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Recently, the wide-band dielectric mapping system Kodex-EPD was introduced. This study reports the first clinical experience using a novel system to guide pulmonary vein isolation (PVI) with radiofrequency (RF) ablation. METHODS AND RESULTS: The study included 20 consecutive patients undergoing de-novo PVI for symptomatic paroxysmal or persistent atrial fibrillation guided by Kodex-EPD. The primary efficacy endpoint was successful PVI. Secondary endpoints included procedural parameters and complications. In all 20 patients (mean age 68 ± 8 years, 12 male patients, paroxysmal fibrillation in 14/20 [70%] patients), PVI was successfully completed. One patient underwent additional cavo-tricuspid isthmus ablation for concomitant typical atrial flutter and one patient required additional ablation of a focal atrial tachycardia. A conventional three-dimensional image of the left atrium as well as the innovative endocardial panoramic view were used to guide catheter manipulation and ablation. Median procedure time was 115 [1st; 3rd quartile 93,75; 140] min and median total fluoroscopy time was 9.9 [9.7; 11.2] min, of which a median of 0.8 [0.6; 0.9] min was required to create left atrial maps. Complete left atrial imaging using Kodex-EPD was achieved within a median of 7.1 [5.7; 8.3] min. Median RF ablation time was 45.1 [34.6; 58.7] min. No major complications were observed.RF ablation PVI guided by Kodex-EPD seems safe and feasible. The system provides effective three-dimensional guidance for PVI.

Aims Cardiac arrhythmia originating from the papillary muscle (PM) can trigger ventricular fibrillation (VF) and cause sudden cardiac death even in the absence of structural heart disease. Most premature ventricular contractions, however, are benign and hitherto difficult to distinguish from a potentially fatal arrhythmia. Altered repolarization characteristics are associated with electrical instability, but electrophysiological changes which precede degeneration into VF are still not fully understood. Methods and results Ventricular arrhythmia (VA) was induced by aconitine injection into PMs of healthy sheep. To investigate mechanisms of degeneration of stable VA into VF in structurally healthy hearts, endocardial high-density and epicardial mapping was performed during sinus rhythm (SR) and VA. The electrical restitution curve, modelling the relation of diastolic interval and activation recovery interval (a surrogate parameter for action potential duration), is steeper in VA than in non-arrhythmia (ventricular pacing and SR). Steeper restitution curves reflect electrical instability and propensity to degenerate into VF. Importantly, we find the parameter repolarization time in relation to cycle length (RT/CL) to differentiate self-limiting from degenerating arrhythmia with high specificity and sensitivity. Conclusion RT/CL may serve as a simple index to aid differentiation between self-limiting and electrically instable arrhythmia with the propensity to degenerate to VF. RT/CL is independent of cycle length and could easily be measured to identify electrical instability in patients.

Catheter-ablation (CA) of consecutive left atrial tachycardias (LAT) can be challenging. Pulsed field ablation (PFA) yields a novel nonthermal CA technology for treatment of atrial fibrillation (AF). There is no data regarding PFA of LAT. This study sought to investigate PFA of consecutive LAT following prior CA of AF.Consecutive patients with LAT underwent ultrahigh-density (UHDx) mapping. Subsequent to identification of the AT mechanism, PFA was performed at the assumed critical sites for LAT maintenance. Continuous ablation lines were performed if required and evaluated with pre- and post-PFA HDx-mapping.Fifteen patients (age 70 ± 10, male 73%) who underwent 3.6 ± 2 prior AF-CA procedures were included. The total mean procedure and fluoroscopy times were 141 ± 43 and 18 ± 10 min, respectively. All 19 of 19 (100%) LAT were successfully ablated with PFA. Two AT located at the right atria required RF-ablation. LAT were identified as localized reentry (n = 1) and macro-reentry LAT (n = 18) and targeted with PFA. All LAT terminated with PFA either to sinus rhythm (9/15) or a secondary AT (6/15 and subsequently to SR); 63% (12/19) terminated with the first PFA-application. All lines (13 roof, 11 anterior, 1 mitral) were blocked. LA-posterior-wall isolation (LAPWI) was successfully achieved when performed (10/10). AF/AT free survival was 80% (12/15) after 153 [88-207] days of follow-up. No procedure-related complications occurred.PFA of consecutive LAT is feasible and safe. Successful creation of ablation lines and LAPWI can be achieved in a short time. PFA may offer the opportunity for effective ablation of atrial arrhythmias beyond AF.

ZusammenfassungVorhofflimmern ist die weltweit häufigste, anhaltende Herzrhythmusstörung. Trotz des Fortschritts und der Innovationen im Management der betroffenen Patienten bleibt Vorhofflimmern mit einer signifikanten Morbidität und Mortalität, bedingt durch das Auftreten von unter anderem thrombembolischen Ereignissen, Herzinsuffizienz, kardiovaskulären Ereignissen und plötzlichem Herztod, vergesellschaftet. Es konnte kürzlich gezeigt werden, dass eine frühzeitige rhythmuserhaltende Therapie das Risiko für einen Tod durch kardiovaskuläre Ursache, Schlaganfälle und Hospitalisierungen aufgrund von Herzinsuffizienz reduzieren kann. Die Katheterablation von Vorhofflimmern ist zwar effektiver in der Wiederherstellung und Erhaltung von Sinusrhythmus als eine medikamentöse Therapie, aber lediglich in spezifischen Patientengruppen, die von Herzinsuffizienz und Vorhofflimmern betroffen sind, konnte die Ablationsbehandlung mit einer Reduktion der Gesamtmortalität und von Hospitalisierungen assoziiert werden.

