. Follow-up data were obtained for all subjects.
An early repolarization pattern manifested as notched or slurred J-point elevation mainly in lateral leads was observed in 35 subjects (12%). The prevalence of the early repolarization pattern was significantly higher in male subjects (P = .004). During a mean follow-up period of 44.9 +/- 27.5 months, 22 subjects (8%) displayed an arrhythmic event including sudden cardiac death. There were no significant differences regarding spontaneous ECG type of Brugada syndrome, symptoms, family history of sudden cardiac death, and positive genetic test between subjects with and without the early repolarization pattern. The presence of early repolarization pattern was not associated with arrhythmic events during follow-up (Hazard ratio HR 1.090; 95% confidence interval 0.349-3.403; P = .882).
The early repolarization pattern in inferolateral leads is not an uncommon finding in Brugada syndrome. In our population, the early repolarization features were not associated with a worse outcome in subjects with Brugada syndrome.
Linear radiofrequency ablation at the cavotricuspid isthmus (CTI) is the treatment of choice for typical flutter. Despite a high acute success rate, reconduction through the CTI may occur in ...approximately 15% of patients and eventually lead to flutter recurrence.
The purpose of this study was to test the hypothesis that injection of adenosine may reveal transient CTI reconduction and predict early relapse of permanent CTI conduction.
Thirty-one patients with CTI-dependent flutter (mean age 65 ± 11 years, 87% male, ejection fraction 55% ± 11%) were included in the study. CTI ablation was performed using an open-irrigated ablation catheter. Bidirectional conduction block was confirmed using conventional criteria. Subsequently, transisthmus conduction was reevaluated after adenosine injection. During a 30-minute waiting period, permanent recovery of CTI conduction was monitored. During a mean follow-up of 6 ± 3 months, clinical recurrences of typical flutter were assessed.
Bidirectional isthmus block was achieved in all patients. Injection of 16 ± 3 mg adenosine IV induced transient second- or third-degree AV block in all patients. An adenosine-induced brief sequence reversal at the right lateral wall occurred in 6 of 31 patients (19%) and revealed transient CTI reconduction. Among these 6 patients, 4 (67%) had permanent recovery of transisthmus conduction in the subsequent waiting period; the remaining 2 patients (33%) had clinical recurrence of common flutter. Importantly, no patient without adenosine-mediated dormant transisthmus conduction (25/31 81%) showed permanent recovery during the waiting period or clinical flutter recurrence during follow-up.
Adenosine-induced "dormant transisthmus conduction" precedes early relapse of permanent CTI conduction. Patients without "dormant transisthmus conduction" develop no recovery of conduction during the postablation waiting period. Routine use of adenosine for assessment of ablation lines may help to reduce the clinical recurrence of the underlying arrhythmia.
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