Cardiac pacing in paediatric patients with congenital heart defects: transvenous or epicardial?

HRS Call to Action: Improved MRI Access for Patients with Cardiovascular Implantable Electronic Devices

Access to magnetic resonance imaging (MRI) remains limited for many patients with cardiovascular implantable electronic devices (CIEDs), despite evidence demonstrating safety under appropriate conditions. This call-to-action statement from the Heart Rhythm Society (HRS) aims to describe persistent barriers to MRI access for patients with a CIED and to provide practical, actionable recommendations for improvement of clinical care. Developed by a multidisciplinary writing committee, this document addresses regulatory, operational, and institutional challenges; highlights findings from a recent HRS member survey on MRI access; and outlines the impact of evolving vendor-specific MRI exclusions. Specific populations discussed include patients with multiple MRI-conditional devices, mixed-vendor systems, abandoned leads, and epicardial leads or subcutaneous arrays. The statement also calls attention to the clinical and administrative burden on electrophysiology teams and the need for fair recognition and reimbursement of MRI-related care. Collaboration across specialties, industry, and regulatory bodies is essential to eliminate non-data-driven barriers and to ensure equitable access to clinically indicated MRI for all patients with a CIED.

Dual Chamber Aveir Retrievable Leadless Pacemaker Implant via the Right Internal Jugular Vein in a 13-Year-Old With Congenital Complete Heart Block

INTRODUCTION

Congenital complete heart block is a condition where there is a risk of Stokes Adam's attacks and sudden death may occur. Once the escape rate is too low, or other high-risk factors occur, these patients ultimately need pacemakers placed. Epicardial or transvenous pacemakers have typically been in employed dependent on size of the patient and other circumstances. We describe the first case of an implant via internal jugular vein (right) of a dual chamber leadless pacemaker implant in a symptomatic pediatric patient with congenital complete heart block.

METHODS

The study was approved by the University of California and consent was waived due to retrospective nature of this case report.

CASE

A 13-year-old presented with presyncope at rest after years of being followed for her congenital complete heart block. Her average rate on Holter monitoring was below 50 bpm, which coincided with her recent symptoms. After discussion with family, and our own cardiology/surgical team, she had a dual chamber leadless pacemaker implanted. Stable 3-month atrial parameters included an impedance of 340 Ω, sensing of 3.2 mV, and threshold of 0.25 V at 0.2 ms, while ventricular parameters showed an impedance of 780 Ω, sensing of 14.2  mV, and threshold of 0.5 V at 0.2 ms.

CONCLUSION

Dual chamber leadless pacemaker implant is feasible via right internal jugular vein access and in a pediatric patient.

Atrial leadless pacemaker implant using Aveir VR in an adolescent with congenital heart disease

INTRODUCTION

Pediatric patients with congenital heart disease repair may develop sinus node dysfunction. Leadless pacemakers have provided an alternative option to transvenous and epicardial device implants for pediatric patients in need of ventricular pacing. We describe the first adolescent patient to receive a leadless pacemaker in the atrium due to symptomatic sinus pauses.

METHODS

The study was approved by the internal review board of the University of California at Davis. Femoral vein implant was performed of an Aveir VR due to the higher impedance and larger battery capacity.

RESULTS

The 16-year-old male with dextro-transposition of the great arteries and ventricular septal defect repair had an uncomplicated atrial appendage implant of an Atrial Aveir VR, under transesophageal echocardiographic guidance. Three-month follow-up demonstrated stable threshold of 0.5 V @ 0.2 milliseconds, impedance of 720 Ω and sensing of 9.1 mV, with 10 % pacing and predicted battery longevity of 22.8 years.

CONCLUSION

Atrial implant of a leadless pacemaker is possible in the older pediatric population without complications, including of the Aveir VR.

Conduction System Pacing in Children and Congenital Heart Disease

Permanent cardiac pacing in children with congenital complete atrioventricular block (CCAVB) and/or congenital heart disease (CHD) is challenging. Conduction system pacing (CSP) represents a novel pacing strategy aiming to preserve physiological ventricular activation. Patients with CCAVB or CHD are at high risk of developing pacing-induced cardiomyopathy with chronic conventional right ventricular myocardial pacing. CSP may be a valuable pacing modality in this particular setting because it can preserve ventricular synchrony. In this review, we summarise implantation techniques, the available clinical evidence and future directions related to CSP in CCAVB and CHD.

