Cardiac Implantable Electronic Devices in Patients With Left Ventricular Assist Systems

Recent progress and evolution in device engineering, surgical implantation practices, and periprocedural management have advanced the promise of durable support with left ventricular assist systems (LVAS) in patients with stage D heart failure. With greater uptake of LVAS globally, a growing population of LVAS recipients have pre-existing cardiac implantable electronic devices (CIEDs). Strategies for optimal clinical management of CIEDs in patients with durable LVAS are evolving, and clinicians will increasingly face complex decisions regarding implantation, programming, deactivation, and removal of CIEDs. Traditional decision-making pathways for CIEDs may not apply to LVAS-supported patients, as few patients die of arrhythmic causes and many arrhythmias may be well tolerated. Given limited data, treatment decisions must be individualized and made collaboratively among electrophysiologists, advanced heart failure specialists, and patients and their caregivers. Large, prospective, well-conducted studies are needed to better understand the contemporary utility of CIEDs in patients with newer-generation LVAS.     

Arrhythmias in patients with congenital heart disease

Improved surgical outcome for patients with congenital heart disease (CHD) has created a rapidly expanding population of adolescents and young adult survivors. Cardiac arrhythmias are a common late sequelae of this form of heart disease. Effective treatment requires clear understanding of the underlying anatomic defect as well as the specific surgical interventions. Intraatrial reentrant tachycardia (IART) is the most common and difficult arrhythmia encountered in these patients. Traditional IART treatment with medication has been largely unsuccessful, but radiofrequency ablation has emerged in recent years as a promising option for many patients. The availability of three-dimensional mapping systems and irrigated-tip ablation catheters has improved acute success rates for IART to better than 90%. Postablation recurrence of IART still remains problematic for patients who have undergone the Fontan operation, in which case atrial maze surgery may be considered. Ventricular tachycardia (VT) is seen in a smaller number of CHD patients, most notably those with tetralogy of Fallot or aortic stenosis. The adoption of implantable defibrillator (ICD) therapy for these patients has improved outcome. Owing to their complex anatomy, the CHD population presents unique challenges during both catheterization and device implant. Multicenter study of this unique patient group is needed in order to develop more objective treatment guidelines.     

Performing Cardiac Magnetic Resonance Imaging in Patients With Cardiac Implantable Electronic Devices: A Contemporary Review

There are expanding indications for cardiac magnetic resonance imaging (CMR) in patients with cardiac implantable electronic devices (CIEDs). The presence of a CIED had been regarded as a contraindication to CMR due to concerns of arrhythmias, significant changes to lead parameters, and detrimental changes to device programming. The risk of these potential adverse events is theoretically higher in patients undergoing CMR as compared with other anatomic sites. Recent studies have observed low rates of adverse events in patients undergoing CMR (< 1% to 2%), prompting a shift in the recommendations on CMR in patients with CIEDs. The 2017 Heart Rhythm Society Expert Consensus Statement now states that CMR can be performed in patients with both conditional and nonconditional CIEDs at a magnetic strength of 1.5 T, provided there are no fractured, abandoned, or epicardial leads and modifications to MRI parameters are made. The purpose of this review is to (a) outline the potential concerns of performing CMR in patients with CIEDs, (b) define categories of CIEDs as they pertain to MRI safety, (c) summarize the emerging data on adverse events, and (d) provide a practical approach, integrating the key modifications required to perform CMR in patients with CIEDs.     

