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Background: Rapid technologic development and expansion of procedural expertise have led to widespread proliferation of catheter-based electrophysiology procedures. It is unclear whether these advances come at cost to patient safety., Objective: This meta-analysis aimed to assess complication rates after modern electrophysiology procedures during the lifetime of the procedures., Methods: A comprehensive search was performed to identify relevant data published before May 30, 2023. Studies were included if they met the following inclusion criteria: prospective trials or registries, including comprehensive complications data; and patients undergoing atrial fibrillation ablation, ventricular tachyarrhythmia ablation, leadless cardiac pacemaker implantation, and percutaneous left atrial appendage occlusion. Pooled incidences of procedure-related complications were individually assessed by random effects models to account for heterogeneity. Temporal trends in complications were investigated by clustering trials by publication year (2000-2018 vs 2019-2023)., Results: A total of 174 studies (43,914 patients) met criteria for analysis: 126 studies of atrial fibrillation ablation (n = 24,057), 25 studies of ventricular tachyarrhythmia ablation (n = 1781), 21 studies of leadless cardiac pacemaker (n = 8896), and 18 studies of left atrial appendage occlusion (n = 9180). The pooled incidences of serious procedure-related complications (3.49% [2000-2018] vs 3.05% [2019-2023]; P < .001), procedure-related stroke (0.46% vs 0.28%; P = .002), pericardial effusion requiring intervention (1.02% vs 0.83%; P = .037), and procedure-related death (0.15% vs 0.06%; P = .003) significantly decreased over time. However, there was no significant difference in the incidence of vascular complications over time (1.86% vs 1.88%; P = .888)., Conclusion: Despite an increase in cardiac electrophysiology procedures, procedural safety has improved over time., Competing Interests: Disclosures Dr Reddy reports no disclosures related to this manuscript; but unrelated to this manuscript, he serves as a consultant for and has equity in Ablacon, Acutus Medical, Affera-Medtronic, Apama Medical–Boston Scientific, Anumana, APN Health, Aquaheart, Atacor, Autonomix, Axon Therapies, Backbeat, BioSig, CardiaCare, CardioNXT/AFTx, Circa Scientific, CoRISMA, Corvia Medical, Dinova-Hangzhou DiNovA EP Technology, East End Medical, EPD-Philips, EP Frontiers, Epix Therapeutics–Medtronic, EpiEP, Eximo, Farapulse–Boston Scientific, Field Medical, Focused Therapeutics, HRT, Intershunt, Javelin, Kardium, Keystone Heart, Laminar Medical, LuxMed, Medlumics, Middlepeak, Neutrace, Nuvera–Biosense Webster, Oracle Health, Restore Medical, Sirona Medical, SoundCath, Valcare; unrelated to this work, has served as a consultant for Abbott, Adagio Medical, AtriAN, Biosense-Webster, BioTel Heart, Biotronik, Boston Scientific, Cairdac, Cardiofocus, Cardionomic, CoreMap, Fire1, Gore & Associates, Impulse Dynamics, Medtronic, Novartis, Philips, Pulse Biosciences; and has equity in DRS Vascular, Manual Surgical Sciences, Newpace, Nyra Medical, Surecor, and Vizaramed. Dr Koruth has received grant support and stock options from Affera-Medtronic; unrelated to this manuscript, he has also served as a consultant to and has received grant support from Cardiofocus; has served as a consultant for Abbott, Boston Scientific, Biosense Webster, and Medtronic; and has received grant support from Pulse Bioscience. All other authors report no conflicts., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Introduction: The coronavirus disease (COVID-19) pandemic has generated serious repercussions on the health system, reducing the number of all cardiology procedures worldwide., Objectives: Describe the impact of the COVID-19 pandemic on the procedures performed by the electrophysiology department in a national referral center., Methods: We made a retrospective review of our data base and we compared procedures made in the past 3 years since 2017-2019 with the procedures made in the 2020. We divided the procedures into two large groups: Cardiac Implantable Electronic Devices (CIED) related procedures and electrophysiological procedures (EP) which included conventional and complex ablations., Results: There was a significant reduction in all the procedures, the average of procedures performed in the last 3 previous years was 467, while in 2020, we performed only 319 (p = 0.01); this represents a reduction of 33.4% in the total number of procedures. There was no statistical difference regarding the CIED related procedures, the average of procedures in the past 3 previous years was 174, and in 2020 we performed 190 procedures (p = 0.46). Regarding the EP, the average of the past 3 previous years was 293, while in 2020, we performed only 129 procedures (p < 0.01). The reduction in the EP was 55.97%. The most affected months were April, May, and June., Conclusions: The COVID-19 pandemic considerably affected the number of the procedures in our center, reducing it by 33.4%. The reduction of procedures fundamentally affected the ablations, with a reduction of 55.97%. The number of CIED related procedures was not affected.

Aims: The aim of this study was to evaluate the sensitivity of right ventricular endomyocardial biopsy (EMB) in myocarditis patients with cardiac magnetic resonance (CMR) and electroanatomical mapping (EAM) showing left ventricular abnormalities., Methods: We performed right ventricular EMB in 144 consecutive patients (66% men, age 43 ± 15 years) with acute symptoms and CMR-proved diagnosis of left ventricular myocarditis. Right ventricular EMB sensitivity has been evaluated in patients with different localization and extension of abnormal substrate at both CMR and -- when performed -- EAM. Abnormal substrate was defined, respectively, by late gadolinium enhancement (LGE) and low-voltage areas (LVAs)., Results: Globally, right ventricular EMB sensitivity was 87.5%. EMB-negative cases had significantly smaller fragment sizes (cumulative area 2.8 ± 1.7 vs. 3.8 ± 1.8 mm2, P = 0.023), and lower LGE surface extension (24.7 ± 14.2 vs. 38.5 ± 20.2%, P = 0.006) and transmurality (32.0 ± 26.1 vs. 49.3 ± 22.6, P = 0.003). Right ventricular EMB sensitivity in patients with LGE involving both right ventricular and interventricular septum (IVS), isolated right ventricular or IVS, and remote left ventricular areas (n = 10, 49 and 67 cases) was 83.3, 84.4 and 90.5%, respectively (P = 0.522). Overall, 34 patients (23.6%) underwent EAM. On the basis of EAM, right ventricular EMB sensitivity was 85.3%: in detail, it was 50.0, 88.2 and 86.7% in patients with both right ventricular and IVS, isolated right ventricular/IVS and distant left ventricular involvement (n = 2, 17 and 15, respectively, P > 0.05). Sample size area was the only factor associated with right ventricular EMB sensitivity (hazard ratio = 1.6/mm2, 95% confidence interval 1.1-2.4, P = 0.013)., Conclusion: Right ventricular EMB is still an accurate technique to confirm diagnosis in patients with CMR-proved left ventricular myocarditis. In particular, provided there is an adequate sample size, its sensitivity is comparable among patients with heterogeneous LGE or LVA localization., (Copyright © 2021 Italian Federation of Cardiology - I.F.C. All rights reserved.)

