A randomized comparison of pulmonary vein isolation with versus without concomitant renal artery denervation in patients with refractory symptomatic atrial fibrillation and resistant hypertension.

OBJECTIVES: The aim of this prospective randomized study was to assess the impact of renal artery denervation in patients with a history of refractory atrial fibrillation (AF) and drug-resistant hypertension who were referred for pulmonary vein isolation (PVI). BACKGROUND: Hypertension is the most common cardiovascular condition responsible for the development and maintenance of AF. Treating drug-resistant hypertension with renal denervation has been reported to control blood pressure, but any effect on AF is unknown. METHODS: Patients with a history of symptomatic paroxysmal or persistent AF refractory to ≥2 antiarrhythmic drugs and drug-resistant hypertension (systolic blood pressure >160 mm Hg despite triple drug therapy) were eligible for enrolment. Consenting patients were randomized to PVI only or PVI with renal artery denervation. All patients were followed ≥1 year to assess maintenance of sinus rhythm and to monitor changes in blood pressure. RESULTS: Twenty-seven patients were enrolled, and 14 were randomized to PVI only, and 13 were randomized to PVI with renal artery denervation. At the end of the follow-up, significant reductions in systolic (from 181 ± 7 to 156 ± 5, p < 0.001) and diastolic blood pressure (from 97 ± 6 to 87 ± 4, p < 0.001) were observed in patients treated with PVI with renal denervation without significant change in the PVI only group. Nine of the 13 patients (69%) treated with PVI with renal denervation were AF-free at the 12-month post-ablation follow-up examination versus 4 (29%) of the 14 patients in the PVI-only group (p = 0.033). CONCLUSIONS: Renal artery denervation reduces systolic and diastolic blood pressure in patients with drug-resistant hypertension and reduces AF recurrences when combined with PVI.

Ganglionated plexi ablation directed by high-frequency stimulation and complex fractionated atrial electrograms for paroxysmal atrial fibrillation.

BACKGROUND: The effectiveness of ganglionated plexi (GP) ablation in patients with atrial fibrillation (AF) is ambiguous. Some researchers had already suggested that additional identification of complex fractionated atrial electrograms (CFAE) around the areas with a positive reaction to high-frequency stimulation (HFS) might improve the accuracy of GP's boundaries location, then enhancing the success rate of ablation. The purpose of this study was to assess the safety and efficacy of GP ablation directed by HFS and CFAE in patients with paroxysmal AF (PAF). METHODS AND RESULTS: Sixty-two patients with PAF (age 57±8 years) underwent GP ablation. Ablation targets were the sites where vagal reflexes were evoked by HFS and additional extended ablation CFAE area around the areas where vagal reflexes were evoked. At 12 months, 71% of patients were free of symptomatic AF. At 3 months after ablation the root mean square successive differences and HF were significantly lower in patients without AF recurrence (P < 0.0001 and P = 0.004). The LF/HF ratio was significantly higher in patients without AF recurrence (P = 0.02). CONCLUSION: Enhanced GP ablation directed by HFS and CFAE can be safely performed and enables maintenance of sinus rhythm in the majority of patients with PAF for a 12-month period. Denervation of the intrinsic cardiac autonomic nervous system may be the preferable target of catheter ablation of AF.

Does atrial fibrillation burden measured by continuous monitoring during the blanking period predict the response to ablation at 12-month follow-up?

