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Complex ablation for persistent atrial fibrillation (AF) aims to modify the arrhythmogenic substrates to become incapable to perpetuate the arrhythmia. Ablation-associated determinants of atrial tachycardia (AT) rather than AF recurrences are unknown. The aim of the study was to evaluate the association between the type of arrhythmia recurrence and electrophysiological findings during redo procedures. A total number of 384 consecutive patients with persistent AF underwent complex ablation consisting of PV isolation (PVI), biatrial electrogram-guided ablation, and linear ablation with the desired procedural endpoint of AF termination. Electrophysiological findings during redo procedures and its relation to AR type are the subject of this study. Overall, 177 (46%) patients underwent a second procedure. Patients with AT recurrences had significantly more often persistent PVI (47 vs. 25%; P = 0.002). Moreover, a higher number of recovered PVs were associated with AF recurrence (3 PVs recovered, AF = 16.1% vs. AT = 5.2%; P = 0.02; 4 PVs recovered, AF = 18.5% vs. AT = 6.3%; P = 0.01), regardless of the extent of substrate ablation during the first procedure. Durable PV isolation but not the extent of atrial substrate ablation determines the type of arrhythmia recurrence. Thus, the PVs may represent dominant perpetuators (and not only triggers) of persistent AF even in the presence of a significantly modified atrial substrate.

Key Teaching Points • Despite proven catecholaminergic polymorphic ventricular tachycardia (CPVT) with pathogen RyR2 mutation and recurrent syncope, patients could have a favorable long-term outcome over 35 years under treatment. • Propafenone could be effective for treatment of patients with CPVT. • The beneficial effect of the monotherapy with propafenone in our patient may result from the combined antiarrhythmic effect of this drug with Na+ channel blockade and beta blocker capabilities.

Underrecognized consequence of three-dimensional mapping tool selection for atrial fibrillation ablation: when the operators’ decision determines the amount of silent micro-embolic burden Thomas Rostock MD, Torsten Konrad MD, Raphael Spittler MDFrom the University Hospital Mainz, Center for Cardiology,Cardiology II / Electrophysiology, Mainz, GermanyWord count: 1460Funding: (None)Disclosures: (None)

Background Annoyance is a common reaction in populations exposed to environmental noise and is associated with cardiovascular diseases. We investigated for the first time the existence of an association between noise annoyance and atrial fibrillation (AF). Methods and results Cross-sectional data from 14,639 participants of the Gutenberg Health Study were collected between 2007 and 2012. Annoyance from road traffic, aircraft, railways, industrial/construction and neighbourhood noise during daytime and sleep were collected from all participants through questionnaires using a 5-point scale. AF was assessed via self-reported medical history and/or documentation of AF on the study electrocardiogram. 80% of the study participants were annoyed by noise to a certain degree. The major sources of annoyance during daytime and sleep were aircraft, road traffic and neighbourhood noise. We found significant associations between annoyance (per point increase) and AF for aircraft noise annoyance during daytime (odds ratio (OR) 1.04; 95% confidence interval (CI) 1.00–1.08) and during sleep (OR 1.09; 95% CI 1.05–1.13), road traffic noise annoyance during sleep (OR 1.15; 95% CI 1.08–1.22), neighbourhood noise annoyance during daytime (OR 1.14; 95% CI 1.09–1.20) and during sleep (OR 1.14; 95% CI 1.07–1.21), industrial noise annoyance during daytime (OR 1.11; 95% CI 1.04–1.18) and railway noise annoyance during sleep (OR 1.13; 95% CI 1.04–1.22). Different degrees of annoyance were not associated with changes in cardiovascular risk factors. Discussion The results suggest for the first time that noise annoyance is associated with AF. Further studies are warranted to gain insight in the mechanisms underlying the noise-annoyance-disease relationship.

Atrioventricular node ablation (AVNA) is generally reserved for patients whose atrial fibrillation (AF) is refractory all other therapeutic options, since the recipients will often become pacemaker dependent. In such patients, this approach may prove particularly useful, especially if a tachycardia-induced cardiomyopathy is suspected. Historically, an "ablate and pace" approach has involved AVNA and right ventricular pacing, with or without an atrial lead. There is also an evolving role for atrioventricular node ablation in patients with AF who require cardiac resynchronisation therapy for treatment of systolic heart failure. A mortality benefit over pharmacotherapy has been demonstrated in observational studies and this concept is being further investigated in multi-centre randomised control trials.

The role of catheter ablation in patients with ventricular tachycardia (VT) has evolved over the last two decades into an established treatment option. In patients with idiopathic VT catheter ablation is the gold standard treatment option with high effectiveness and low risk of complications. Due to the high risk of side effects the use of antiarrhythmic drugs is only indicated in exceptional cases. In patients with structural heart diseases, such as ischemic and dilated cardiomyopathy, VT is the most frequent cause of death. Furthermore, recurrent shocks from implantable cardioverter defibrillators (ICD) are one of the main reasons for the high morbidity and mortality; however, in these patients a complex myocardial substrate is present and consequently there is a relevant risk of recurrence after VT ablation. A periprocedural mortality of approximately 3% must be considered in these often severely ill patients. Nevertheless, there is no reasonable alternative to catheter ablation, particularly in patients who continue to have VT episodes even under therapy with amiodarone. Questions with respect to the optimal procedural technique for VT ablation, the endpoint and optimal timing of ablation need to be clarified in clinical trials.