Aims: This study aims to compare procedural parameters and clinical efficacy of remote magnetic navigation (RMN) vs. manual navigation (MAN) approach for radiofrequency ablation (RFA) in patients with atrial fibrillation (AF)., Methods: 146 patients with AF were enrolled in the study. In the RMN group (n=57), patients were treated with the CARTO® 3 in combination with the Niobe ES system. In the MAN group (n=89), ablation was performed with the EnSite Velocity and TactiCath™ Quartz catheter with direct contact force measurement. Procedural time, ablation time, fluoroscopy time, radiation dose and ablation counts were measured and compared between the groups. Recurrence of AF was evaluated after 6 months of follow-up., Results: Mean procedure times (236.87±64.31 vs. 147.22±45.19 min, P<0.05), counts of RF applications (74.30±24.77 vs. 49.15±20.33, P<0.05) and total RFA times (4323.39±1426.69 vs. 2780.53±1157.85 s, P<0.05) were all significantly higher in the RMN than in the MAN group, respectively. In the same order, mean X-ray dose (9722.6±7507.4 vs. 8087.9±6051.5 mGy/cm 2 , P=0.12) and mean total X-ray exposure time (8.07±4.20 vs. 9.54±5.47 min, P=0.08) were not statistically different. At 6-month follow-up, freedom from AF was similar in RMN and MAN group for paroxysmal (60.8% and 73%, respectively, P=0.42) and persistent AF (69.6% and 75.0%, respectively, P=0.77)., Conclusions: Due to the fact that mid-term clinical outcomes showed no significant differences in AF recurrences between groups and manual ablation strategy provided more favorable results regarding acute procedural parameters, we can conclude that the remote magnetic navigation is not superior to the manual approach.

COVID-19 is a rapidly evolving public health emergency that has largely impacted the provision of healthcare services around the world. The challenge for electrophysiology teams is double; on one side preventing disease spread by limiting all nonessential face-to-face interactions, but at the same time ensuring continued care for patients who need it. These guidelines contain recommendations regarding triaging in order to define what procedures, device checks and clinic visits can be postponed during the pandemic. We also discuss best practices to protect patients and healthcare workers and provide guidance for the management of COVID-19 patients with arrhythmic conditions.

Introduction: Knowledge of the activity performed in a country enables it to be positioned within the community of which it is part., Objective: We present the results of the National Registry of Cardiac Electrophysiology of the Portuguese Association for Arrhythmology, Pacing and Electrophysiology (APAPE) for 2015 and 2016., Methods: This is a voluntary, observational, annual registry collected retrospectively., Results: The data on the electrophysiological studies and ablations performed in these two years are presented., Conclusion: Changes in these data over the years are analyzed and the relation of the Portuguese data in the European panorama and possible implications are discussed., (Copyright © 2020 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.)

Russia is the largest country in the world based on the landmass, covering more than one-eighth of the earth's inhabited area. Russia faces challenges in electrophysiology (EP) care including insufficient and uneven financing, complicated system for identifying optimal treatment for individual patients, relative paucity of reasonable educational and certification scope for electrophysiologists, suboptimal national statistical data gathering regarding heart rhythm disorders and EP devices in use, and weak networking of medical information. In comparison with the average level of EP utilization in ESC countries, Russia utilizes around 50% in pacemaker; 10% in ICD; 8% in cardiac resynchronization therapy; 55% in ablations; and 45% in AF ablations. As projected, Russia has the biggest unmet demand in EP procedures, so-called developmental potential in the European region. Nearly 37% of implanted single-chamber and 63% dual-chamber devices are manufactured outside of Russia. The price of the Russian devices is slightly (by 10-20%) lower than the one imported and they are readily provided for patients by the Russian Ministry of Health. Based on the analysis of the data available, we suggest some strategies for the improvement of the EP care in Russia. Solutions include the institution of formal EP education and standardization of it, development of international educational, and scientific collaboration; implementation quality-assessment tools for professional knowledge and skills; wide application of national medical databases and collection of heart rhythm disorders' statistics; growth of financial support of electrophysiology and transparent distribution of financing between state/municipal and private medical centers; enhancement of medical care accessibility countrywide; development of technologies for local EP devices production; and collection of data regarding usage and effectiveness of it.

Although bipolar electrograms (Bi-egms) are commonly used for catheter mapping and ablation of cardiac arrhythmias, the accuracy and reproducibility of Bi-egms have not been evaluated. We aimed to clarify the influence of the catheter orientation (CO), catheter contact angle (CA), local conduction velocity (CV), scar size, and catheter type on the Bi-egm morphology using an in silico 3-dimensional realistic model of atrial fibrillation. We constructed a 3-dimensional, realistic, in silico left atrial model with activation wave propagation including bipolar catheter models. Bi-egms were obtained by computing the extracellular potentials from the distal and proximal electrodes. The amplitude and width were measured on virtual Bi-egms obtained under different conditions created by changing the CO according to the wave direction, catheter-atrial wall CA, local CV, size of the non-conductive area, and catheter type. Bipolar voltages were also compared between virtual and clinically acquired Bi-egms. Bi-egm amplitudes were lower for a perpendicular than parallel CO relative to the wave direction (p<0.001), lower for a 90° than 0° CA (p<0.001), and lower for a CV of 0.13m/s than 0.48m/s (p<0.001). Larger sized non-conductive areas were associated with a decreased bipolar amplitude (p<0.001) and increased bipolar width (p<0.001). Among three commercially available catheters (Orion, Pentaray, and Thermocool), those with more narrowly spaced and smaller electrodes produced higher voltages on the virtual Bi-egms (p<0.001). Multiple factors including the CO, CA, CV, and catheter design significantly influence the Bi-egm morphology. Universal voltage cut-off values may not be appropriate for bipolar voltage-guided substrate mapping., Competing Interests: The authors have declared that no competing interests exist.

In vitro multi-electrode array (MEA) technology is nowadays involved in a wide range of applications beyond neuroscience, such as cardiac electrophysiology and bio-interface studies. However, the cost of commercially available acquisition systems severely limits its adoption outside specialized laboratories with high budget capabilities. Thus, the availability of low-cost methods to acquire signals from MEAs is important to allow research labs worldwide to exploit this technology for an ever-expanding pool of experiments independently from their economic possibilities. Here, we provide a comprehensive toolset to assemble a multifunctional in vitro MEA acquisition system with a total cost 80% lower than standard commercial solutions. We demonstrate the capabilities of this acquisition system by employing it to i) characterize commercial MEA devices by means of electrical impedance measurements ii) record activity from cultures of HL-1 cells extracellularly, and iii) electroporate HL-1 cells through nanostructured MEAs and record intracellular signals., Competing Interests: The authors have declared that no competing interests exist.

Background: Traditionally, insertable cardiac monitor (ICM) procedures have been performed in the cardiac catheterization (CATH) or electrophysiology (EP) laboratory. The introduction of the miniaturized Reveal LINQ ICM has led to simplified and less invasive procedures, affording hospitals flexibility in planning where these procedures occur without compromising patient safety or outcomes., Methods: The present analysis of the ongoing, prospective, observational, multicenter Reveal LINQ Registry sought to provide real-world feasibility and safety data regarding the ICM procedure performed in the CATH/EP lab or operating room and to compare it with insertions performed outside of these traditional hospital settings. Patients included had at least a 30-day period after the procedure to account for any adverse events., Results: We analyzed 1222 patients (58.1% male, age 61.0 ± 17.1 years) enrolled at 18 centers in the US, 17 centers in Middle East/Asia, and 15 centers in Europe. Patients were categorized into 2 cohorts according to the location of the procedure: in-lab (CATH lab, EP lab, or operating room) (n = 820, 67.1%) and out-of-lab (n = 402, 32.9%). Several differences were observed regarding baseline and procedure characteristics. However, no significant differences in the occurrence of procedure-related adverse events (AEs) were found; of 19 ICM/procedure-related AEs reported in 17 patients (1.4%), 11 occurred in the in-lab group (1.3%) and 6 in the out-of-lab group (1.5%) (P = .80)., Conclusions: This real-world analysis demonstrates the feasibility of performing Reveal LINQ ICM insertion procedures outside of the traditional hospital settings without increasing the risk of infection or other adverse events., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: To review 10 years of clinical practice of cardiac electrophysiology study and radiofrequency catheter ablation in the treatment of supraventricular tachycardia., Methods: The retrospective chart review was conducted at the National Institute of Cardiovascular Diseases, Karachi, and comprised records of all patients who underwent electrophysiological study and / or radiofrequency catheter ablation from January2007 to December 2016. SPSS 21 was used for data analysis., Results: Of the 627 patients, 335(53.4%) were females. The overall mean age was 40.99}13.59 years. The major indication for procedure was supraventricular tachycardia 376(59.97%). Final electrophysiological study diagnosis was typical slow fast atrioventricular nodal re-entrant tachycardia in 303(48.3%) patients. The overall success rate was 472(75.3%). Procedure-related complications were reported in 25(4%) patients, and there was 1(0.15%) mortality., Conclusions: Cardiac electrophysiology studies and radiofrequency catheter ablation were found to be an effective and safe method for diagnosis and treatment of supraventricular tachycardia.