Dual-chamber leadless pacemaker in complex adult congenital heart disease: a case report

Background

Atrioventricular block is common with adult congenital heart disease and pacemaker implantation is challenging. Atrioventricular synchronous pacing is important for better haemodynamics. This case reports the implantation of a dual-chamber leadless pacemaker in a patient with univentricular heart physiology and contributes to the literature regarding the management option in complex adult congenital heart disease patients with conduction abnormalities.

Case summary

A 25-year-old male with double inlet left ventricular, transposition of great arteries, hypoplastic aortic arch receive multiple surgeries including the Glenn shunt at the age of 1. He presented with 2:1 and 3:1 heart block at the age of 13 with a transvenous dual-chamber pacemaker implanted by pacing the superior vena cava stump and puncturing the Glenn shunt for the ventricular lead. A decade later, lead malfunctioned and the patient progressed to complete heart block. A subcutaneous implantable cardioverter defibrillator was implanted when he was 23 for monomorphic ventricular tachycardia. Given the anticipated challenges with transvenous lead extraction and epicardial pacemaker implantation, we implanted the novel dual-chamber leadless pacemakers which resulted in satisfactory atrioventricular synchronous pacing performance immediately post-op and 2 weeks after the procedure.

Discussion

We present a case of a novel dual-chamber leadless pacemaker implantation to maintain atrioventricular synchrony in the patient with complete heart block and univentricular physiology. This case illustrates an additional pacing option in complex adult congenital heart to maintain atrioventricular synchrony.

Aveir VR, retrievable leadless pacing in the young

INTRODUCTION

Successful implantations of the Aveir VR, have been effectively demonstrated in adults; however, there remain limited reports supporting safe and feasible implantation of the Aveir VR in the young population.

METHODS

Retrospective, observational study of Aveir VR implantation of young patients (≦21 years old) at UC Davis Medical Center from November 2022 to January 2024 via the internal jugular or femoral vein implantation approaches. Indications for pacing, patient demographics, pacing thresholds and longevity were reported at the time of implantation and last follow-up.

RESULTS

A total of 10 patients received the Aveir VR with a median age of years (IQR 12.5-17) and median weight of 50.8 kg (IQR 44.6-60.9) kg. The majority were male (80%). Aveir VR leadless pacemaker occurred via internal jugular venous (90%) or femoral venous (10%) approaches. Indications for placement were intermittent complete heart block (60%) and sinus pauses (40%). Adequate impedance, sensing and thresholds were maintained from implantation to a median follow-up of 9 months. Predicted pacemaker longevity at follow-up median was 23.8 years. There were no complications in any of the 10 patients.

CONCLUSION

Aveir VR implantation via the internal jugular and femoral veins is feasible in the young patient population with stable pacing parameters at follow-up.

Updates in Arrhythmia Management in Adult Congenital Heart Disease

Arrhythmias are highly prevalent in adults with congenital heart disease. For the clinician caring for this population, an understanding of pathophysiology, diagnosis, and management of arrhythmia is essential. Herein we review the latest updates in diagnostics and treatment of tachyarrhythmias and bradyarrhythmias, all in the context of congenital anatomy, hemodynamics, and standard invasive palliations for congenital heart disease.

New Guidelines of Pediatric Cardiac Implantable Electronic Devices: What Is Changing in Clinical Practice?