Background Surgical replacement of the aortic root is the only intervention that can prevent aortic dissection and cardiovascular death in Marfan syndrome (MFS). However, in some individuals, MFS also causes sleep apnea. If sleep apnea predicts cardiovascular death, a new target for predictive, preventive, and personalized medicine (PPPM) may emerge for those individuals with MFS who have sleep apnea. Methods This is an investigator-initiated study with long-term follow-up data of 105 individuals with MFS. All individuals were screened for sleep apnea regardless of symptoms. Cardiovascular death served as a primary endpoint, and aortic events as a secondary outcome. Results Sleep apnea with an apnea–hypopnea index (AHI) > 5/h was observed in 21.0% (22/105) with mild sleep apnea in 13% (14/105) and moderate to severe sleep apnea in 7.6% (8/105). After a median follow-up of 7.76 years (interquartile range: 6.84, 8.41), 10% (10/105) had died, with cardiovascular cause of death in 80% (8/10). After adjusting for age and body mass index (BMI), the AHI score emerged as an independent risk factor for cardiovascular death (hazard ratio 1.712, 95% confidence interval [1.061–2.761], p = 0.0276). The secondary outcome of aortic events occurred in 33% (35/105). There was no effect of the AHI score on aortic events after adjusting for age and BMI (hazard ratio 0.965, 95% confidence interval [0.617–1.509]), possibly due to a high number of patients with prior aortic surgery. Interpretation Sleep apnea is emerging as an independent predictor of cardiovascular death in MFS. It seems mandatory to screen all individuals with MFS for sleep apnea and to include these individuals, with both MFS and sleep apnea, in further studies to evaluate the impact of preventive measures with regard to cardiovascular death.

Aims Weight management seems to be beneficial for obese atrial fibrillation (AF) patients; however, randomized data are sparse. Thus, this study aimed to investigate the influence of weight reduction on AF ablation outcomes. Methods and results SORT-AF is an investigator-sponsored, prospective, randomized, multicentre, and clinical trial. Patients with symptomatic AF (paroxysmal or persistent) and body mass index (BMI) 30–40 kg/m2 underwent AF ablation and were randomized to either weight-reduction (group 1) or usual care (group 2), after sleep–apnoea–screening and loop recorder (ILR) implantation. The primary endpoint was defined as AF burden between 3 and 12 months after AF ablation. Overall, 133 patients (60 ± 10 years, 57% persistent AF) were randomized to group 1 (n = 67) and group 2 (n = 66), respectively. Complications after AF-ablation were rare (one stroke and no tamponade). The intervention led to a significant reduction of BMI (34.9 ± 2.6–33.4 ± 3.6) in group 1 compared to a stable BMI in group 2 (P Conclusion The SORT-AF study shows that AF ablation is safe and successful in obese patients using continuous monitoring via ILR. Although the primary endpoint of AF burden after ablation did not differ between the two groups, the effects of weight loss and improvement of exercise activity were beneficial for obese patients with persistent AF demonstrating the relevance of life-style management as an important adjunct to AF ablation in this setting. Trial registration number NCT02064114.

Substrate-based catheter ablation approaches to ventricular tachycardia (VT) focus on low-voltage areas and abnormal electrograms. However, specific electrogram characteristics in sinus rhythm are not clearly defined and can be subject to variable interpretation. We analyzed the potential ablation target size using automatic abnormal electrogram detection and studied findings during substrate mapping in the VT isthmus area.Electrogram characteristics in 61 patients undergoing scar-related VT ablation using ultrahigh-density 3D-mapping with a 64-electrode mini-basket catheter were analyzed retrospectively. Forty-four complete substrate maps with a mean number of 10319 ± 889 points were acquired. Fractionated potentials detected by automated annotation and manual review were present in 43 ± 21% of the entire low-voltage area (1.0 mV), highly fractionated potentials in 7 ± 8%, late potentials in 13 ± 15%, fractionated late potentials in 7 ± 9% and isolated late potentials in 2 ± 4%, respectively. Highly fractionated potentials (10 ± 1 fractionations) were found in all isthmus areas of identified VT during substrate mapping, while isolated late potentials were distant from the critical isthmus area in 29%.The ablation target area varies enormously in size, depending on the definition of abnormal electrograms. Clear linking of abnormal electrograms with critical VT isthmus areas during substrate mapping remains difficult due to a lack of specificity rather than sensitivity. However, highly fractionated, low-voltage electrograms were found to be present in all critical VT isthmus sites.

Aims S100B, a well-known damage-associated molecular pattern protein is released acutely by central and peripheral nerves and upon concomitant denervation in pulmonary vein isolation (PVI). We aimed to investigate whether the ablation technique used for PVI impacts S100B release in patients with paroxysmal atrial fibrillation (AF). Methods and results The study population consisted of 73 consecutive patients (age: 62.7 ± 10.9 years, 54.8% males) undergoing first-time PVI with either radiofrequency (RF; n = 30) or cryoballoon (CB; n = 43) for paroxysmal AF. S100B determined from venous plasma samples taken immediately before and after PVI increased from 33.5 ± 1.8 to 91.1 ± 5.3 pg/mL (P Conclusion The ablation technique used for PVI has an impact on the release of S100B, a well-established biomarker for neural damage.

