Intra-His bundle block with Wenckebach phenomenon.

A 66-year-old lady presented with shortness of breath and a Wenckebach atrioventricular (AV) conduction pattern on the ECG. The electrophysiologic study showed split-His potentials and intra-Hisian Wenckebach. The case highlights the interesting finding of Wenckebach conduction in the His bundle.

Age-Related Changes in the Anatomy of the Triangle of Koch: Implications for Catheter Ablation of Atrioventricular Nodal Re-entry Tachycardia.

Background: Atrioventricular nodal re-entrant tachycardia is the most common type of paroxysmal supraventricular tachycardia. We sought to assess whether important anatomic factors, such as the location of the slow pathway, proximity to the bundle of His, and coronary sinus ostium dimensions, varied with patient age, and whether these factors had an impact on procedural duration, acute success, and complications.

Methods: Baseline demographic and procedural data were collected, and the maps were analyzed.

Challenge and Impact of Quinidine Access in Sudden Death Syndromes: A National Experience.

Objectives: This study sought to determine the nature of quinidine use and accessibility in a national network of inherited arrhythmia clinics.

Background: Quinidine is an antiarrhythmic medication that has been shown to be beneficial in select patients with Brugada syndrome, early repolarization syndrome, and idiopathic ventricular fibrillation. Because of the low prevalence of these conditions and restricted access to quinidine through a single regulatory process, quinidine use is rare in Canada.

Clinical research: remote magnetic navigation vs. manually controlled catheter ablation of right ventricular outflow tract arrhythmias: a retrospective study.

Aims: Remote magnetic navigation (RMN) is an alternative to manual catheter control (MCC) radiofrequency ablation of right ventricular outflow tract (RVOT) arrhythmias. The data to support RMN approach is limited. We aimed to investigate the clinical and procedural outcomes in a cohort of patients undergoing RVOT premature ventricular complex/ventricular tachycardia (PVCs/VT) ablation procedures using RMN vs.

Are there increased periprocedural complications with the MRI-conditional Medtronic Revo SureScan Pacing System? : A meta-analysis.

Background: The use of magnetic resonance imaging (MRI)-conditional permanent pacemakers has increased significantly. In this meta-analysis, we examine the safety of MRI-conditional pacing systems in comparison with conventional systems.

Methods: An electronic search was performed using major databases, including studies that compared the outcomes of interest between patients receiving MRI-conditional pacemakers (MRI group) versus conventional pacemakers (control group).

Pacing Spikes All Over.

Ventricular safety pacing (VSP) is used to avoid cross talk by delivering ventricular stimulus shortly after an atrial-paced event if ventricular-sensed event occurs. Although VSP is a protective feature that exists for decades in different pacing devices, there are some reports of unfavorable outcomes of this algorithm. More so, health care providers sometimes face difficulties in interpreting and dealing with VSP strips.

The gap between indicated and prescribed stroke prevention therapies in a high-risk geriatric population.

Purpose: The use of oral anticoagulation (OAC) in the elderly population with atrial fibrillation (AF) treated in long-term care (LTC) facilities is inconsistent. We examined the magnitude and sources of the gap between indicated and prescribed OAC in the elderly population with AF.

Methods: We retrospectively scanned the electronic medical record (EMR) and pharmacy data of 25 LTC facilities in Ontario, Canada.

Is lower base rate detrimental to transcatheter aortic valve implantation patients requiring pacemakers?

Sudden cardiac death related to polymorphic ventricular tachycardia/ventricular fibrillation has been well reported post atrioventricular junction ablation. The practice of faster pacing rate immediately after atrioventricular junction ablation is well recognized to decrease the risk of sudden cardiac death. We propose that this practice (faster pacing rate) be implemented in patients who need permanent pacemakers secondary to transcatheter aortic valve implantation (or even surgical aortic valve interventions).

Validation of a Novel Digital Tool in Automatic Scoring of an Online ECG Examination at an International Cardiology Meeting.

Background: We have previously developed a novel digital tool capable of automatically recognizing correct electrocardiography (ECG) diagnoses in an online exam and demonstrated a significant improvement in diagnostic accuracy when utilizing an inductive-deductive reasoning strategy over a pattern recognition strategy. In this study, we sought to validate these findings from participants at the International Winter Arrhythmia School meeting, one of the foremost electrophysiology events in Canada.

Methods: Preregistration to the event was sent by e-mail.

Impact of Contact Force Technology on Atrial Fibrillation Ablation: A Meta-Analysis.

Background: Catheter-tissue contact is essential for effective lesion formation, thus there is growing usage of contact force (CF) technology in atrial fibrillation ablation. We conducted a meta-analysis to assess the impact of CF on clinical outcomes and procedural parameters in comparison to conventional catheter for atrial fibrillation ablation.

Methods And Results: An electronic search was performed using major databases.

Atrial fibrillation ablation using remote magnetic navigation and the risk of atrial-esophageal fistula: international multicenter experience.

Purpose: Remote magnetic navigation (RMN) has been used in various electrophysiological procedures, including atrial fibrillation (AF) ablation. Atrial-esophageal fistula (AEF) is one of most disastrous complications of AF ablation. We aimed to evaluate the incidence of AEF during AF ablation using RMN in comparison to manual ablation.

Magnetic resonance estimates of the extent and heterogeneity of scar tissue in ICD patients with ischemic cardiomyopathy predict ventricular arrhythmia.

