Circulation: Arrhythmia and Electrophysiology最新文献

{"title":"Does Ventricular Tachycardia Ablation Targeting Local Abnormal Ventricular Activity Elimination Reduce Ventricular Fibrillation Incidence?","authors":"T. Kitamura, P. Maury, A. Lam, F. Sacher, P. Khairy, Ruairidh Martin, K. Vlachos, A. Frontera, M. Takigawa, Y. Nakatani, N. Thompson, G. Massouillie, G. Cheniti, Claire A. Martin, F. Bourier, J. Duchâteau, N. Klotz, T. Pambrun, A. Denis, N. Derval, H. Cochet, M. Hocini, M. Haissaguerre, P. Jais","doi":"10.1161/CIRCEP.118.006857","DOIUrl":"https://doi.org/10.1161/CIRCEP.118.006857","url":null,"abstract":"BACKGROUND\u0000Various strategies for ablation of ventricular tachycardia (VT) have been described, but their impact on ventricular fibrillation (VF) is largely unknown. The aim of our study was to assess the effect of substrate-based VT ablation targeting local abnormal ventricular activity (LAVA) on recurrent VF events in patients with structural heart disease.\u0000\u0000\u0000METHODS\u0000A retrospective 2-center study was performed on patients with structural heart disease and both VT and VF, with incident VT ablation procedures targeting LAVAs. Generalized estimating equations with a Poisson loglinear model were used to assess the impact of catheter ablation on VF episodes. The change in VF events before and after catheter ablation was compared with matched controls without ablation.\u0000\u0000\u0000RESULTS\u0000From a total of 686 patients with an incident VT ablation procedure targeting LAVAs, 21 patients (age, 57±14 years; left ventricular ejection fraction, 30±10%) had both VT and VF and met inclusion criteria. A total of 80 VF events were recorded in the implantable cardioverter-defibrillator logs the 6 months preceding ablation. Complete and partial LAVA elimination was achieved in 11 (52%) and 10 (48%) patients, respectively. Catheter ablation was associated with a highly significant reduction in VF recurrences (P<0.0001), which were limited to 3 (14%) patients at 6 months. The total number of VF events thereby decreased from 80 to 3, from a median of 1.0 (range, 1-29) to 0.0 (range, 0-1) in the 6 months before and after ablation, respectively. The reduction in VF events was significantly greater in patients with catheter ablation compared with 21 matched controls during 6-month periods following and preceding a baseline assessment (Poisson β-coefficient, 1.39; P=0.0003).\u0000\u0000\u0000CONCLUSIONS\u0000Substrate-guided VT ablation targeting LAVAs may be associated with a significant reduction in recurrent VF, suggesting that VT and VF share overlapping arrhythmogenic substrates in patients with structural heart disease.","PeriodicalId":10167,"journal":{"name":"Circulation: Arrhythmia and Electrophysiology","volume":"433 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91464046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial Accuracy of a Clinically Established Noninvasive Electrocardiographic Imaging System for the Detection of Focal Activation in an Intact Porcine Model.","authors":"S. Hohmann, M. Rettmann, H. Konishi, Anna Borenstein, Songyun Wang, A. Suzuki, G. Michalak, K. Monahan, K. D. Parker, L. K. Newman, D. Packer","doi":"10.1161/CIRCEP.119.007570","DOIUrl":"https://doi.org/10.1161/CIRCEP.119.007570","url":null,"abstract":"BACKGROUND\u0000Noninvasive electrocardiographic imaging (ECGi) is used clinically to map arrhythmias before ablation. Despite its clinical use, validation data regarding the accuracy of the system for the identification of arrhythmia foci is limited.\u0000\u0000\u0000METHODS\u0000Nine pigs underwent closed-chest placement of endocardial fiducial markers, computed tomography, and pacing in all cardiac chambers with ECGi acquisition. Pacing location was reconstructed from biplane fluoroscopy and registered to the computed tomography using the fiducials. A blinded investigator predicted the pacing location from the ECGi data, and the distance to the true pacing catheter tip location was calculated.\u0000\u0000\u0000RESULTS\u0000A total of 109 endocardial and 9 epicardial locations were paced in 9 pigs. ECGi predicted the correct chamber of origin in 85% of atrial and 92% of ventricular sites. Lateral locations were predicted in the correct chamber more often than septal locations (97% versus 79%, P=0.01). Absolute distances in space between the true and predicted pacing locations were 20.7 (13.8-25.6) mm (median and [first-third] quartile). Distances were not significantly different across cardiac chambers.