Long-term follow-up after surgery for atrial fibrillation with concomitant open heart surgery. / Langtidsoppfølging etter atrieflimmeroperasjon og samtidig åpen hjertekirurgi.

BACKGROUND: Patients with atrial fibrillation and atrial flutter scheduled to undergo open heart surgery can receive ablation treatment of arrhythmogenic foci during the same intervention. Sinus rhythm is restored in the majority in the short term, but the long-term results are more uncertain. This study, which is part of the international CURE-AF trial, evaluates results after Cox-Maze IV surgery for atrial fibrillation in Norway at six-year follow-up. MATERIAL AND METHOD: Nineteen patients were included in this prospective cohort study. Atrial fibrillation had persisted for 40 months in the group with long-standing persistent atrial fibrillation (n = 12) and 6 months in the group with persistent atrial fibrillation (n = 7). Surgery for atrial fibrillation was performed according to the Cox-Maze IV procedure in the CURE-AF protocol. Follow-up in the first 12 months was strictly according to the CURE-AF protocol, thereafter conducted by the primary health service. RESULTS: Sinus rhythm was restored in 11 patients at the time of discharge and in 14 patients six months postoperatively. After 5-6 years of follow-up, all patients with long-standing persistent atrial fibrillation had experienced recurrence. Two achieved sinus rhythm after electroconversion. Six of the seven in the group with persistent atrial fibrillation had sinus rhythm after 5-6 years. INTERPRETATION: The results were good initially, with restoration of sinus rhythm in more than two thirds of the patients after 6-9 months. Five years later, a high recurrence rate was found in patients with long-standing persistent atrial fibrillation. Several recurrences had not been detected by the public health service or treatment had not been attempted.

Entrapment and retrieval of a diagnostic electrophysiological catheter in the Chiari network.

The Chiari networks are reticulated fibers of embryological remnant venous valves in the right atrium. In patients with this congenital variation, manipulation of diagnostic catheters can be difficult, and there is a substantial risk of entrapment during electrophysiological studies. We report a case of successful retraction of a diagnostic catheter entangled in the Chiari network with the use of a lead extraction tool during a scheduled atrial fibrillation ablation. Rescheduled cryoablation was performed without complication and provided a good outcome.

Long-term follow-up in patients treated by stent implantation for post-ablation pulmonary vein stenosis.

PURPOSE: Symptomatic severe pulmonary vein stenosis (PVS) after catheter ablation of atrial fibrillation (AF) is a rare but well-recognized complication. Treatment options include pulmonary vein angioplasty with or without drug eluting balloons or angioplasty with stent implantation. The treatment of choice is unclear. In our center, pulmonary vein stenting is the treatment of choice for significantly stenotic veins. We present the long-term clinical outcome of 9 patients treated with stent implantation. METHODS: Between 2001 and 2015, 3048 patients with AF were treated with catheter ablation at our institution, of which 9 developed symptomatic PVS. A total of 11 PVS were treated. Pre-procedural imaging (CT, MR, transesophageal echocardiography, angiography) was performed in all patients. RESULTS: Mean time from ablation to stenting was 18 months. Three patients had recurrent pneumonia and the remaining reduced functional capacity (NYHA 2). All patients were in functional capacity NYHA 1 (p < 0.05) after a mean follow-up of 64 (18-132) months. Three patients still had paroxysmal AF, of which two have undergone repeated ablation. CONCLUSIONS: Symptomatic PVS after AF ablation can be successfully treated by stent implantation with durable results and good clinical outcome. AF ablation is still a feasible option after stent deployment.

Incidence and clinical predictors of subsequent atrial fibrillation requiring additional ablation after cavotricuspid isthmus ablation for typical atrial flutter.