Ethical and legal views regarding deactivation of cardiac implantable electrical devices in patients with hypertrophic cardiomyopathy

Little is known about patients' views surrounding the ethical and legal aspects of managing pacemakers (PMs) and implantable cardioverter-defibrillators (ICDs) near the end of life. Patients with hypertrophic cardiomyopathy (HC) are at heightened risk of sudden cardiac death and are common recipients of such devices. Patients with HC recruited from the membership of the Hypertrophic Cardiomyopathy Association were surveyed about their clinical histories, advance care planning, legal knowledge, and ethical beliefs relating to the withdrawal of PM and ICD therapy. The mean age of the 546 patients was 49.1 years, 47% were women, and 57% had ICDs. Only 46% of the respondents had completed an advance directive, only 51% had a healthcare proxy, and cardiac implantable electrical devices (CIEDs) were commonly not addressed in either (92% and 58%, respectively). Many patients characterized deactivating PMs or ICDs as euthanasia or physician-assisted suicide (29% for PMs and 17% for ICDs), and >50% expressed uncertainty regarding the legality of device deactivation. Patients viewed deactivation of ICDs and PMs as morally different from other life-sustaining therapies such as mechanical ventilation and dialysis, and these views varied substantially according to the CIED type (p <0.0001). The respondents expressed concerns regarding clinical conflicts related to religion, ethical and legal uncertainty, and informed consent. In conclusion, patients who have, or are eligible to receive, CIEDs might require improved advance care planning and education regarding the ethical and legal options for managing CIEDs at the end of life.     

Catheter Ablation of Atrial Arrhythmias in Patients Post-Fontan

Atrial arrhythmias are highly prevalent in the aging Fontan population and contribute importantly to morbidity and mortality. Although the most common arrhythmia is scar-based intra-atrial re-entrant tachycardia, various other arrhythmias may occur, including focal atrial tachycardia, atrioventricular node-dependent tachycardias, and atrial fibrillation. The type and prevalence of atrial arrhythmia is determined, in part, by the underlying congenital defect and variant of Fontan surgery. Although the cumulative incidence of atrial tachyarrhythmias has decreased substantially from the atriopulmonary anastomosis to the more recent total cavopulmonary-connection Fontan, the burden of atrial arrhythmias remains substantial. Management is often multifaceted and can include anticoagulation, anti-arrhythmic drug therapy, pacing, and cardioversion. Catheter ablation plays a key role in control of arrhythmia. Risks and benefits must be carefully weighed. Among the important considerations are the clinical burden of arrhythmia, ventricular function, hemodynamic stability in tachycardia, suspected arrhythmia mechanisms, risks associated with anaesthesia, venous access, approaches to reaching the pulmonary venous atrium, and accompanying comorbidities. Careful review of surgical notes, electrocardiographic tracings, and advanced imaging is paramount, with particular attention to anatomic abnormalities such as venous obstructions and displaced conduction systems. Despite numerous challenges, ablation of atrial arrhythmias is effective in improving clinical status. Nevertheless, onset of new arrhythmias is common during long-term follow-up. Advanced technologies, such as high-density mapping catheters and remote magnetic guided ablation, carry the potential to further improve outcomes. Fontan patients with atrial arrhythmias should be referred to centres with dedicated expertise in congenital heart disease including catheter ablation, anaesthesia support, and advanced imaging.     

ISHNE/EHRA expert consensus on remote monitoring of cardiovascular implantable electronic devices (CIEDs)

We are in the midst of a rapidly evolving era of technology-assisted medicine. The field of telemedicine provides the opportunity for highly individualized medical management in a way that has never been possible before. Evolving medical technologies using cardiac implantable devices (CIEDs) with capabilities for remote monitoring permit evaluation of multiple parameters of cardiovascular physiology and risk, including cardiac rhythm, device function, blood pressure values, the presence of myocardial ischaemia, and the degree of compensation of congestive heart failure. Cardiac risk, device status, and response to therapies can now be assessed with these electronic systems of detection and reporting. This document reflects the extensive experience from investigators and innovators around the world who are shaping the evolution of this rapidly expanding field, focusing in particular on implantable pacemakers (IPGs), implantable cardioverter-defibrillators (ICDs), devices for cardiac resynchronization therapy (CRT) (both, with and without defibrillation properties), loop recorders, and haemodynamic monitoring devices. This document covers the basic methodologies, guidelines for their use, experience with existing applications, and the legal and reimbursement aspects associated with their use. To adequately cover this important emerging topic, the International Society for Holter and Noninvasive Electrocardiology (ISHNE) and the European Heart Rhythm Association (EHRA) combined their expertise in this field. We hope that the development of this field can contribute to improve care of our cardiovascular patients.     