BACKGROUND: Recurrences are common within the first months following atrial fibrillation (AF) ablation. However, prior studies using only intermittent ECG recording have not shown a powerful correlation with ultimate response. OBJECTIVE: The purpose of this study was to use continuous AF monitoring with an implanted monitor to assess the AF burden measured continuously during the first months postablation and the relationship to subsequent AF recurrences. METHODS: Six hundred thirteen patients with symptomatic drug-refractory AF (17% with persistent AF) were part of this retrospective analysis. All patients underwent circumferential pulmonary vein isolation and were implanted with a subcutaneous AF monitor (Reveal XT, Medtronic) for collecting data on AF burden (AF%) during a 12-month follow-up period. AF freedom (responders) was defined as AF% ≤0.5% during each monthly telemetric follow-up. A receiver operating characteristic curve analysis was performed to identify the value in AF% during the first months in the postablation blanking period that was predictive of later recurrence of AF. Sensitivity of 90% was selected as the target value. RESULTS: After the first ablation procedure, 396 of the 613 patients (65%) were responders (AF ≤0.5%) at 12 months: 346 of 508 (68%) in the paroxysmal AF group and 50 of 105 (47%) in the persistent AF group. Using the receiver operating characteristic curve, the specificity corresponding to 90% sensitivity was 85% for AF% at 2 months. The corresponding threshold in the AF burden during the blanking period able to identify patients at risk for late recurrences was 4.5%, corresponding to a cumulative 65.9 hours (2.75 days) spent in AF during the first 2 months. In a multivariate analysis, AF% <4.5% during the first 2 months was highly significant (P <.001), and the odds ratio of responders/nonresponders was 39.8 (95% CI, 19.1-82.9). CONCLUSION: The AF burden measured during the blanking period can predict the response to catheter ablation at 12 months. AF% ≥4.5% at 2 months assessed by continuous monitoring is a powerful predictor of subsequent AF recurrences after initial ablation, thus providing relevant clinical information to select patients for early reintervention.

Use of an implantable monitor to detect arrhythmia recurrences and select patients for early repeat catheter ablation for atrial fibrillation: a pilot study.

BACKGROUND: Catheter ablation of atrial fibrillation (AF) has proved effective in curing highly symptomatic patients with paroxysmal AF. The aim of this prospective, randomized study was to identify the optimal treatment of patients with AF recurrences after the first ablation. METHODS AND RESULTS: Two hundred eighty-six patients with paroxysmal AF underwent ablation (circumferential pulmonary vein isolation with linear lesions) and were monitored with an implantable cardiac monitor (Reveal XT, Medtronic). Patients without AF recurrences during the 3-month postablation period were assigned to group 1; those with AF recurrences to group 2. Patients in group 2 were randomly assigned to group 3 or group 4. Group 3 patients were treated only with antiarrhythmic drugs for 6 weeks, with no early reablation during the 3-month postablation period. In the case of AF recurrence after the 3-month postablation period, patients underwent reablation. Group 4 patients were treated according to the onset mechanism of AF recurrences, as detected and stored by the implantable cardiac monitor: antiarrhythmic drug therapy, but no reablation if AF was not preceded by triggers; early reablation if premature atrial beats or atrial tachycardias or flutter triggered AF. All patients were followed up for 1 year to assess maintenance of sinus rhythm in each group. On 12-month follow-up examination, of the 119 (42%) patients in group 1, 112 (94%) had no AF recurrences. Among the 83 patients in group 3, only 27 (33%) had no recurrences. Of the 84 group 4 patients, 67 (80%) had no AF recurrences (P<0.0001 versus group 3). CONCLUSIONS: Patients with recurrences after the first AF ablation are likely to respond to a second early ablation when AF is triggered by supraventricular arrhythmias or premature contractions. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01164319.

Ablation of paroxysmal and persistent atrial fibrillation: 1-year follow-up through continuous subcutaneous monitoring.

BACKGROUND: The aim of this prospective observational study was to identify responders to ablation through continuous subcutaneous monitoring for 1 year after ablation in patients with paroxysmal atrial fibrillation (PAF) or persistent AF (PersAF). METHOD: Patients with symptomatic drug refractory AF were enrolled. Real-time three-dimensional (3D) left atrium maps were reconstructed by using a nonfluoroscopic navigation system (CARTO, Biosense-Webster Inc., Diamond Bar, CA, USA). The ipsilateral left and right pulmonary veins (PVs) were encircled in 1 lesion line by circumferential PV isolation. All patients were implanted with Reveal XT (Medtronic Inc.) for continuous AF monitoring and data collected every month during the 12-month follow-up. RESULTS: We enrolled 129 patients (56 ± 9 years, 102 males), all of whom were followed-up for 12 months after the last ablation procedure: 58 (45%) had a history of PersAF. After only 1 ablation procedure, 76 (59%) of the 129 patients were AF-free at 12-month: 48 out of 71 (68%) in the PAF group and 28 out of 58 (48%) in the PersAF group. After 1 or more ablation procedures, 94 (73%) of the 129 patients were AF-free 12 months after the last procedure: 57 out of 71 (80%) in the PAF group and 37 out of 58 (64%) in the PersAF group. CONCLUSION: Ablation is highly effective in treating AF, as assessed through detailed 1-year continuous monitoring: success rate is higher in PAF than in PersAF patients. The use of subcutaneous monitors is a valuable means of identifying responders and nonresponders, and can potentially guide antiarrhythmic and antithrombotic therapies.