Introduction and Objectives: The Spanish Automatic Defibrillator Registry has provided activity data since 2002., Methods: The data in this registry are submitted by implantation centers that voluntarily complete a data collection sheet., Results: During 2017, a total of 6273 implant sheets were received, compared with 6429 reported by Eucomed (European Confederation of Medical Suppliers Associations). Therefore, the registry contains data on 97.6% of the devices implanted in Spain. Compliance ranged from 99.7% for the field "name of the implanting hospital" to 46.1% for the variable "New York Heart Association functional class". A total of 181 hospitals reported data to the registry, representing an increase compared with the number of participating hospitals in 2016 (177) and in previous years (169 in 2015, 162 in 2014, 154 in 2013, and 153 in 2012)., Conclusions: The number of implants per million inhabitants in Spain increased for several years but decreased in 2017. As in previous years, the total number of implants in Spain is still much lower than the European Union average, and the gap continues to widen. There are still substantial differences between autonomous communities., (Copyright © 2018 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.)

Purpose: Femoral venous access is required for most electrophysiology procedures. Limited data are available regarding post-procedure venous thromboembolism (VTE), specifically deep vein thrombosis (DVT) and pulmonary embolism (PE). Potential preventative strategies are unclear. We aimed to survey Canadian centers regarding incidence of VTE and strategies for prevention of VTE after procedures that do not require post-procedure anticoagulation., Methods: An online survey was distributed to electrophysiologists representing major Canadian EP centers. Participants responded regarding procedural volume, incidence of VTE post-procedure, and their practice regarding pharmacological and non-pharmacological peri-procedural VTE prophylaxis., Results: The survey included 17 centers that performed a total of 6062 procedures in 2016. Ten patients (0.16%) had VTE (including 9 DVTs and 6 PEs) after diagnostic electrophysiology studies and right-sided ablation procedures excluding atrial flutter. Five centers (41.6%) administered systemic intravenous heparin during both diagnostic electrophysiology studies and right-sided ablation procedures. For patients taking oral anticoagulants, 10 centers (58.8%) suspend therapy prior to the procedure. Two centers (11.8%) routinely prescribed post-procedure pharmacologic prophylaxis for VTE. Four centers (23.5%) used compression dressings post-procedure and all prescribed bed rest for a maximum of 6 h. Of the variables collected in the survey, none were found to be predictive of VTE., Conclusions: VTE is not a common complication of EP procedures. There is significant variability in the strategies used to prevent VTE events. Future research is required to evaluate strategies to reduce the risk of VTE that may be incorporated into EP practice guidelines.

Objectives: This study provides an update and comparison to a 2010 nationwide survey on cardiac electrophysiology (EP), types and numbers of interventional electrophysiological procedures, and training opportunities in 2015., Background: In 2010, German cardiology centers performing interventional EP were identified and contacted to provide a survey on cardiac EP., Methods: German cardiology centers performing interventional EP in 2015 were identified from quality reports and contacted to repeat the 2010 questionnaire., Results: A majority of 131 centers (57%) responded. EP (ablation procedures and device therapy) was mainly part of a cardiology department (89%) and only independent (with its own budget) in 11%. The proportion of female physicians in EP training increased from 26% in 2010 to 38% in 2015. In total, 49,356 catheter ablations (i.e., 81% of reported ablations in 2015) were performed by the responding centers, resulting in a 44% increase compared with 2010 (the median number increased from 180 to 297 per center). Atrial fibrillation (AF) was the most common arrhythmia interventionally treated (47%). At 66% of the centers, (at least) 2 physicians were present during most catheter ablations. A minimum of 50 (75) AF ablations were performed at 80% (70%) of the centers. Pulmonary vein isolation with radiofrequency point-by-point ablation (62%) and cryoablation (33%) were the preferred ablation strategies. About one-third of centers reported surgical AF ablations, with 11 centers (8%) performing stand-alone surgical AF ablations. Only one-third of the responding 131 centers fulfilled all requirements for training center accreditation., Conclusions: Comparing 2010 with 2015, an increasing number of EP centers and procedures in Germany are registered. In 2015, almost every second ablation was for therapy for AF. Thus, an increasing demand for catheter ablation is likely, but training opportunities are still limited, and most centers do not fulfil recommended requirements for ablation centers., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Interventional cardiac catheterization (cath) and electrophysiology (EP) procedures are not routinely performed together. There are several perceived barriers affecting this practice, though there are also advantages for both the patient and practitioner to a combined approach., Methods: This was a single-center retrospective study reviewing combined cath and EP procedures with a preprocedural intention to intervene at Texas Children's Hospital from 2001 to 2014. We excluded procedures in which the intended procedure was purely diagnostic in nature., Results: A total of 121 patients requiring 125 procedures were identified, of which 61 patients underwent 62 procedures that met our inclusion criteria. Potential subgroups of interest included adult congenital heart disease patients (26% of cohort), single ventricle anatomy (34%), and heterotaxy (19%) and collectively 58% of procedures involved a patient in one of these groups. The combined nature of the procedure did not preclude a cath or EP intervention in any patient. There were no mortalities. There were three adverse events, affecting 4.8% of procedures., Conclusions: Combined interventional cardiac cath and EP procedures in pediatric patients and those with congenital heart disease can be performed safely in a high-volume center. These combined procedures save patients the risk and inconvenience of multiple procedures, and further investigation into cost savings is warranted., (© 2017 Wiley Periodicals, Inc.)

Background: Peripartum cardiomyopathy (PPCM) is associated with significant morbidity and mortality. Arrhythmogenic causes of death have been implicated in a significant number of patients. However, there is a dearth of systematic studies evaluating the burden of arrhythmias in PPCM., Methods: We used the Healthcare Utilization Project, Nationwide Inpatient Sample database (2007-2012) and identified 9841 hospitalizations for women aged ≥18years with a primary diagnosis of PPCM. Frequency of arrhythmias, utilization of electrophysiologic procedures, length of stay, hospitalization costs and outcomes associated with arrhythmias were determined., Results: Mean age was 30.05±6.69years. Arrhythmias were present in 18.7% of hospitalized PPCM cohort. Ventricular tachycardia was the most common arrhythmia and was noted in 4.2%. Approximately 2.2% of cases experienced cardiac arrest. Electrical cardioversion was performed in 0.3%, Catheter ablation in 1.9%, PPM implantation in 3.4% and ICD in 6.8% of hospitalizations for PPCM with arrhythmias. In-hospital mortality was 3-times more frequent in arrhythmia cohort (2.1% vs. 0.7%). Hospitalization costs were significantly higher in PPCM with arrhythmias. Elixhauser comorbidity score (adjusted OR:1.10; 95%CI:1.02-1.18; p=0.016), in-hospital mortality (adjusted OR:2.35; 95%CI:1.38-4.02; p=0.002), cardiogenic shock (adjusted OR:2.61; 95%CI:1.44-4.72; p=0.002), utilization of balloon pump (adjusted OR:13.4; 95%CI: 2.55-70.53; p<0.001), Swan-Ganz catheterization (adjusted OR:3.12; 95%CI:1.21-8.06; p=0.019), and coronary angiography (adjusted OR:1.79; 95%CI:1.19-2.70; p=0.005) were significantly associated with arrhythmias in PPCM., Conclusions: Arrhythmias were present in 18.7% of PPCM related hospitalizations. Morbidity, in-hospital mortality, length of inpatient stay, hospitalization costs and cardiac procedure utilization were significantly higher in the arrhythmia cohort., (Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.)