Guidelines are important tools to guide the diagnosis and treatment of patients to improve the decision-making process of health professionals. They are periodically updated according to new evidence. Four new Guidelines in 2021, 2022 and 2023 referred to pediatric pacing and defibrillation. There are some relevant changes in permanent pacing. In patients with atrioventricular block, the heart rate limit in which pacemaker implantation is recommended was decreased to reduce too-early device implantation. However, it was underlined that the heart rate criterion is not absolute, as signs or symptoms of hemodynamically not tolerated bradycardia may even occur at higher rates. In sinus node dysfunction, symptomatic bradycardia is the most relevant recommendation for pacing. Physiological pacing is increasingly used and recommended when the amount of ventricular pacing is presumed to be high. New recommendations suggest that loop recorders may guide the management of inherited arrhythmia syndromes and may be useful for severe but not frequent palpitations. Regarding defibrillator implantation, the main changes are in primary prevention recommendations. In hypertrophic cardiomyopathy, pediatric risk calculators have been included in the Guidelines. In dilated cardiomyopathy, due to the rarity of sudden cardiac death in pediatric age, low ejection fraction criteria were demoted to class II. In long QT syndrome, new criteria included severely prolonged QTc with different limits according to genotype, and some specific mutations. In arrhythmogenic cardiomyopathy, hemodynamically tolerated ventricular tachycardia and arrhythmic syncope were downgraded to class II recommendation. In conclusion, these new Guidelines aim to assess all aspects of cardiac implantable electronic devices and improve treatment strategies.

Transvenous endocardial pacing with SelectSecure™ 3830 lead in pediatric patients: case series of two infants and a literature review

BACKGROUND

The SelectSecure™ 3830 lead is an innovative, lumenless, and thin active fixed lead with a nonretractable screw-in tip and a diameter of 4.1 Fr, making it the thinnest pacing lead available. Its high anti-extrusion properties and durability have shown favorable outcomes in cardiac pacing, especially in pediatric patients. The superfine design and easy implantation of the lead have rendered it a preferred choice in children, particularly in cases of congenital heart disease.

CASE PRESENTATION

This case series presents two infant patients who underwent transvenous endocardial pacing using the SelectSecure™ 3830 lead, along with a comprehensive literature review on the topic. The study followed the patients for 5 years and 3 years, respectively, and observed stable pacing parameters, indicating a positive therapeutic outcome and safety. This article discusses the optimal age and body shape for transvenous lead implantation in infants and highlights the advantages and disadvantages of endocardial and epicardial pacing approaches. Although endocardial pacing offers several benefits such as minimal trauma, short hospital stay, and longer battery life, it may not be suitable for intracardiac shunts, and venous occlusion remains a concern. On the other hand, epicardial pacing may be considered for children with challenging endocardial access but comes with higher risk of lead failure and coronary artery compression. This study emphasizes the importance of careful follow-up in pediatric patients with pacing, as lead failure can occur in young patients owing to growth and development, leading to syncope and battery depletion. The article also underscores the significance of selecting the appropriate pacing location to minimize the impact of cardiac function, with right ventricular septal pacing emerging as a preferable option.

CONCLUSIONS

The SelectSecure™ 3830 lead presents a promising solution for transvenous endocardial pacing in pediatric patients with high degree atrioventricular block and bradycardia, ensuring safe and effective pacing as they grow and develop.

Aveir retrievable, 38-mm length, leadless pacemaker implantation in a 23-kg pediatric patient with congenital heart disease

INTRODUCTION

Complications are more prevalent in pediatric patients receiving pacemaker implants.

METHODS

We performed a retrospective review of a retrievable, 38 mm leadless pacemaker implantation in a 23-kg pediatric patient.

CASE/DISCUSSION

An active 9-year-old, 23 kg male patient with tetralogy of Fallot with intermittent pacing need presented with a fractured lead and pacing need. He underwent implant of a retrievable leadless pacemaker (Abbott Aveir) via internal jugular vein access, without complication, and with echocardiographic guidance. His threshold was stable at 1.25 V @0.4 ms, with stable impedance and sensing at 5-month follow-up.

CONCLUSION

Aveir retrievable leadless pacemakers can be implanted safely in a child with tetralogy of Fallot, as small as 23 kilograms.

Endocardial pacing compared to epicardial left ventricle pacing and right ventricle pacing: A single-center long-term experience in a pediatric population

BACKGROUND AND AIMS

Pediatric pacing is usually performed as epicardial pacing in small children in need of pacemaker therapy. Epicardial pacing compared with transvenous pacing for pediatric complete atrioventricular block (CAVB) has different strengths and weaknesses. The epicardial left ventricular wall position of the lead has been considered superior, in terms of contraction pattern, compared to a transvenous right ventricular stimulation. We aimed to compare QRS duration and cardiac function before and after the switch from epicardial to transvenous pacing in a pediatric population.

