Complex fractionated atrial electrogram or linear ablation in patients with persistent atrial fibrillation--a prospective randomized study.

BACKGROUND: Catheter ablation of complex fractionated atrial electrograms (CFAE) for persistent atrial fibrillation (AF) is a promising treatment strategy. We tested the hypothesis that CFAE ablation is superior to linear ablation in patients with persistent or long-standing persistent AF. METHODS: In this study, 116 patients with persistent AF were randomly assigned to undergo circumferential PVI plus additional lines (linear ablation group; 59 patients) or CFAE ablation plus ostial pulmonary vein isolation (PVI) (spot ablation group; 57 patients). Primary endpoint was freedom from atrial tachyarrhythmia after a single ablation procedure (clinical and repeat 7-day Holter), 12 months after ablation without antiarrhythmic medication. RESULTS: The primary endpoint was reached in 22 of 59 (37%) patients of the linear ablation group and in 22 of 57 (39%) patients of the spot ablation group (P = 0.9). Freedom from atrial tachyarrhythmias, including reablations, was achieved in 54% of patients (linear ablation group) versus 56% of patients (spot ablation group; P = 0.8). The incidence of recurrent persistent AF was higher after linear ablation than after spot ablation (21/37 vs 11/35 patients; P = 0.03); atrial tachycardia (AT) was seen more often after spot ablation (10/35 vs 4/37 patients; P = 0.03). CONCLUSION: In patients with persistent AF, CFAE ablation plus PVI reaches the same results as circumferential PVI plus lines, in terms of freedom from symptomatic atrial tachyarrhythmias within the first year after a single ablation procedure. Arrhythmia recurrences in patients after spot ablation were caused more often by AT, whereas recurrent persistent AF was more prevalent after the linear ablation approach.

Congenital and surgically acquired Wolff-Parkinson-White syndrome in patients with tricuspid atresia.

OBJECTIVES: There are reports associating an increased incidence of Wolff-Parkinson-White syndrome with tricuspid atresia. Here we report on electrophysiologic studies in patients with tricuspid atresia and Wolff-Parkinson-White syndrome after the Fontan operation. In these patients the atrial arrhythmia often seen in patients undergoing the Fontan operation triggered atrioventricular re-entrant tachycardia or caused life-threatening arrhythmias. METHODS: Five patients with tricuspid atresia after palliation with a modified Fontan operation (atrioinfundibular connections) and Wolff-Parkinson-White syndrome are presented. RESULTS: Four of these patients had symptomatic paroxysmal orthodromic atrioventricular re-entrant tachycardia and a history of syncope; one of them additionally had atrial flutter with 2:1 conduction to the ventricle. A fifth patient presented with a life-threatening broad-complex tachycardia. In electrophysiologic studies an accessory pathway was localized in the right septal area in 3 patients. In 2 patients the accessory atrioventricular pathways were created by means of surgical intervention, connecting the right atrial appendage to the right ventricular outflow tract. All patients could be managed successfully by means of catheter ablation. CONCLUSIONS: In patients with tricuspid atresia, there are congenital and surgically acquired accessory pathways responsible for the increased rate of Wolff-Parkinson-White syndrome. Both types of accessory pathways can and should be treated by means of catheter ablation because atrial arrhythmia often seen in patients undergoing the Fontan operation can trigger atrioventricular re-entrant tachycardia or cause life-threatening tachycardia. Congenital accessory pathways should be excluded carefully before surgical intervention for total cavopulmonary anastomosis in patients with tricuspid atresia.

Rescue ablation of electrical storm in patients with ischemic cardiomyopathy: a potential-guided ablation approach by modifying substrate of intractable, unmappable ventricular tachycardias.