Aims: In an effort to minimize periprocedural stroke risk, increasingly, electrophysiological (EP) procedures are being performed on anticoagulation. The decrease in stroke has been accompanied by an increase in potentially devastating vascular access complications. Ultrasound guidance for femoral vein cannulation reduces complications in other applications. The aim of this study is to determine the utility of real-time two-dimensional (2D) ultrasound guidance for femoral vein cannulation in EP., Methods and Results: A comprehensive literature search of Medline, Embase, Google Scholar, and the Cochrane Central Register of Controlled Trials was performed. Five years of conference abstracts from the Heart Rhythm Society, European Heart Rhythm Association, and European Cardiac Arrhythmia Society were reviewed. Two independent reviewers identified trials comparing ultrasound-guided with standard cannulation in EP procedures. Data were extracted on study design, study size, operator and patient characteristics, use of anticoagulation, vascular complication rates, first-pass success rate, and inadvertent arterial puncture. Four trials, with a total of 4065 subjects, were included in the review, with 1848 subjects in the ultrasound group and 2217 subjects in the palpation group. Ultrasound guidance for femoral vein cannulation was associated with a 60% reduction of major vascular bleeding (relative risk, 0.40; 95% confidence interval, 0.28-0.91). Additionally, there was a 66% reduction in minor vascular complications (relative risk, 0.34; 95% confidence interval, 0.15-0.78)., Conclusion: The use of real-time 2D ultrasound guidance for femoral vein cannulation decreases access-related bleeding rates and life-threatening vascular complications., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Background: Catheter ablations have been traditionally performed with the use of fluoroscopic guidance, which exposes the patient and staff to the inherent risks of radiation. We have developed techniques to eliminate the use of fluoroscopy during cardiac ablations and have been performing completely fluoroless catheter ablations on our patients for over 5 years., Methods: We present a retrospective analysis of the safety, efficacy, and feasibility data from 500 consecutive patients who underwent nonfluoroscopic catheter ablation, targeting a total of 639 arrhythmias, including atrioventricular reciprocating tachycardia (AVRT), atrioventricular nodal reentrant tachycardia (AVNRT), atrial tachycardia (AT), atrial fibrillation (AF), premature ventricular contractions (PVCs), and ventricular tachycardia (VT). We perform fluoroless ablations using intracardiac electrograms, electroanatomic mapping, and for most cases intracardiac echocardiography. Our experience includes exclusively endocardial cardiac ablations., Results: The mean follow-up was 20.5 months. Recurrence rate for AVRT was 6.5%, for AVNRT 2.5%, for macro-reentrant AT 6.4%, for focal AT 5.4%, for AF 22.6%, for PVC 6.7%, and for VT 21.4%. Major complications occurred in five patients (1.0%); minor complications occurred in three patients (0.6%). No deaths occurred. Fluoroscopy was used in one instance, for 0.3 minutes, to confirm venous access., Conclusions: Completely fluoroless catheter ablations may be routinely performed for all endocardial ablations without compromising safety, efficacy, or procedural duration., (© 2017 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals, Inc.)

Background: The very long-term prognostic significance of ventricular late potentials (VLP) in patients post ST-elevation myocardial infarction (STEMI) is unclear., Objectives: To evaluate the long-term predictive value of VLP for mortality post-STEMI., Methods: We conducted serial signal-averaged electrocardiography (SAECG) measurements in 63 patients on the 1st, 2nd and 3rd day pre-discharge, and 30 days after STEMI in patients admitted in 2001. We followed the patients for 10 years and correlated the presence of VLP with all-cause and cardiovascular mortality., Results: The mean age was 59.9 ± 12.3 years. Thrombolysis was performed in 41 patients (65%). Percutaneous coronary intervention was performed pre-discharge in 40 patients (63%) and coronary artery bypass grafting in 7 (11%). Five consecutive measurements to define the presence of VLP were obtained in 52 patients (21 with VLP and 31 without). We found a higher prevalence of VLP in males compared to females (QRS segment > 114 msec, 51% vs. 12%, P = 0.02, duration of the low amplitude signal < 40 mV) in the terminal portion of the averaged QRS complex > 38 msec, 47% vs. 25%, P = 0.05). Over 10 years of follow-up, 14 (22%) patients died, 10 (70%) due to cardiovascular non-arrhythmic complications, 6 with VLP compared to only 3 without (28.6% vs. 9.7%, P = 0.125, hazard ratio = 2.96, confidence intervals = 0.74-11.84) (are these numbers meant to total 10?)., Conclusions: Over 10 years of follow-up, the presence of VLP in early post-STEMI is not predictive of arrhythmic or non-arrhythmic cardiovascular mortality.

Background: Ascertainment of hospitalizations is critical to assess quality of care and the effectiveness and adverse effects of various therapies. Smartphones, mobile geolocators that are ubiquitous, have not been leveraged to ascertain hospitalizations. Therefore, we evaluated the use of smartphone-based geofencing to track hospitalizations., Methods and Results: Participants aged ≥18 years installed a mobile application programmed to geofence all hospitals using global positioning systems and cell phone tower triangulation and to trigger a smartphone-based questionnaire when located in a hospital for ≥4 hours. An in-person study included consecutive consenting patients scheduled for electrophysiology and cardiac catheterization procedures. A remote arm invited Health eHeart Study participants who consented and engaged with the study via the internet only. The accuracy of application-detected hospitalizations was confirmed by medical record review as the reference standard. Of 22 eligible in-person patients, 17 hospitalizations were detected (sensitivity 77%; 95% confidence interval, 55%-92%). The length of stay according to the application was positively correlated with the length of stay ascertained via the electronic medical record ( r =0.53; P =0.03). In the remote arm, the application was downloaded by 3443 participants residing in all 50 US states; 243 hospital visits at 119 different hospitals were detected through the application. The positive predictive value for an application-reported hospitalization was 65% (95% confidence interval, 57%-72%)., Conclusions: Mobile application-based ascertainment of hospitalizations can be achieved with modest accuracy. This first proof of concept may ultimately be applicable to geofencing other types of prespecified locations to facilitate healthcare research and patient care., (© 2017 American Heart Association, Inc.)

Purpose: The purpose of this study was to evaluate electrophysiologic study (EPS) in risk stratification of relative indications for pacemaker implantation (PMI) after transcatheter aortic valve implantation (TAVI)., Methods: We reviewed files of all patients who had a left bundle branch block (LBBB) and underwent EPS after TAVI between 3/2009 and 5/2015. The indications for EPS were new-onset LBBB and the presence of an old or a new-onset LBBB associated with either PR prolongation after TAVI (∆PR >20 ms) or with "slow" atrial fibrillation (<100/min). Pacemakers were implanted when significant infranodal disease was demonstrated. The control group comprised of 55 consecutive patients who underwent TAVI and had an indication for an EPS per our definitions. These patients were discharged without further intervention. All patients were followed during 1 year for the composite endpoint of mortality or PMI after hospital discharge., Results: Indications for EPS were new LBBB (n = 8, 30.8%), new LBBB + ∆PR >20 ms (n = 9, 34.6%), baseline LBBB + ∆PR >20 ms (n = 7, 26.9%) and new LBBB + slow AF <100 bpm (n = 2, 7.7%). Multilevel conduction disturbances involving the AV node (n = 19, 73.1%), the His (n = 3, 11.5%), and the infra-His system (n = 4, 15.4%) were found. Post discharge, there were 5 (9%) deaths and 3 (5.5%) PMI in the control group compared to none in the EPS group corresponding to event-free survival of 85 and 100%, respectively (p = 0.04)., Conclusions: Patients with LBBB with or without ∆PR >20 ms are at a higher risk of mortality and late PMI at 1-year follow-up. EPS can be used to safely identify patients in whom a PMI is needed.