Vorhofflimmern (VHF) ist die haufigste anhaltende Herzrhythmusstorung und mit einer erhohten Mortalitat assoziiert, sodass eine effektive Differenzialtherapie der Patienten notwendig ist. Nach Risikostratifikation muss, abhangig vom individuellen Schlaganfallrisiko, eine orale Antikoagulation (OAK) eingeleitet werden. Insbesondere bei Kontraindikationen fur eine OAK und hohem Blutungs- und/oder Schlaganfallrisiko kann alternativ die Implantation eines Vorhofohrverschlusssystems erwogen werden. Symptomatische Patienten sollten moglichst einer Rhythmuskontrolle zugefuhrt werden. Hier spielt die Katheterablation (KA) aufgrund der Nutzen-Risiko-Abwagung, auch im Hinblick auf eine dauerhafte medikamentose Therapie, eine zunehmend grose Rolle. Durch eine Pulmonalvenenisolation kann bei einem paroxysmalen VHF mit einer Einjahres-VHF-Freiheitsrate von etwa 70–80 % gerechnet werden. Ein Uberlebensvorteil konnte bislang lediglich bei Patienten mit Herzinsuffizienz fur die KA nachgewiesen werden, sodass es sich hierbei meist um eine symptomatische Therapie zur Verbesserung der Lebensqualitat handelt.

Introduction The aim of this study was to investigate electrophysiological findings in patients with arrhythmia recurrence undergoing a repeat ablation procedure using ultra-high-density (UHDx) mapping following an index procedure using either contact-force (CF)-guided radiofrequency current (RFC) pulmonary vein isolation (PVI) or second-generation cryoballoon (CB) PVI for treatment of atrial fibrillation (AF). Methods and results Fifty consecutive patients with recurrence of AF and/or atrial tachycardia (AT) following index CF-RFC PVI (n = 21) or CB PVI (n = 29) were included. A 64-pole mini-basket mapping catheter in combination with an UHDx-mapping system-guided ablation was used. RFC was applied using a catheter tip with three incorporated mini-electrodes. PV reconnection rates were higher after CF-RFC PVI (CF-RFC: 2.5 ± 1.3 PVs vs CB: 1.4 ± 0.9 PVs; P = .0025) and left PVs were more frequently reconnected (CF-RFC: 64% PVs vs CB: 35% PVs; P = .0077). Fractionated signals along the antral index ablation line (FS) were found in 30% of CB-PVI patients (CF-RFC: 9.5% vs CB:30%; P = .098) targeted for ablation. In five cases, FS were a critical part of maintaining consecutive AT. The main AT mechanism found during reablation (n = 45 ATs) was macroreentry (80% [36/45], CF-RFC: 78.9% vs CB: 80.8%; P = 1.0) with a variety of circuits throughout both atria. Conclusion UHDx mapping is sensitive in detecting conduction gaps along the index ablation line. Left PVs are more frequently reconnected after initial CF-RFC PVI. FS are a common finding after CB PVI and can maintain certain forms of ATs. ATs after index PVI are mostly macroreentries with a broad spectrum of entities.

Introduction Respiratory sinus arrhythmia (RSA) describes heart rate (HR) changes in synchrony with respiration. It is relevant for exercise capacity and mechanistically linked with the cardiac autonomic nervous system. After pulmonary vein isolation (PVI), the current therapy of choice for patients with paroxysmal atrial fibrillation (AF), the cardiac vagal tone is often diminished. We hypothesized that RSA is modulated by PVI in patients with paroxysmal AF. Material and methods Respiratory sinus arrhythmia, measured by using a deep breathing test and heart rate variability parameters, was studied in 10 patients (64 ±3 years) with paroxysmal AF presenting in stable sinus rhythm for their first catheter-based PVI. Additionally, heart rate dynamics before and after PVI were studied during sympathetic/parasympathetic coactivation by using a cold-face test. All tests were performed within 24 h before and 48 h after PVI. Results After PVI RSA (E/I difference: 7.9 ±1.0 vs. 3.5 ±0.6 bpm, p = 0.006; E/I ratio: 1.14 ±0.02 vs. 1.05 ±0.01, p = 0.003), heart rate variability (SDNN: 31 ±3 vs. 14 ±3 ms, p = 0.006; RMSSD: 17 ±2 vs. 8 ±2 ms, p = 0.002) and the HR response to sympathetic/parasympathetic coactivation (10.2 ±0.7% vs. 5.7 ±1.1%, p = 0.014) were diminished. The PVI-related changes in RSA correlated with the heart rate change during sympathetic/parasympathetic coactivation before vs. after PVI (E/I difference: r = 0.849, p = 0.002; E/I ratio: r = 0.786, p = 0.007). One patient with vagal driven arrhythmia experienced AF recurrence during follow-up (mean: 6.5 ±0.6 months). Conclusions Respiratory sinus arrhythmia is reduced after PVI in patients with paroxysmal AF. Our findings suggest that this is related to a decrease in cardiac vagal tone. Whether and how this affects the clinical outcome including exercise capacity need to be determined.

