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Single procedure success rates of pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (PAF) are still unsatisfactory. In patients with persistent atrial fibrillation (AF), ablation of complex fractionated atrial electrograms (CFAEs) after PVI results in improved outcomes.We aimed to investigate if PAF-patients with intraprocedurally sustained AF after PVI might benefit from additional CFAE ablation.A total of 1134 consecutive patients underwent a first catheter ablation procedure of PAF between June 2008 and December 2012. In most patients, AF was either not inducible or terminated during PVI. In 68 patients (6%), AF sustained after successful PVI. These patients were randomized to either cardioversion (PVI-alone group; n = 33) or additional CFAE ablation (PVI+CFAE group; n = 35) and followed up every 1-3 months and serial Holter recordings were also obtained. The primary end point was the recurrence of AF/atrial tachycardia (AT) after a blanking period of 3 months.Procedure duration (127 ± 6 minutes vs 174 ± 10 minutes), radiofrequency application time (44 ± 3 minutes vs 74 ± 5 minutes), and fluoroscopy time (26 ± 2 minutes vs 41 ± 3 minutes) were longer in the PVI+CFAE group (all P.001). In 30 of 35 patients (86%) in the PVI+CFAE group, ablation terminated AF. There was no significant group difference with respect to freedom from AF/AT (22 of 33 [67%] vs 22 of 35 [63%]; P = .66). Subsequently, 10 of 11 patients in the PVI-alone group (91%) and 11 of 13 patients in PVI+CFAE group (85%) underwent repeat ablation (P = 1.00). Overall, 29 of 33 [88%] vs 30 of 35 [86%] patients (P = 1.00) were free from AF/AT after 1.4 ± 0.1 vs 1.4 ± 0.2 (P = .87) procedures.Patients with sustained AF after PVI in a PAF cohort are rare. Regarding AF/AT recurrence, these patients did not benefit from further CFAE ablation compared to PVI alone, but are exposed to longer procedure duration, fluoroscopy time, and radiofrequency application time.

Background Stepwise ablation is an effective treatment for persistent atrial fibrillation (AF), although it often requires multiple procedures to eliminate recurrent arrhythmias. Objective This study evaluated single- and multiple-procedure long-term success rates and potential predictors of a favorable single-procedure outcome of stepwise ablation for persistent AF. Methods This study comprised 395 patients with persistent AF (duration 16 months) undergoing de novo catheter ablation using the stepwise approach. Procedural success was defined as the absence of any arrhythmia recurrence. Patient characteristics and electrophysiological parameters were analyzed with respect to single- and multiple-procedure outcomes. Results After a follow-up of 27 ± 7 months, 108 (27%) patients were free of arrhythmia recurrences with a single procedure. After 2.3 ± 0.6 procedures, 312 (79%) patients were free of arrhythmia with concomitant antiarrhythmic treatment in 38% (23% on β-blocker). Female gender, duration of persistent AF, and congestive heart failure were predictive for the outcome after first ablation. However, the strongest predictors for single-procedure success were longer baseline AF cycle length (CL) and procedural AF termination. Moreover, procedural AF termination during the index procedure also predicted a favorable outcome after the last procedure, while the existence of congestive heart failure was associated with an increased risk for eventual arrhythmia recurrences. Conclusions Single-procedure long-term success is anticipated in approximately a quarter of patients undergoing de novo ablation of persistent AF. Baseline AFCL emerged as the strongest predictor of single-procedure success, while AF termination during index ablation predicts the overall outcome. However, an overall success rate of 79% is achievable with multiple procedures.