OBJECTIVES: We sought to investigate the incidence of atrial fibrillation after catheter ablation for typical atrial flutter and to determine the predictors for symptomatic atrial fibrillation that required a further additional dedicated ablation procedure. DESIGN: 127 patients underwent elective cavotricuspid isthmus ablation with the indication of symptomatic, typical atrial flutter. The occurrence of atrial flutter, atrial fibrillation, cerebrovascular events and the need for additional ablation procedures for symptomatic atrial fibrillation was assessed during long-term follow-up. RESULTS: The majority of patients (70%) manifested atrial fibrillation during a follow-up period of 68 ± 24 months, and a significant proportion (42%) underwent one or multiple atrial fibrillation ablation procedures after an average of 26 months from the index procedure. Recurrence of typical atrial flutter was rare. Ten patients (8%) suffered cerebrovascular events. Earlier documentation of atrial fibrillation (OR 3.53), previous use of flecainide (OR 3.33) and left atrial diameter (OR 2.96) independently predicted occurrence of atrial fibrillation during the follow-up. A combination of pre- and intra-procedural documentation of atrial fibrillation (OR 3.81) and previous use of flecainide (OR 2.43) independently predicted additional atrial fibrillation ablation. DISCUSSION: Atrial fibrillation occurred in the majority of patients after ablation for typical atrial flutter and 42% of them required an additional dedicated ablation procedure. Pre- and intraprocedural documentation of atrial fibrillation together with previous use of flecainide independently predicted atrial fibrillation occurrence and a need for additional ablation. Anticoagulation treatment should be continued in high-risk patients in spite of clinical disappearance of atrial flutter.

Atrioventricular nodal ablation in patients with resynchronization therapy and atrial fibrillation - long term results.

OBJECTIVES: Atrioventricular nodal ablation (AVNA) is recommended for patients (pts) with cardiac resynchronization therapy (CRT) having atrial fibrillation (AF) and incomplete ventricular capture (Class IIa, level B). AVNA reduces mortality and improves the New York Heart Association (NYHA) functional class during intermediate term follow-up. The objectives were to study the long-term outcome regarding quality of life (QoL) and survival of our CRT pts after AVNA. DESIGN: 37 CRT-pts undergoing AVNA due to inadequate biventricular pacing were included in the study. Data were retrospectively obtained from clinical records and through telephone interviews. RESULTS: Twenty pts died during the follow-up period of average 30.6 ± 24 months. After AVNA the ventricular capture improved significantly from 68.4 ± 23% to 98.5 ± 2% (p < 0.001). A significant and sustained improvement of average 0.3 ± 0.5 (p = 0.001) in NYHA functional class was found. Additionally a large percentage of pts discontinued taking rate reducing drugs with potential severe side effects. CONCLUSION: AVNA in CRT pts was safe and effective. The treatment resulted in a sustained improvement in QoL, including long-term improvement in NYHA functional class.

10-year follow-up after radiofrequency ablation of idiopathic ventricular arrhythmias from right ventricular outflow tract.

BACKGROUND: The aim of this study was to examine the effect of radiofrequency ablation (RFA) of ventricular arrhythmias from right ventricular outflow tract (RVOT) during long-term follow-up. METHODS: A follow-up analysis was conducted using an in-house questionnaire, as well as a qualitative assessment of the patients' medical records. The study population of 34 patients had a previous diagnosis of idiopathic VT or frequent PVCs from the RVOT, and received RFA treatment between 2002 and 2005. RESULTS: The main symptoms prior to RFA were palpitations (82.4%) and dizziness (76.5%). A reduction in symptoms following RFA was reported by 91.2% of patients (p < 0.001). Furthermore, there was a reduced use of antiarrhythmic medication after RFA (p < 0.001). General health perception classified on a scale of 1 (poor) to 4 (excellent), improved from median class 1 to 3 (p < 0.001) during long-term follow-up. The fitness to work increased from median class 3 to class 5 (1 = incapacitated, 5 = full time employment, p = 0.038), while the rate of patients in full time employment increased from 26.5% to 55.9% after RFA (p = 0.02). CONCLUSIONS: A reduction of symptoms and use of antiarrhythmic medication, as well as an improvement in the general health perception and fitness to work after RFA of idiopathic ventricular arrhythmias can be demonstrated at ten-year follow-up.

