Electrophysiology Practice Research Articles

Practical issues in the management of novel oral anticoagulants-cardioversion and ablation.

Recent research and publication of various landmark trials have led to the approval and subsequent use of novel oral anticoagulants (NOACs) in clinical practice. The use of these newer agents for anticoagulation offers several benefits such as greater specificity, relatively rapid onset and offset of action and a predictable pharmacological profile as compared to warfarin. With the increasing use of these agents, several key issues ranging from appropriate selection to management of complications and considerations for concurrent procedures (cardioversion and catheter ablation) have also emerged. The timing of interruption of anticoagulants prior to catheter ablation and re-initiation after the procedure to minimize the peri-procedural thromboembolism risk without increasing the bleeding risk is of key relevance in electrophysiology practice. The use of NOACs in patients undergoing catheter ablation and cardioversion also requires special considerations based on the pharmacological properties of the individual agent and the presence of comorbidities such as renal and or hepatic impairment. In this review we aim to discuss the practical considerations with the use of NOACs in the setting of cardioversion and catheter ablation based on the currently available data.

What Currents Underlie Pulmonary Vein Automaticity?

What Currents Underlie Pulmonary Vein Automaticity?

A New Approach to Objective Evaluation of Human Visual Acuity

The subject matter of this paper refers to the objective visual acuity assessment methods using non-invasive measurements of visual evoked potentials (VEP) by means of special electrodes. An attempt was made to classify the data acquired enabling prompt and objective visual acuity evaluation. The purpose of the comparative measurements carried out in the paper was an attempt to calibrate the peak-to-peak VEP curve sections in the visual acuity function. Full Text: PDF References Cysewska-Sobusiak A., Hulewicz A., Grzybowski A., and Boltrukiewicz M., Obtaining and analysis of multifocal electroretinogram, Proc. of the 3rd European Medical and Biologi-cal Engineering Conference EMBEC 2005, Prague, Czech Republik, 20-25 November 2005, IFMBE Proceedings, vol. 11, pp. 1-6. Cysewska-Sobusiak A., Hulewicz A., Grzybowski A., and Boltrukiewicz M., Computer-assisted acquisition and statistical evaluation of multifocal Visual Evoked Potentials, Proc. of the IEEE International Conference on Virtual Environments, Human-Computer Interfaces, and Measurement Systems VECIMS 2006, La Coruna, Spain, pp. 149-153, 10-12 July 2006. Cysewska-Sobusiak A., Hulewicz A., and Grzybowski A., Application of visual evoked potentials to objective visual accuity assessment, Proc. of the 4th IET International Conference on Advances in Medical, Signal and Information Processing MEDSIP 2008, Santa Margherita Ligure, Italy, 14-16 July 2008. Heckenlively J. and Arden G. B., Principles and practice of clinical electrophysiology of vision, Mosby Year Book, 1991. Marmor M.F., Fulton A.B., Holder G.E., et al, ISCEV Standard for full-?eld clinical electroretinography, Documenta Ophthalmologica, vol. 118, pp. 69-77, February 2009. CrossRef Odom J. V., Bach M., Brigell M., et al., ISCEV standard for clinical visual evoked potentials, Documenta Ophthalmologica, vol. 120, 2010, pp. 111-119. CrossRef RETIport21: VEP, EOG, ERG Version 06.02, Instruction manual, Roland Consult, Germany, 2006. Smith G., Atchison D. A., The eye and visual optical instrument, Cambridge University Press, New York, 1997. CrossRef W. H. Ridder III, Methods of visual acuity determination with the spatial frequency sweep visual evoked potential, Documenta Ophthalmologica, vol. 109, pp. 239-247, November 2004. CrossRef

Abstract 9923: The Ethics of Unilateral ICD and CRT-D Deactivation: Patient Perspectives