Catheter ablation (CA) is considered the treatment of choice for patients with atrioventricular nodal reentrant tachycardia (AVNRT). However, there is a tendency to avoid CA in the elderly because of a presumed increased risk of periprocedural atrioventricular (AV) nodal block.The purpose of this prospective registry was to assess age-related differences in the efficacy and safety of CA within a large population with AVNRT.A total of 3,234 consecutive patients from 48 German trial centers who underwent CA of AVNRT between March 2007 and May 2010 were enrolled in this study. The cohort was divided into three age groups:50 years (group 1, n = 1,268 [39.2%]; median age = 40 [30.0-45.0] years, 74.1% women), 50-75 years old (group 2, n = 1,707 [52.8%]; 63.0 [58.0-69.0] years, 63.0% women), and75 years old (group 3, n = 259 [8.0%]; 79.0 [77.0-82.0] years, 50.6% women).CA was performed with radiofrequency current (RFC) in 97.7% and cryoablation technology in 2.3% of all cases. No differences were observed among the three groups with regard to primary CA success rate (98.7% vs. 98.8 % vs. 98.5%; P = .92) and overall procedure duration (75.0 minutes [50.0-105.0]; P = .93). Hemodynamically stable pericardial effusion occurred in five group 2 (0.3%) and two group 3 (0.8%) patients but in none of the group 1 (P.05) patients. Complete AV block requiring permanent pacemaker implantation occurred in two patients in group 1 (0.2%) and six patients in group 2 (0.4%) but none in group 3 (P = 0.41). During a median follow-up period of 511.5 days (396.0-771.0), AVNRT recurrence occurred in 5.7% of all patients. Patients75 years (group 3) had a significantly longer hospital stay (3.0 days [2.0-5.0]) compared with group 1 (2.0 days [1.0-2.0]) or group 2 (2.0 days [1.0-3.0]) patients (P.0001).CA of AVNRT is highly effective and safe and does not pose an increased risk for complete AV block in patients over 75 years of age, despite a higher prevalence of structural heart disease. Antiarrhythmic drug therapy is often ineffective in this age group; thus, CA for AVNRT should be considered the preferred treatment even in elderly patients.

Conventional catheter ablation for common-type atrial flutter (AFL) is a widely established therapy but has not been compared with the use of a robotic navigation system (RNS) thus far.The purpose of this study was to investigate the feasibility of a new, nonmagnetic RNS with regard to safety, efficacy, and X-ray exposure to investigator and patient compared with the conventional ablation approach in patients with AFL.Fifty patients (65.7 +/- 9.3 years, 40 male) undergoing de novo catheter ablation for AFL were randomly assigned to conventional or RNS-guided cavotricuspid isthmus (CTI) ablation.Complete bidirectional isthmus block was achieved for all patients without occurrence of procedure-related complications. The fluoroscopy time and the investigator X-ray exposure (8.2 +/- 4.6 vs. 5.8 +/- 3.6, P = .038; and 8.2 +/- 4.6 vs. 1.9 +/- 1.1 minutes, P.001) as well as the mean radiofrequency (RF) duration and the energy delivered were significantly higher in the conventional than in the RNS group (321.7 +/- 214.6 vs. 496.4 +/- 213.9 seconds, P = .006; 8279 +/- 5767 vs. 16,308 +/- 6870 J, P.001, respectively). The overall procedure time in the RNS group was significantly longer than in the conventional group (79.2 +/- 30.6 vs. 58.4 +/- 17.7 minutes; P = .04) but significantly decreased comparing the first 10 with the last 10 patients in the RNS group (105.3 +/- 34.8 vs. 60.6 +/- 6.3 minutes; P = .003). Starting ablation during AFL, bidirectional block instantly after termination was observed in 90% of the RNS and 50% of the conventionally treated patients (P = .03).The present study demonstrates the safety and feasibility of RNS for performing CTI ablation in patients with common-type AFL for use in the clinical routine. As a result of the remote navigation, X-ray exposure and RF duration to achieve bidirectional block were significantly decreased and occurred more often immediately after AFL termination. These findings are consistent with increased catheter stability and RF application efficacy using RNS compared with conventional catheter manipulation.