Background: Dexmedetomidine is a selective alpha-2 adrenergic agonist with sedative, analgesic, and anxiolytic properties. Dexmedetomidine has not been approved for use in pediatrics. Dexmedetomidine has been reported to depress sinus node and atrioventricular nodal function in pediatric patients; it has been suggested that the use of dexmedetomidine may not be desirable during electrophysiological studies., Aim: We hypothesize that the use of dexmedetomidine does not inhibit the induction of supraventricular tachyarrhythmias (SVT) during electrophysiological studies and does not inhibit the ablation of such arrhythmias., Methods: In this retrospective, observational cohort study, we reviewed all cases presenting to the cardiac catheterization laboratory for diagnosis or treatment of SVT since 2007. All cases were performed by the same electrophysiologist. The anesthesia was provided by one of the three cardiac anesthesiologists. One cardiac anesthesiologist did not use dexmedetomidine during electrophysiological studies. A second used dexmedetomidine, but only with an infusion. The third used dexmedetomidine with a primary bolus and an infusion. Thus, the patients were stratified into three different groups: Group 1 patients did not receive any dexmedetomidine. Group 2 patients received a dexmedetomidine infusion of 0.5-1 μg·kg -1 ·h -1 . Group 3 patients received a dexmedetomidine infusion of 0.5-1 μg·kg -1 ·h -1 and a dexmedetomidine bolus prior to the infusion of 0.5-1 μg·kg -1 . We then compared those patients for the following variables: demographic data including age, sex, height, weight; anesthetic data such as, mask vs intravenous induction, identity of induction agent, amount of sevoflurane and propofol used; amount of dexmedetomidine used; presence of congenital heart disease and other comorbidities; the need for isoproterenol and dose, the need for adenosine and dose, and the need for any other medications to affect rhythm both before and after radiofrequency ablation; the ability to induce the arrhythmia, the type of arrhythmia, the presence of Wolff-Parkinson-White syndrome, the presence of an accessory pathway, the ablation rate, and the recurrence rate., Results: There was no difference in the anesthetic agents, except there was a lesser amount of propofol used in the dexmedetomidine groups (χ 2 (2) = 48.2, P < 0.001). There was no difference in the electrophysiological parameters among groups, except the Group 1 patients did require the use of isoproterenol in the preablation period less often compared to the dexmedetomidine groups (χ 2 (2) = 15.2, P < 0.01). However, with the greater use of isoproterenol, there was no difference in the ability to induce the arrhythmia. Moreover, the percentage of patients ablated, and the recurrence rate among groups was the same., Conclusions: We conclude that dexmedetomidine does not interfere with the conduct of electrophysiological studies for SVT and the successful ablation of such arrhythmias. However, dexmedetomidine use did result in a greater need for isoproterenol., (© 2016 John Wiley & Sons Ltd.)

The cardiac conduction velocity (CV) can be estimated by analysing the activation times (ATs) and the locations of the electrodes that are used for the intracardiac electrogram (IEGM) recording. Here, we study the problem of the CV estimation in sequential mapping without using any independent electrogram as a time alignment reference. We assume that the IEGMs are sequentially recorded from several sites, where at each site, at least two of the catheter's electrodes are in contact with the cardiac tissue. We consider the planar wavefront with stable CV that propagates within the recording sites throughout our data collection period. Assuming the zero-mean Gaussian AT estimation error, we derive the maximum likelihood estimations of the CV and AT at a desired location on the cardiac shell. The CV is estimated when the variance of the AT estimation error and the time delay between the sequential recordings are unknown variables. Our simulation results show that the proposed method can precisely estimate the CV of the planar wavefront.

Background: The QT interval measures cardiac repolarization, and prolongation is associated with adverse cardiovascular outcomes and death. The exponential Bazett correction formula overestimates the QT interval during tachycardia., Objective: We evaluated 4 formulas of QT interval correction in individuals with sinus tachycardia for the identification of coronary artery disease, heart failure, and mortality., Methods: The Penn Atrial Fibrillation Free study is a large cohort study of patients without atrial fibrillation. The present study examined 6723 Penn Atrial Fibrillation Free study patients without a history of heart failure and with baseline sinus rate ≥100 beats/min. Medical records were queried for index clinical parameters, incident cardiovascular events, and all-cause mortality. The QT interval was corrected by using Bazett (QT/RR(0.5)), Fridericia (QT/RR(0.33)), Framingham [QT + 0.154 * (1000 - RR)], and Hodges (QT + 105 * (1/RR - 1)) formulas., Results: In 6723 patients with a median follow-up of 4.5 years (interquartile range 1.9-6.4 years), the annualized cardiovascular event rate was 2.3% and the annualized mortality rate was 2.2%. QT prolongation was diagnosed in 39% of the cohort using the Bazett formula, 6.2% using the Fridericia formula, 3.7% using the Framingham formula, and 8.7% using the Hodges formula. Only the Hodges formula was an independent risk marker for death across the range of QT values (highest tertile: hazard ratio 1.26; 95% confidence interval 1.03-1.55)., Conclusion: Although all correction formulas demonstrated an association between QTc values and cardiovascular events, only the Hodges formula identified one-third of individuals with tachycardia that are at higher risk of all-cause mortality. Furthermore, the Bazett correction formula overestimates the number of patients with a prolonged QT interval and was not associated with mortality. Future work may validate these findings and result in changes to automated algorithms for QT interval assessment., (Copyright © 2016 Heart Rhythm Society. All rights reserved.)

Introduction and Objectives: This report presents the findings of the 2014 Spanish Catheter Ablation Registry., Methods: For data collection, each center was allowed to choose freely between 2 systems: retrospective, requiring the completion of a standardized questionnaire, and prospective, involving reporting to a central database., Results: Data were collected from 85 centers. A total of 12 871 ablation procedures were performed, for a mean of 149.5±103 procedures per center. The ablation targets most frequently treated were atrioventricular nodal reentrant tachycardia (n=3026; 23.5%), cavotricuspid isthmus (n=2833; 22.0%), and atrial fibrillation (n=2498; 19.4%). The number of ablation procedures for ventricular arrhythmias was similar to that of 2013, but there was a slight increase in the treatment of all the ventricular substrates, especially those associated with idiopathic ventricular tachycardia and scarring following myocardial infarction. The overall success rate was 95%, the rate of major complications was 1.3%, and the mortality rate was 0.02%., Conclusions: The 2014 registry shows that the number of ablation procedures performed continued its upward trend and that, overall, the success rate was high and the number of complications low. Ablation of complex conditions continued to increase., (Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.)

Purpose: To determine whether monomorphic ventricular tachycardias (VTs) have different characteristics and/or responses to antitachycardia pacing (ATP) with respect to the indication-primary prevention (PP) versus secondary prevention (SP)-among ICD patients with left ventricular dysfunction., Methods: We prospectively studied 551 VT (cycle length [CL] 329 ± 35 ms; PP 34%) occurring in 67 ICD patients with left ventricular dysfunction (LVEF 35 ± 8%). ICD programming was standardized, including ATP for slow (CL 400-321 ms) and fast VT (CL 250-320 ms). We analyzed the following aspects: CL, percentage of variability of the 12 RR intervals prior to ATP (P-RR)-which was calculated by dividing the mean difference between each R-R interval with the next one by the CL × 100-and type of termination: immediate (VT ceased immediately upon ATP completion) or delayed (VT persisted after ATP)., Results: ATP was successful in 86% of VTs. VTs occurring in SP patients had a lower P-RR, median (IQR) 2.7% (1.2-3.7) versus 1.9% (0.9-3.2); p = 0.002; they terminated immediately after ATP less frequently (27% versus 12%; p < 0.001), and although they were more frequently slow (51% versus 67%; p = 0.01), ATP was less effective in them, 92 versus 80% (p = 0.02)., Conclusions: VTs occurring in SP patients are slower, more stable, and they terminate less frequently at ATP. Therefore, compared with PP, SP patients seem to have fewer self-terminating VTs.