Background: Decisions about deactivation of implantable cardioverter defibrillators (ICDs) are complicated. Unilateral Do-Not-Resuscitate (DNR) orders (against patient/family wishes) have been ethically justified in cases of medical futility. Unilateral deactivation of ICDs may be seen as a logical extension of a unilateral DNR order. Methods: 60 respondents who had an ICD or cardiac resynchronization therapy ICD (CRT-D) were interviewed at a quaternary medical center outpatient electrophysiology practice. Survey questions addressed the inclusion of ICD deactivation in advanced directives, whether ICD deactivation constitutes physician-assisted suicide, and whether unilateral ICD deactivation can be ethically justified. The average age was 59 (range 23-89), and 70% were male. Of the respondents, 35% had ICDs, and 65% had CRT-Ds. Respondents had had their devices for an average of 6.74 years (range 0.11-25). 82% of respondents were Caucasian, 15% were African American and 3% were Hispanic. Results: Only 15% of patients had thought about device deactivation if they were to develop a serious illness from which they were not expected to recover, and single respondents were more likely to have considered this point (38%, p=0.03). A small majority (53%) had advance directives, and only one mentioned what to do with the device. Only 3% had discussed device management with clinicians. Most (55%) believed turning off a patient’s pacemaker was no different than not performing CPR or administering external defibrillation. A majority (77%) did not consider device deactivation in accordance with patient wishes to be physician-assisted suicide. A majority (78%) responded that it was not ethical/moral for doctors to deactivate ICDs against patients’ wishes. Conclusion: In an era of cost-consciousness and scrutiny of resources, management of ICDs and CRT-Ds as patients near the end of their lives create ethical dilemmas. Few patients consider device deactivation at end of life, though a large majority believes that unilateral deactivation is not ethical or moral, even in the setting of medical futility. Advance care planning for these patients should address device deactivation.

Heart Rythm Society expert consensus statement on electrophysiology laboratory standards: process, protocols, equipment, personnel, and safety.

ABBREVIATIONS CIED = cardiovascular implantable electronic device; CT=computed tomography; EP=electrophysiology; FDA= U.S. Food and Drug Administration; ICD=implantable cardioverterdefibrillator; MRI = magnetic resonance imaging; QA = quality assurance; QI = quality improvement; RF = radiofrequency; VT = ventricular tachycardia (Heart Rhythm 2014;11:e9–e51)

Ablation of atrioventricular nodal reentrant tachycardia: predictors of long-term success

Atrioventricular nodal reentrant tachycardia (AVNRT) is the commonest regular supraventricular tachyarrhythmia. Ablation in the area of slow pathway (SP) has been successfully implemented in everyday clinical electrophysiological practice for more than 20 years. Although the procedure is generally regarded as effective and safe, data on long-term effects and predictors of success or failure are incomplete. To identify predictors of successful AVNRT ablation. The study group consisted of 359 patients (105 males, mean age 51.1 ± 16.7 years) who underwent AVNRT radiofrequency ablation using typical combined electrophysiological and anatomical approach. Acute success was achieved in 342 (95%) patients, including 187 (52%) with SP ablation and 155 (43%) with SP modification. Patients with SP modification were younger, had shorter AVNRT cycle length, less often had typical echo, and had more frequent isoproterenol usage after ablation. Long-term follow-up data was available for 308 patients (86% of the total study group). During the mean follow-up of 52.9 ± 27.3 months (median 48, range 12-130 months), 22 patients experienced AVNRT recurrences (long-term efficacy 93%). These patients had less often complete SP abolition than SP modification (27% vs. 56%, p < 0.001) and typical jump (vs. no jump or multiple jumps) at baseline (74% vs. 89%, p < 0.06) than patients without recurrences. Multivariate Cox regression analysis showed that typical jump was associated with a favourable outcome (HR 5.8, 95% CI 0.44-3.1, p = 0.0089). There were no significant differences in the use of 2 or > 2 electrode approaches between patients with or without AVNRT recurrences. Typical jump and complete SP elimination are associated with a better outcome. A 2-electrode approach is as effective as > 2 electrode approach. The electrophysiological profile of patients in whom complete SP elimination was achieved may differ from that of patients in whom only SP modification was possible.

US Health Care Policy and Reform: implications for cardiac electrophysiology

In response to unsustainably rising costs, variable quality and access to health care, and the projected insolvency of vital safety net insurance programs, the federal government has proposed important health policy and regulatory changes in the USA. The US Supreme Court's decision to uphold most of the major provisions of the Affordable Care Act will lead to some of the most sweeping government reforms on entitlements since the creation of Medicare. Furthermore, implementation of new organizational, reimbursement, and health care delivery models will strongly affect the practice of cardiac electrophysiology. In this brief review, we will provide background and context to the problem of rising health care costs and describe salient reforms and their projected impacts on the field and practice of cardiac electrophysiology.

Learning from Others

While a fool does not learn from his experience, an intelligent man does;But, a wise man learns from the experience of others.—From Sanskrit ProverbThe practice of cardiac electrophysiology requires not only a thorough understanding of established knowledge and new research findings but also a deliberate application of the known principles to solve difficult electrophysiologic puzzles in the laboratory, making clinical decisions under uncertainty and continuously learning from experience.