Effects of ECT in treatment of depression: study protocol for a prospective neuroradiological study of acute and longitudinal effects on brain structure and function.

BACKGROUND: Major depression can be a serious and debilitating condition. For some patients in a treatment resistant depressive episode, electroconvulsive treatment (ECT) is the only treatment that is effective. Although ECT has shown efficacy in randomized controlled trials, the treatment is still controversial and stigmatized. This can in part be attributed to our lack of knowledge of the mechanisms of action. Some reports also suggest potential harmful effects of ECT treatment and memory related side effects have been documented. METHODS/DESIGN: The present study will apply state of the art radiology through advanced magnetic resonance imaging (MRI) techniques to investigate structural and functional brain effects of ECT. As a multi-disciplinary collaboration, imaging findings will be correlated to psychiatric response parameters, neuropsychological functioning as well as neurochemical and genetic biomarkers that can elucidate the underlying mechanisms. The aim is to document both treatment effects and potential harmful effects of ECT. SAMPLE: n = 40 patients in a major depressive episode (bipolar and major depressive disorder). Two control groups with n = 15 in each group: age and gender matched healthy volunteers not receiving ECT and patients undergoing electrical cardioversion (ECV) for atrial fibrillation (AF). Observation time: six months. DISCUSSION: The study will contribute to our understanding of the pathophysiology of major depression as well as mechanisms of action for the most effective treatment for the disorder; ECT.

Effect of flecainide on the extension and localization of complex fractionated electrogram during atrial fibrillation.

AIMS: Complex fractionated electrogram (CFE) ablation in addition to pulmonary vein isolation is an accepted strategy for the treatment of non-paroxysmal atrial fibrillation (AF). We sought to determine the effect of flecainide on the distribution and extension of CFE areas. METHODS: Twenty-three non-paroxysmal AF patients were enrolled in this prospective study. A first CFE map was obtained under baseline conditions by sampling 5 s of continuous recording from the distal electrodes of the ablation catheter. Intravenous flecainide (1 mg/kg) was administered over 10 min and followed by 30-min observation time. A second CFE map was obtained with the same modalities. CFE-mean values, CFE areas, and atrial electrogram amplitude were retrieved from the electro-anatomical mapping system (Ensite NavX). RESULTS: After flecainide administration, CFE-mean values increased (111.5 ± 55.3 vs. 132.3 ± 65.0 ms, p < 0.001) with a decrease of CFE area (32.9%) in all patients. Atrial electrogram amplitude decreased significantly (0.30 ± 0.31 vs. 0.25 ± 0.20 mV, p < 0.001). We observed 80.9% preservation of CFE areas. A CFE mean of 78 ms was the best cutoff for predicting stable CFE areas. CONCLUSIONS: Flecainide reduces the extension of CFE areas while preserving their spatial localization. A CFE-mean value <80 ms may be crucial to define and locate stable CFE areas.

Prospective European survey on atrial fibrillation ablation: clinical characteristics of patients and ablation strategies used in different countries.

BACKGROUND: Atrial fibrillation (AF) ablation is widely adopted. Our aim was to conduct a prospective multicenter survey to verify patients' characteristics, approaches, and technologies adopted across Europe. METHODS AND RESULTS: A total of 35 centers in 12 countries actively participated in the study and 940 patients (median age 60 years) were enrolled. AF was paroxysmal, persistent, and long-lasting persistent in 52.4%, 36%, and 11.6% of patients, respectively; 95.5% of patients were symptomatic and 91.4% were refractory to antiarrhythmic therapy. Redo procedures were performed in 20.9%. Pulmonary vein isolation (PVI) emerged as the cornerstone of ablative therapy and has been performed in 98.7% of procedures, with confirmation of PVI in 92.9% of cases. The ablation of nonparoxysmal AF was not generally limited to isolating the PVs and several adjunctive approaches are adopted, particularly in the case of long-lasting persistent AF. Linear lesions or elimination of complex fractionated atrial electrograms were more frequently added. Circular mapping catheters and imaging techniques were seen to be used in about two-thirds of cases. Radiofrequency energy was delivered through open irrigated catheters in 68% of cases. CONCLUSIONS: European centers are largely following the recommendations of the guidelines and the expert consensus documents for AF ablation. AF ablation is mainly performed in relatively young patients with symptomatic drug refractory AF and no or minimal heart disease. Patients with paroxysmal AF are the most frequently treated with a quite uniform ablative approach across Europe. A less standardized approach was observed in nonparoxysmal AF patients.