Considerations in Critical-Care and Anesthetic Management of Adult Patients Living With Fontan Circulation

The Fontan procedure is a staged palliation for various complex congenital cardiac lesions, including tricuspid atresia, pulmonary atresia, hypoplastic left heart syndrome, and double-inlet left ventricle, all of which involve a functional single-ventricle physiology. The complexity of the patients’ original anatomy combined with the anatomic and physiologic consequences of the Fontan circulation creates challenges. Teens and adults living with Fontan palliation will need perioperative support for noncardiac surgery, peripartum management for labour and delivery, interventions related to their structural heart disease, electrophysiology procedures, pacemakers, cardioversions, cardiac surgery, transplantation, and advanced mechanical support. This review focuses on the anesthetic and intensive care unit (ICU) management of these patients during their perioperative journey, with an emphasis on the continuity of preintervention planning, referral pathways, and postintervention ICU management. Requests for recipes and doses of medications are frequent; however, as in normal anesthesia and ICU practice, the method of anesthesia and dosing are dependent on the presenting medical/surgical conditions and the underlying anatomy and physiologic reserve. A patient with Fontan palliation in their early 20s attending school full-time with a cavopulmonary connection is likely to have more reserve than a patient in their late 40s with an atriopulmonary Fontan at home waiting for a heart transplant. Each case will require an anesthetic and critical care plan tailored to the situation. The critical care environment is a natural extension of the anesthetic management of a patient, with complex considerations for a patient with Fontan palliation.     

Practices of cardiac implantable electronic device follow-up: results of the European Heart Rhythm Association survey

This survey analyses some details of follow-up of patients with cardiac implantable electronic devices (CIEDs) in 40 centres-the members of the European Heart Rhythm Association (EHRA) research network. Results of this survey show that practices of CIED follow-up are not homogeneous between EHRA research network centres, and recommended clinical evaluation of the patients regarding possible device up-grade is not always performed. Remote device monitoring appears to be an evolving practice, mostly used in implantable cardioverter defibrillators and cardiac resynchronization therapy defibrillator recipients.     

2021 Update on Safety of Magnetic Resonance Imaging: Joint Statement From Canadian Cardiovascular Society/Canadian Society for Cardiovascular Magnetic Resonance/Canadian Heart Rhythm Society

Magnetic resonance imaging (MRI) is often considered the gold-standard test for characterizing cardiac as well as noncardiac structure and function. However, many patients with cardiac implantable electronic devices (CIEDs) and/or severe renal dysfunction are unable to undergo this test because of safety concerns. In the past 10 years, newer-generation CIEDs and gadolinium-based contrast agents (GBCAs) as well as coordinated care between imaging and heart rhythm device teams have mitigated risk to patients and improved access to MRI at many hospitals. The purpose of this statement is to review published data on safety of MRI in patients with conditional and nonconditional CIEDs in addition to patient risks from older and newer GBCAs. This statement was developed through multidisciplinary collaboration of pan-Canadian experts after a relevant and independent literature search by the Canadian Agency for Drugs and Technologies in Health. All recommendations align with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Key recommendations include: (1) the development of standardized protocols for patients with a CIED undergoing MRI; (2) patients with MRI nonconditional pacemakers and pacemaker dependency should be programmed to asynchronous mode and those with MRI nonconditional transvenous defibrillators should have tachycardia therapies turned off during the scan; and (3) macrocyclic or newer linear GBCAs should be used in preference to older GBCAs because of their better safety profile in patients at higher risk of nephrogenic systemic fibrosis.     