Percutaneous epicardial ablation of ventricular tachycardia after failure of endocardial approach in the pediatric population with arrhythmogenic right ventricular dysplasia.

BACKGROUND: Despite the high efficacy of catheter ablation of ventricular tachycardia (VT) in patients with arrhythmogenic right ventricular dysplasia (ARVD), in some patients, conventional endocardial ablation is ineffective. These failures could be explained by the presence of epicardial arrhythmogenic substrate. In these cases, a percutaneous epicardial ablation may be required. OBJECTIVE: This study sought to report the feasibility and results of epicardial VT ablation in a pediatric population of ARVD patients in whom endocardial ablation was unsuccessful. METHODS: Seventeen ARVD pediatric patients (mean age 14 ± 4 years) in whom a percutaneous epicardial radiofrequency ablation of VT was attempted were included in this retrospective analysis. A total of 20 mappable, hemodynamically stable, monomorphic VTs were induced (2 macroreentrant and 18 focal). All patients underwent right ventricular epicardial VT ablation. RESULTS: At the end of the procedure, 16 (94.1%) of the 17 patients had no inducible VT. Pericardial effusion occurred in 4 patients (23.5%), with 1 (5.9%) patient having tamponade that required percutaneous pericardial drainage. During a mean follow-up of 26 ± 15 (range 6 to 42) months, 12 (70.6%) patients remained free of any episodes of VT. All patients with successful RF ablation were free from any antiarrhythmic drugs. There were no deaths during the follow-up period. Recurrences of VT were recorded in 5 (29.4%) patients. CONCLUSION: Percutaneous epicardial catheter ablation is feasible and relatively safe in pediatric ARVD patients with recurrent VT in whom conventional endocardial ablation failed.

Left atrial ablation at the anatomic areas of ganglionated plexi for paroxysmal atrial fibrillation.

BACKGROUND: Modification of left atrial ganglionated plexi (GP) is a promising technique for the treatment of paroxysmal atrial fibrillation (AF) but its therapeutic efficacy is not established. This study aimed at evaluating the effectiveness of anatomic GP modification by means of an implantable arrhythmia monitoring device. METHODS: In 56 patients with paroxysmal AF, radiofrequency ablation at anatomic sites, where the main clusters of GP have been identified in the left atrium, was performed. In all patients, an electrocardiogram monitor (Reveal XT, Medtronic Inc., Minneapolis, MN, USA) was implanted before (n = 7) or immediately after (n = 49) AF ablation. RESULTS: Average duration of the procedure was 142 ± 18 min and average fluoroscopy time 20 ± 7 min. In total, 53-81 applications of RF energy were delivered (mean of 18.2 ± 3.8 at each of the four areas of GP ablation). Heart rate variability was assessed in 31 patients. Standard deviation of RR intervals over the entire analyzed period, the root mean square of differences between successive RR intervals, and high frequencies decreased, while HRmin, HRmean, and LF to HF ratio increased immediately postablation; these values returned to baseline 6 months after the procedure. At end of 12-month follow-up, 40 (71%) patients were free of arrhythmia recurrence. Ten patients had AF recurrence, two patients had left atrial flutter, and four patients had episodes of flutter as well as AF recurrence. Duration of episodes of AF after ablation gradually decreased over the follow-up period. CONCLUSIONS: Regional ablation at the anatomic sites of the left atrial GP can be safely performed and enables maintenance of sinus rhythm in 71% of patients with paroxysmal AF for a 12-month period.

Ganglionated plexi ablation for longstanding persistent atrial fibrillation.