Aims Non-invasive electrocardiogram (ECG) mapping allows the activation of the entire atrial epicardium to be recorded simultaneously, potentially identifying mechanisms critical for atrial fibrillation (AF) persistence. We sought to evaluate the utility of ECG mapping as a practical tool prior to ablation of persistent AF (PsAF) in centres with no practical experience of the system. Methods and results A total of 118 patients with continuous AF duration

Background and purpose The detection of paroxysmal atrial fibrillation (pAF) in patients presenting with ischaemic stroke shifts secondary stroke prevention to oral anticoagulation. In order to deal with the time- and resource-consuming manual analysis of prolonged electrocardiogram (ECG)-monitoring data, we investigated the effectiveness of pAF detection with an automated algorithm (AA) in comparison to a manual analysis with software support within the IDEAS study [study analysis (SA)]. Methods We used the dataset of the prospective IDEAS cohort of patients with acute ischaemic stroke/transient ischaemic attack presenting in sinus rhythm undergoing prolonged 72-h Holter ECG with central adjudication of atrial fibrillation (AF). This adjudicated diagnosis of AF was compared with a commercially available AA. Discordant results with respect to the diagnosis of pAF were resolved by an additional cardiological reference confirmation. Results Paroxysmal AF was finally diagnosed in 62 patients (5.9%) in the cohort (n = 1043). AA more often diagnosed pAF (n = 60, 5.8%) as compared with SA (n = 47, 4.5%). Due to a high sensitivity (96.8%) and negative predictive value (99.8%), AA was able to identify patients without pAF, whereas abnormal findings in AA required manual review (specificity 96%; positive predictive value 60.6%). SA exhibited a lower sensitivity (75.8%) and negative predictive value (98.5%), and showed a specificity and positive predictive value of 100%. Agreement between the two methods classified by kappa coefficient was moderate (0.591). Conclusion Automated determination of 'absence of pAF' could be used to reduce the manual review workload associated with review of prolonged Holter ECG recordings.

INTRODUCTION Procedural atrial fibrillation (AF) termination is considered as a predictor of long-term success after catheter ablation for persistent AF (persAF). However, some patients remain free of arrhythmia recurrences despite failure to achieve AF termination. The objective of this study was to assess long-term outcome and prognostic factors in patients undergoing complex ablation without procedural AF termination. METHODS AND RESULTS This study comprised 419 patients (63.8 ± 10.2 years, 63.4% male) undergoing complex ablation for persAF. Patients without procedural AF termination (n = 137, 64.2 ± 9.7 years, 63.5% male) were categorized into patients who remained in sinus rhythm (SR) in long-term outcome (SR-group) and patients with recurrence of AF or atrial tachycardia (AT) (AR-group). During a follow-up (FU) of 19.6 ± 14.6 months, the SR-group consisted of 65 (47.5%) and the AR-group of 69 (50.4%) patients. Three patients (2.2%) were lost to FU. Left atrial appendage (LAA) flow velocity and left atrium volume index (LAVI) could be identified as predictors for long-term success. LAA flow velocity and baseline AF cycle length (AFCL) were significantly associated with the type of arrhythmia recurrence (AF vs AT), ie, higher values of both are predictive for AT rather than AF recurrences. Patients with a LAVI

Aims Overlap syndromes of long QT 3 syndrome (LQT3) and the Brugada syndrome (BrS) have been reported. Identification of patients with an overlapping phenotype is crucial before initiation of Class I antiarrhythmic drugs for LQT3. Aim of the present study was to elucidate the yield of ajmaline challenge in unmasking the Brugada phenotype in patients with LQT3 caused by the most common mutation, SCN5A-E1784K. Methods and results Consecutive families in tertiary referral centres diagnosed with LQT3 caused by SCN5A-E1784K were included in the study. Besides routine clinical work-up, ajmaline challenge was performed after informed consent. A total of 23 subjects (11 female, mean age 27 ± 14 years) from 4 unrelated families with a family history of sudden cardiac death and familial diagnosis of the SCN5A-E1784K mutation underwent ajmaline challenge and genetic testing. Sixteen subjects (9 female) were found to be heterozygous carriers of SCN5A-E1784K. Ajmaline challenge was positive in 12 out of the 16 (75%) mutation carriers, but negative in all non-carriers. Following ajmaline, a significant shortening of the rate-corrected JT (JTc) interval was observed in mutation carriers. The baseline JTc interval was significantly longer in mutation carriers with a positive ajmaline challenge compared with those with a negative one. Conclusion Overlap of LQT3 and BrS in patients carrying the most common mutation is high. Therefore, ajmaline challenge represents an important step to rule out potential BrS overlap in these patients before starting sodium channel blockers for the beneficial effect of QT shortening in LQT3.

Introduction The aim of this study was to evaluate a spatial correlation between active atrial fibrillation (AF) drivers measured by electrocardiographic imaging and complex fractionated atrial electrograms (CFAEs) in patients with persistent AF. Methods Sixteen patients with persistent AF were included. A biatrial geometry relative to an array of 252-body-surface-electrodes was obtained from a noncontrast computed tomography scan. The reconstructed unipolar AF electrograms were signal-processed (ECVUE™, CardioInsight Technologies Inc., Cleveland, OH, USA) to identify AF drivers. Before driver ablation, a biatrial mapping using the NavX system (St. Jude Medical, St. Paul, MN, USA) was performed to identify CFAEs. CFAE and driver regions were then quantified and compared. Results AF was terminated by driver ablation in 11/16 (70%) patients. The mean number of ablated driver regions was 4 ± 1 per patient. The most frequent driver locations were the inferior left atrium and coronary sinus, the right pulmonary veins, and the right atrium. In 49/63 (78%) of the driver locations, more than 75% of the driver site showed CFAEs. The mean ablated driver area was 58 ± 24 cm2 (19 ± 11% of total surface area). The mean CFAE area was 178 ± 59 cm2 (49 ± 16%). The percentage of non-ablated CFAE area was 76 ± 13% of total CFAEs. In 9/11 patients with AF termination, the termination site showed CFAEs. Conclusions There is a significant overlap between AF driver regions identified by the ECVUE™ system and CFAE areas identified by the NavX system. AF driver regions are smaller and mostly embedded in larger CFAE areas. Selective ablation of drivers in CFAE areas seems sufficient to terminate persistent AF in the majority of patients.