Ablation effect indicated by impedance fall is correlated with contact force level during ablation for atrial fibrillation.

INTRODUCTION: Previous studies have validated the use of impedance fall as a measure of the effects of ablation. We investigated whether catheter-to-tissue contact force correlated with impedance fall during atrial fibrillation ablation. METHODS AND RESULTS: A total of 394 ablation points from 35 patients who underwent atrial fibrillation ablation were selected and analyzed in terms of the presence of stable catheter contact in non-ablated areas in the left atrium. A fixed power output (30 W) was applied for 60 seconds. Contact force, impedance fall, and force-direction angle were retrieved and exported for off-line analysis. Qualified points were divided into 5 groups according to the level of contact force (1-5 g, 6-10 g, 11-15 g, 16-20 g, and >20 g). An acute impedance fall was observed in the first 10 seconds followed by a plateau in group I and by a further fall in the other groups. Group V showed a rise in impedance during the last 20 seconds of ablation. Levels of impedance fall at each time point were significantly different among all the groups (P<0.001) except between groups III and IV. There was a significant correlation between contact force and maximum impedance fall (rho = 0.54, P<0.01). Lesions with a force-direction angle of 0-30° had significantly lower contact force and maximum impedance fall than those with angles of 30-60° and 60-135° (P<0.01). CONCLUSIONS: Under stable catheter conditions, contact force correlates with impedance fall during 60 seconds of ablation. Contact force exceeding 5 g produces greater impedance fall, which probably indicates adequate lesion formation. A contact force greater than 20 g may lead to late tissue overheating.

Evaluation of the appropriateness and outcome of in-hospital telemetry monitoring.

The American Heart Association classifies monitored patients into 3 categories. The aims of this study were to (1) investigate how patients are assigned according to the American Heart Association classification, (2) determine the number and type of arrhythmic events experienced by these patients, and (3) describe subsequent changes in management. A prospective observational study design was used. All patients assigned to telemetry during a 3-month period were consecutively enrolled in our study. Data were collected 24/7. Only arrhythmias that might require a change in management were recorded. Monitor watchers at the central monitoring station completed a standard data sheet assessing 64 variables. These data, as well as medical records, were reviewed by the investigator. Overall, 1,194 patients were included. Eighteen percent of the patients were assigned to American Heart Association class I (monitoring indicated), 71% to class II (monitoring may be of benefit), and 11% to class III (monitoring not indicated). The overall arrhythmia event rate was 33%. Forty-three percent of class I patients, 28% of class II patients, and 47% of class III patients experienced arrhythmia events. Change in management occurred in 25% of class I patients, 14% of class II patients, and 29% of class III patients. Although the number of class III indications should have been reduced, nearly 1/2 of class III patients experienced arrhythmia events and 1/3 of them received management changes. This outcome challenges existing guidelines. In conclusion, most patients in this study were monitored appropriately, according to class I and II indications.

Long-term outcomes of adjunctive complex fractionated electrogram ablation to pulmonary vein isolation as treatment for non-paroxysmal atrial fibrillation.