The purposes of this study were to characterize and quantify concordance between consecutive atrial and ventricular activation time points through analysis of phases and to explore its association with outcomes in patients with implantable cardioverter-defibrillator (ICD). Patients with structural heart disease and dual-chamber ICDs underwent 5min baseline right ventricular (V) near-field and atrial (A) electrogram (EGM) recording. The cross-dependencies of phase dynamics of the changes in consecutive A (AA') and V (VV') were quantified and the AV phase dependency index was determined. In Cox regression analysis, a high AV phase index (in the highest quartile, >0.259) was significantly associated with higher risk of ventricular tachyarrhythmias (HR 2.84; 95% CI 1.05-7.67; P=0.04). In conclusion, in ICD patients with structural heart disease, high sinus AV phase dependency index on EGM is associated with the risk of ventricular arrhythmia., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Introduction: High dominant frequency (DF) sites during atrial fibrillation (AF) play an important role in the perpetuation of AF. We investigated the relationship between the DFs from intracardiac electrograms (iEGM) and the surface electrocardiogram (ECG) during AF, and the relationship between the surface ECG DF and atrial remodeling., Methods: In 48 patients (57±11 years, 47 males, 20 paroxysmal), the V1-6 precordial leads and specific V7-9 ECG leads were recorded for 8s for an off-line analysis before AF ablation. The QRS-T complex was canceled by a template subtraction algorithm using the CEPAS™ system (Cuoretech Pty Ltd, Sydney, Australia). The iEGM DF maps, reconstructed using the Ensite NavX (St. Jude Medical, Inc., St. Paul, MN, USA) system, were simultaneously created for the right atrium and left atrium (LA) during AF., Results: The DF in leads V8 and V9 correlated well with the DF in the LA floor (R=0.55, p<0.01; R=0.68, p<0.01, respectively), and that in V1 with the right inferior pulmonary vein (R=0.45, p=0.01). Persistent AF patients had a significantly lower DF in lead V9 (5.7±1.0Hz vs. 6.7±1.5Hz, p=0.02) than paroxysmal AF patients., Conclusions: A frequency analysis from lead V9 reflects the LA electrical activity., (Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Introduction: There are several methods to induce ventricular fibrillation (VF) during defibrillation threshold (DFT) testing. Delivering a shock at a critical time during the T wave (T-shock) is the conventional approach, while delivering a constant direct current voltage (DC stim) from the implantable cardioverter defibrillator is an alternative method. Only a few reports compare VF induction methods. The purpose of this study was to evaluate the effects and safety of DC stim versus T-shock., Methods: We retrospectively investigated 414 consecutive patients undergoing DFT testing. We compared the two groups (DC stim and T-shock) with respect to clinical characteristics, electrocardiogram (ECG) changes, and complications., Results: Ventricular arrhythmia, including ventricular tachycardia (VT) and VF, was induced by DC stim in 93 patients or T-shock in 321 patients. No more than three attempts were performed during one procedure. There was no significant difference in the baseline ECG, induced tachycardia cycle length (TCL), or complications between the two groups. However, the induced TCL was significantly shorter than the clinical TCL regardless of induction method (P = 0.001). Five patients suffered major complications (i.e., electromechanical dissociation or incessant VT). A history of atrial fibrillation was significantly greater in patients with major complications than the others (80% vs 24%, P = 0.004), and was an independent predictor on multivariate analysis., Conclusions: There is no significant difference in induced TCL or complications between the DC stim and T-shock. The induced TCL is significantly shorter than clinical TCL regardless of induction method., (© 2015 Wiley Periodicals, Inc.)

Despite the advent of non-fluoroscopic technologies, fluoroscopy remains the cornerstone of imaging in most interventional electrophysiological procedures, from diagnostic studies to ablation interventions and device implantation. The purpose of the European Heart Rhythm Association survey was to provide an insight into regulatory policies and physicians' clinical practice when using fluoroscopy during ablation procedures and device implantation. The survey has shown that only 50% of the participating centres worked with low frame rates (3-6 frames per second) and that the left anterior oblique projection, with higher radiation exposure for the physician, is used for nearly every ablation target. Although three-dimensional imaging systems may reduce the radiation exposure, most centres never used these systems for standard ablation procedures and a trend is that non-fluoroscopy technologies are even less frequently used than in 2012, when the use of robotic systems was still rare. Even less costly equipment such as lead gloves, lead glass cabins, or radiation absorbing pads are still not routinely used., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Aims: Children and adolescents with ventricular pre-excitation (VPE) are at increased risk for sudden cardiac death (SCD). Although antiarrhythmic therapy and catheter ablation are well established temporary or definitive treatments for patients with Wolff-Parkinson-White (WPW) syndrome, the optimal management of children with asymptomatic VPE remains to be clearly defined. On the basis of the most recent guidelines and recommendations, the aim of this study was to determine the electrophysiological characteristics of young patients with VPE and WPW syndrome to assess and compare their potential risk of SCD., Methods and Results: We retrospectively investigated 124 consecutive young patients with VPE (51 with WPW syndrome and 73 asymptomatic) who underwent transoesophageal electrophysiological study. At baseline, atrioventricular reentrant tachycardia (AVRT) was induced in 13 WPW vs. 10 asymptomatic patients (25.5 vs. 13.7%, P = NS). Atrial fibrillation (AF) was induced in 13 WPW vs. 15 asymptomatic patients (25.5 vs. 20.5%, P = NS). A shortest pre-excited R-R interval (SPERRI) ≤250 ms during AF was found in four WPW vs. six asymptomatic patients (30.8 vs. 40%, P = NS). During isoproterenol infusion or stress testing, AVRT was induced in 31 of 44 WPW vs. 33 of 69 asymptomatic patients (70.4 vs. 47.8%, P = 0.018). Atrial fibrillation was induced in 12 of 44 WPW vs. 21 of 69 asymptomatic patients (27.3 vs. 30.4%, P = NS). A SPERRI ≤ 210 ms was found in 6 of 12 WPW vs. 10 of 21 asymptomatic patients (50 vs. 47.6%, P = NS). No statistically significant correlation was observed between accessory pathway location and symptoms, AVRT/AF inducibility, or mean APERP/SPERRI values., Conclusion: Children and adolescents with WPW syndrome have a higher rate of AVRT inducibility than asymptomatic patients. However, no differences between the two groups were found in atrial vulnerability and parameters related to the risk of SCD., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Aims: There has been large variations in the use of invasive electrophysiological therapies in the member countries of the European Society of Cardiology (ESC). The aim of this analysis was to provide comprehensive information on cardiac implantable electronic device (CIED) and catheter ablation therapy trends in the ESC countries over the last five years., Methods: The European Heart Rhythm Association (EHRA) has collected data on CIED and catheter ablation therapy since 2008. Last year 49 of the 56 ESC member countries provided data for the EHRA White Book. This analysis is based on the current and previous editions of the EHRA White Book. Data on procedure rates together with information on economic aspects, local reimbursement systems and training activities are presented for each ESC country and the five geographical ESC regions., Results: In 2013, the electrophysiological procedure rates per million population were highest in Western Europe followed by the Southern and Northern European countries. The CIED implantation and catheter ablation rate was lowest in the Eastern European and in the non-European ESC countries, respectively. However, in some Eastern European countries with relative low gross domestic product procedure rates exceeded those of some wealthier Western countries, suggesting that economic resources are not the only driver for utilization of arrhythmia therapies., Conclusion: These statistics indicate that despite significant improvements, there still is considerable heterogeneity in the availability of arrhythmia therapies across the ESC area. Hopefully, these data will help identify areas for improvement and guide future activities in cardiac arrhythmia management., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Based on a survey sent to Portuguese centers that perform diagnostic and interventional electrophysiology and/or implantable cardioverter-defibrillator (ICD) implantations, the authors analyze the number and type of procedures performed during 2012 and compare these data with previous years. In 2012, a total of 2561 diagnostic electrophysiologic studies were performed, which were followed by ablation in 2017 cases, representing a steady situation compared with the previous year. There was a 12% increase in the number of ablation procedures for atrial fibrillation, making it for the first time the most frequent indication for ablation, overtaking atrioventricular nodal reentrant tachycardia. The total number of first ICD implantations was 1048 (around 100 per million population), of which 375 were cardiac resynchronization devices (BiV ICDs). This represents a slight decrease (3.3%) in the total number of new implants, with an increase of 10% in the number of BiV ICDs compared to the previous year. However, there was a considerable increase in the number of ICD generator replacements, resulting in an overall increase of 3.5% in implantations performed in 2012. Some comments are made regarding developments in this activity and its current status, and on some factors that may influence the dynamics of this area of interventional cardiology., (Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.)