\u0000\u0000\u0000CONCLUSIONS\u0000The ECGi system is able to correctly identify the chamber of origin for focal activation in the vast majority of cases. Determination of the true site of origin is possible with sufficient accuracy with consideration of these error estimates.","PeriodicalId":10167,"journal":{"name":"Circulation: Arrhythmia and Electrophysiology","volume":"14 1","pages":"e007570"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89130576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electromechanics of the Normal Human Heart In Situ.","authors":"Christopher M. Andrews, B. Cupps, M. Pasque, Y. Rudy","doi":"10.1161/CIRCEP.119.007484","DOIUrl":"https://doi.org/10.1161/CIRCEP.119.007484","url":null,"abstract":"November 2019 1 Knowledge of the spatiotemporal relationship between electrical excitation and mechanical contraction in the human heart is essential for understanding cardiac physiology and disease. However, electromechanical data from nondiseased human hearts are currently lacking. The present study is the first to combine Electrocardiographic Imaging (ECGI; a noninvasive method for cardiac electrophysiology mapping) with tagged magnetic resonance imaging (MRI) to study the electromechanics of healthy adult hearts in situ. This also represents the largest ECGI study of healthy adults to date. We provide 3-dimensional data of the normal cardiac electrical and mechanical activation sequences, obtained from the same hearts under complete physiological conditions. These are important baseline data for studies and diagnosis of cardiac disorders and for constraining computer models of the human heart. Twenty healthy adults were enrolled at Washington University in St. Louis. Healthy volunteer demographics are provided in Table I in the Data Supplement. The study was approved by the Human Research Protection Office at Washington University in St. Louis. All participants provided written informed consent. Data are available upon reasonable request. The ECGI method, developed and validated in our laboratory, was described previously.1 A schematic of the procedure is presented in Figure I in the Data Supplement. The method consists of recording ≈250 simultaneous ECGs from the torso, using electrode strips. Heart-torso geometries of subjects were imaged using a navigated anatomic MRI sequence. Electrode positions were marked with MRIvisible capsules. ECG recordings were combined with the heart-torso geometries to construct epicardial potentials and unipolar epicardial electrograms. Local activation times were computed from electrograms using the minimum dV/dt during the QRS, and recovery times using the maximum dV/dt during the T wave. Activation-recovery intervals (ARIs), a surrogate of local action potential duration, were computed by subtracting the local activation time from the local recovery time. Activation and recovery maps were edited based on overall sequence and neighboring electrograms. Tagged MR images were obtained and analyzed using previously described methods.2 ECG-gated images were obtained in short-axis and long-axis views for a complete cardiac cycle beginning at end diastole. Tagged and nontagged images were acquired during the same breath hold to ensure similar anatomic positioning. Tag lines in the myocardium were tracked and 3-dimensional displacements were calculated from the movement of intramural tag surface intersection points during systole. StressCheck software (ESRD, Inc, St. Louis, MO) was used to compute strain values throughout the left ventricle. Additional details of the ECGI and tagged MRI analyses are provided in the Data Supplement. SPECIAL REPORT","PeriodicalId":10167,"journal":{"name":"Circulation: Arrhythmia and Electrophysiology","volume":"223 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86682967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arrhythmia Mechanisms and Outcomes of Ablation in Pediatric Patients With Congenital Heart Disease.","authors":"C. Houck, Stephanie F. Chandler, A. Bogers, J. Triedman, E. Walsh, N. D. de Groot, D. Abrams","doi":"10.1161/CIRCEP.119.007663","DOIUrl":"https://doi.org/10.1161/CIRCEP.119.007663","url":null,"abstract":"BACKGROUND\u0000In contrast to the adult population with congenital heart disease (CHD), arrhythmia mechanisms and outcomes of ablation in pediatric patients with CHD in recent era have not been studied in detail. Aims of this study were to determine arrhythmia mechanisms and to evaluate procedural and long-term outcomes in pediatric patients with CHD undergoing catheter ablation.