PURPOSE: The adjunctive ablation of areas of complex fractionated electrogram (CFE) to pulmonary vein isolation (PVI) is an emerging strategy for patients with non-paroxysmal atrial fibrillation (AF). We studied the long-term outcomes of this approach. METHODS: Sixty-six patients (mean age 58 ± 9, 86.4 % male) with non-paroxysmal AF underwent ablation procedures consisting of PVI plus extensive CFE ablation. Post-ablation atrial tachycardia (AT) was also targeted if presented. All patients were followed up regularly on an ambulatory basis by means of ECG and Holter recordings. RESULTS: After a mean follow-up period of 40 ± 14 months and 1.7 ± 0.7 procedures, 38 patients (57.6 %) were free of arrhythmias, 15 (22.7 %) displayed clinical improvement and 13 (19.7 %) suffered recurrences of persistent AF/AT. Females displayed poorer long-term outcomes than males (arrhythmia-free 22.2 vs. 63.2 %, p < 0.05). Multivariate analysis demonstrated that long duration of uninterrupted AF prior to the procedure was an additional predictor of long-term failure (odds ratio 1.49, p < 0.01). ROC analysis (area under curve 0.80; p < 0.001) estimated 3.5 years as the optimal cut-off point for predicting long-term failure (sensitivity 85 %, specificity 74 %). The cumulative data showed a significantly higher percentage of arrhythmia-free patients when the duration of AF had been ≤ 2 years (69.7 %) and ≤ 4 years (68.9 %) than when it was > 4 years (33.3 %; p < 0.01). CONCLUSIONS: PVI + CFE ablation in non-paroxysmal AF appears to provide a reasonable proportion of arrhythmia-free patients during long-term follow-up. Poorer long-term results can be expected among female patients and those with an uninterrupted AF duration of > 4 years.

Ventricular arrhythmias originating from the aortomitral continuity: an uncommon variant of left ventricular outflow tract tachycardia.

AIMS: Ventricular arrhythmias arising from the fibrous rings have been demonstrated, but knowledge about the aortomitral continuity (AMC) as a source of the arrhytmias is still limited. The objective is to describe the characteristics of ventricular arrhythmias originating from the AMC in patients without structural heart disease. METHODS AND RESULTS: Ten patients with ventricular tachycardia (VT) and/or premature ventricular contractions, who had been successfully treated by catheter ablation at the AMC beneath the aortic valve, were enrolled. Clinical data and electrocardiographic characteristics were analysed. Three of the 10 patients had previously registered episodes of supraventricular tachycardia and had undergone catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT). In four patients with anterior AMC location, early R/S wave transition was found in the precordial leads, with equal R and S amplitudes in V2, rS in V1, and R in V3. In six patients whose VT arose from the middle part of the AMC, we demonstrated a special ('rebound') transition pattern, with which equal R and S amplitudes occurred in V2, and high R waves in V1 and V3. In the anterior AMC location, the S/R ratios in leads V1 and V2 were >1 and statistically significantly higher than those located in the middle (V1: 1.59 vs. 0.23, P< 0.001; V2: 1.52 vs. 0.41, P< 0.01). CONCLUSIONS: We report a series of ventricular arrhythmias arising from the AMC with different R/S wave transition patterns in the precordial leads on the electrocardiogram. There may be a relationship between ventricular arrhythmias from AMC and AVNRT.

N-terminal pro-B-type natriuretic peptide level at long-term follow-up after atrial fibrillation ablation: a marker of reverse atrial remodelling and successful ablation.