INTRODUCTION Persistent atrial fibrillation (persAF) can occur either as a sustained arrhythmia that has progressed from initially paroxysmal AF or as primary persAF without a history of any spontaneously terminated episode. There is a paucity of data differentiating between the 2 different persAF entities. Thus, we prospectively evaluated baseline characteristics, electrophysiological features, and ablation outcome in these 2 patient cohorts. METHODS AND RESULTS A total number of 154 consecutive persAF patients (63 ± 10 years, f = 42, longstanding persAF = 60) were characterized in terms of having primary persAF (P-persAF group) or persAF that secondarily progressed from paroxysmal AF (S-persAF group). All patients underwent de novo catheter ablation using the stepwise approach. PersAF entities were characterized by detailed patient history, sequential Holter monitoring, and reports of documented modes of AF conversion, respectively. The P-persAF group had a higher number of young patients (

Durch die zunehmende interventionelle Behandlung von linksseitigen atrialen Tachyarrhythmien mittels Katheterablation ist die Differenzialdiagnostik von atrialen Tachykardien durch Interpretation des Oberflachen-EKGs bedeutsamer geworden, insbesondere fur die Planung der Katheterintervention. Rechtsatriales typisches Vorhofflattern uber den Isthmus breitet sich von inferior septal nach kranial aus und zeichnet sich daher durch negative sagezahnartige Flatterwellen aus, die in II, III und aVF zunachst langsam negativ abfallen und dann steil wieder ansteigen. Die Flatterfrequenz betragt dabei meist 240–250/min. Dagegen finden sich bei rechtsatrialem Flattern im Uhrzeigersinn („clockwise“), bei Flattern um die V. cava inferior oder superior sowie um eine Narbe (z. B. nach Anschluss der Herz-Lungen-Maschine) positive oder biphasische Flatterwellenmorphologien (perikavaler Reentry). Linksatriales Vorhofflattern (z. B. um die Mitralklappe oder um die Pulmonalvenen) ist ausgesprochen heterogen, zeigt jedoch typischerweise eine positive Flatterwelle in V1, da der linke Vorhof im hinteren Mediastinum liegt. Spezielle Kenntnisse der Flatterwellenmorphologie im Oberflachen-EKG vereinfachen die Planung und Durchfuhrung der Ablationsstrategie.

Dabigatran etexilate, a direct thrombin inhibitor and non-vitamin K antagonist oral anticoagulant (NOAC), has been shown to effectively prevent thromboembolic events in patients with non-valvular atrial fibrillation (AF). However, there is a paucity of data on the antithrombotic efficacy and safety of dabigatran in the resolution of left atrial appendage (LAA) thrombi in AF patients. The primary objective of the RE-LATED AF trial is to assess whether dabigatran results in a faster complete LAA thrombus resolution as compared to vitamin K antagonist phenprocoumon. Secondary objectives are to assess the impact of dabigatran on complete LAA thrombus resolution rate within 6 weeks of treatment and change in LAA thrombus volume under treatment. Furthermore, this study aims to assess and compare safety and tolerability of dabigatran vs. phenprocoumon. The study is designed as a prospective, randomized, open-label, controlled, explorative, blinded endpoint (PROBE) trial. Patients with AF and left atrial appendage thrombus confirmed by transoesophageal echocardiography (TEE) will be randomized to receive either dabigatran (150 mg bid) or phenprocoumon (INR 2–3) for the resolution of LAA thrombus formation for at least 21 days. Thrombus resolution will be determined by TEE 3 weeks after treatment initiation and subsequently at weeks 4 and 6, if the LAA thrombus has not been resolved before. A total of 110 patients are planned to be randomized. This is the first prospective, multicentre, randomized controlled clinical trial investigating safety and efficacy of a NOAC for the resolution of LAA thrombi in patients with non-valvular AF.

Sex differences in cardiovascular risk factors, cardiac structure and function, and disease and symptom burden in the common arrhythmia atrial fibrillation (AF) have not been investigated systematically at the population level. Cross-sectional data of 14,796 subjects (age range 35 to 74 years, 50.5% men) from the population-based Gutenberg Health Study were examined to show the distribution of cardiovascular risk factors by AF status and sex, and to determine sex-specific predictors for AF. The prevalence of AF was higher in men (4.3%) than in women (1.9%). Men had a worse cardiovascular risk factor profile, a higher prevalence of cardiovascular disease, but fewer symptoms than women. Age-adjusted Cox regressions showed sex interactions in the association of high-density lipoprotein-cholesterol, triglycerides, diabetes mellitus, coronary artery disease, myocardial infarction, generalized anxiety disorder, and heart rate with AF. After multivariable adjustment, sex interactions were seen for thickness of interventricular end-diastolic septum, odds ratio (OR) per standard deviation (SD), 95% confidence interval women: 0.9 (0.8, 1.1), men: 1.2 (1.1, 1.4), interaction p value = 0.02; left atrial diameter index, OR per SD women: 1.5 (1.3, 1.8), men: 1.9 (1.7, 2.1), interaction p value = 0.03; and myocardial infarction, OR women: 2.7 (1.3, 5.6), men: 0.7 (0.5, 1.1), interaction p value = 0.002. In conclusion, in our large cohort, we observed substantial sex differences in AF distribution and clinical characteristics including comorbidities, symptom burden, and structural cardiac changes.

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.

Persistent atrial fibrillation is a common heart rhythm disturbance and a leading cause of hospitalization and death. Current available therapy remains suboptimal. Catheter ablation of responsible cardiac tissue is more effective than medications, but a substantial proportion of patients require repeat procedures. Also the optimal ablation strategy remains unclear. Organized re-entrant circuits (rotors) and focal impulses may sustain persistent atrial fibrillation. Body-Surface-Mapping techniques are available from the medical companies Amycard and CardioInsight. These systems can analyse the atrial fibrillation activity from the body surface and localize it with a high spatial resolution (with up to 252 electrodes covering the thorax). These systems are under investigation for ablation of persistent atrial fibrillation.

ICD Shock Reduction by Subthreshold Pacing Introduction Implantable cardioverter defibrillators (ICD) may have the capacity to provoke or worsen ventricular tachyarrhythmias (VT). It has been reported that ICD shocks by itself can increase mortality. This study aimed to determine the role of back-up pacing-induced VT (PIT) in the overall ICD shock burden by avoiding pause-related ventricular back-up pacing. Methods and Results A population of 550 single-chamber ICD patients was studied. Of them, 17 (3%, 69 ± 16 years, 14 male) patients had documented episodes of PIT. A total of 431 VT episodes were documented including 89 (21%) due to PIT. In 3 patients, VT events were exclusively PITs. After ≥2 documented PITs, the pacing output for VVI pacing was set to a subthreshold level resulting in noncapturable ventricular back-up pacing. All other device parameters remained unchanged to prove a potential proarrhythmic effect of pause related back-up pacing. During a follow-up of 99 ± 39 months after reducing the pacing output to a subthreshold level, no further episodes of PIT were observed (P < 0.001). Moreover, with the prevention of PITs, the ICD shock burden decreased significantly (pre: 150 vs. post: 18, P < 0.001). However, a single event of pause-induced VT occurred due to missing back-up pacing. Conclusions PIT is a frequent mechanism of VTs in ICD patients resulting in a substantially increased shock burden. Elimination of pause-related back-up pacing by subthreshold pacing output effectively abolishes PIT and thus significantly reduces ICD shock burden.