The procedural end point of electrical isolation of the pulmonary veins (PVs) for the treatment of atrial fibrillation (AF) has been debated extensively. After identifying the PVs as the dominant arrhythmogenic site of paroxysmal AF, 2 fundamentally different approaches to the interventional treatment of AF were introduced. Haissaguerre et al developed a technique to electrically isolate the PVs by targeting electrophysiological (EP) breakthroughs from the left atrium to the PVs guided by a circular mapping catheter. In contrast, Pappone et al implemented an anatomical approach that used circumferential ablation lines around the PVs guided by a 3-dimensional mapping system. This latter approach used the procedural end point of local electrogram amplitude reduction on the line and assessment of voltage maps within the encircled area but not the demonstration of PV isolation. For a considerably long time, these 2 different approaches separated the EP community in terms of AF ablation into 2 fractions according to their affinity to either of these techniques. Subsequently, 2 independent groups performed each a prospective randomized trial comparing the 2 approaches. However, these 2 studies ultimately did not clarify which one of the approaches is the more effective and therefore more appropriate technique. In contrast, the completely divergent results of the 2 studies further heated up this debate. Interestingly, although no additional clarifying data were published afterward, the 2007 Heart Rhythm Society/European Heart Rhythm Association/European Cardiac Arrhythmia Society consensus documents recommended for the first time that in AF ablation approaches targeting the PVs, complete electrical isolation should be the goal. With this statement, discussions on whether electrical isolation should be used as the EP end point of PV ablation abated subsequently. The contemporary approach to PV isolation consolidates the combination of both techniques, a wide circumferential linear ablation around the ipsilateral PVs with the end point of electrical isolation guided by a circular PV mapping catheter. Recently, the German Gap-AF (AFNET 1) study demonstrated

Background The accuracy of three-dimensional mapping systems is affected by cardiac contraction and respiration. Objective The study sought to determine relative motion of cardiac and thoracic structures to assess positional errors and guide the choice of an optimized spatial reference. Methods Motion of catheters placed at the coronary sinus (CS), pulmonary vein (PV) ostia, left atrial (LA) isthmus and roof, cavotricuspid isthmus (CTI), and right atrial appendage (RAA) were recorded for 30 patients using Ensite-NavX. The right subclavian vein, left brachiocephalic vein, azygos vein, pulmonary arteries, and a static reference were included. The displacement from a mean position was calculated for each pair of sites. Respiration effects were assessed by the shift of the motion curve during in- and expiration phases. Results The PVs showed a mean interpair displacement of 4.1 ± 0.2 mm and a shift of 5.0 ± 0.5 mm. Proximal CS references for all LA structures (4.0 ± 1.1 mm) were superior to the static reference (4.9 ± 0.7 mm; P = .01). In addition, the shift due to respiration was less pronounced at 3.5 ± 0.8 mm versus 4.9 ± 0.5 mm ( P = .004), respectively. Motion of extracardiac vessels was influenced by a mean shift of 6.8 ± 1 mm. The remote subclavian and brachiocephalic veins were more affected (7.6 ± 0.7 mm) than the pulmonary arteries (5.9 ± 0.4 mm; P = .002). For the CTI, a minimized mean displacement of less than 4.6 ± 2.0 mm relative to the proximal CS, RAA, and azygos vein was found. Conclusion Respiration is the major source of relative motion, which increases with distance from the heart. For LA procedures, a proximal CS reference position is superior to a static reference position.

Background Areas of complex fractionated atrial electrograms (CFAEs) have been implicated in the atrial substrate of atrial fibrillation (AF). The mechanisms underlying CFAE in humans are not well investigated. Objectives The purpose of this study was to investigate the regional activation pattern associated with CFAE using a high-density contact mapping catheter. Methods Twenty patients with paroxysmal AF were mapped using a high-density multielectrode catheter. CFAE were mapped at 10 different sites (left atrium [LA]: inferior, posterior, roof, septum, anterior, lateral; right atrium [RA]: anterior, lateral, posterior, septum). Local atrial fibrillation cycle length (AFCL) was measured immediately before and after the occurrence of CFAE, and the longest electrogram duration (CFAE max ) was assessed. Results Longer electrogram durations were recorded in the LA compared with the RA (CFAE max 118 ± 21 ms vs 104 ± 23 ms, P = .001). AFCL significantly shortened before the occurrence of CFAE max compared with baseline (LA: 174 ± 32 ms vs 186 ± 32 ms, P = .0001; RA: 177 ± 31 ms vs 188 ± 31 ms, P = .0001) and returned to baseline afterwards. AFCL shortened by ≥10 ms in 91% of mapped sites. Two different local activation patterns were associated with occurrence of CFAE max : a nearly simultaneous activation in all spines in 84% indicating passive activation, and a nonsimultaneous activation sequence suggesting local complex activation or reentry. Conclusion Fractionated atrial electrograms during AF demonstrate dynamic changes that are dependent on regional AFCL. Shortening of AFCL precedes the development of CFAE; thus, cycle length is a major determinant of fractionation during AF. High-density mapping in AF may help to differentiate passive activation of CFAE from CFAE associated with an active component of the AF process.