BACKGROUND: Atrial fibrillation is the most common type of cardiac arrhythmia; the lifetime risk for a 55-year-old person to develop atrial fibrillation is 37%. In recent years, there have been various distinct changes in the clinical management of AF. METHODS: This review is based on a selective search for literature on the treatment of AF and the prevention of thromboembolic complications. The updated guideline of the European Society of Cardiology (ESC) for the diagnosis and treatment of AF was also taken into consideration. RESULTS: The main components of AF management are the comprehensive treatment of risk factors and concomitant diseases, as well as the prevention of thromboembolic complications, usually with non–vitamin-K-dependent oral anticoagulants or vitamin K antagonists, according to individual risk stratification. Beyond this, either rate or rhythm control are viable treatment concepts. Symptomatic patients in whom reversible causes have been ruled out should be offered rhythm-control therapy early in their course. In patients with risk factors and/or heart failure, an early rhythm control strategy has been found to be beneficial. As antiarrhythmic drugs often prove to be ineffective over the long term, catheter ablation is now becoming increasingly important in AF management. CONCLUSION: The clinical management of atrial fibrillation consists of a multimodal approach with risk stratification, lifestyle modification, prevention of thromboembolism, and, if possible, early rhythm control therapy.

AIMS Catheter contact and local tissue characteristics are relevant information for successful radiofrequency current (RFC)-ablation. Local impedance (LI) has been shown to reflect tissue characteristics and lesion formation during RFC-ablation. Using a novel ablation catheter incorporating three mini-electrodes, we investigated LI in relation to generator impedance (GI) in patients with ventricular tachycardia (VT) and its applicability as an indicator of effective RFC-ablation. METHODS AND RESULTS Baseline impedance, Δimpedance during ablation and drop rate (Δimpedance/time) were analyzed for 625 RFC-applications in 28 patients with recurrent VT undergoing RFC-ablation. LI was lower in scarred (87.0 Ω [79.0-95.0]) compared to healthy myocardium (97.5 Ω ([82.75-111.50]; P = .03) while GI did not differ between scarred and healthy myocardium. ΔLI was higher (18 Ω [9.4-26.0]) for VT-terminating as compared to non-terminating RFC-ablation (ΔLI 13 Ω [8.85-18.0]; P = .03), but did not differ for ΔGI between terminating vs nonterminating RFC-ablation. Correspondingly, LI drop rate was higher for RFC-ablation terminating the VT compared with RFC-ablation not terminating the VT (0.63 Ω/s [0.52-0.76] vs 0.32 Ω [0.20-0.58]; P = .008) while there was no difference for GI drop rate. ΔLI was higher in patients with nonischemic cardiomyopathy vs patients with ischemic cardiomyopathy (16 Ω [11.0-20.0] vs 11.0 Ω [7.85-17.00]; P = .003). CONCLUSION Our findings suggest that LI is a sensitive parameter to guide RFC-ablation in patients with VT. LI indicates differences in tissue characteristics and generally is higher in patients with nonischemic cardiomyopathy. Hence, the etiology of the underlying cardiomyopathy needs to be considered when adopting LI for monitoring catheter ablation of VT.

Ultra-high-density (UHD) mapping can improve scar area detection and fast activation mapping in patients undergoing catheter ablation of ventricular tachycardia (VT). The aim of the present study was to compare the outcome after VT ablation guided by UHD and conventional point-by-point 3D-mapping. The acute and long-term ablation outcome of 61 consecutive patients with UHD mapping (64-electrode mini-basket catheter) was compared to 61 consecutive patients with conventional point-by-point 3D-mapping using a 3.5 mm tip catheter. Patients, whose ablation was guided by UHD mapping had an improved 24-months outcome in comparison to patients with conventional mapping (cumulative incidence estimate of the combination of recurrence or disease-related death of 52.4% (95% confidence interval (CI) [36.9–65.7]; recurrence: n = 25; disease-related death: n = 4) versus 69.6% (95% CI [55.9–79.8]); recurrence: n = 31; disease-related death n = 11). In a cause-specific Cox proportional hazards model, UHD mapping (hazard ratio (HR) 0.623; 95% CI [0.390–0.995]; P = 0.048) and left ventricular ejection fraction > 30% (HR 0.485; 95% CI [0.290–0.813]; P = 0.006) were independently associated with lower rates of recurrence or disease-related death. Other procedural parameters were similar in both groups. In conclusion, UHD mapping during VT ablation was associated with fewer VT recurrences or disease-related deaths during long-term follow-up in comparison to conventional point-by-point mapping. Complication rates and other procedural parameters were similar in both groups.

Background Cryoballoon-based pulmonary vein isolation (cbPVI) is a standardized treatment of atrial fibrillation. In complex anatomies, radiofrequency ablation (rfPVI) is usually preferred. We describe the first cbPVI in a rare patient with SI and levocardia. Case summary A 41-year-old male patient with paroxysmal atrial fibrillation was referred to our clinic after a previous, unsuccessful cbPVI procedure. Observation of an atypical lead-wire position due to an abnormal anatomy of the inferior vena cava led to its initial termination. A subsequent thoraco-abdominal computed tomography revealed situs inversus abdominalis and levocardia and the procedure was re-attempted in our clinic. Transseptal puncture (TSP) was guided via transoesophageal echocardiography and fluoroscopy, using a SL0-Sheath and a standard BRK-needle. Advancement of the sheath initially failed but after additional dilatation with an Inoue® dilator, transseptal passage of the sheath was successful. Due to the unusual antero-cranial TSP, the septal pulmonary veins (PV) contrasted poorly. After repeat TSP, a steerable FlexCath Advance® sheath was introduced into the left atrium using an Amplatz Super Stiff® guidewire. Subsequently, all PV were intubated with the Achieve® catheter, over which a 2nd generation cryoballoon was introduced. Despite the practical challenges in this case, all PV were isolated. Discussion The main challenges include the achievement of transseptal access and manipulation of the cryoballoon to achieve a patent seal of the pulmonary veins. cbPVI eliminates the need for constant re-positioning of the ablation catheter and might facilitate the creation of durable lesions under such difficult anatomical conditions.