\u0000\u0000\u0000METHODS\u0000Consecutive patients <18 years of age with CHD undergoing catheter ablation over an 11-year period (2007-2018) were included. Procedural outcome included complete or partial success, failure or empirical ablation. Long-term outcome included arrhythmia recurrence and burden according to a 12-point clinical arrhythmia severity score.\u0000\u0000\u0000RESULTS\u0000The study population consisted of 232 patients (11.7 years [0.01-17.8], 33.5 kg [2.2-130.1]). The most common diagnoses were Ebstein's anomaly (n=44), septal defects (n=39), and single ventricle (n=36). Arrhythmia mechanisms included atrioventricular reentry tachycardia (n=104, 90 patients), atrioventricular nodal reentry tachycardia (n=33, 29 patients), twin atrioventricular nodal tachycardia (n=3, 2 patients), macroreentrant atrial tachycardia (n=59, 56 patients), focal atrial tachycardia (n=33, 25 patients), ventricular ectopy (n=10, 8 patients), and ventricular tachycardia (n=15, 13 patients). Fifty-six arrhythmias (39 patients) were undefined. Outcomes included complete success (n=189, 81%), partial success (n=7, 3%), failure (n=16, 7%), or empirical ablation (n=20, 9%). Over 3.6 years (0.3-10.7) arrhythmia recurred in 49%. Independent of arrhythmia recurrence, arrhythmia scores decreased from 4 (0-10) at baseline to 0.5 (0-8) at 4 years follow-up (P<0.001). In 23/51 repeat procedures (45%), a different arrhythmia substrate was found. Overall adverse event rate was 9.4%, although only 1.6% (n=4) were of major severity and 0.8% (n=2) of moderate severity.\u0000\u0000\u0000CONCLUSIONS\u0000Pediatric patients with CHD demonstrate a broad spectrum of arrhythmia mechanisms. Despite recurrence and emergence of novel mechanisms after a successful procedure, ablation can be performed safely and successfully resulting in decreased arrhythmia burden.","PeriodicalId":10167,"journal":{"name":"Circulation: Arrhythmia and Electrophysiology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79941293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Catheter Ablation in Pediatric Congenital Heart Disease: A Modern Perspective.","authors":"J. Silva, G. V. Van Hare","doi":"10.1161/CIRCEP.119.008019","DOIUrl":"https://doi.org/10.1161/CIRCEP.119.008019","url":null,"abstract":"Arrhythmias in pediatric patients with congenital heart disease (CHD) represent a significant cause of morbidity and mortality in these vulnerable children. Unfortunately, to date, there has been no systematic depiction of the arrhythmic substrates and median term clinical outcome measurements in these patients in the more recent era of catheter ablation. In this issue of Circulation: Arrhythmia and Electrophysiology, Houck et al1 present a detailed retrospective 2-institution review of consecutive pediatric patients with CHD who underwent transcatheter ablation from 2007 to 2018, collecting a cohort of 232 patients. Greater than 75% of the patients presented had 2-ventricle substrates or surgical repairs, with Ebstein anomaly being the most common substrate. Accessory pathways were the most common electrophysiological substrate identified, followed by macroreentrant atrial tachycardias. Complete or partial procedural ablation success was achieved in 84% of cases with an adverse event rate of 9.4%. By 3.6 years follow-up, there were recurrent arrhythmias observed in 49% of patients. Importantly, recurrent arrhythmias following initial ablation were found to represent a different or new electrophysiological substrate in 26% of patients who underwent repeat electrophysiology studies. We congratulate the authors on reporting their ablation results such a large group of children with CHD, who for most programs represent a small minority of the total ablation population. There are several noteworthy takeaways. Acute procedural success rates for patients with CHD have remained rather steady in the current area of ablation. Recent data from the Multicenter Pediatric and Congenital EP Quality Initiative registry2 compiled acute procedural success rates across 12 centers with an acute success rate of 84% in patients with CHD. Papagiannis et al3 published a comprehensive retrospective study of over 100 patients with CHD from 16 centers specifically with atrioventricular nodal reentrant tachycardia and showed success rates of ≥82% with long term success of ≥86% at 3.2 years. This is particularly interesting because 22 patients (20%) presented with atypical