Background Pulmonary vein (PV) isolation and linear lesions are effective in eliminating paroxysmal atrial fibrillation (AF), but linear lesions probably are not required in all patients. Noninducibility of AF has been shown to be associated with freedom from arrhythmia in 87% of patients. Objectives The purpose of this study was to prospectively evaluate the role of noninducibility in guiding a stepwise approach tailored to the patient. Methods In 74 patients (age 53 ± 8 years) with paroxysmal AF, PV isolation was performed during induced or spontaneous AF. If AF was inducible after PV isolation, one to two additional linear lesions were placed at the mitral isthmus and/or left atrial roof, with the endpoint of noninducibility of AF or atrial flutter. Inducibility (AF/atrial flutter, lasting ≥10 minutes) was assessed using burst pacing at an output of 20 mA down to refractoriness from the coronary sinus and both atrial appendages. Results In 42 patients (57%), PV isolation restored sinus rhythm and rendered AF noninducible. In the 32 patients with persistent or inducible AF after PV isolation, a single linear lesion achieved noninducibility in 20, whereas two linear lesions were required in 12 and resulted in conversion to sinus rhythm and noninducibility in 10. Using this stepwise approach, a total of 69 patients (93%) were rendered noninducible. During follow-up of 18 ± 4 months, 67 patients (91%) were free from arrhythmia without antiarrhythmic drugs. Repeat procedures were performed in 23 patients: repeat ablation was required to consolidate prior targets in 15 patients (20%), and "new" linear lesions, which were not predicted by inducibility during the index procedure, were required in 8 (11%). Conclusion Noninducibility can be used as an endpoint for determining the subset of patients with paroxysmal AF who require additional linear lesions after PV isolation. This tailored approach is effective in 91% of patients while preventing delivery of unnecessary linear lesions.

The purpose of this study was to evaluate a possible correlation between atrial ECG amplitude in common atrial flutter (AFL) and radiofrequency (RF) energy required to achieve cavotricuspid isthmus block.The amount of RF delivery required for ablation of typical AFL is variable. This variation has been attributed to the cavotricuspid isthmus anatomy. Atrial ECG amplitude can be a marker of atrial anatomic variations and therefore may correlate with RF duration required to achieve cavotricuspid isthmus block.Seventy consecutive patients were prospectively studied. Ablation of the cavotricuspid isthmus was performed by creating a line of block between the inferior tricuspid annulus and the inferior caval vein using 8-mm-tip electrode catheters. If more than 20 minutes of RF time was required to achieve conduction block, the catheter was changed to an irrigated-tip catheter. Atrial ECG amplitude was assessed in leads II, III, aVF, and aVL.A total of 14 +/- 11 minutes of RF energy was delivered to achieve block in all patients; 12 patients (8%) required more than 20 minutes. Atrial ECG amplitude showed highly significant correlations with cumulative RF energy (F and P waves in lead II: r = 0.703 and r = 0.737, P.001). P-wave amplitude0.2 mV and/or flutter wave amplitude0.35 mV in lead II have a high negative predictive value to predict20 min RF delivery (96% and 89% respectively).A significant correlation exists between atrial ECG amplitude and amount of RF required to ablate typical AFL. Atrial ECG amplitude may be a surrogate marker of characteristics of isthmus anatomy. These findings may influence the choice of catheter used for cavotricuspid isthmus ablation.

apical healthy tissue (c) no motion scar (d) dominant outward motion aneurysm. An analysis of the EC-delay (fig c) revealed areas of passive contraction, e.g. the LAT LCT (black), and slowly contracting myocardium with up to 300ms EC-delay (yellow). Conclusion: Slow conduction as well as long EC-intervals are responsible for delayed contraction that can be differentiated with the described mapping technique.