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): DZHK (German Center for Cardiovascular Research) Introduction Cardiac arrhythmia originating from the papillary muscle can trigger ventricular fibrillation and cause sudden cardiac death even in the absence of structural heart disease. Yet, no clinical parameters are known to reflect the propensity of arrhythmia to degenerate into ventricular fibrillation. Purpose We aimed at identification of parameters associated with degeneration of ventricular arrhythmia into ventricular fibrillation. Methods Ventricular arrhythmia was induced by aconitine injection into the papillary muscle of healthy sheep (n = 12) in an open-chest model. Endocardial high-density-mapping and epicardial mapping were performed. We determined repolarization time and activation-recovery-interval according to the Wyatt method. Results During focal arrhythmia faster conduction occurred in longitudinal and basal direction than transversal and apical direction. The electrical restitution curve, modelling relation of diastolic interval and activation-recovery-interval, is steeper in aconitine-induced ventricular arrhythmia than in ventricular pacing or sinus rhythm. Steeper restitution curves reflect electrical instability and propensity to degenerate into ventricular fibrillation. The repolarization-related parameters activation-recovery interval and repolarization time exhibit higher heterogeneity per beat in ventricular arrhythmia preceding degeneration into ventricular fibrillation. Repolarization time in relation to cycle length (RT/CL), which can easily be measured during electrophysiological procedures, differentiates self-limiting from degenerating arrhythmia with high specificity and sensitivity. Conclusion In structurally normal ovine hearts, the ratio of repolarization and cycle length (RT/CL) in ventricular arrhythmia and greater dispersion of repolarization are indicators of subsequent degeneration into ventricular fibrillation. While dispersion of repolarization is not easily acquired in clinical routine, a simple index (RT/CL) may be sufficient to differentiate between self-limiting and electrically instable arrhythmia with propensity to degenerate to ventricular fibrillation. Abstract Figure. Repolarization in VA model

Objectives: This study sought to characterize primary left atrial tachycardia (LAT) mechanisms, electrical properties and substrate using high-density mapping.Background: Nonfocal LAT can b...

AIMS A novel measure of local impedance (LI) has been found to predict lesion formation during radiofrequency current (RFC) catheter ablation. The aim of this study was to investigate the utility of this novel approach, while comparing LI to the well-established generator impedance (GI). METHODS AND RESULTS In 25 consecutive patients with a history of atrial fibrillation, catheter ablation was guided by a 3D-mapping system measuring LI in addition to GI via an ablation catheter tip with three incorporated mini-electrodes. Local impedance and GI before and during RFC applications were studied. In total, 381 RFC applications were analysed. The baseline LI was higher in high-voltage areas (>0.5 mV; LI: 110.5 ± 13.7 Ω) when compared with intermediate-voltage sites (0.1-0.5 mV; 90.9 ± 10.1 Ω, P < 0.001), low-voltage areas (

Background High-density mapping (HDM) has been found to precisely identify the practical isthmus of scar-related atrial tachycardia (AT) circuits. Since practical isthmuses have been found to be shorter than the usual anatomical isthmuses targeted ablation has been proposed. However, outcome data are sparse. Here we describe HDM-guided catheter ablation by targeting the practical isthmus in patients with scar-related ATs. Methods and results In 250 consecutive patients with scar-related ATs HDM-guided catheter ablation with the support of a 64-electrode mini-basket catheter has been performed. Most patients underwent a prior catheter ablation (98%) while 13% had a prior cardiac valve surgery and 6% an underlying congenital heart disease. A total of 355 ATs occurred in the index procedure, of which 64% had a macro-, 26% a micro-reentry and 10% a focal mechanism. The ATs had a mean cycle length of 304±4.3 ms and in 237 patients (95%) an acute termination into sinus rhythm was achieved. They were mainly located in the left atrium (72%) but also in the right atrium (25%), bi-atrially (5%) or in the CS (3%) (see figure). Targeting the practical isthmus revealed arrhythmia freedom in 53% of patients after a single procedure during a mid-term follow-up (median 489 days, range 95–1407 days). Freedom from any arrhythmia could be achieved in 74% of patients after multiple procedures and in 93% of patients after multiple procedures and optimal clinical therapy, including pharmaceutical or electrical cardioversion. Conclusions HDM-guided catheter ablation of the practical isthmus in patients with scar-related ATs leads to a high acute success rate. Nevertheless, multiple procedures are necessary in a relevant number of patients resulting in a low recurrence rate. Funding Acknowledgement Type of funding source: None