Clinical electrophysiology (EP) and catheter ablation of arrhythmias are rapidly evolving in recent years. More than 50 000 catheter ablations are performed every year in Europe. Emerging indications, an increasing number of procedures, and an expected high quality require national and international standards as well as trained specialists. The purpose of this European Heart Rhythm Association (EHRA) survey was to assess the practice of requirements for EP personnel, equipment, and facilities in Europe. Responses to the questionnaire were received from 52 members of the EHRA research network. The survey involved high-, medium-, and low-volume EP centres, performing >400, 100-399, and under 100 implants per year, respectively. The following topics were explored: (i) EP personnel issues including balance between female and male operators, responsibilities within the EP department, age profiles, role and training of fellows, and EP nurses, (ii) the equipments available in the EP laboratories, (iii) source of patient referrals, and (iv) techniques used for ablation for different procedures including sedation, and peri-procedural use of anticoagulation and antibiotics. The survey reflects the current EP personnel situation characterized by a high training requirement and specialization. Arrhythmia sections are still most often part of cardiology departments and the head of cardiology is seldom a heart rhythm specialist. Currently, the vast majority of EP physicians are men, although in the subgroup of physicians younger than 40 years, the proportion of women is increasing. Uncertainty exists regarding peri-procedural anticoagulation, antibiotic prophylaxis, and the need for sedation during specific procedures., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Purpose: Interventional cardiac electrophysiology (EP) has experienced a significant growth in Canada. Our aim is to establish a periodic registry as a nationwide initiative., Methods: The registry is designed to collect information regarding EP laboratory infrastructure, human resources, and the spectrum and volumes of EP procedures. Respective administrative staff were contacted electronically., Results: Out of 25 identified Canadian EP centers, 19 centers (76%) have participated in the registry. Responding centers have access on average to 5.3 lab days per week to perform EP studies/ablations; average lab time per full- and part-time (prorated to 0.5) EP physician is 0.8 day per week. Diagnostic EP studies and radio-frequency ablations are performed in all (19) centers; cryoablation is available in 83% of centers. Two centers have remote magnetic navigation systems. EnSite NavX is the most widely available 3D mapping system utilized in 15 (83%) centers, followed by CARTO and intracardiac echo which are each available in 14 (78%) centers; LocaLisa is actively used in one center. The number of full-time physicians ranges between 0 and 7, with a mean of 3.5 full-time physicians per center. The ratio of staff to trainees is 1.6:1. A total of 8,041 EP procedures are performed in the 19 centers per annum. On an annual average, 104 procedures per one operator and 159 procedures per trainee are performed., Conclusions: This registry provides contemporary information on invasive EP lab resources and procedures in Canada. It also demonstrates that Canadian EP procedural intensities of practice and training are comparable to international standards.

Background: Brugada syndrome (BrS) can be difficult to diagnose and treat, especially in the young patient. As there is currently no consensus on the evaluation and treatment of BrS in the pediatric population, we sought to describe the current practice for the diagnosis and treatment of BrS among pediatric electrophysiologists., Methods: A web-based survey was distributed to 204 physician members (MDs) of The Pediatric and Adult Congenital Electrophysiology Society (PACES). Practice characteristics, BrS patient attributes, and diagnostic and therapeutic preferences were collected., Results: Responses were obtained from 83 pediatric electrophysiologists. The most common initial presentation was family history. There is a large variation in testing, particularly in the use of electrophysiology (EP) studies, drug challenge testing, and genetic testing. Despite limited treatment options, there is only consensus in the therapeutic approach to the pediatric patient with symptomatic BrS with 97% of physicians recommending an implantable cardioverter defibrillator (ICD). In the asymptomatic patient, a wide variation in therapy was seen with only 27% of physicians recommending an ICD CONCLUSIONS: Significant practice variation exists among pediatric electrophysiologists with deviation from accepted diagnostic and therapeutic practices for adult BrS patients. Further studies are necessary to establish best practice guidelines for BrS in the pediatric EP community., (©2014 Wiley Periodicals, Inc.)

Objective: This article aims to give a comprehensive description of cardiac resource utilization in adults at a freestanding children's hospital., Design: Retrospective chart review., Setting: Large, tertiary, freestanding children's hospital., Patients: Adults (18 years of age and older) seen within the heart center or evaluated by heart center personnel from January 1, 2006 through December 31, 2010., Results: There were 2794 adults that utilized cardiology services during the study period. The mean patient age was 23.5 ± 8.4 years (18-70.5). The 1748 (62.6%) patients had a diagnosis of congenital heart disease. There were a total of 525 catheterization laboratory encounters and 104 cardiac surgical procedures performed on adult patients during the 5-year study period. The in-hospital mortality for all invasive encounters was 0%. The minor adverse event rate for all invasive encounters was 6.7% and 4.8%, respectively. Also, the overall major adverse event rates were 1.9% and 4.8%, respectively. There were 162 cardiology evaluations performed on adults in the emergency room. There were a total of 5489 adult cardiology clinic visits. The most common congenital heart disease diagnoses were: tetralogy of Fallot: 228 (13%), D-transposition of the great arteries: 208 (11.9%), single ventricle physiology: 187 (10.7%), atrial septal defect 128: (7.3%), and ventricular septal defect: 117 (6.7%). Overall, the complexity of congenital heart disease was: simple: 41%, moderate: 37%, and complex: 22%., Conclusions: A significant and growing number of adult patients are currently being cared for at pediatric institutions. Excellent outcomes have been achieved at these centers with dedicated adult congenital heart disease services, consisting of both cardiologists and other faculty trained in adult medicine. Others with training in adult medicine, whether they be staff or contracted consulting services, are also required to help manage adult comorbidities., (© 2014 Wiley Periodicals, Inc.)