METHODS

Pediatric patients with congenital or acquired CAVB, who underwent a switch from epicardial-to transvenous pacing at our center from 2005 to 2021, were identified through the national ICD- and Pacemaker Registry. Data regarding clinical status, ECG, and echocardiography before and after the switch and at last follow-up were collected.

RESULTS

We included 15 children. The median age at the switch was 6.7 (4.4-11.7) years with a median weight of 21 (15-39) Kg. The median QRS duration with the transvenous systems was 136 (128-152) ms vs. a QRS duration during epicardial stimulation of 150 (144-170) ms with a median difference in QRS duration of 14 (6-20) ms. Children with a post-surgical AV block had a broader QRS duration, both with epicardial and endocardial stimulation. Before the switch, there was one patient with impaired left ventricular function (LVF) but with normal left ventricular end-diastolic diameters. After the switch, one patient developed symptomatic LV dysfunction with the recovery of LVF at the last follow-up after being implanted with a cardiac resynchronization therapy device.

CONCLUSIONS

Our report of pediatric patients after switching from epicardial to transvenous pacing shows how transvenous pacing is not inferior to epicardial pacing in terms of QRS duration and no significant deterioration of cardiac function was detectable.

Current State of Cardiac Implantable Electronic Device Remote Monitoring in Pediatrics and Congenital Heart Disease: A PACES-Sponsored Quality Improvement Initiative

Cardiac implantable electronic device (CIED) remote transmissions are an integral part of longitudinal follow-up in pediatric and adult congenital heart disease (ACHD) patients. To evaluate baseline CIED remote monitoring (RM) data among pediatric and ACHD centers prior to implementation of a Pediatric and Congenital Electrophysiology  Society (PACES)-sponsored quality improvement (QI) project. This is a cross-sectional study of baseline CIED RM. Centers self-reported baseline data: individual center RM compliance was defined as high if there was > 80% achievement and low if < 50%. A total of 22 pediatric centers in the USA and Australia submitted baseline data. Non-physicians were responsible for management of the RM program in most centers: registered nurse (36%), advanced practice provider (27%), combination (23%), and third party (9%). Fifteen centers (68%) reported that > 80% of their CIED patients are enrolled in RM and only two centers reported < 50% participation. 36% reported high compliance of device transmission within 14 days of implant and 77% of centers reported high compliance of CIED patients enrolled in RM. The number of centers achieving high compliance differed by device type: 36% for pacemakers, 50% for ICDs, and 55% for Implantable Cardiac Monitors (ICM). All centers reported at least 50% adherence to recommended follow-up for PM and ICD, with 23% low compliance rate for ICMs. Based on this cross-sectional survey of pediatric and ACHD centers, compliance with CIED RM is sub-optimal. The PACES-sponsored QI initiative will provide resources and support to participating centers and repeat data will be evaluated after PDSA cycles.

Epicardial Versus Endocardial Pacing in Paediatric Patients with Atrioventricular Block or Sinus Node Dysfunction: A Systematic Review and Meta-analysis

Pacing indications in children are clearly defined, but whether an epicardial (EPI) or an endocardial (ENDO) pacemaker performs better remains to be elucidated. This systematic review and meta-analysis aimed to directly compare the incidence of pacemaker (PM) lead-related complications, mortality, hemothorax and venous occlusion between EPI and ENDO in children with atrioventricular block (AVB) or sinus node dysfunction (SND). Literature search was conducted in MEDLINE (via PubMed), Scopus by ELSEVIER, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and OpenGrey databases until June 25, 2022. Random-effects meta-analyses were performed to assess the pacing method's effect on lead failure, threshold rise, post-implantation infection and battery depletion and secondarily on all-cause mortality, hemothorax and venous occlusion. Several sensitivity analyses were also performed. Of 22 studies initially retrieved, 18 were deemed eligible for systematic review and 15 for meta-analysis. Of 1348 pediatric patients that underwent EPI or ENDO implantation, 542 (40.2%) had a diagnosis of congenital heart disease (CHD). EPI was significantly associated with higher possibility of PM-lead failure [pooled odds ratio (pOR) 3.00, 95% confidence interval (CI) 2.05-4.39; I2 = 0%]; while possibility for threshold rise, post-implantation infection and battery depletion did not differ between the PM types. Regarding the secondary outcome, the mortality rates between EPI and ENDO did not differ. In sensitivity analyses the results were consistent results between the two PM types. The findings suggest that EPI may be associated with increased PM-lead failure compared to ENDO while threshold rise, infection, battery depletion and mortality rates did not differ.