AIMS: We investigated the relationship between arrhythmia burden, left atrial volume (LAV) and N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) at baseline and after long-term follow-up of atrial fibrillation (AF) ablation. METHODS: We studied 38 patients (23 paroxysmal, 6 women, mean age 56 ± 11) scheduled for AF ablation. LAV was calculated on the basis of computed tomography images at baseline and long-term follow-up, and arrhythmia burden was graded from self-reported frequency and duration of AF episodes. RESULTS: After a mean period of 22 ± 5 months, 28/38 patients (11/15 persistent) were free from AF recurrence. At baseline there were no differences in mean LAV (125 vs. 130 cm(3), p = 0.7) or median NT-pro-BNP (33.5 vs. 29.5 pmol/L, p = 0.9) between patients whose ablation had been successful or otherwise. At long-term follow-up, there was a marked decrease in LAV (105 vs. 134 cm(3), p < 0.05) and level of NT-pro-BNP (7 vs. 17.5 pmol/L, p < 0.05) in the successful ablation patients. NT-pro-BNP correlated with LAV both at baseline (r = 0.71, p < 0.001) and at follow-up (r = 0.57, p < 0.001). Arrhythmia burden correlated with both NT-pro-BNP (r = 0.47, p < 0.01) and LAV (r = 0.52, p < 0.01). A decrease in NT-pro-BNP at follow-up of >25% of baseline value had a specificity of 0.89 and a sensitivity of 0.6 (receiver operator characteristics, accuracy 0.82) for ablation success. CONCLUSIONS: NT-pro-BNP correlates with LAV and arrhythmia burden in AF patients and both NT-pro-BNP and LAV decrease significantly after successful ablation. A decrease in NT-pro-BNP of >25% from the baseline value could be useful as a marker of ablation success.

Remote magnetic versus manual catheters: evaluation of ablation effect in atrial fibrillation by myocardial marker levels.

BACKGROUND: A remote magnetic navigation (MN) system is available for radiofrequency ablation of atrial fibrillation (AF), challenging the conventional manual ablation technique. The myocardial markers were measured to compare the effects of the two types of MN catheters with those of a manual-irrigated catheter in AF ablation. METHODS: AF patients underwent an ablation procedure using either a conventional manual-irrigated catheter (CIR, n = 65) or an MN system utilizing either an irrigated (RMI, n = 23) or non-irrigated catheter (RMN, n = 26). Levels of troponin T (TnT) and the cardiac isoform of creatin kinase (CKMB) were measured before and after ablation. RESULTS: Mean procedure times and total ablation times were longer employing the remote magnetic system. In all groups, there were pronounced increases in markers of myocardial injury after ablation, demonstrating a significant correlation between total ablation time and post-ablation levels of TnT and CKMB (CIR r = 0.61 and 0.53, p < 0.001; RMI r = 0.74 and 0.73, p < 0.001; and RMN r = 0.51 and 0.59, p < 0.01). Time-corrected release of TnT was significantly higher in the CIR group than in the other groups. Of the patients, 59.6% were free from AF at follow-up (12.2 ± 5.4 months) and there were no differences in success rate between the three groups. CONCLUSIONS: Remote magnetic catheters may create more discrete and predictable ablation lesions measured by myocardial enzymes and may require longer total ablation time to reach the procedural endpoints. Remote magnetic non-irrigated catheters do not appear to be inferior to magnetic irrigated catheters in terms of myocardial enzyme release and clinical outcome.

[Magnetic navigation for ablation of cardiac arrhythmias]. / Magnetstyrt ablasjonsbehandling av hjerterytmeforstyrrelser.

BACKGROUND: The first use of magnetic navigation for radiofrequency ablation of supraventricular tachycardias, was published in 2004. Subsequently, the method has been used for treatment of most types of tachyarrhythmias. This paper provides an overview of the method, with special emphasis on usefulness of a new remote-controlled magnetic navigation system. MATERIAL AND METHODS: The paper is based on our own scientific experience and literature identified through a non-systematic search in PubMed. RESULTS: The magnetic navigation system consists of two external electromagnets (to be placed on opposite sides of the patient), which guide an ablation catheter (with a small magnet at the tip of the catheter) to the target area in the heart. The accuracy of this procedure is higher than that with manual navigation. Personnel can be quickly trained to use remote magnetic navigation, but the procedure itself is time-consuming, particularly for patients with atrial fibrillation. The major advantage is a considerably lower radiation burden to both patient and operator, in some studies more than 50 %, and a corresponding reduction in physical strain on the operator. The incidence of procedure-related complications seems to be lower than that observed with use of manually operated ablation catheters. Work is ongoing to improve magnetic ablation catheters and methods that can simplify mapping procedures and improve efficacy of arrhythmia ablation. The basic cost for installing a complete magnetic navigation laboratory may be three times that of a conventional electrophysiological laboratory. INTERPRETATION: The new magnetic navigation system has proved to be applicable during ablation for a variety of tachyarrhythmias, but is still under development.