Acute Complication Rate in AF Ablation Introduction Catheter ablation (CA) has emerged as a widespread therapeutic option in the treatment of atrial fibrillation (AF). Currently, no safety data with regard to the impact of the underlying structural heart diseases (SHD) are available. We sought to assess the risk for acute and long-term complications during CA of AF in relation to underlying SHD. Methods and Results We included 6,211 patients in a prospective registry undergoing CA of AF in 41 nationwide centers. All patients were divided into 4 groups according to the underlying heart disease: No SHD (69.4%), hypertensive heart disease (HHD) (12.0%), coronary artery disease (CAD) (15.1%), and cardiomyopathy (CM) (3.6%). In univariate analysis, patients with HHD had an overall complication rate of 7.28%, whereas patients without an SHD had a significantly lower rate of 6.01% (P < 0.01). Multivariate analysis revealed that HHD (adjusted odds ratio [OR]: 1.97 [95% confidence interval (CI): 1.02–3.83], P = 0.0442) and age (years; OR: 1.04 [95% CI: 1.01–1.07], P = 0.0155) were independent predictors of severe, nonfatal complications and death. Other SHD including CAD (OR: 1.48 (0.73–3.00), P = 0.2797) and CM (OR: 2.37 [0.70–7.99], P = 0.1630) failed to reach statistical significance. Male sex was protective (OR: 0.47 [95% CI: 0.27–0.81], P = 0.0062). Conclusion In general, CA of AF has a low number of severe complications. In our prospective registry HHD emerged as an independent predictor of severe, nonfatal complications during AF ablation but other SHD including CAD and CM did not. The influence of HHD on the complication rate should be considered in patient selection.

Background— The role of subsequent atrial tachycardias (AT) in the context of persistent atrial fibrillation (AF) remains undetermined. This study evaluated the prognostic role of subsequent ATs for arrhythmia recurrences after catheter ablation of persistent AF. Methods and Results— A total of 110 patients with persistent AF (63±9 years; 22 women; 61 long-lasting persistent AF) underwent pulmonary vein isolation followed by electrogram-guided ablation. After AF terminated to AT, patients were separated by the randomization protocol to receive either direct cardioversion (group A) or further ablation of subsequent ATs to sinus rhythm (group B). After a mean follow-up of 20.1±13.3 months after the first procedure, significantly more group B patients were in sinus rhythm as compared with patients in group A (30 [57%] versus 18 [34%]; P =0.02). Moreover, recurrences of AF were significantly less frequent of group B than in group A patients (10 [19%] versus 26 [49%]; P =0.001). After the last procedure (follow-up, 34.0±6.4 months), significantly more group B patients were free of AF as compared with patients of group A (49 [92%] versus 39 [74%]; P =0.01). The proportion of AT recurrences did not differ between the 2 groups after the first and final procedures. The strongest predictor for an arrhythmia-free survival after a single procedure was randomization to the procedural end point of termination to sinus rhythm by elimination of subsequent ATs ( P =0.004). Conclusions— Catheter ablation of subsequent ATs increases freedom from AF but not AT, suggesting a contributing role of subsequent ATs in the mechanisms of persistent AF. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01896570.

Objectives This study was conducted to determine if an additional procedural endpoint of unexcitability (UE) to pacing along the ablation line reduces recurrence of atrial fibrillation (AF) or atrial tachycardia (AT) after radiofrequency catheter ablation. Background AF/AT recurrence is common after pulmonary vein isolation (PVI). Methods We included 102 patients from 2 centers (age 63 ± 10 years; 33 women; left atrium 38 ± 7 mm; left ventricular ejection fraction 61 ± 6%) with symptomatic paroxysmal AF. A 3-dimensional mapping system and circumferential mapping catheter were used in all patients for PVI. In group 1 (n = 50), the procedural endpoint was bidirectional block across the ablation line. In group 2 (n = 52), additional UE to bipolar pacing at an output of 10 mA and 2-ms pulse width was required. The primary endpoint was freedom from any AF/AT (>30 s) after discontinuation of antiarrhythmic drugs. Results Procedural endpoints were successfully achieved in all patients. Procedure duration was significantly longer in group 2 (185 ± 58 min vs. 139 ± 57 min; p Conclusions The use of pacing to ensure UE along the PVI line markedly improved near-term single-procedure success, compared with demonstration of bidirectional block alone. This additional endpoint significantly improved patient outcomes after PVI. (Unexcitability Along the Ablation as an Endpoint for Atrial Fibrillation Ablation; NCT01724437 )

Reversible Dysfunction After Persistent AF Ablation Introduction There is a paucity of data on atrial injury following ablation of persistent atrial fibrillation (AF). This study aimed at assessing reversibility of atrial dysfunction after successful persistent AF ablation using cardiovascular magnetic resonance (CMR). Methods and Results CMR was performed during sinus rhythm (SR) in 20 consecutive patients with persistent AF at baseline (BL) within 24 hours after ablation and after 6-month follow-up (FU). Catheter ablation included atrial substrate modification using the stepwise approach following pulmonary vein isolation (PVI) in order to attempt termination of persistent AF. Active left (LA) and right atrial (RA) function were quantified by calculating the active emptying fraction (AEF) from transvalvular flow profiles using velocity encoded (VENC) CMR. LA appendage (LAA) function was quantified by measurements of peak a-wave velocities from flow profiles perpendicular to the LAA orifice. Peri-atrial edema was assessed using black-blood T2-weighted CMR. A significant improvement was found in LA-AEF from 18 (12–26)% at BL to 25 (22–35)% at FU (P = 0.0001). Furthermore, RA-AEF significantly increased from 31 (19–35)% at BL to 40 (35–51)% at FU (P < 0.0001). A significant improvement was also found for LAA a-wave velocities from 45 (31–65) cm/s at BL to 62 (49–75) cm/s at FU (P < 0.01). The area of peri-atrial edema on T2-weighted CMR decreased from 1393 (1098–1797) mm2 at BL to 24 (1–92) mm2 at FU (P < 0.0001). Conclusion CMR demonstrates reversibility of LA, LAA, and RA dysfunction associated with resorption of peri-atrial edema in patients with SR after persistent AF ablation.