Introduction Tailored catheter ablation of atrial tachycardias (ATs) is increasingly recommended as a potentially easy treatment strategy in the era of high-density mapping (HDM). As follow-up data are sparse, we here report outcomes after HDM-guided ablation of ATs in patients with prior catheter ablation or cardiac surgery. Methods and results In 250 consecutive patients (age 66.5 ± 0.7 years, 58% male) with ATs (98% prior catheter ablation, 13% prior cardiac surgery) an HDM-guided catheter ablation was performed with the support of a 64-electrode mini-basket catheter. A total of 354 ATs (1.4 ± 0.1 ATs per patient; mean cycle length 304 ± 4.3 ms; 64% macroreentry, 27% localized reentry, and 9% focal) with acute termination of 95% were targeted in the index procedure. A similar AT as in the index procedure recurred in five patients (2%) after a median follow-up time of 535 days (interquartile range (IQR) 25th-75th percentile: 217-841). Tailored ablation of reentry ATs with freedom from any arrhythmia was obtained in 53% after a single procedure and in 73% after 1.4 ± 0.4 ablation procedures (range: 1-4). A total of 228 patients (91%) were free from any arrhythmia recurrence after 210 days (IQR: 152-494) when including optimal usual care. Conclusions Tailored catheter ablation of ATs guided by HDM has a high acute success rate. The recurrence rate of the index AT is low. In patients with extensive atrial scaring further ablation procedures need to be considered to achieve freedom from any arrhythmia.

BackgroundPhrenic nerve injury (PNI) remains one of the most frequent complications during cryoballoon-based pulmonary vein isolation (CB-PVI). Since its introduction in 2013, the use of compound motor action potential (CMAP) for the prevention of PNI during CB-PVI is increasing; however, systematic outcome data are sparse.MethodsThe CMAP technique was applied in conjunction with abdominal palpation during pacing manoeuvres (10 mV, 2 ms) from the superior vena cava for 388 consecutive patients undergoing CB-PVI between January 2015 and May 2017 at our tertiary arrhythmia centre. Cryoablation was immediately terminated when CMAP amplitude was reduced by 30%.ResultsReductions in CMAP amplitude were observed in 16 (4%) of 388 patients during isolation of the right veins. Of these, 11 (69%) patients did not manifest a reduction in diaphragmatic excursions. The drop in CMAP amplitude was observed in 10 (63%) patients during ablation of the right superior pulmonary veins (PVs) and in 7 (44%) patients during ablation of the right inferior PVs. Postprocedural persistent PNI was observed in three of four patients for a duration of 6 months, with one of these patients remaining symptomatic at the 24-month follow-up. One of the four patients was lost to long-term follow-up.ConclusionsAll PNIs occurred during right-sided CB-PVI and were preceded by a reduction in CMAP amplitude. Thus, the standardized use of CMAP surveillance during CB-PVI is easily applicable, reliable and compared with other studies, results in a lower number of PNIs.

BACKGROUND Recent evidence indicates that sympathetic/parasympathetic coactivation (CoA) is causally linked to changes in heart rate (HR) dynamics. Whether this is relevant for patients with atrial fibrillation (AF) is unknown. MATERIAL AND METHODS In patients with paroxysmal AF (n=26) and age-matched controls, (n=10) we investigated basal autonomic outflow and HR dynamics during separate sympathetic (cold hand immersion) and parasympathetic activation (O2-inhalation), as well as during CoA (cold face test). In an additional cohort (n=7), HR response was assessed before and after catheter-based pulmonary vein isolation (PVI). Ultra-high-density endocardial mapping was performed in patients (n=6) before and after CoA. RESULTS Sympathetic activation increased (control: 74±3 vs. 77±3 bpm, p=0.0098; AF: 60±2 vs. 64±2 bpm, p=0.0076) and parasympathetic activation decreased HR (control: 71±3 vs. 69±3 bpm, p=0.0547; AF: 60±1 vs. 58±2 bpm, p

Contact force (CF) catheters provide catheter-tissue contact information to improve outcome of pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (PAF). We evaluated different target-CF values for achievement of the additional endpoint of an unexcitable ablation line. A total of 106 patients undergoing PVI were randomized into three groups (G) (G1: target-CF 15 g, G2: target-CF 10 g, G3: CF concealed from operator). The PVI encircling line was divided into predefined sections. Excitable tissue along the PVI-line identified by high output pacing (10 V, 2 ms) was targeted for further ablation. Mean average CF was 17.4 ± 4.7 g (G1) vs. 12.3 ± 6.0 g (G2) vs. 11.1 ± 6.5 g (G 3) (p

Background: The severity of symptoms during atrial fibrillation (AF) may be influenced by heart rate and blood pressure variation, due to irregular beats and the related adaptations in baroreflex sensitivity. This study investigated whether heart rate turbulence (HRT) as a reflection of baroreflex sensitivity is related to symptom severity during AF. Method: Ninety-seven patients (pts) who underwent electrophysiological study were enrolled. Consecutive 56 pts had paroxysmal AF (21 with milder symptoms [EHRA I or II; Group-M], 35 with severe symptoms [EHRA III or IV; Group-S]), and 41 age-matched controls without AF were included. After delivering a single ventricular extrastimulus during sinus rhythm and repeating the process 10 times, the quantification of HRT was performed by measuring turbulence onset (TO: heart rate acceleration) and turbulence slope (TS: rate of heart rate deceleration). Results: Group-M pts showed significantly diminished TO as compared to controls and Group-S pts (P = 0.012). There was no significant difference of the TS between the 3 groups. Given that a TO ≥ 0% or TS ≤ 2.5 ms/RR was considered abnormal, Group-M pts showed significantly higher incidences of abnormal HRT as compared to controls and Group-S pts (71% vs 40% vs 21%, respectively, P = 0.0012). Regression analysis demonstrated an independent and significant association between a diminished TO and milder AF symptoms (P