Background: Low conduction velocity (CV) in the area showing low electrogram amplitude (EA) is characteristic of reentry circuit of atypical atrial flutter (AFL). The quantitative relationship between CV and EA remains unclear. We characterized AFL reentry circuit in the right atrium (RA), focusing on the relationship between local CV and bipolar EA on the circuit., Methods and Results: We investigated 26 RA AFL (10 with typical AFL; 10 atypical incisional AFL; 6 atypical nonincisional AFL) using CARTO system. By referring to isochronal and propagation maps delineated during AFL, points activated faster on the circuit were selected (median, 7 per circuit). At the 196 selected points obtained from all patients, local CV measured between the adjacent points and bipolar EA were analyzed. There was a highly significant correlation between local CV and natural logarithm of EA (lnEA) (R(2) = 0.809, P < 0.001). Among 26 AFL, linear regression analysis of mean CV, calculated by dividing circuit length (152.3 ± 41.7 mm) by tachycardia cycle length (TCL) (median 246 msec), and mean lnEA, calculated by dividing area under curve of lnEA during one tachycardia cycle by TCL, showed y = 0.695 + 0.191x (where: y = mean CV, x = lnEA; R(2) = 0.993, P < 0.001). Local CV estimated from EA with the use of this formula showed a highly significant linear correlation with that measured by the map (R(2) = 0.809, P < 0.001)., Conclusion: The lnEA and estimated local CV show a highly positive linear correlation. CV is possibly estimated by EA measured by CARTO mapping., (© 2013 Wiley Periodicals, Inc.)

Purpose: Electrophysiological studies and radiofrequency catheter ablations require single or multiple sheath placements through femoral vein cannulation. The objective of this study was to determine the incidence, predictors, and outcomes of deep vein thrombosis (DVT) following such procedures., Methods and Results: We prospectively enrolled 220 consecutive patients with a median age of 70 [60-79] years. The median duration of the procedures from insertion to removal of sheaths was 45 [30-75] min. At least two sheaths were inserted in 158 (72%) of the cases. Duplex ultrasonography evaluation of the lower leg veins was performed 6 h after the procedure and revealed common femoral vein thrombosis in 11 (5%) patients. All thrombi were partial and none was complete. Thrombi were mobile in four patients and extended to the external iliac vein in three patients. None of the patients presented with clinical signs of DVT or pulmonary embolism. Anticoagulation was prescribed for 2-4 weeks and a follow-up duplex ultrasonography obtained in the first seven patients revealed complete resolution of thrombi in all cases. On multivariate analysis, two predictors of thrombosis occurrence were identified: a greater sum of sheath diameters (odds ratio, 1.41 [95% confidence interval, 1.25-1.60] per 1-French increase; p < 0.001) and a longer procedural duration (odds ratio, 1.02 [95% confidence interval, 1.00-1.04] per 1-min increase; p = 0.04)., Conclusions: Asymptomatic femoral DVT occur in 5% of electrophysiological studies and right-heart radiofrequency catheter ablations, particularly when large sheaths are inserted for a longer period. The role of anticoagulation in this clinical setting warrants further evaluation.

Aims: To provide a nationwide survey (and reference for the future) on cardiac electrophysiologists, types and numbers of invasive electrophysiological procedures, and training opportunities in 2010., Methods and Results: German cardiology centres performing invasive electrophysiology were identified from quality reports and contacted to fill a questionnaire. A majority of 122 centres (65%) responded. Electrophysiology (ablation procedures and device therapy) was mainly part of a cardiology department (82%), and only in 9% independent (own budget). In only 58% of the centres, (at least) two physicians were present during catheter ablations. Although in 2010, women represented 59.4% of physicians <35 years old, only 26% of physicians in electrophysiology training were female. In total, 33 420 catheter ablations were performed with a median number of 180 per centre. Atrial fibrillation (AF) was the most common arrhythmia invasively treated (35%). At least 50 AF ablations were performed in 53% of the centres. Of the centres performing AF ablations, consecutive left atrial arrhythmias were treated by catheter ablation only in 75%, and only 44% had in-house surgical backup. Only one-fourth of the 122 centres fulfilled all requirements for training centre accreditation according to the European Heart Rhythm Association and the German Cardiac Society., Conclusion: The results indicate a high number of electrophysiology centres and procedures in Germany. Atrial fibrillation was the most common arrhythmia invasively treated. An increasing demand for catheter ablation is likely, but training opportunities are limited. Women are clearly underrepresented. A co-operation of higher and lower volume electrophysiology centres may be necessary for training purposes.

Background: It has been suggested that more-complex fibrillation requires higher energy shocks to terminate. Furthermore, animal studies have demonstrated that shock timing also plays a role. The objective of this study was to test these assertions in a clinical context., Methods: Near- and far-field electrograms were collected during defibrillation threshold testing. Fibrillation complexity was measured by quantifying the organization in the signals with wavelet-based methods, scaling exponent, and cross-correlation analysis. Receiver operator characteristic curves were used to determine predictive value. The effect of the phase at which defibrillation shocks were applied was also determined., Results: No measure was able to classify whether a particular shock would be successful. All performed very poorly. Shock timing played no role in defibrillation outcome., Conclusions: Signal organization of a local electrogram and phase of shock delivery do not relate to minimum defibrillation shock energy immediately after ventricular fibrillation onset., (Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

The purpose of this European Heart Rhythm Association (EHRA) survey is to assess the implementation and use of imaging techniques in cardiac electrophysiology (EP) and device procedures across European cardiovascular centres. Forty European centres, all members of the EHRA EP research network, responded to this survey. Thirty-one centres (88%) use transthoracic echocardiography (TTE) to evaluate left atrial size and/or volume before atrial fibrillation (AF) ablation. Sixteen centres (46%) perform delayed-enhancement cardiac magnetic resonance imaging (MRI) to guide ventricular tachycardia ablation. Electroanatomical mapping (EAM) systems are available in >65% of responding centres and the use of robotic catheter and remote magnetic navigation systems is limited to <10%. Fusion of EAM data with cardiac computed tomography (CT) and/or MRI is performed in up to 43% of AF ablation procedures. Seventeen out of 35 (49%) responding centres also perform TTE to predict a favourable response to cardiac resynchronization therapy (CRT). Imaging of the cardiac venous system with CT and identification of myocardial scar using CT or MRI, is not routinely performed in the majority of centres [32 (91%) and 26 (75%) centres, respectively) prior to CRT. This EHRA survey shows that several imaging techniques are used to guide catheter ablation and CRT procedures in European centres. Echocardiographic imaging, EAM techniques, and cardiac CT/MRI are commonly used.

Background: Syncope in Wolff-Parkinson-White syndrome (WPW) is without relationship with WPW or reveals a poorly tolerated arrhythmia. Electrophysiologic study (EPS) is recommended. The purpose of the study was to evaluate the influence of the patient's age on the causes and prognosis of syncope., Methods: A total of 98 patients, mean age 35 ± 18 years, with WPW were admitted for syncope. Note that 29 were aged between 9 and 19 years (mean 15 ± 3) (children and teenagers/group I), 45 between 20 and 49 years (mean 34 ± 8) (adults/group II), and 24 between 50 and 70 years (mean 60 ± 8) (elderly/group III). EPS consisted of atrial pacing and programmed atrial stimulation in control state and after isoproterenol., Results: Potentially malignant form (rapid conduction in accessory pathway >240 beats/min in control state or >300 beats/min after isoproterenol and atrial fibrillation [AF] induction) was more frequent in group I (34%) than in groups II (7%) (P < 0.002) and III (0%) (P < 0.001). Orthodromic atrioventricular reentrant tachycardia (AVRT) and AF were induced as frequently in groups I (59, 34%), II (47, 15.5%), and III (54, 17%). AVRT was induced in all but one patient with malignant form. EPS was as frequently negative in groups I (27.5%), II (44%), and III (37.5%). Natural follow-up (mean 8 ± 6 years) indicated a favorable prognosis, only related to AVRT induction. Induced AF was without significance., Conclusions: Data in syncope and WPW syndrome depended on age: electrophysiological malignant form was frequent in children/teenagers, rare in adults, and absent in elderly. AVRT, the main cause of syncope, was as frequent in all ranges of age. AF's induction alone had no significance. Final prognosis was favorable., (©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.)