Aims Different cardiac arrhythmias have been suggested to be associated with Danon disease, e.g. Wolff–Parkinson–White syndrome. However, a systematic electrophysiological investigation of patients with Danon disease is lacking thus far. Methods and results Seven patients with Danon disease (4 males, 35.8 ± 10.8 years; 3 females, 51.3 ± 19.9 years) from 3 different families were studied. In all patients, the presence of Danon disease was confirmed by western blot of biopsy material or genetic testing. The patients were characterized by 12-lead electrocardiogram (ECG), Holter ECG, echocardiography, and serial implantable cardioverter defibrillator (ICD) interrogations (in ICD recipients). All male patients underwent electrophysiological investigation (EP study). Asymptomatic ventricular tachyarrhythmias were documented in six of the seven patients. Moreover, 5 of the 7 patients suffered from atrial fibrillation (AF), with 1 of them experiencing thromboembolic stroke at the age of 30 years. In male patients, the initial QRS complex was characterized by a slurring upstroke and shortened PQ interval mimicking ventricular pre-excitation. One male patient showed initial QRS complex slurring with prolonged PR interval. However, the presence of an accessory pathway was excluded by an EP study in all patients. In female patients, initial QRS complex slurring was significantly less distinct. In four patients, ICD implantation was performed for primary prevention of sudden cardiac death. However, sustained ventricular arrhythmias were not documented in any of the patients. Conclusions The present study indicates that the distinct surface ECG pattern in Danon disease is not associated with ventricular pre-excitation. Atrial fibrillation is frequently observed in these patients and may be associated with thromboembolic events in the young, while sustained ventricular arrhythmias occur less frequently than previously reported.

There is currently no agreement on the best method of assessing active left atrial (LA) emptying. This study evaluated the relative merits of cine- and velocity encoded (VENC) magnetic resonance imaging (MRI) for the assessment of active LA emptying. Total LA emptying volume (TLAEV) and active LA stroke volume (ALASV) were assessed in 107 consecutive patients using cine-MRI and transmitral flow measurements by VENC-MRI. The fraction of active LA emptying (ALAEF) was calculated as the ratio of ALASV to TLAEV. LA and left ventricular (LV) output were calculated by multiplying TLAEV and LV stroke volume by heart rate, respectively. Intra- and inter-observer variances were significantly larger for cine-MRI than for VENC-MRI measurements of ALASV (24.7 mL2 vs. 3.7 mL2 and 57.7 mL2 vs. 4.2 mL2; P

Aims Patients can expect a cure from atrial fibrillation (AF) with ablation. Procedural safety and success depend on patient comfort, compliance, and immobility. This is difficult to achieve with benzodiazepine and opiate boluses that are the mainstay of current practice. We sought to determine the safety and efficacy of propofol infusion sedation administered to patients without assisted ventilation for AF ablation. Methods and results Procedural data from 1000 consecutive patients undergoing AF ablation were analysed. Sedation with 2% propofol was used in all procedures without assisted ventilation and was administered, monitored, and controlled by electrophysiologists. Primary outcome measures were adverse sedative affects including (i) respiratory depression (SpO2 20 s) and (ii) persistent hypotension [systolic blood pressure (SBP)

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.

Atherosklerotisch verengte, kurven- und knickreiche, aber auch aneurysmatisch erweiterte Beckengefase konnen die endovaskulare Implantation von Gefasendoprothesen in die abdominelle und thorakale Aorta erschweren. Die Verwendung der A. femoralis communis als Zugangsgefas ist in diesen Fallen nicht ohne weitere Masnahmen moglich. Neben endovaskularen Masnahmen zur Erweiterung des Durchmessers der Beckengefase konnen offene Zugange zu den Iliakalarterien und der Aorta sowie Conduits verwendet werden. Die supraaortalen Gefase, die Herzspitze und der transseptale Zugang bieten weitere potenzielle Moglichkeiten, um bei unzureichenden aortoiliakalen Zugangsgefasen Stentprothesen in die Aorta einzufuhren.

Catheter ablation of atrial fibrillation has evolved as a widely accepted therapy approach and is now also incorporated in the current guidelines.A major limitation consists of the limited three-dimensional visualization of the complex three-dimensional structures in the left atrium since most procedures have routinely been performed using fluoroscopy alone. Another unsolved problem is the limited durability of lesions sets performed with radiofrequency ablation and therefore somewhat disappointing long-term ablation results besides fluoroscopy exposition for patient and operator as required for safe catheter manipulation.In the recent years we have gained substantial insight with respect to arrhythmia mechanism. At the same time new techniques and developments have become available to improve catheter ablation results.The present article summarizes the available opportunities with respect to three-dimensional mapping including CT/MRI image integration and gives an overview of the robotic and magnetic systems available for catheter ablation.

Pulmonary veins (PVs) usually drain into the left atrium (LA) and are frequently targeted for electrical isolation, since it became evident that PVs may trigger and maintain paroxysmal atrial fibrillation (AF). We present a patient with right-sided PVs anomalously connecting to the right atrium with lack of electrical PV-atrial connection. Therefore, isolation of the left veins was performed resulting in freedom from AF as shown during a midterm follow-up. These findings indicate that PV connection to the LA may be a prerequisite for the arrhythmogenic properties of the PVs causing AF.

Background— Termination of persistent atrial fibrillation (AF) can be achieved through ablation, with the majority of patients terminating to an atrial tachycardia (AT) and fewer directly to sinus rhythm (SR). We aimed to identify potential predictors for the existence of a substrate for AT on termination to SR. Methods and Results— We assessed 95 persistent AF patients (age, 60±10 years) who underwent catheter ablation to the end point of AF termination. Forty patients terminated directly to SR (SRterm) and 55 to ATs (ATterm). Compared with the ATterm group, the SRterm group were younger (56±10 versus 63±9 years, P =0.001), had shorter durations of AF before ablation (9±26 versus 14±20 months, P P =0.015), and longer baseline AF cycle lengths (178±23 versus 159±31 ms, P =0.005). However, AF cycle length was the sole independent predictor of direct termination to SR. The most frequent AF termination site in SRterm patients was the pulmonary veins (53%), whereas in ATterm patients this was within the left atrium (58%). After follow-up of 12±6 months, there was a trend toward a greater proportion of patients in SR among those who terminated directly to SR after a single procedure. The most frequent type of recurrence was paroxysmal AF in SRterm patients and AT in ATterm patients. Conclusions— Patients who terminate to SR through ablation without an intermediate AT are characterized by a less altered arrhythmogenic substrate. Baseline AF cycle lengths emerged as a sole independent predictor of a substrate for consecutive arrhythmias.