OBJECTIVES: The purpose of this study was to evaluate a substrate-modifying, primarily potential-guided catheter ablation approach as a bailout therapy in patients with complex myocardial infarction and electrical storms due to ventricular tachycardias (VTs). BACKGROUND: Management of electrical storm is a domain of medical treatment. A definite trigger or delineated scar has been characterized as a requirement for substrate-orientated ablation of intractable unmappable ventricular tachyarrhythmias but can be absent, as shown in the presented cases. METHODS: Five patients who presented with ischemic cardiomyopathy and severe reduced left ventricular ejection fraction also suffered from multiple types of unstable VTs that deteriorated into drug-refractory electrical storm. Patients had 96 to 580 VT episodes requiring therapy with an implantable cardioverter-defibrillator (ICD) and received 3 to 310 shock deliveries prior to ablation. Treatment with beta-blockers, amiodarone, class IB antiarrhythmic drugs, deep sedation, and overdrive pacing and/or cardioversion of incessant VTs failed to stabilize the electrical storm but enabled left ventricular electroanatomic voltage mapping. A simplified substrate modification was performed by ablation of delayed fractionated potentials in areas identified by pace mapping, matching three to eight documented types of VTs per patient in complex scar areas. RESULTS: All patients could be stabilized after ablation. During 12 to 30 months of follow-up, three patients remained free of any VT episode requiring ICD treatment, and two patients had <1 VT episode per month. CONCLUSIONS: The cases presented demonstrate that rescue VT ablation of drug-refractory electrical storm is possible by a substrate-orientated ablation approach even in patients with complex chronic infarction and various VTs.

Acute and long-term results of slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia--an analysis of the predictive factors for arrhythmia recurrence.

BACKGROUND: Predictors of atrioventricular nodal reentrant tachycardia (AVNRT) recurrence after radiofrequency ablation including the importance of residual slow pathway conduction are not known. The aim of this study was to report the acute and long-term results of slow pathway ablation in a large series of consecutive patients with AVNRT and to analyze the potential predictors of arrhythmia recurrence with a particular emphasis on the residual slow pathway conduction after ablation. METHODS: The study included 506 consecutive patients with AVNRT (mean age 52.6 +/- 16 years, 315 women) who underwent slow pathway ablation using a combined electrophysiological and anatomical approach. The end point of ablation procedure was noninducibility of the arrhythmia. The primary end point of the study was the recurrence of AVNRT. RESULTS: Acute success was achieved in 500 patients (98.8%). After ablation, 471 patients (93%) were followed up for a mean of 903 +/- 692 days. Of the 465 patients with successful ablation, 24 patients (5.2%) developed AVNRT recurrences during the follow-up. No significant differences in the cumulative rates of AVNRT recurrence were observed in groups with or without electrophysiological evidence of residual slow pathway conduction (P = 0.25, log-rank test). Multivariate analysis identified only age as an independent predictor of AVNRT recurrence (hazard ratio 0.96, 95% confidence interval 0.94-0.99, P = 0.004) with younger patients being at an increased risk for arrhythmia recurrence. CONCLUSIONS: Our study demonstrated that only younger age, but not other clinical or electrophysiological parameters including residual slow pathway conduction predicted an increased risk for AVNRT recurrence after slow pathway radiofrequency ablation.

Prospective randomized comparison of closed cooled-tip versus 8-mm-tip catheters for radiofrequency ablation of typical atrial flutter.

INTRODUCTION: Cooled-tip and 8-mm-tip catheters have been found to be more effective than conventional 4-mm-tip catheters for radiofrequency (RF) ablation of common atrial flutter. The aim of this study was to compare the efficacy and safety of cooled-tip and 8-mm-tip catheters for flutter ablation in a randomized, prospective study. METHODS AND RESULTS: In 100 consecutive patients referred for ablation of common atrial flutter, cavotricuspid ablation was performed with a closed cooled-tip catheter (n = 50) or an 8-mm-tip ablation catheter (n = 50). RF current was applied for 60 to 120 seconds at powers of 40 to 50 W with the closed cooled-tip catheter and in a temperature-controlled mode (65 degrees C/70 W) with the 8-mm-tip catheter. The endpoint was achievement of a bidirectional isthmus conduction block. Cross-over was performed after 15 unsuccessful RF applications for each of the catheters. Complete bidirectional isthmus block was achieved in 99% of patients. Cross-over was performed in 11 patients after primary use of the cooled-tip catheter and in 9 patients after primary ablation with the 8-mm-tip catheter. No significant differences were found in the procedure parameters, such as overall RF applications (12.4 +/- 11.3 vs 12.9 +/- 8.6), ablation duration (42 +/- 43 min vs 39 +/- 27 min), and fluoroscopy time (17.0 +/- 18.7 min vs 15.7 +/- 10.7 min). In a mean follow-up of 8.3 months, 1 patient in the cooled-tip group and 3 patients in the 8-mm-tip group had recurrence of common atrial flutter. CONCLUSION: Use of the closed cooled-tip ablation catheter and the 8-mm-tip catheter have equal and high efficacy for RF ablation of common atrial flutter.