Background: The majority of patients receiving implantable cardioverter-defibrillator (ICD) implantation under current guidelines never develop sustained ventricular arrhythmia; therefore, better markers of risk for sustained ventricular tachycardia and/or ventricular fibrillation are needed.

Objective: The purpose of this study was to identify cardiac magnetic resonance arrhythmic risk predictors of ischemic cardiomyopathy before ICD implantation.

Methods: Forty-three subjects (mean age, 64.

Empiric slow pathway ablation in non-inducible supraventricular tachycardia.

Background: The data supporting the practice of empiric slow pathway ablation (ESPA) in patients with documented supraventricular tachycardia (SVT) who are non-inducible at electrophysiology study (EPS) is limited. The aim of this study is to assess the efficacy of ESPA in adults.

Methods: A multi-center cohort study of patients who had ESPA between January 2008 and October 2013 was performed.

The prevalence and risk factors for atrioesophageal fistula after percutaneous radiofrequency catheter ablation for atrial fibrillation: the Canadian experience.

Purpose: Atrioesophageal fistula (AEF) is an infrequent complication of radiofrequency (RF) ablation for atrial fibrillation (AF). The aim of this study was to determine the prevalence and operator-dependent factors associated with AEF using a nationwide survey of electrophysiologists (EP).

Methods: Thirty-eight EPs performing AF ablation between 2008 and 2012 were invited to complete a web-based questionnaire assessing the prevalence and factors associated with AEF.

Robotically assisted ablation of atrial fibrillation: a systematic review and meta-analysis.

Background: Robotic systems are becoming increasingly common in complex ablation procedures. We conducted systematic review and meta-analysis on the procedural outcomes of Magnetic Navigation System (MNS) in comparison to conventional catheter navigation for atrial fibrillation (AF) ablation.

Methods: An electronic search was performed using multiple databases between 2002 & 2012.

Safety and efficacy of dabigatran compared with warfarin for patients undergoing radiofrequency catheter ablation of atrial fibrillation: a meta-analysis.

Background: The safety and efficacy of dabigatran in the periprocedural period for patients undergoing atrial fibrillation ablation is not well established. We conducted a meta-analysis of the periprocedural use of dabigatran vs warfarin (with or without heparin bridging).

Methods: A literature search was performed using multiple databases.

Remote magnetic navigation for catheter ablation of atrioventricular nodal reentrant tachycardia: a systematic review and meta-analysis.

Catheter ablation has become a well-established, first-line therapy for atrioventricular nodal reentrant tachycardia (AVNRT), the most common reentry supraventricular tachycardia in humans. Robotic systems are becoming increasingly common in both complex and simple ablation procedures with presumed potential improvements in procedural efficacy and safety. The authors of this article conducted a systematic review and meta-analysis on the effectiveness and safety of the magnetic navigation system (MNS) in comparison with conventional catheter navigation for AVNRT ablation.

Three-dimensional localization versus fluoroscopically only guided ablations: a meta-analysis.

Objectives: Data regarding efficacy and safety of three-dimensional localization systems (3D) are limited. We performed a meta-analysis of randomized trials comparing combined fluoroscopy- and 3D guided to fluoroscopically-only guided procedures.

Design: A systematic search was performed using multiple databases between 1990 and 2010.

Approaches to empiric ablation of slow pathway: results from the Canadian EP web survey.

Aim: Dual atrioventricular nodal physiology (DAVNP) is a frequent finding in patients with suspected or documented supraventricular tachycardia (SVT). Empiric slow pathway ablation (ESPA) is sometimes performed in patients with DAVNP without inducible SVT at the time of electrophysiological study. Evidence to guide this practice in the adult population is limited.

Correspondence between simple 3-D MRI-based computer models and in-vivo EP measurements in swine with chronic infarctions.

The aim of this paper was to compare several in-vivo electrophysiological (EP) characteristics measured in a swine model of chronic infarct, with those predicted by simple 3-D MRI-based computer models built from ex-vivo scans (voxel size <1  mm(3)). Specifically, we recorded electroanatomical voltage maps (EAVM) in six animals, and ECG waves during induction of arrhythmia in two of these cases. The infarct heterogeneities (dense scar and border zone) as well as fiber directions were estimated using diffusion weighted DW-MRI.

Utility of three-dimensional echocardiography in assessing and predicting response to cardiac resynchronization therapy.

Background: Cardiac resynchronization therapy (CRT) can be a valuable treatment for heart failure. However, there are high nonresponse rates using current CRT inclusion criteria.

Objective: To assess the value of three-dimensional echocardiography (3DE) in predicting response to CRT.

The impact of catheter-tracking technologies on efficacy and safety in cardiac electrophysiology.

Usage of nonfluoroscopic mapping systems is increasingly common in invasive cardiac electrophysiology. Novel technologies have resulted in numerous systems potentially leading to improved outcomes of the procedures. Apart from the improvement in procedural outcomes, usage of these systems is associated with a significant reduction in x-ray exposure.

Determinants of pacemaker dependency after coronary and/or mitral or aortic valve surgery with long-term follow-up.

The aim of the present study was to investigate potential preoperative, operative, and postoperative predictors of pacemaker (PM) dependency after coronary, mitral valve, and aortic valve surgery. One hundred two patients (mean age 68 +/- 11 years; 62% men) who had received a permanent PM after cardiac surgery were included. The presence of any pacing activity in VVI mode with a lower rate of 30 beats/min was defined as PM dependency.