Technological Advances in Arrhythmia Management Applied to Adults With Congenital Heart Disease

Arrhythmias are a leading cause of morbidity in adults with congenital heart disease. Numerous challenges to managing arrhythmias include vascular access issues, intracardiac shunts, unconventional locations of the conduction system, and anatomical complexities. Technological advances are improving our ability to diagnose and treat arrhythmias. Implantable loop recorders and various technologies developed for consumers to record electrocardiographic tracings using smartphone applications, watches, and dedicated portable devices are expanding our armamentarium of diagnostic tools. Remote magnetic-guided catheter ablation is enhancing access to otherwise difficult to reach arrhythmia substrates. Cryoablation allows perinodal arrhythmias to be safely treated in patients with displaced or difficult to predict locations of the atrioventricular conduction system. Interventions that minimize radiation exposure to near 0 levels are gaining interest and pulmonary vein isolation procedures to treat atrial fibrillation are increasingly performed. Cardiac implantable electronic devices compatible with magnetic resonance imaging have become the norm. Subcutaneous defibrillators and leadless pacemakers are providing effective solutions to patients in whom transvenous leads are contraindicated or not desired. His-bundle pacing is emerging as a viable option to provide more physiological pacing. Progressive advances in multicomponent communicating leadless devices carry the promise of providing leadless dual chamber pacing and cardiac resynchronization therapy in the near future. The safety of transvenous lead extraction procedures is likely to improve with advances such as the low-pressure balloon to manage superior vena cava lacerations. Awareness of these developments and referral to sites with dedicated expertise could contribute to further improving outcomes in adults with congenital heart disease.     

Atriale Isomerie und viszerale Heterotaxie

Atrial isomerism and visceral heterotaxy describe complex pathoanatomic findings with defects in the determination of lateralization. Differentiation of right and left atrial isomerism was based on the anatomy of the atrial appendages and bronchial tree and often associated with asplenia in right atrial isomerism and polysplenia in left atrial isomerism. In these pa tients complex cardiac anomalies determine clinical symptoms and diagnostic procedures.At primary diagnosis in the neonatal period, systemic venous and pulmonary venous connections and intracardiac anatomy are identified using the sequential segmental approach. Therapeutic decisions and palliative procedures can usually be based on these initial echocardiographic findings. As many of the patients were found to have a functionally univentricular heart, surgical procedures following the Fontan principle (lateral tunnel or extracardiac conduit procedure) were introduced in patients with heterotaxy syndrome and successfully performed. Early survival and long-term outcome vary depending on associated cardiac and systemic and pulmonary venous anomalies.The therapeutic options and mid-term results in patients with heterotaxy syndrome undergoing the Fontan procedure are reported.     

Postmarket surveillance of medical devices: current capabilities and future opportunities

Recalls of cardiac implantable electrical devices (CIEDs) currently impact hundreds of thousands of patients worldwide. Premarket evaluation of CIEDs cannot be expected to eliminate all performance defects. Robust postmarket surveillance systems are needed to promote patient safety and reduce harm. Challenges impacting existing surveillance mechanisms include underreporting of defects, low rates of return of explanted CIEDs, lack of integration of surveillance into normal workflow, underutilization of existing resources including registries, a lack of capacity of aging resources, multiple proprietary platforms that lack interoperability, and the unmet need for common data variables as well as newer methods to generate, synthesize, analyze, and interpret evidence in order to respond rapidly to safety signals. Long-term solutions include establishing a unique device identification system; promoting expanded use of registries for surveillance and post-approval studies; developing additional methods to combine evidence from diverse data sources; creating tools and implementing strategies for universal automatic, triggered electronic event reporting; and refining methods to rapidly identify and interpret safety signals. Protection from litigation and creation of financial and other incentives by legislators, regulators, payers, accreditation organizations, and licensing boards can be expanded to increase participation in device surveillance by clinicians and health care facilities. Research to evaluate the comparative effectiveness of surveillance strategies is needed. Interim solutions to improve CIED surveillance while new initiatives are launched and the system strengthened are also presented.     