Robotic Remote Ablation for AF. Aims: A robotic navigation system (RNS, Hansen™) has been developed as an alternative method of performing ablation for atrial fibrillation (AF). Despite the growing application of RNS-guided pulmonary vein isolation (PVI), its consequences and mechanisms of subsequent AF recurrences are unknown. We investigated the acute procedural success and persistence of PVI over time after robotic PVI and its relation to clinical outcome. Methods and Results: Sixty-four patients (60.7 ± 9.8 years, 53 male) with paroxysmal AF underwent robotic circumferential PVI with 3-dimensional left atrial reconstruction (NavX™). A voluntary repeat invasive electrophysiological study was performed 3 months after ablation irrespective of clinical course. Robotic PVI was successful in all patients without complication (fluoroscopy time: 23.5 [12–34], procedure time: 180 [150–225] minutes). Fluoroscopy time demonstrated a gradual decline but was significantly reduced after the 30th patient following the introduction of additional navigation software (34 [29–45] vs 12 [9–17] minutes; P < 0.001). A repeat study at 3 months was performed in 63% of patients and revealed electrical conduction recovery in 43% of all PVs. Restudied patients without AF recurrence (n = 28) showed a significantly lower number of recovered PVs (1 (0–2) vs 2 (2–3); P = 0.006) and a longer LA-PV conduction delay than patients with AF recurrences (n = 12). Persistent block of all PVs was associated with freedom from AF in all patients. At 3 months, 67% of patients were free of AF, while reablation of recovered PVs led to an overall freedom from AF in 81% of patients after 1 year. Conclusion: Robotic PVI for PAF is safe, effective, and requires limited fluoroscopy while yielding comparable success rates to conventional ablation approaches with PV reconduction as a common phenomenon associated with AF recurrences. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1079-1084)

Catheter ablation of atrial fibrillation (AF), particularly longer lasting AF, often requires extensive ablation within the atria and their annexed structures. Immediate procedural success is commonly defined as termination of AF during ablation. While this end point is associated with fewer AF recurrences and maintained sinus rhythm, recurrent atrial tachycardias are common and present a fresh challenge for the electrophysiologist. These atrial tachycardias are often more symptomatic than the initial AF, but are invariably more suited to mapping and ablation with an excellent prospect of maintained sinus rhythm.

Background— Atrial tachycardias (AT) often occur after ablation of long-lasting persistent AF (CAF) and are difficult to treat conservatively. This study evaluated mechanisms and success rates of conventional mapping and catheter ablation of recurrent ATs occurring late after stepwise ablation of CAF. Methods and Results— A total of 320 patients underwent de novo ablation of CAF using a stepwise ablation approach in 2006 to 2007 at our institution. This study comprised patients who presented with recurrent ATs at their first redo procedure after initial de novo CAF ablation. All procedures were guided by conventional mapping techniques exclusively. Sixty-one patients (63�10 years, 14 women) presented with their clinical AT at their redo procedure 7.7�4.4 months after initial de novo CAF ablation. A total of 133 ATs (2.2�0.9 per patient) were mapped. Forty-four (72%) were due to reentry; 17 (28%) were focal ATs. Reentry ATs were mainly characterized as roof and perimitral flutter (43% and 34%, respectively). Focal ATs mainly originated from the great thoracic veins (pulmonary veins: 41%, coronary sinus: 23%). Forty-five (74%) patients had conduction recovery of at least 1 pulmonary vein (mean, 1.2�0.8). Overall, 124 (93%) ATs could be ablated successfully. The mean procedure duration was 181�59 minutes, with a mean fluoroscopy time of 45�21 minutes. After a mean follow-up of 21�4 months, 50 (82%) patients were free of any arrhythmia recurrences after a single redo procedure. Conclusions— Although late recurrent ATs may have complex mechanisms, catheter ablation guided exclusively by conventional techniques is highly effective with excellent acute and long-term success rates.

External cardioversion is an established and very important tool to terminate symptomatic atrial flutter. The superiority of the biphasic waveform has been demonstrated for atrial flutter, but whether electrode position affects the efficacy of cardioversion in this population is not known. The aim of this trial was to evaluate whether anterior-lateral (A-L) compared with anterior-posterior (A-P) electrode position improves cardioversion results. Of 130 screened patients, 96 (72 men, mean age 62 ± 12 years) were included and randomly assigned to a cardioversion protocol with either A-L or A-P electrode position. In each group, 48 patients received sequential biphasic waveform shocks using a step-up protocol consisting of 50, 75, 100, 150, or 200 J. The mean energy (65 ± 13 J for A-L vs 77 ± 13 J for A-P, p = 0.001) and mean number of shocks (1.48 ± 1.01 for A-L vs 1.96 ± 1.00 for A-P, p = 0.001) required for successful cardioversion were significantly lower in the A-L group. The efficacy of the first shock with 50 J in the A-L electrode position (35 of 48 patients [73%]) was also highly significantly greater than the first shock with 50 J in the A-P electrode position (18 of 48 patients [36%]) (p = 0.001). In conclusion, the A-L electrode position increases efficacy and requires fewer energy and shocks in external electrical cardioversion of common atrial flutter. Therefore, A-L electrode positioning should be recommended for the external cardioversion of common atrial flutter.

The vast majority of patients with supraventricular tachycardias present with specific 12-lead surface ECG characteristics allowing the diagnosis of the underlying mechanisms prior to the invasive electrophysiological study. However, an accurate diagnosis remains challenging in a subset of patients, even when using well-established stimulation maneuvers and sophisticated conventional mapping methods. Thus, the aim of the present manuscript is to describe some cases with uncommon entities of supraventricular tachycardias where the combined interpretation of 12-lead ECG presentation and invasive electrophysiological characteristics revealed the correct diagnoses.