AIMS To evaluate the incidence of newly diagnosed intracardiac thrombi (ICT) in respect to the mode of OAC in patients undergoing cardioversion (CV). METHODS AND RESULTS We prospectively assessed transesophageal echocardiography (TEE) and OAC therapy prior to CV in AF patients with ≥48-hour duration scheduled for CV. A total of 60 first-time ICT (4.7%) were diagnosed in 1,286 TEE, with highest rate in patients without OAC (9.6% vs. OAC 4.1%, P = 0.009) and an apparently lower rate in nonvitamin K antagonist anticoagulants (NOAC) therapy compared to vitamin K antagonist (VKA) (2.5% vs. 5.3%, P = 0.02). VKA therapy control 4 weeks prior to CV was overall average (time in therapeutic range 60%) and patients showed more frequently clinical characteristics and TEE parameters associated with risk for ICT. Even among patients with effective OAC therapy (uninterrupted NOAC and VKA therapy with international normalized ratio (INR) ≥2.0 for 3 weeks), ICT occurred in 2.7%, but with no difference between both groups (P = 0.22). There was no difference between different types of NOAC. Independent predictors for ICT were history of embolism, hypertension, BMI, absence of OAC, renal function, reduced atrial appendage flow, and presence of spontaneous echo contrast. CONCLUSION NOAC therapy seems favorable in the overall prevention of ICT, although this is likely to be caused by suboptimal VKA therapy control and differences in the overall health status between VKA and NOAC patients. ICT occurred even with effective OAC therapy suggesting individual TEE-guided cardioversion in patients at risk.

Background Ablation of scar-related ventricular tachycardia (VT), especially in non-inducible VT or hemodynamically unstable patients, can be challenging. Thus, we evaluated feasibility of an ultra high-density 3D-mapping approach to characterize the ventricular substrate and, if possible, to map VT. Methods and results Twenty-two patients (67±2 years, mean LV-EF 36±3%) with both ischemic and non-ischemic cardiomyopathy and documented VT underwent mapping and catheter ablation using a 64-electrode mini-basket catheter. Substrate characterization included ultra high-density voltage maps, identification of areas of slow conduction and late potentials. Whenever VT was inducible activation mapping was performed. In 13/22 patients the presumed clinical VT (in 16/22 any VT) was inducible. A total of 50 maps were generated (22 substrate maps, 28 during VT), mapping time was 33±4 minutes, number of points was 10937±1923. Low voltage areas were related with the site of origin in all mapped VT. Isochronal maps indicated areas of slow conduction in 14/22 patients, all in border zone scar. In 95% of patients late potentials were found. Mapping time during VT was 9±2 minutes, number of points 6740±1140. Covered cycle length was 82±5% (16 re-entry, 10 focal and 2 undetermined). During 4 months follow-up 90% remained free from VT recurrence. Conclusion Ultra high-density mapping in patients with scar-related VT is feasible, safe and enables detailed insight into tachycardia mechanisms. Critical sites can be identified (1) by precise substrate characterization when VT is not inducible or hemodynamically not tolerated and (2) during short lasting episodes of VT in order to guide catheter ablation. This article is protected by copyright. All rights reserved

Aims During ablation in the vicinity of the coronary arteries establishing a safe distance from the catheter tip to the relevant vessels is mandatory and usually assessed by fluoroscopy alone. The aim of the study was to investigate the feasibility of an image integration module (IIM) for continuous monitoring of the distance of the ablation catheter tip to the main coronary arteries during ablation of ventricular arrhythmias (VA) originating in the sinus of valsalva (SOV) and the left ventricular summit part of which can be reached via the great cardiac vein (GCV). Methods and results Of 129 patients undergoing mapping for outflow tract arrhythmias from June 2014 till October 2015, a total of 39 patients (52.4 ± 18.1 years, 17 female) had a source of origin in the SOV or the left ventricular summit. Radiofrequency (RF) ablation was performed when a distance of at least 5 mm could be demonstrated with IIM. A safe distance in at least one angiographic plane could be demonstrated in all patients with a source of origin in the SOV, whereas this was not possible in 50% of patients with earliest activation in the summit area. However, using the IIM a safe position at an adjacent site within the GCV could be obtained in three of these cases and successful RF ablation performed safely without any complications. Ablation was successful in 100% of patients with an origin in the SOV, whereas VAs originating from the left ventricular summit could be abolished completely in only 60% of cases. Conclusion Image integration combining electroanatomical mapping and fluoroscopy allows assessment of the safety of a potential ablation site by continuous real-time monitoring of the spatial relations of the catheter tip to the coronary vessels prior to RF application. It aids ablation in anatomically complex regions like the SOV or the ventricular summit providing biplane angiograms merged into the three-dimensional electroanatomical map.