Electromagnetic interference and implanted cardiac devices: the nonmedical environment (part I)

The number of patients with cardiovascular implantable electronic devices (CIEDs), such as permanent pacemakers and implantable cardioverter-defibrillators, is dramatically rising due to an aging population and recent clinical trials showing benefits in mortality and morbidity. Coupled with this increase in the number of patients with CIEDs is the proliferation of technology that emits electromagnetic signals, which can potentially interfere with CIED function through electromagnetic interference (EMI). Despite continuous efforts of manufacturers to create "EMI-proof" CIEDs, adverse events from EMI still occur. Physicians caring for patients with CIEDs should be aware of potential sources of EMI and appropriate management options. This 2-part review aims to provide a contemporary overview of the current knowledge regarding risks attributable to EMI interactions from the most common nonmedical (Part I) and medical (Part II) sources.     

Arrhythmien bei Patienten mit operativ korrigierter Fallot-Tetralogie

The population of adults with surgically corrected tetralogy of Fallot (TOF) is increasing. Atrial and ventricular arrhythmias are prevalent, and therapeutical approaches including implantable cardioverter-defibrillators and radiofrequency catheter ablation need to be considered carefully for the prevention of hemodynamic deterioration and sudden cardiac death. Complex anatomy, myocardial hypertrophy, and broad channels of slow conduction may in part explain some challenges regarding risk stratification, and identification/modification of the arrhythmogenic substrate in these patients. The aim of this brief review is 2-fold: (1.) To present insights into characteristics of typical TOF related arrhythmias and (2.) to reflect therapeutical concepts targeting tachyarrhythmias in these patients by focusing on catheter ablation.     

Advanced Therapies for Congenital Heart Disease: Ventricular Assist Devices and Heart Transplantation

Improvement in pre-, peri-, and postoperative management of congenital heart disease (CHD) has significantly increased long-term survival in children with CHD. However, there is a subset of patients with CHD who are either poor candidates for surgical palliation or in whom surgical intervention has failed and require advanced cardiac support. Heart transplant (HT) as a therapy for CHD has undergone tremendous evolution. Though transplantation remains the standard of care to improve survival and quality of life when conventional medical and surgical therapies have failed, it remains limited by the scarcity and unpredictability of donor organ availability. As such, the use of ventricular assist devices (VADs) as a bridge to transplant is gaining increasing popularity. Because of improvement in device technology, and reduced rate of VAD-related complications, the use of these devices is expanding to smaller children and more complex congenital anatomy. Challenges with VAD support and HT in the congenital heart population will be addressed in this review with focus on: (1) reasons for VAD implantation; (2) VAD support in Fontan circulation; (3) challenges with human leukocyte antigen (HLA) sensitization in HT; and (4) effect of VAD support on HT in CHD.     

REVIEW: Cardiovascular Implantable Electronic Devices in Athletes

Cardiovascular implantable electronic device (CIED) implantation indications have greatly increased over the past decade, with use of pacemakers and implantable cardiac defibrillators now growing more common even in athletes. Management of CIEDs in this subgroup is of greater complexity due to augmented physical stressors, a longer exposure time to system components in a younger population, and less common, highly clinically variable underlying cardiac pathologies. We will review management issues specific to CIED therapy, sudden cardiac death, and consensus recommendations for physical activity.     