Impact of collimation on radiation exposure during interventional electrophysiology

Fluoroscopy remains a cornerstone imaging technique in contemporary electrophysiology practice. We evaluated the impact of collimation to the 'minimal required field size' on clinically significant parameters of radiation exposure. Radiation dose measured by dose area product (DAP) and radiation dose rate measured by DAP per minute of fluoroscopy were determined for all 571 electrophysiology procedures performed in a single electrophysiology laboratory from January 2010 to December 2010. Data from 205 procedures performed by one interventional electrophysiologist, who instituted a practice of routinely collimating to the minimum required visual fluoroscopy field on a case-by-case basis, were compared with data from 366 procedures performed by the three other experienced interventional electrophysiologists using the laboratory who continued their existing practice of ad hoc collimation. Significant reductions in radiation exposure were seen with the practice of routine maximal collimation. The largest reductions were seen during 'simple' ablation procedures. A practice of routinely collimating to the minimum required visual fluoroscopy field results in significant reductions in radiation exposure when compared with a usual approach to collimation. This may have important implications for risk of malignancy in patients and operators.

Rethinking QRS Duration as an Indication for CRT

Cardiac resynchronization therapy (CRT), radiofrequency ablation for atrial fibrillation,1,2 and the invasive management of ventricular tachycardia are likely the 3 major changes that have impacted cardiac electrophysiology practice over the last 2 decades. Of these, the literature basis for CRT use is by far the strongest, and the evidence is such that the potential for benefit from left ventricular pacing for drug refractory heart failure (HF) patients is beyond question.3-5 Several major and fundamental challenges remain in terms of optimizing CRT benefit and particularly with preprocedural identification of patients most likely to benefit from this therapy. Following the course of various contentions in terms of ideal method of selecting patients,6,7 including echocardiographic parameters for mechanical dyssynchrony, has been a veritable rollercoaster ride with initial promise followed by the absence of verifiable utility in larger well-conducted studies.8 From the very earliest discussion on CRT, QRS duration was recognized as a potentially simple and intuitive variable that could guide patient selection and subsequent device optimization. However, it was quickly recognized that this parameter may be simplistic and evidence for its utility, particularly for patient selection, not forthcoming.9,10 In this issue of the Journal of Cardiovascular Electrophysiology, Stavrakis et al.11 present important findings from a well-conducted meta-analysis of 5 trials (COMPANION,12 CARE-HF,13 REVERSE,14 MADIT CRT,15 and RAFT5), specifically with regard to QRS duration and CRT benefits. In this meticulously conducted and clearly written manuscript, the authors present important evidence for their potentially practice-impacting conclusion that CRT should not be routinely considered for patients with QRS duration <150 ms. Before the readers and practitioners of electrophysiology and HF management decide on whether we rethink one of our primary indications for CRT (QRS duration ≥120 ms), it is worthwhile to examine from cardiac electrophysiology why and why not QRS duration should impact or may impact CRT benefit.

A General Likelihood Framework for Characterizing the Time Course of Neural Activity

We develop a general likelihood-based framework for use in the estimation of neural firing rates, which is designed to choose the temporal smoothing parameters that maximize the likelihood of missing data. This general framework is algorithm-independent and thus can be applied to a multitude of established methods for firing rate or conditional intensity estimation. As a simple example of the use of the general framework, we apply it to the peristimulus time histogram and kernel smoother, the methods most widely used for firing rate estimation in the electrophysiological literature and practice. In doing so, we illustrate how the use of the framework can employ the general point process likelihood as a principled cost function and can provide substantial improvements in estimation accuracy for even the most basic of rate estimation algorithms. In particular, the resultant kernel smoother is simple to implement, efficient to compute, and can accurately determine the bandwidth of a given rate process from individual spike trains. We perform a simulation study to illustrate how the likelihood framework enables the kernel smoother to pick the bandwidth parameter that best predicts missing data, and we show applications to real experimental spike train data. Additionally, we discuss how the general likelihood framework may be used in conjunction with more sophisticated methods for firing rate and conditional intensity estimation and suggest possible applications.

2010 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Training Standards and Maintenance of Competency in Adult Clinical Cardiac Electrophysiology

The last guidelines on training for adult cardiac electrophysiology (EP) were published by the Canadian Cardiovascular Society in 1996. 1 Since then, substantial changes in the knowledge and practice of EP have mandated a review of the previous guidelines by the Canadian Heart Rhythm Society, an affiliate of the Canadian Cardiovascular Society. Novel tools and techniques also now allow electrophysiologists to map and ablate increasingly complex arrhythmias previously managed with pharmacologic or device therapy. Furthermore, no formal attempt had previously been made to standardize EP training across the country. The 2010 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Training Standards and Maintenance of Competency in Adult Clinical Cardiac Electrophysiology represent a consensus arrived at by panel members from both societies, as well as EP program directors across Canada and other select contributors. In describing program requirements, the technical and cognitive skills that must be acquired to meet training standards, as well as the minimum number of procedures needed in order to acquire these skills, the new guidelines provide EP program directors and committee members with a template to develop an appropriate curriculum for EP training for cardiology fellows here in Canada.