Lead Management in Patients with Congenital Heart Disease

Pediatric patients with congenital heart disease present unique challenges when it comes to cardiac implantable electronic devices. Pacing strategy is often determined by patient size/weight and operator experience. Anatomic considerations, including residual shunts, anatomic obstructions and barriers, and abnormalities in the native conduction system, will affect the type of CIED implanted. Given the young age of patients, it is important to have an "eye on the future" when making pacemaker/defibrillator decisions, as one can expect several generator changes, lead revisions, and potential lead extractions during their lifetime.

Transvenous lead extraction in children with bidirectional rotational dissection sheaths

Objectives

Due to the limited longevity of endovascular leads, children require thoughtful lifetime lead management strategies including conservation of access vessel patency. Consequently, there is an increasing interest in transvenous lead extraction (TLE) in children, however, data on TLE and the use of powered mechanical dissection sheaths is limited.

Methods

We performed a retrospective cohort study analyzing all children <18 years that underwent TLE in our institution from 2015 to 2022. Procedural complexity, results and complications were defined as recommended by recent consensus statements.

Results

Twenty-eight children [median age 12.8 (interquartile range 11.3-14.6) years] were included. Forty-one leads were extracted [median dwell time 85 (interquartile range 52-102) months]. Extractions of 31 leads (76%) in 22 patients (79%) were complex, requiring advanced extraction tools including powered bidirectional rotational dissection sheaths in 14 children. There were no major complications. Complete procedural success was achieved in 18 (64%) and clinical success in 27 patients (96%), respectively. Procedural success and complexity varied between lead types. The Medtronic SelectSecure™ lead was associated with increased odds of extraction by simple traction (p = 0.006) and complete procedural success (p < 0.001) while the Boston Scientific Fineline™ II lead family had increased odds of partial procedural failure (p = 0.017).

Conclusions

TLE with the use of mechanical powered rotational dissection sheaths is feasible and safe in pediatric patients. In light of rare complications and excellent overall clinical success, TLE should be considered an important cornerstone in lifetime lead management in children. Particular lead types might be more challenging and less successful to extract.

Advancing the science of management of arrhythmic disease in children and adult congenital heart disease patients within the last 25 years

This review article reflects how publications in EP Europace have contributed to advancing the science of management of arrhythmic disease in children and adult patients with congenital heart disease within the last 25 years. A special focus is directed to congenital atrioventricular (AV) block, the use of pacemakers, cardiac resynchronization therapy devices, and implantable cardioverter defibrillators in the young with and without congenital heart disease, Wolff-Parkinson-White syndrome, mapping and ablation technology, and understanding of cardiac genomics to untangle arrhythmic sudden death in the young.

Pediatric Epicardial Devices: Early and Midterm Outcomes

BACKGROUND

Lead performance is suboptimal in young patients and a main cause of device system failure. Our objective was to assess early and midterm outcomes after epicardial device implantation in a contemporary pediatric cohort.

METHODS

A total of 116 consecutive pediatric patients underwent 137 epicardial device implantations from 2010 to 2019. Forty pacemakers and 97 implantable cardioverter defibrillators (ICDs) were implanted. Lead failure was defined as leads repaired, replaced, or abandoned due to fracture, dislodgement, or dysfunction. Freedom from device system failure was determined using Kaplan-Meier analysis.