dure and integrated with real-time electroanatomical mapping (EAM) to guide cardiac mapping. However, because the MRI in this image integration paradigm is acquired pre-procedure, the cardiac anatomy during the procedure can change due to biological factors. Interventional MR imaging (iMRI) could combine real-time EAM with real-time MR imaging, thereby providing real-time anatomical information to guide catheter mapping. Methods & Results: Imaging and tracking data were acquired using a 1.5 T GE Signal CVi MRI, and electrogram information with a modified CardioLab 7000 EP recording system. Both in vitro and in vivo experiments were conducted to evaluate catheter tracking and EAM in the iMRI environment. During in vitro stuides, MR angiography (MRA) was completed on a fluid filled phantom of the aorta and left heart. These images were then semi-automatically segmented (CardEP, GE Medical) and 3D reconstructions prepared. An MR-compatible mapping catheter (see Figure; St. Jude Medical) with 3 MR tracking coils was advanced into the lumen of the phantom. During the in vivo porcine experiments, contrastenhanced MRA was completed. Following reconstruction of the imaging data, the deflectable catheter was manipulated under real-time iMRI image guidance. Real-time catheter position was updated continuously at 30 frames per second, and continuous MR imaging during tracking provided real-time update of the imaging planes. Using this methodology, mapping of the cardiac chambers to display the electrical information on the MR 3D anatomy was possible. Conclusions: This feasibility study demonstrates real-time tracking of an MR-compatible catheter to perform electroanatomical mapping within the MR environment. With further refinements, iMRI may be a clinicallyfeasible navigation paradigm.

in AP-direction and SI-direction. Results: Common ostia of left PV were observed in 33(79%) patients with MSCT and 31(74%) patients with ICE. Common ostia of right PV were observed in 13(31%) and 16(38%) patients, respectively. Additional PV were observed in 13(31%) patients with MSCT and in 7(17%) patients with ICE. Ostial diameters by MSCT in AP-direction were similar to 2-D measurements by ICE. By contrast, diameters by MSCT in SI-direction were significantly larger than 2-D diameters measured with ICE. Venous ostium indexes were 0.77 0.18 and 0.90 0.15 (p 0.01) for left and right PV respectively, indicating an oval shape of particularly left PV ostia. Conclusions: Variation in PV anatomy is frequently observed with both MSCT and ICE. The sensitivity for detection of additional pulmonary venous branches is higher for MSCT. Results of measurements of PV ostia suggest an underestimation of ostial size by ICE. 3-D imaging techniques, such as MSCT, are required to demonstrate an oval shape of PV ostia.

Previous studies have suggested that long term sport practice may be a risk factor for the development of atrial fibrillation (AF). The aim of the study was to analyze the incidence of lone AF in a cohort of Marathon runners and in a sample of the general population followed for 10 years. Methods: A cohort of 270 healthy individuals that run de Marathon of Barcelona in 1993 were included. A group of 305 healthy sedentary individuals of the general population recruited at the REGICOR study in 1995 were used as controls. The Minnesota leisure time questionnaire was administered at inclusion and at the end of follow up. All individuals were questioned about clinical history of documented arrhythmias and hospital admissions. Physical examination was performed and, ECG and blood samples were obtained. Results: 16% and 5% of individuals were lost for follow up in the Marathon and control groups respectively. Marathon runners were younger than control patients (38 8 vs, 50 12 years p 0.001) they had lower systolic arterial pressure (125 14 vs 132 19 mmHg p 0.001) and a lower heart rate (63 10 vs. 68 11 beats/min, p 0.001). They had a higher physical activity energy expenditure (663 252 vs. 159 78 Kcal/ day p 0.001). They also had a lower values of total cholesterol, LDL cholesterol, triglycerides and glucose. AF was documented in 8 Marathon runners (3.5%) as compared to 2 controls (0.7%) p 0.025. The odds ratio for AF was 5.3 (95% CI:1.1-25.1) and 8.6 (95% CI:1.4-54.9) when adjusted by age. In conclusion, long term endurance sport practice increased the risk for AF as compared to sedentary individuals. On the other hand Marathon runners had a more favorable risk factor profile.

ventricular end-systolic and diastolic diameter, potassium and bilirubine levels and ventricular ectopic beats/h (HR 2.17, 95%CI 1.25-3.92, p .006). Conclusions: These data indicate that BRS (both when depressed or not assessable because of arrhythmia) remains an independent predictor of poor survival even in the presence of BB treatment and adds to currently used risk predictors in CHF. This information might help identifying patients who may benefit from cardiac resynchronization therapy.