Background— Termination of chronic atrial fibrillation (CAF) can be achieved by catheter ablation using a stepwise approach. However, there are limited data on the contribution of the right atrium to the CAF process. Furthermore, the prognostic value of CAF termination remains unclear. Methods and Results— Eighty-eight patients (61�10 years of age) underwent de novo ablation of CAF in 2006 at our institution. The ablation procedure was performed sequentially in the following order: pulmonary vein isolation, defragmentation of the left atrium, coronary sinus, and right atrium. Attempted procedural end point was termination of CAF. Consecutive arrhythmias occurring after AF termination were mapped, and ablation was attempted. AF termination was achieved in 68 (77%) patients: in 37 (55%) patients it occurred in the left atrium, in 18 (26%) patients in the right atrium, and in 13 (19%) patients in the coronary sinus. In 54 patients, at least one redo was performed (total number of procedures: 154). After the first redo, another 30 patients were in sinus rhythm (total 63), 8 patients were in atrial tachycardia (AT), and 17 patients were in AF. Another 11 patients underwent a second redo. After a mean follow-up of 20�4 months, 71 (81%) patients were in sinus rhythm, 1 (1%) patient was in AT, and 16 (18%) patients were in AF. Patients with CAF termination had predominantly ATs as recurrent arrhythmias (83%), whereas those without mainly presented with recurrent CAF (85%). The overall success rate in patients with CAF termination was 95% compared with 5% of patients without CAF termination in 2 procedures (n=12). In almost all redo procedures attributable to AT, at least 1 AT during redo was documented previously. Conclusions— AF termination is a prognostic important end point of catheter ablation for CAF. Termination of AF was achieved in both atria and the coronary sinus, suggesting a biatrial substrate of CAF. Subsequent arrhythmias often recur during follow-up and, therefore, should be targeted for ablation.

Durch seinen Hausarzt wurde uns ein 47-jahriger Patient mit paroxysmalem Vorhofflimmern zugewiesen. Seit etwa 2 Jahren beklagte der Patient ein anfallsartiges Herzrasen mit unregelmasigem Charakter. Die Rhythmusstorungen traten etwa zwei- bis dreimal im Monat auf und hatten eine Dauer von mehreren Stunden (meist 3–5 h). Der Patient fuhlte sich hierunter deutlich beeintrachtigt. In einem Langzeit-EKG konnte ursachlich Vorhofflimmern diagnostiziert werden. An Vorerkrankungen bestand eine diskrete arterielle Hypertonie, die (auch zur Behandlung des Vorhofflimmerns) seit einigen Wochen mit einem β-Blocker (Metoprolol 47,5 mg/Tag) eingestellt war. Die weitere Medikation bestand aus Acetylsalicylsaure (ASS) 100 mg taglich. Der Patient stellte sich in unserer Rhythmusambulanz mit der Frage weiterer Therapieoptionen vor. Bei der Untersuchung zeigten sich ein unauffalliges Sinusrhythmus-EKG sowie ein echokardiographischer Normalbefund. Hinweise auf das Vorliegen einer koronaren Herzerkrankung (KHK) ergaben sich nicht, so dass wir den Patienten auf Flecainid (2 × 100 mg) einstellten und einen Wiedervorstellungstermin in 4 Monaten vereinbarten. Beim zweiten Besuch gab der Patient schon deutlich seltenere und kurzer anhaltende Vorhofflimmerepisoden an, jedoch seien die Beschwerden noch nicht ganzlich unterdruckt. Auserdem storte ihn die regelmasige Tabletteneinnahme. Wir besprachen mit dem Patienten die Therapieoption einer Pulmonalvenenisolation, fur welche der Patient sich nach Darlegung der Erfolgsrate und der moglichen Risiken entschied. 2 Monate spater fuhrten wir eine Pulmonalvenenisolation durch, das Flecainid wurde 3 Tage vor Aufnahme pausiert. Zu Beginn des Eingriffs wurde mittels Burst-Stimulation Vorhofflimmern induziert, welches bei Ablation der linken unteren Pulmonalvene in den Sinusrhythmus konvertierte. Alle Pulmonalvenen konnten erfolgreich isoliert werden, das Flecainid wurde abgesetzt. 1 Woche nach Ablation wurde mit einer effektiven Antikoagulation mit Marcumar begonnen (bis dahin erfolgte die Gabe von niedermolekularem Heparin). Bei der Wiedervorstellung zur Verlaufskontrolle 3 Monate nach Ablation berichtete der Patient, insgesamt noch drei Vorhofflimmerepisoden verspurt zu haben, jeweils wieder mit spontaner Terminierung nach wenigen Stunden. Mit dem Verdacht auf Pulmonalvenenleitungserholung bestellten wir den Patienten erneut zur interventionellen Behandlung ein. Hier zeigte sich, wie vermutet, eine Leitungserholung von zwei der vier Pulmonalvenen. Es erfolgte eine komplikationslose Reisolation der linken unteren und der rechten oberen Pulmonalvene. Abschliesend war kein Vorhofflimmern mehr induzierbar. Im Verlauf zeigte der Patient auch ohne antiarrhythmische Therapie 1 Jahr nach dem zweiten Eingriff keine weiteren Episoden von Vorhofflimmern mehr. Dies konnte in Langzeit-EKGs belegt werden. Die antihypertensive Therapie wurde aufgrund von Nebenwirkungen auf einen ACE-Hemmer umgestellt, das Marcumar konnte mittlerweile abgesetzt werden.

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.