atrioventricular nodal reentry tachycardia, which is known to have higher rates of procedural failure likely secondary to abnormal anatomy coupled with displaced conduction tissue and challenging access to the slow pathway. Looking at earlier reports from 2004, Hebe et al4 report acute success rates in CHD ablations of 88%. Despite the technological advances made in the field of cardiac ablation over the past 15 years that have demonstrated improvements in procedural success rates for certain patient cohorts, outcomes have not markedly EDITORIAL","PeriodicalId":10167,"journal":{"name":"Circulation: Arrhythmia and Electrophysiology","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84874725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Letter by Ganesan et al Regarding Article, \"Wavefront Field Mapping Reveals a Physiologic Network Between Drivers Where Ablation Terminates Atrial Fibrillation\".","authors":"A. Ganesan, D. Dharmaprani, A. McGavigan","doi":"10.1161/CIRCEP.119.007930","DOIUrl":"https://doi.org/10.1161/CIRCEP.119.007930","url":null,"abstract":"November 2019 1 Anand N. Ganesan, MBBS, PhD Dhani Dharmaprani, BEng Andrew D. McGavigan, MD To the Editor: Leef et al1 present an important study using wavefront field mapping to reveal a physiological network between drivers in cases where atrial fibrillation terminates. The directed vector approach utilized to demonstrate the connection of counterchiral spiral waves recalls the topological restrictions on phase singularities (PSs), outlined by Gray et al2: (1) phase lines cannot intersect; (2) PSs are joined by other isophasic lines to PS of opposite chirality or nonconducting boundaries; (3) PSs form and terminate as oppositely rotating pairs. Given the intrinsic topological connectedness of counter-chiral spiral waves via isophasic lines, it would be interesting to study these phenomena in cases where termination did not occur because these may also be present in the absence of AF termination. This is certainly a feature observable in the phase maps presented by Child et al.3 A further point addressed during the study is fluctuating nature of PS, which the authors postulated occurs via undefined mechanisms.1 In fact, the fluctuation of PS may potentially be an intrinsic topological property. Because each PS creates zones where all phases of the cycle are simultaneously present, the timing of incoming waves is likely to stochastically encounter tissue in the critical phase for new wavebreak and thus cause a new PS to form.4 This creates an endless cycle of PS regeneration that is a feature of the perpetuation of AF and VF.5 A final point made by Winfree4 and Gray et al2 is on the nature of PS termination. For topological reasons, PS termination can only occur via fusion with a wave emanating from a migrating spiral or migration to a boundary. The ability to terminate the arrhythmia at a distance from the PS observed by Leef et al could equally be consistent with the notion that AF termination is a form of stochastic ergodicity breaking, rather than via a direct effect on individual PS. The interesting approach presented by Leef et al points to the need for further studies of the mechanisms of AF and VF termination.","PeriodicalId":10167,"journal":{"name":"Circulation: Arrhythmia and Electrophysiology","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75731186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Irrigated Temperature-Controlled Lattice Ablation Catheter for Ventricular Ablation: A Preclinical Multimodality Biophysical Characterization.","authors":"Ayelet Shapira-Daniels, M. Barkagan, H. Yavin, J. Sroubek, V. Reddy, P. Neužil, E. Anter","doi":"10.1161/CIRCEP.119.007661","DOIUrl":"https://doi.org/10.1161/CIRCEP.119.007661","url":null,"abstract":"BACKGROUND\u0000Ventricular tachycardia ablation is often limited by insufficient lesion creation. A novel radiofrequency catheter with an expandable lattice electrode has a larger surface area capable of delivering higher currents at a lower density to potentially increase lesion dimensions without overheating.