RESULTS

Mean age at implantation was 10 ± 5 years, 46 (34%) were younger than 8 years old, 41 (30%) had prior cardiac surgery, and 38 (28%) had prior devices. Main indications were acquired heart block (17/40 [43%]), sinus node dysfunction (14/40 [35%]), and congenital heart block (7/40 [18%]) for pacemakers, and hypertrophic cardiomyopathy (46/97 [47%]), long QT syndrome (31/97 [32%]), and ventricular arrhythmia (17/97 [18%]) for ICDs. There were no early deaths. Three-year freedom from device system failure was 80% (95% CI 73%, 88%) for all patients and 88% (95% CI 79%, 99%) for patients <8 years old. Device system failure causes included lead fracture (20/34 [59%]), lead dysfunction (5/34 [15%]), lead dislodgement (5/34 [15%]), infection (3/34 [9%]), and pericarditis (1/34 [3%]). Reintervention was required in 26/34 (76%) device system failures.

CONCLUSIONS

Epicardial device implantation is safe, shows acceptable midterm outcomes in children, and is an effective option in patients younger than 8 years old. Close device surveillance continues to be essential to detect lead failure early and ensure timely reintervention.

Micra pacemaker in adult congenital heart disease patients: a case series

INTRODUCTION

implantation of transvenous endocardial or epicardial pacemakers presents specific challenges in adult congenital heart disease (ACHD) patients. Micra leadless pacemaker (Micra PPM) may overcome some of these difficulties.

METHODS

15 ACHD patients who underwent Micra PPM insertion were retrospectively evaluated.

RESULTS

males 53.3%. Mean age at study: 37.5±10.7 years. Mean age at Micra PPM insertion: 35.5±11.0 years. Mean follow-up so far: 2.0±0.3 years. Concerning the ACHD patients, 6.7% had a simple defect, 66.6% had a moderately complex defect, 26.7% were complex. Four patients (26.7%) had a previous PPM implantation. Three patients (20%) had a systemic right ventricle. Two patients (13.3%) had a single ventricle physiology. Five (33.3%) had Trisomy 21. The most commonly used Micra PPM modality was VVI (73.3%). Mean threshold post implantation was 0.48 V [range: 0.25-1.13 V], while mean threshold at 6 months control was 0.60 V [range: 0.38-1.13 V] (p=ns). Mean R wave post implantation was 10.3 V [range: 3.25-19.4 V], whilst mean R wave at 6 months follow-up was 10.1 V [range:3.5-19.0 V] (p=ns). No major peri and post-procedural complications were encountered.

CONCLUSIONS

since ACHD patients are living longer and surviving into adulthood, the incidence of conduction disorders continues to increase, as part of the natural history of some lesions or as early or late complication of surgery. The Micra leadless PPM can be successfully implanted in ACHD patients and have significant theoretical advantages. They should be considered when transvenous and epicardial pacing are either contraindicated or represent an otherwise suboptimal approach. This article is protected by copyright. All rights reserved.

ICD Outcome in Pediatric Cardiomyopathies

Background: Pediatric patients with cardiomyopathies are at risk of malignant arrhythmias and sudden cardiac death (SCD). An ICD may prevent SCD. The aim of this study was to evaluate ICD implantation outcomes, and to compare transvenous and subcutaneous ICDs (S-ICDs) implanted in pediatric patients with cardiomyopathies. Methods: The study is single center and retrospective, and includes pediatric patients with cardiomyopathies who required ICD implantation (2010–2021). Outcomes were recorded for appropriate/inappropriate ICD therapy and surgical complications. Transvenous ICD and S-ICD were compared. Data are presented as median values (25th–75th centiles). Results: Forty-four patients with cardiomyopathies (hypertrophic 39%, arrhythmogenic 32%, dilated 27%, and restrictive 2%) underwent transvenous (52%) and S-ICD (48%) implantation at 14 (12–17) years of age, mostly for primary prevention (73%). The follow-up period was 29 (14–60) months. Appropriate ICD therapies were delivered in 25% of patients, without defibrillation failures. Lower age at implantation and secondary prevention were significant risk factors for malignant ventricular arrhythmias that required appropriate ICD therapies. ICD-related complications were surgical complications (18%) and inappropriate shocks (7%). No significant differences in outcomes were recorded, either when comparing transvenous and S-ICD or comparing the different cardiomyopathies. Conclusions: In pediatric patients with cardiomyopathy, ICD therapy is effective, with a low rate of inappropriate shocks. Neither ICD type (transvenous and S-ICDs) nor the cardiomyopathies subgroup revealed divergent outcomes.