Twenty years of interventional cardiac electrophysiology: Meeting future challenges with continuing innovations

The “Sixth International Symposium on Interventional Elec-trophysiology in the Management of Cardiac Arrhythmias”was held in Newport, Rhode Island on September 24–26,2010. This symposium commemorated a special landmark inclinical cardiac electrophysiology. Twenty years had elapsedsince the first in this series of symposia recognized interven-tional electrophysiology as a distinct scientific discipline. In1990,thissymposiumwastheveryfirst internationalmeetingdevoted exclusively to the fundamentals of science andclinical practice of interventional electrophysiology. Theumbrella of “interventional electrophysiology” gathered suchdiverse but fundamentally linked sciences of experimentalelectrophysiology, epidemiology, pharmacotherapy, cardiacpacing, defibrillation, catheter and surgical ablation, imaging,and clinical trials as applied to the management of cardiacarrhythmias. The crystallization of this discipline and thebreadthanddepthofscienceinthisfieldledtotheevolutionofa committed scientific journal devoted to it, the Journal ofInterventional Cardiac Electrophysiology. The meeting con-tinues a longstanding tradition of providing a scientificforum for experts from Europe and North America to presentfrontiers in research as well as critically evaluate develop-ments in interventional cardiac electrophysiology in ascientific forum. The presentations at this meeting are thebasisforaseriesofreviewarticlesthathavebeencriticallyacclaimed in past years and memorialized in print, initially intextbook form and more recently as special issues of theJournal of Interventional Cardiac Electrophysiology.This symposium’s scientific program was restructured tofocus on translational science, new technology, and therestructuring of clinical practice based on clinical trials inour field. Regenerative medicine, genomics, and molecularbiologic research into inherited or acquired heart rhythmdisorders assumed center stage in basic science presentations.Innovations in technology bought imaging methods in clinicalelectrophysiology into focus. New catheter navigation tech-nology, computed tomographic and magnetic resonanceimaging methods, intracardiac and three-dimensional echocar-diography, and essentials of clinical interpretation of theseimagingdatafortheinterventionalistboughtanewfrontierintoview, the “integrated” electrophysiologic laboratory. Newdevelopments in device and ablation therapy were reviewedin the context of evidence-based practice. The rise ofperformance standards and metrics for arrhythmia programs,impact of clinical trials, and registries on interventionalelectrophysiologic practice and outcomes research in clinicalelectrophysiologyfocusedthediscussionsonthepathaheadforthe interventional electrophysiologist.TheNewportsymposiumhasnowbeenmemorializedwiththe authors preparing state-of-the-art review articles for twospecial issues of the journal. The first issue encompassesadvances in basic and translation science, imaging, newtechnology and developing standards for patient follow-upand management, catheter and surgical ablation, and clinicaltrials in drug, device, and ablation therapies. Special issueslikethisonearenot possiblewithout the enormoussupport ofour authors and our editorial staff. We are grateful to theauthors for this serious effort to critically assess our current

Role of Echocardiography in Atrial Fibrillation

Atrial fibrillation (AF) is most common arrhythmia and its prevalence appears to be increasing as the population ages. Echocardiography can play a key role in risk stratification and management of patients with AF. Transthoracic echocardiography allows rapid and comprehensive assessment of cardiac anatomical structure and function. Pulmonary vein flow monitoring using echocardiography has the potential to an increasing role in the evaluation of cardiac function and AF ablation procedures. Transesophageal echocardiography also provides accurate information about the presence of a thrombus in the atria and thromboembolic risk. The novel technique of intracardiac echocardiography has emerged as a popular and useful tool in the everyday practice of interventional electrophysiology. Other imaging modalities, such as computed tomography and magnetic resonance imaging have complementary roles in risk stratification and assessment of patients with AF. Echocardiography continues to be the foundation of clinical evaluation and management of AF.

Sudden cardiac death stratification in asymptomatic ventricular preexcitation

The second survey deals with risk stratification in subjects, either adults or children, with ventricular preexcitation and no symptoms in their history. Current European electrophysiological practice is still variable among different centres. Although invasive stratification is still part of the practical management of asymptomatic subjects, a not negligible proportion of physicians do not completely rely on cut off values provided in the literature, proceeding to ablation irrespective of the stratification process. These concerns are mainly due to the perception of lack of strong evidence that, according to the majority of centres, is still needed.