Seit der Entdeckung, dass die fokale Triggerung aus den Pulmonalvenen (PV) die entscheidende Rolle bei der Entstehung der paroxysmalen Form des Vorhofflimmerns (PAF) spielt, hat die Katheterablation dieser Arrhythmie eine rasche Verbreitung erfahren. Die Elimination der PV-Leitungseigenschaft ist dabei heute das allgemein akzeptierte primare Ziel bei PAF und fuhrt in 60–85% der Falle nach der ersten Prozedur zur Freiheit von Vorhofflimmern (AF). Bei Wiederholung der Katheterablation liegen die Erfolgsraten bei > 80%. Gestutzt durch die aktuellen Leitlinien ist dies bei symptomatischen und medikamentos therapierefraktaren Patienten (nach Versuch mit einem Antiarrhythmikum) ein gezielt einsetzbares und in erfahrenen Zentren etabliertes Verfahren. Bei chronisch persistierendem Vorhofflimmern (CAF) hat es in den letzten 2 Jahren einen enormen Fortschritt durch die Einfuhrung einer neuen, schrittweisen Strategie gegeben. Hierbei werden die herkommlichen Ansatze (Pulmonalvenenisolation [PVI], Defragmentierung und ggf. lineare Lasionen) kombiniert und mit dem Ziel der Terminierung des AF durch die Ablation angewendet. Dabei ist die erste Prozedur auch oft nur der erste Schritt auf dem Weg zum Sinusrhythmus bei allerdings sehr guter Prognose nach Terminierung des Vorhofflimmerns (> 80% Sinusrhythmus). Uber die Halfte der Patienten bedarf mehr als nur einer Prozedur, welche dann oft die Behandlung konsekutiv auftretender atrialer Tachyarrhythmien zum Ziel hat. Aufgrund der limitierten Nachbeobachtungszeit sowie des zeitlichen Aufwands, der mangelnden Ubertragbarkeit und der moglichen Komplikationen ist die Katheterablation bei CAF derzeit noch nicht klinisch „etabliert“ und insbesondere beim Vorliegen einer Herzinsuffizienz als experimentell zu bezeichnen. Gerade deshalb ist es wichtig, in zukunftigen Untersuchungen Pradiktoren zu identifizieren, welche ein Fehlschlagen der Prozedur bei CAF vorhersagen (Grose des linken Vorhofs, Dauer des AF, atriale Zykluslange) und somit helfen, die Patientenauswahl zu verbessern. Fur PAF gilt es, die unbefriedigenden Ergebnisse bezuglich der hohen Rezidivrate nach der ersten Prozedur zu optimieren. Hier konnte die Anwendung neuer Strategien (z.B. Testung der PV-Leitung durch Adenosin) und Technologien (z.B. robotische Navigation) hilfreich sein.

Objectives Our purpose was to investigate the impact of short-lasting atrial fibrillation (AF) on the electrophysiological properties of the atria and pulmonary veins (PVs) in patients devoid of AF. Background The presence of AF is associated with electrical remodeling processes that promote a substrate for arrhythmia maintenance in the atria, which has been termed “AF begets AF.” However, it is unclear whether those electrical alterations also occur in the PVs. Methods Thirty-five patients with a left-sided accessory pathway and without a prior history of AF were included. After successful ablation, the effective refractory periods (ERPs) and conduction times of the right atrium (RA), left atrium (LA), and the PVs were determined. Afterwards, AF was induced and maintained for a period of 15 min. Thereafter, the stimulation protocol was repeated. Results At baseline, the PVs had significantly longer ERPs than the atria. After exposure to AF, the ERPs of both the atria and the PVs decreased significantly. The ERPs of the PVs, however, decreased by a significantly greater extent than the ERPs of the atria (PVs: 248 ± 27 ms vs. 211 ± 40 ms, p Conclusions New-onset, short-lasting AF creates electrical characteristics similar to those of patients with AF. However, these alterations are pronounced in the PVs compared with the atria, indicating that “AF begets AF in the PVs” (Electrophysiological Properties of the Pulmonary Veins; NCT00530608).

Background: Early repolarization is a common electrocardiographic finding that is generally considered to be benign. Its potential to cause cardiac arrhythmias has been hypothesized from experimental studies, but it is not known whether there is a clinical association with sudden cardiac arrest. Methods: We reviewed data from 206 case subjects at 22 centers who were resuscitated after cardiac arrest due to idiopathic ventricular fibrillation and assessed the prevalence of electrocardiographic early repolarization. The latter was defined as an elevation of the QRS-ST junction of at least 0.1 mV from baseline in the inferior or lateral lead, manifested as QRS slurring or notching. The control group comprised 412 subjects without heart disease who were matched for age, sex, race, and level of physical activity. Follow-up data that included the results of monitoring with an implantable defibrillator were obtained for all case subjects. Results: Early repolarization was more frequent in case subjects with idiopathic ventricular fibrillation than in control subjects (31% vs. 5%, P

Objectives This study sought to determine the characteristics of atrial electrograms predictive of slowing or termination of atrial fibrillation (AF) during ablation of chronic AF. Background There is growing recognition of a role for electrogram-based ablation. Methods Forty consecutive patients (34 male, 59 ± 10 years) undergoing ablation for chronic AF persisting for a median of 12 months (range 1 to 84 months) were included. After pulmonary vein isolation and roof line ablation, electrogram-based ablation was performed in the left atrium and coronary sinus. Targeted electrograms were acquired in a 4-s window and characterized by: 1) percentage of continuous electrical activity; 2) bipolar voltage; 3) dominant frequency; 4) fractionation index; 5) mean absolute value of derivatives of electrograms; 6) local cycle length; and 7) presence of a temporal gradient of activation. Electrogram characteristics at favorable ablation regions, defined as those associated with slowing (a ≥6-ms increase in AF cycle length) or termination of AF were compared with those at unfavorable regions. Results The AF was terminated by electrogram-based ablation in 29 patients (73%) after targeting a total of 171 regions. Ablation at 37 (22%) of these regions was followed by AF slowing, and at 29 (17%) by AF termination. The percentage of continuous electrical activity and the presence of a temporal gradient of activation were independent predictors of favorable ablation regions (p = 0.016 and p = 0.038, respectively). Other electrogram characteristics at favorable ablation regions were not significantly different from those at unfavorable ablation regions. Conclusions Catheter ablation at sites displaying a greater percentage of continuous activity or a temporal activation gradient is associated with slowing or termination of chronic AF.

Pulmonary veins (PVs) are the predominant sources of paroxysmal atrial fibrillation (AF), and electrical PV isolation has become an established interventional treatment for patients suffering from AF. There are a few cases describing PV tachycardias; however, mechanisms of PV arrhythmogenicity resulting in PV tachycardias remain incompletely understood. We report on a patient who underwent PV isolation for paroxysmal AF, in whom a persistent PV tachycardia was observed within an isolated vein. This tachycardia was stable in nature and different pacing manoeuvres revealed electrophysiological features consistent with reentry (Lasso displaying the entire tachycardia cycle length, concealed entrainment, overdrive termination, and induction by programmed stimulation) as the underlying mechanism.