Magnetic resonance imaging safety in patients with abandoned or functioning epicardial pacing leads

OBJECTIVES

The European Society of Cardiology Guidelines on cardiac pacing from 2021 allow magnetic resonance imaging (MRI) in patients with cardiac implantable electronic devices (CIEDs) but do not recommend MRI in patients with epicardial pacing leads. The clinical dilemma remains whether performing an MRI in patients with CIED and epicardial leads is safe. We aimed to evaluate the safety of performing an MRI in patients with CIED and abandoned or functioning epicardial pacing leads.

METHODS

We included all adult patients who underwent clinically indicated MRIs with CIED and functioning or abandoned epicardial leads in a single tertiary hospital between November 2011 and October 2019. The data were retrospectively collected.

RESULTS

Twenty-six MRIs were performed on 17 patients with functioning or abandoned epicardial pacing leads. Sixty-nine percent of the MRI scans (18/26) were conducted on patients with functioning epicardial pacing leads. A definite adverse event occurred in one MRI scan. This was a transient elevation of the pacing threshold in a patient with a functioning epicardial ventricular pacing lead implanted 29 years previously. An irreversible atrial pacing lead impedance elevation was detected 6 months after the MRI in another patient; the association with the previous MRI remained unclear. No adverse events were detected in MRIs performed on patients with modern (implanted in 2000 or later) functioning epicardial leads.

CONCLUSIONS

MRIs in patients with CIED and modern functioning epicardial pacing leads were performed without detectable adverse events. Further large-scale studies are necessary to confirm MRI safety in patients with epicardial pacing leads.

KEY POINTS

• Currently, MRI in patients with cardiac implantable electronic devices (CIEDs) and functioning or abandoned epicardial pacing leads is not recommended. • MRIs in patients with CIED and modern functioning epicardial leads (implanted in 2000 or later) were performed without detectable adverse events in our patient cohort. • Allowing MRI in patients with epicardial pacing leads may significantly improve the diagnostic work-up, especially in specific patient groups, such as patients with congenital heart disease.

Angiography-guided mid/high septal implantation of ventricular leads in patients with congenital heart disease

BACKGROUND

Conduction system pacing prevents pacing-induced cardiomyopathy, but it can be challenging to perform in patients with congenital heart disease (CHD), and mid/high septal lead implantation is an alternative. This study aimed to assess intraprocedural angiography's utility as a guide for mid/high-septal lead implantation in CHD patients.

METHODS

The study subjects were CHD patients with Class I/IIa indications for permanent pacemaker implantation. To guide septal lead implantation, we performed an intraprocedural right ventricular angiogram in anteroposterior, 40° left anterior oblique, and 30° right anterior oblique. The primary endpoint was the lead tip in the mid/high septum on computed tomography (CT). The secondary endpoints were complications and systemic ventricular function on follow-up.

RESULTS

From January 2008 to December 2018, we enrolled 27 patients (mean age: 30 ± 20 years; M:F 17:10) with CHD (unoperated: 20, operated: 7). The mean paced QRS duration was 131.7 ± 5.8 ms, and CT done in 22/27 patients confirmed the lead tip in the mid-septum in 16, high septum in 5, and apical septum in 1 patient. There were no procedural complications, and during a mean follow-up of 58 ± 35.2 months, there was no significant change in the systemic ventricular ejection fraction (56.4 ± 8.3% vs 53.9 + 5.9%, P = .08). Two patients with Eisenmenger syndrome died because of refractory heart failure.

CONCLUSIONS

Intraprocedural angiography is safe and useful to guide mid/high-septal lead implantation in CHD patients. Mid/high septal lead position preserves systemic ventricular function in patients with CHD during medium-term follow-up.