Characteristics and distribution of complex fractionated atrial electrograms in patients with paroxysmal and persistent atrial fibrillation.

INTRODUCTION: Substrate-based radiofrequency ablation for treatment of atrial fibrillation (AF) is still under development. The purpose of this study was to investigate the different characteristics and distribution of complex fractionated atrial electrograms (CFAE) in both atria in patients with paroxysmal and persistent AF. METHODS AND RESULTS: The NavX system was used to map the left and right atria and the coronary sinus in 20 AF patients (ten persistent). An automated algorithm calculates the average time interval between consecutive deflections (complex fractionated electrogram (CFE) mean). All recordings were visually inspected off-line and interpreted either as continuous, fragmented, mixed CFAE, or non-CFAE, and their locations were determined. Electrograms with intermittent CFAE characteristics were also regarded as non-CFAEs. There were more CFAEs in persistent AF than in paroxysmal AF (52% vs. 44% of total registrations, p < 0.05), and CFAEs were more widespread in both atria in persistent AF patients. There were also more continuous CFAEs (70% vs. 59% of total CFAEs, p < 0.05), and less mixed and intermittent CFAEs (22% vs. 30% and 16% vs. 21% of total CFAEs, respectively, p < 0.05) in persistent AF. Fragmented CFAEs had more high-voltage signals than other groups. Employing the automated algorithm for CFAE mapping, a CFE mean cut-off value of < or =80 ms provides a sensitivity and specificity of 87.4% and 81.2%, respectively. CONCLUSIONS: CFAEs distribute in preferential areas and arrange in different patterns in both atria. Patients with persistent AF have more continuous CFAEs and higher temporal signal stability than patients with paroxysmal AF.

Spatial relationships between the pulmonary veins and sites of complex fractionated atrial electrograms during atrial fibrillation.

BACKGROUND: Pulmonary vein (PV) isolation is used for the treatment of atrial fibrillation (AF). Complex fractionated atrial electrogram (CFAE) mapping has been introduced to guide AF ablation. However, the spatial relationship between PV and CFAE is not well defined. METHODS AND RESULTS: The study included 21 patients (mean age 57 +/- 11 years, 17 men, 14 paroxysmal, two persistent, and five long-standing persistent AF) referred for PV isolation. Electrograms were sampled for 8 seconds at each site during stable AF (13 induced). High-frequency was defined as <80 ms of CFAE value. The distance between CFAE and the nearest PV ostium was measured. The PV ostia and antra were demarcated by fluoroscopy guidance and endocardial reconstruction. Among 82 PV mapped (left common four, superior 17, inferior 17; right superior 21, inferior 21, middle 2), 52.4% and 25.6% of high-frequency CFAE were located on the anterior and posterior walls, respectively, inside the PV or at the ostium. No high-frequency CFAE was observed in two out of 60 and one out of 20 PV anteriorly, versus seven out of 60 and 11 out of 20 PV (P < 0.001) posteriorly, in paroxysmal and persistent AF, respectively. In the PV with high-frequency CFAE, the mean shortest distances to the PV ostia in paroxysmal versus persistent AF were 2.7 +/- 5.1 versus 7.4 +/- 5.4 mm anteriorly (P < 0.01), and 6.5 +/- 6.4 versus 9.4 +/- 8.4 mm posteriorly (ns). CONCLUSIONS: During PV isolation, extending the ablation lesions by up to 10 mm from the PV ostia might cover most high-frequency CFAE around the PV antra. High-frequency CFAE were more often located in the PV ostia in paroxysmal than in persistent AF.