Safety of mechanical lung vibrator and high‐frequency chest wall oscillation in patients with cardiac implantable electronic device

BackgroundChest physiotherapy (CPT) is a non‐pharmacological therapy to facilitate airway secretion removal. There have been concerns about potential electromagnetic interference (EMI) and lead integrity problems during the use of vibrating CPT devices in patients with cardiac implantable electronic devices (CIEDs).HypothesisTwo CPT devices can be used safely in patients with CIED.MethodsVolunteer patients with CIED underwent device interrogation to check lead integrity and device function before and after application of CPT devices. Mechanical lung vibrator and high‐frequency chest wall oscillation (HFCWO) vests were used while monitoring surface electrocardiograms and intra‐cardiac electrograms.ResultsWe prospectively enrolled 46 patients with CIEDs (25 pacemakers, 15 implantable cardioverter‐defibrillators, and six cardiac resynchronization therapy‐defibrillators). There was no noise detection or EMI during CPT in any patient. None of the patients showed clinically significant changes in lead integrity parameters. HFCWO inappropriately accelerated the pacing rate up to the maximal programmed value in five patients with pacemakers and two with cardiac resynchronization therapy‐defibrillators.ConclusionCPT may be safely applied to patients with CIED without compromising lead integrity or device function, except for unwanted increase in pacing rate caused by misdetection of chest wall vibration as patients'' activity while using HFCWO. Deactivation of the accelerometer‐based activity sensor may be needed when HFCWO is planned for CPT.     

Arrhythmias and Other Electrophysiology Issues in Cancer Patients Receiving Chemotherapy or Radiation

Enhanced understanding of cancer biology has significantly increased treatment options and dramatically improved outcomes for patients with malignancies. Despite these advances, many therapies have cardiovascular toxicities which can affect morbidity and mortality independent of the oncologic prognosis. Arrhythmias and other electrophysiology issues are increasingly identified as common complications of cancer therapy. Atrial fibrillation and other supraventricular arrhythmias are frequently observed in cancer patients receiving chemotherapy, often due to their effects on intracellular signaling pathways. Similarly, many oncologic pharmaceuticals can lead to QT prolongation and possible ventricular arrhythmias including torsades do pointes. Management of these arrhythmias can be challenging as typical treatment strategies may not be feasible in cancer patients. Finally, a proportion of individuals with cancer will present with an implantable cardiac device (pacemaker or defibrillator) which poses unique challenges should radiation be necessary in the region of the device. Given the frequency of electrophysiology complications in cancer patients, it is essential for cardio-oncologists to possess knowledge of these issues in order to provide optimal care.     

Development of device therapy for ventricular arrhythmias

The past 25 years have seen the implantable cardioverter defibrillator emerge as the treatment of choice for ventricular arrhythmias with reduction in size but increased therapeutic options. Understanding the complex mechanisms of ventricular arrhythmias and defibrillation in normal and diseased hearts has been the focus of many research teams including that of John Uther at the Westmead Hospital Department of Cardiology. Marked improvements in capacitor and battery technologies, arrhythmia discrimination, pacing algorithms, shock waveforms and monitoring capabilities enable wider use and patient acceptance. Emergence of cardiac resynchronisation therapy and the implantable defibrillator for treatment of chronic heart failure is not only giving quality of life and extended survival for heart failure patients but has also cast new light on the evolution of heart failure.     

The pathway to physician reimbursement for cardiac implantable electronic devices (CIEDs): a history and brief synopsis

Cardiac implantable electronic devices (CIEDs), despite their proven effectiveness in large clinical trials for a wide range of patients with arrhythmia and heart failure, are frequent targets for criticism regarding cost-efficiency and alleged overuse. Newer indications, such as sinus node dysfunction for pacemakers and primary prevention for implantable cardioverter-defibrillators, increased eligible patient population significantly. This lead to heightened scrutiny from payors and legislative agencies, such as prior authorization and mandatory registry participation. Despite the significant administrative burden, the efficiency of these measures to decrease abuse is not clear. In addition, professional societies, regulatory agencies, and payors may not always agree whether use of a device is appropriate for a given patient. The review focuses on past and current issues related to utilization of CIEDs, which lead to increased regulatory oversight, and the effort of professional societies, payors, and governmental agencies to improve access to these life-saving therapeutical modalities while maintaining a just and cost-efficient healthcare system.