\u0000\u0000\u0000METHODS\u0000This 8F bidirectional irrigated catheter (Sphere-9, Affera Inc) has a 9 mm spherical lattice tip (\"lattice\") with an effective surface area 10-fold larger than standard linear catheters. Nine surface thermocouples provide temperature feedback to a proprietary high-current generator operating in a temperature-controlled mode. Ex vivo phase: in 11 bovine hearts, unipolar ablation at 30, 60, and 120 seconds was compared between the lattice (Tmax60°C) and a standard linear irrigated-tip catheter (40 W) at contact force of 10 g. In 5 porcine hearts, bipolar ablation was compared between the catheters (Tmax60°C versus 40 W; 60 seconds). In vivo phase: in 9 swine, ventricular ablation at Tmax60°C versus 40 W was performed for 60 seconds. In addition, direct tissue temperature at 3- and 7-mm tissue depth was measured in a thigh muscle preparation.\u0000\u0000\u0000RESULTS\u0000Ex vivo: lattice produced deeper lesions at 30, 60, and 120 seconds application duration (6.7±1.3 versus 4.8±1.2 mm; 8.3±1.4 versus 5.4±0.8 mm; 10.0±1.6 versus 6.1±1.6 mm, respectively, P≤0.001 for all). Bipolar lesions were deeper (15.8±4.1 versus 10.5±1.4 mm, P<0.001) and more likely to be transmural (80% versus 0%, P=0.002). In vivo: lattice produced deeper lesions (10.5±1.4 versus 6.5±0.8 mm, P≤0.001). Tissue temperature at 7 mm was higher with the lattice (+15.1±2.4°C; P<0.001). The steam-pop occurrence was lower with the lattice (total: 4% versus 18%, P=0.02; in vivo 0% versus 14.2%, P=0.13).\u0000\u0000\u0000CONCLUSIONS\u0000This novel radiofrequency system produces larger ventricular lesions compared with standard irrigated catheters and at a lower risk of tissue overheating. This may improve the efficacy of ventricular tachycardia ablation procedures while reducing the number of applications and procedural duration.","PeriodicalId":10167,"journal":{"name":"Circulation: Arrhythmia and Electrophysiology","volume":"241 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73964880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antiarrhythmic Drugs or Catheter Ablation in the Management of Ventricular Tachyarrhythmias in Patients With Implantable Cardioverter-Defibrillators: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.","authors":"B. Kheiri, Mahmoud Barbarawi, Yazan Zayed, Michael Hicks, M. Osman, L. Rashdan, H. Kyi, Ghassan Bachuwa, Mustafa Hassan, E. Stecker, B. Nazer, Deepak L. Bhatt","doi":"10.1161/CIRCEP.119.007600","DOIUrl":"https://doi.org/10.1161/CIRCEP.119.007600","url":null,"abstract":"BACKGROUND\u0000In patients with an implantable cardioverter-defibrillator (ICD), shocks are associated with increased morbidity and mortality. Therefore, we conducted this study to evaluate the efficacy and safety of antiarrhythmic drugs and catheter ablation (CA) in the treatment of ventricular tachyarrhythmias (VT) in patients with an ICD.\u0000\u0000\u0000METHODS\u0000An electronic database search for randomized controlled trials that evaluated antiarrhythmic drugs and CA in patients with ICD was conducted. The primary outcome was recurrent VT. Secondary outcomes were ICD shocks and any deaths. Bayesian and frequentist network meta-analyses were performed to calculate hazard ratios (HRs) and 95% credible intervals (CrIs)/CIs.\u0000\u0000\u0000RESULTS\u0000Twenty-two randomized controlled trials were identified (3828 total patients; age 64.3±11.4; 79% males). The use of amiodarone was associated with a significantly reduced rate of VT recurrence compared with control (HR=0.34 [95% CrI=0.15-0.74]; absolute risk difference=-0.23 [95% CrI=-0.23 to -0.09]; number needed to treat=4). Sotalol was associated with increased risk of VT recurrence compared with amiodarone (HR=2.88 [95% CrI=1.35-6.46]). Compared with control, amiodarone (HR=0.33 [95% CrI=0.15-0.76]; absolute risk difference=-0.17 [95% CrI=-0.32 to -0.06]; number needed to treat=6) and CA (HR=0.52 [95% CrI=0.30-0.89; absolute risk difference=-0.12 [95% CrI=-0.24 to -0.03]; number needed to treat=8) were associated with significantly reduced ICD shocks. Compared with amiodarone, sotalol was associated with significantly increased ICD shocks (HR=2.70 [95% CrI=1.17-6.71]). The rate of death was not significantly different between the competing strategies. The node-splitting method showed no inconsistency.