AIMS: To study the potential efficacy of ganglionated plexi (GP) ablation in the setting of longstanding persistent atrial fibrillation (AF). METHODS AND RESULTS: Anatomic ablation at the areas of GP in the left atrium was performed in 89 patients with symptomatic, drug-refractory, persistent AF (71 men, 56 +/- 7 years of age). In 29 patients, a second procedure by means of circumferential pulmonary vein (PV) isolation was performed, and 5 of them were subjected to a third circumferential ablation. At 16 +/- 7 months after the final ablation procedure, 53 (59.6%) of the 89 patients were in sinus rhythm in the absence of antiarrhythmic drug therapy, 5 (5.6%) patients had permanent AF, and 31 (34.8%) patients had paroxysmal AF. The long-term success rate for patients who underwent a single ablation procedure with only GP ablation was 38.2% over a follow-up of 24 +/- 3 months. Independent predictors of later arrhythmia recurrences were left atrial diameter [HR 1.039 (1.00-1.07), P = 0.028] and duration of AF prior to ablation [HR 1.116 (1.02-1.22), P = 0.008]. CONCLUSION: Ganglionated plexi ablation in chronic AF results in long-term maintenance of sinus rhythm in 38.2% of cases. Repeat procedures with circumferential isolation of all PV offer a success rate of 59.6% over a follow-up of 16 +/- 7 months.

Selective ganglionated plexi ablation for paroxysmal atrial fibrillation.

BACKGROUND: Selective ganglionated plexi (GP) ablation guided by high-frequency stimulation has been proposed for the treatment of paroxysmal atrial fibrillation (AF), but the efficacy of the method is not established. OBJECTIVE: This study sought to compare selective ablation of GP identified by high-frequency stimulation with extensive regional ablation targeting the anatomic areas of GP in patients with paroxysmal AF. METHODS: Eighty patients with paroxysmal AF (age 53 +/- 9 years) were randomized to undergo selective GP ablation or regional left atrial ablation at the anatomic sites of GP. For selective GP ablation (n = 40), ablation targets were the sites where vagal reflexes were evoked by high-frequency stimulation. Vagal reflexes were defined as prolongation of the R-R interval by >50% and a concomitant decrease in blood pressure (>20 mm Hg) during AF. The end point of the procedure was failure to reproduce vagal reflexes with repeated high-frequency stimulation. For anatomic ablation, lesions were delivered at the sites of GP clustering. RESULTS: At 13.1 +/- 1.9 months, 42.5% of patients with selective GP and 77.5% of patients with anatomic ablation were free of symptomatic paroxysmal AF (PAF) (P = .02). Parasympathetic denervation was more prominent in patients with anatomic than selective GP ablation, and in patients free of AF compared to these with AF recurrence immediately after ablation, but this trend was abolished at 6 months. CONCLUSION: Selective GP ablation directed by high-frequency stimulation does not eliminate paroxysmal AF in the majority of patients. An anatomic approach for regional ablation at the sites of GP confers better results.

Successful epicardial catheter ablation of micro-reentrant ventricular tachycardia in a 14-year-old child.

The article describes successful epicardial catheter ablation of ventricular tachycardia using the transpericardial approach in a 14-year-old adolescent. Conventional mapping of endocardial surface revealed criteria consistent with subpericardial localization of arrythmogenic substrate. Epicardial mapping using a transpericardial approach enabled localization and successful elimination of the ventricular tachycardia on the lateral wall of the right ventricle.

Catheter ablation of left atrial ganglionated plexi for atrial fibrillation.

Radiofrequency ablation of pulmonary vein ostia does not provide complete and long-term elimination of atrial fibrillation. Combining this procedure with local radiofrequency application on sites with strong vagal reflexes results in partial parasympathetic denervation and increases the antiarrhythmic effect. A novel catheter-ablation technique to modify ganglionated plexi in the left atrium was assessed in 58 patients (mean age, 52.1 +/- 1.9 years, 67% male) with drug-refractory atrial fibrillation, which was chronic in 21 (36%; mean duration, 14.3 +/- 2.9 months; range, 5-39 months). The mean left atrial volume was 93.1 +/- 6.1 mL. The patients underwent ablation of 4 areas of ganglionated plexi in the left atrium, with no circumferential ablation of the pulmonary veins; atrial fibrillation ceased immediately in 94.1% of them. Transient vagal bradycardia was seen in 93% of patients. For 7.2 +/- 0.4 months after the procedure, 86.2% of them were free from arrhythmias, and no antiarrhythmic drugs were administered. Ganglionated plexi ablation is an efficient treatment for atrial fibrillation.