The anatomy of the coronary sinus venous system for the cardiac electrophysiologist

Cardiac electrophysiologists' use of the coronary sinus (CS) to map and ablate accessory pathways and implant left ventricular leads has emphasized the need for understanding CS anatomy. In this review, we briefly examine the developmental and radiological anatomy of the CS and discuss in detail the gross anatomy of this cardiac vein. We highlight the correlations of the acquired anatomical knowledge relevant to clinical electrophysiology practice.

Intracardiac Echocardiography in Electrophysiology: A Review of Current Applications in Practice

Intracardiac echocardiography (ICE) has emerged as a widespread useful tool in the everyday practice of interventional electrophysiology. Advances in catheter-based ultrasound transducers and imaging technology have made this modality integral to guiding evaluation of anatomy and ablation therapy. Evolution of ablative procedures of the left heart for tachyarrhythmia has highlighted the importance of direct visualization of anatomic landmarks to guide transseptal catheterization and immediately identify complications. The ability to position mapping and ablation catheters according to anatomic landmarks (Fig. 1) has greatly enhanced the safety and efficacy of catheter ablation procedures. ICE has supplanted fluoroscopy as the gold standard for precise imaging of endocardial structures during complex procedures.

Self-reported Adjustment to Implanted Cardiac Devices

Although implantations of devices to support cardiovascular function are increasing, little is known about the factors involved in adjusting psychologically to having an implanted device. This study provides factor analysis of the Implanted Device Adjustment Scale (IDAS) and self-reported data on quality of life, mood states, and global adjustment. This cross-sectional correlational design study included 174 subjects (46 women and 128 men). A convenience sample was recruited from electrophysiology practices in 2 large Midwestern cities. Subjects completed the IDAS, the SF-36 quality-of-life measure, the Profile of Mood States, and a device adjustment visual analog scale. The factor analysis produced 4 subscales for the IDAS: fear/anxiety, attitude, preparation, and body awareness. Perceived adjustment was "good" for 89% of persons and was unrelated to age, sex, type of device, and whether a shock was received. All 4 subscales of the IDAS correlated negatively with adjustment (higher IDAS score means poorer adjustment). The overall IDAS was internally consistent with a Cronbach alpha = .89. Adjustment, as measured by the overall IDAS, had a weak but significant relationship with measures of quality of life including the mental component summary scale of the SF-36 (r = 0.19), but not the physical component summary scale of the SF-36. All the Profile of Mood States subscales correlated positively with the IDAS subscale anxiety/fear with the exception of vigor/activity which had a negative correlation. No sex differences in total adjustment were seen in this group of patients, although there were differences in body awareness, physical functioning, and fatigue. Although patients with implanted cardioverter defibrillator were more fearful/anxious than patients with pacemaker only, no differences in total adjustment were seen between the 2 groups. A better understanding of the experience of adjusting to an implanted device is foundational to the development of appropriate interventions.

Principles and Practice of Clinical Electrophysiology of Vision, 2nd ed.

Principles and Practice of Clinical Electrophysiology of Vision, 2nd ed.

Percutaneous epicardial ablation of atrial fibrillation

E a T p f d u h t i a v l s d d a f w t o f 8 ( u t d t g d c d ntroduction atheter ablation of arrhythmias has revolutionized the clincal practice of cardiac electrophysiology (EP). Several arhythmias can now be cured with a high degree of success n the outpatient setting. In addition to this, catheter-based echniques are now being widely used for the management f atrial fibrillation. The standard approach to catheter blation is from the endocardial aspect of the heart. Reently, percutaneous epicardial mapping has been develped and is routinely being used in several EP laboratories round the world. Epicardial mapping and ablation was nitially used for the management of ventricular tachycaria. Subsequently, this technique has been used successully for the management of accessory pathways, atrial rrhythmias, and atrial fibrillation. Epicardial mapping nd ablation has proven to be safe and effective and s associated with a low risk of complications based on he available data from the institutional experiences reorted at the Heart Rhythm meeting in 2007. The meaningul success rates seen with surgical approaches for the anagement of atrial fibrillation (especially stand-alone rocedures) have prompted a need for the assessment of picardial mapping and ablation of atrial arrhythmias in the P lab. This viewpoint article will review key aspects of the picardial approach as it relates to the management of atrial rrhythmias, highlight the current limitations, and reflect on he future prospects of this approach.