\u0000\u0000\u0000CONCLUSIONS\u0000Among patients with an ICD, amiodarone significantly reduced VT recurrence and ICD shocks, while CA reduced ICD shocks. Sotalol significantly increased VT recurrence and ICD shocks compared with amiodarone. The long-term side effects of amiodarone and early complications of CA should be weighed carefully according to specific patient characteristics.","PeriodicalId":10167,"journal":{"name":"Circulation: Arrhythmia and Electrophysiology","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88897232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spontaneous Atrial Fibrillation in Transgenic Goats With TGF (Transforming Growth Factor)-β1 Induced Atrial Myopathy With Endurance Exercise.","authors":"M. Regouski, O. Galenko, Jason Doleac, A. Olsen, Victoria Jacobs, D. Liechty, K. White, T. Bunch, Pamela M Lee, H. Rutigliano, I. Polejaeva, M. Cutler","doi":"10.1161/CIRCEP.119.007499","DOIUrl":"https://doi.org/10.1161/CIRCEP.119.007499","url":null,"abstract":"BACKGROUND\u0000There is increasing evidence that endurance exercise is associated with increased risk of atrial fibrillation (AF). However, it is unknown if the relationship between endurance exercise and AF is dependent on an atrial myopathy.\u0000\u0000\u0000METHODS\u0000Six cardiac-specific TGF (transforming growth factor)-β1 transgenic and 6 wild-type (WT) goats were utilized for these studies. Pacemakers were implanted in all animals for continuous arrhythmia monitoring and AF inducibility. AF inducibility was evaluated using 5 separate 10 s bursts of atrial pacing (160-200 ms). Three months of progressive endurance exercise (up to 90 minutes at 4.5 mph) was performed. Quantitative assessment of circulating microRNAs and inflammatory biomarkers was performed.\u0000\u0000\u0000RESULTS\u0000Sustained AF (≥30 s) was induced with 10 s of atrial pacing in 4 out of 6 transgenic goats compared with 0 out of 6 WT controls at baseline (P<0.05). No spontaneous AF was observed at baseline. Interestingly, between 2 and 3 months of exercise 3 out of 6 transgenic animals developed self-terminating spontaneous AF compared with 0 out of 6 WT animals (P<0.05). There was an increase in AF inducibility in both transgenic and WT animals during the first 2 months of exercise with partial normalization at 3 months (transgenic 67%; 100%; 83% versus WT 0%; 67%; 17%). These changes in AF susceptibility were associated with a decrease in circulating microRNA-21 and microRNA-29 during the first 2 months of exercise with partial normalization at 3 months in both transgenic and WT animals. Finally, MMP9 (matrix metallopeptidase 9) was increased during the second and third months of exercise training.\u0000\u0000\u0000CONCLUSIONS\u0000This study demonstrates a novel transgenic goat model of cardiac fibrosis (TGF-β1 overexpression) to demonstrate that endurance exercise in the setting of an underlying atrial myopathy increases the incidence of spontaneous AF. Furthermore, endurance exercise seems to increase inducible AF secondary to altered expression of key profibrotic biomarkers that is independent of the presence of an atrial myopathy.","PeriodicalId":10167,"journal":{"name":"Circulation: Arrhythmia and Electrophysiology","volume":"119 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88247769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insight Into the Mechanism of Macroreentrant Atrial Tachycardia With Cycle Length Alternans Using Ultrahigh Density Mapping System.","authors":"Jin-lin Zhang, Liangrong Zheng, Dongchen Zhou, Anquan Zhao, Cheng Tang, Yong-hua Zhang, X. Su","doi":"10.1161/CIRCEP.119.007634","DOIUrl":"https://doi.org/10.1161/CIRCEP.119.007634","url":null,"abstract":"BACKGROUND\u0000Atrial tachycardia (AT) with cycle length (CL) alternans is a rare phenomenon. We aimed to identify the characteristics and precise mechanism of this special category of ATs by using an ultrahigh density mapping system.\u0000\u0000\u0000METHODS\u0000We identified 7 ATs with alternating CL in a total of 478 ATs from 2 institutions mapped with an ultrahigh density mapping system. Activation maps were performed for long CL (289±35 ms; mapping points, 21 520±11 103) and short CL (251±18 ms; mapping points,17 594±8059) separately.\u0000\u0000\u0000RESULTS\u0000We classified ATs with CL alternans into 2 types. Type 1: There existed 2 potential loops with different routes. CL alternans resulted from an intermittently 2:1 conducting block within the channel of the smaller loop. Type 2: CL alternans resulted from different conduction velocity through 2 closely spaced gaps within preexisting linear lesions. Catheter ablation successfully terminated all the 7 ATs.\u0000\u0000\u0000CONCLUSIONS\u0000Ultrahigh density mapping provides an opportunity to delineate the precise mechanism of AT with CL alternans. Intermittent conduction block or slowing of a channel was essential for the maintenance of AT.","PeriodicalId":10167,"journal":{"name":"Circulation: Arrhythmia and Electrophysiology","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80136002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}