Background: Ultra-high density mapping (HDM) is a promising tool in the treatment of patients with complex arrhythmias. In adults with congenital heart disease (CHD), rhythm disorders are among the most common complications but catheter ablation can be challenging due to heterogenous anatomy and complex arrhythmogenic substrates. Here, we describe our initial experience using HDM in conjunction with novel automated annotation algorithms in patients with moderate to great CHD complexity. Methods: We studied a series of consecutive adult patients with moderate to great CHD complexity and an indication for catheter ablation due to symptomatic arrhythmia. HDM was conducted using the Rhythmia™ mapping system and a 64-electrode mini-basket catheter for identification of anatomy, voltage, activation pattern and critical areas of arrhythmia for ablation guidance. To investigate novel advanced mapping strategies, postprocedural signal processing using the Lumipoint™ software was applied. Results: In 19 patients (53±3 years; 53% male), 21 consecutive ablation procedures were conducted. Procedures included ablation of atrial fibrillation (n=7; 33%), atrial tachycardia (n=11; 52%), atrioventricular accessory pathway (n=1; 5%), the atrioventricular node (n=1; 5%) and ventricular arrhythmias (n=4; 19%). A total of 23 supraventricular and 8 ventricular arrhythmias were studied with the generation of 56 complete high density maps (atrial n=43; ventricular n=11, coronary sinus n=2) and an average of 12,043±1,679 mapping points. Multiple arrhythmias were observed in n=7 procedures (33% of procedures; range of arrhythmias detected 2–4). A total range of 1–4 critical areas were defined per procedure and treated within a radiofrequency application time of 16 (interquartile range 12–45) minutes. Postprocedural signal processing using Lumipoint™ allowed rapid annotation of fractionated signals within specific windows of interest. This supported identification of a practical critical isthmus in 20 out of 27 completed atrial and ventricular tachycardia activation maps. Conclusions: Our findings suggest that HDM in conjunction with novel automated annotation algorithms provides detailed insights into arrhythmia mechanisms and might facilitate tailored catheter ablation in patients with moderate to great CHD complexity.

Introduction Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM) and is generally associated with a significant deterioration of clinical status. Non-pharmacological treatment such as surgical and catheter ablation has become an established therapy for symptomatic AF but in patients with HCM often having a chronically increased left atrial pressure and extensive atrial cardiomyopathy the long-term outcome is uncertain. Purpose The present study aimed to analyse the long-term outcome of AF ablation in HCM and the mechanism of recurrent atrial arrhythmias using high-density mapping systems. Methods A total of 65 patients (age 64.5±9.9 years, 42 (64.6%) male) with HCM undergoing AF ablation for symptomatic AF were included in our study. The ablation strategy for catheter ablation included pulmonary vein isolation in all patients and biatrial ablation of complex fractionated electrograms with additional ablation lines if appropriate. In patients with suspected atrial tachycardia (AT) high-density activation and substrate mapping were performed. A surgical ablation at the time of an operative myectomy for left ventricular outflow tract obstruction was performed in 8 (12.3%) patients. The outcome was analysed using clinical assessment, Holter ECG and continuous rhythm monitoring of cardiac implantable electric devices. Results Paroxysmal AF was present in 27 (41.6%), persistent AF in 37 (56.9%) and primary AT in 1 (1.5%) patients. The mean left atrial diameter was 54.1±12.5 ml. In 11 (16.9%) patients with AT high-density mapping was used to characterize the mechanism of the ongoing tachycardia. After 1.9±1.2 ablation procedures and a follow-up of 48.5±37.2 months, ablation success was demonstrated in 58.9% of patients. The success rate for paroxysmal and persistent AF was 70.0% and 55.8%, respectively (p=0.023). Of those patients with AT high-density mapping guided ablation was successful in 44.4% of patients. The LA diameter of patients with a successful ablation was smaller (52.2 vs. 58.1 mm; p=0.003). Conclusion Non-pharmacological treatment of AF in HCM is effective during long-term follow-up. Paroxysmal AF and a smaller LA diameter are favourable for successful ablation. In patients with complex AT the use of high-density mapping can guide ablation resulting in further ablation success in a reasonable number of patients.

Atrial fibrillation (AF), the most common sustained heart rhythm disorder worldwide, is linked to dysfunction of the intrinsic cardiac autonomic nervous system (ICNS). The role of ICNS damage occurring during catheter-based treatment of AF, which is the therapy of choice for many patients, remains controversial. We show here that the neuronal injury marker S100B is expressed in cardiac glia throughout the ICNS and is released specifically upon catheter ablation of AF. Patients with higher S100B release were more likely to be AF free during follow-up. Subsequent in vitro studies revealed that murine intracardiac neurons react to S100B with diminished action potential firing and increased neurite growth. This suggests that release of S100B from cardiac glia upon catheter-based treatment of AF is a hallmark of acute neural damage that contributes to nerve sprouting and can be used to assess ICNS damage.

INTRODUCTION Long-term efficacy and safety are uncertain in patients with cardiac implantable electronic devices (CIED) and transvenous leads (TVL) undergoing radiofrequency catheter ablation of atrial fibrillation (AF). Thus, we assessed the outcome of AF ablation in those patients during long-term follow-up using continuous atrial rhythm monitoring (CARM). METHODS AND RESULTS A total of 190 patients (71.3 ± 10.7 years; 108 (56.8% men) were included in this study. At index procedure 81 (42.6%) patients presented with paroxysmal AF and 109 (57.4%) with persistent AF. The ablation strategy included pulmonary vein isolation in all patients and biatrial ablation of complex fractionated electrograms with additional ablation lines, if appropriate. AF recurrences were assessed by CARM- and CIED-related complications by device follow-up. After a mean follow-up of 55.4 ± 38.1 months, freedom of AF was found in 86 (61.4%) and clinical success defined as an AF burden less than or equal to 1% in 101 (72.1%) patients. Freedom of AF was reported in 74.6% and 51.9% (P = 0.006) and clinical success in 89.8% and 59.3% (P