Surgical management of transvenous lead-induced tricuspid regurgitation in adult and pediatric patients with congenital heart disease

OBJECTIVE

The objective of this study was to evaluate outcomes of surgical management of lead-induced tricuspid regurgitation (TR) in patients with congenital heart disease.

METHODS

We analyzed data of 54 consecutive patients who underwent tricuspid valve (TV) surgery from 1998 to 2015 for lead-induced TR. Primary end points, including mortality, TV reinterventions, and longitudinal TR measurements, were analyzed with the Kaplan-Meier method or with repeated measures proportional odds modeling.

RESULTS

The median age of patients was 48.2 years (interquartile range, 37.3-59.0 years); 31 (57.4%) were female; 2 (3.7%) were children. Thirty patients (55.6%) underwent TV repair and 24 (44.4%) had replacement, and 52 underwent concomitant cardiac procedures. Thirty-day mortality was 1.9% (repair: 3.3%, replacement: 0.0%). Five-year survival was 80.4% overall and 79.7% and 81.4% for the repair and replacement groups, respectively. In response to surgery, TR improved in both groups (each P < .001) but more with replacement than repair (P < .001); longitudinal analysis showed that TR trends observed early on favoring replacement were sustained across follow-up (P < .001). The model-estimated risk of moderate or severe TR at 5-year follow-up, conditional on having severe preoperative TR, was 74.4% for the repair and 10.7% for the replacement group. Five-year cumulative risk of TV reintervention was comparable for valve repair and replacement.

CONCLUSIONS

Despite the need for concomitant cardiac procedures in most of the patients, early mortality was low after TV surgery. Survival and rate of TV reintervention were comparable for the repair and replacement groups. However, TV repair was associated with progressive TR during intermediate follow-up, especially in patients with severe preoperative TR.

Updated Approaches to Cardiac Electrical Stimulation and Pacing in Pediatrics

Cardiac electrical stimulation is a rarely used but required skill for pediatric emergency physicians. Children who are in cardiac arrest or who demonstrate evidence of hypoperfusion because of cardiac reasons require rapid diagnosis and intervention to minimize patient morbidity and mortality. Both hospital- and community-based personnel must have sufficient access to, and knowledge of, appropriate equipment to provide potentially lifesaving defibrillation, cardioversion, or cardiac pacing. In this review, we will discuss the primary clinical indications for cardioelectrical stimulation in pediatric patients, including the use of automated external defibrillators, internal defibrillators, and pacemakers. We discuss the types of devices that are currently available, emergency management of internal defibrillation and pacemaker devices, and the role of advocacy in improving delivery of emergency cardiovascular care of pediatric patients in the community.

Synchronized Biventricular Heart Pacing in a Closed-chest Porcine Model based on Wirelessly Powered Leadless Pacemakers

About 30% of patients with impaired cardiac function have ventricular dyssynchrony and seek cardiac resynchronization therapy (CRT). In this study, we demonstrate synchronized biventricular (BiV) pacing in a leadless fashion by implementing miniaturized and wirelessly powered pacemakers. With their flexible form factors, two pacemakers were implanted epicardially on the right and left ventricles of a porcine model and were inductively powered at 13.56 MHz and 40.68 MHz industrial, scientific, and medical (ISM) bands, respectively. The power consumption of these pacemakers is reduced to µW-level by a novel integrated circuit design, which considerably extends the maximum operating distance. Leadless BiV pacing is demonstrated for the first time in both open-chest and closed-chest porcine settings. The clinical outcomes associated with different interventricular delays are verified through electrophysiologic and hemodynamic responses. The closed-chest pacing only requires the external source power of 0.3 W and 0.8 W at 13.56 MHz and 40.68 MHz, respectively, which leads to specific absorption rates (SARs) 2–3 orders of magnitude lower than the safety regulation limit. This work serves as a basis for future wirelessly powered leadless pacemakers that address various cardiac resynchronization challenges.

Pacing in Patients with Congenital Heart Disease: When Is It Helpful and When Is It Harmful?

PURPOSE OF REVIEW

Pacing in pediatric and adult patients with congenital heart disease requires careful evaluation and thoughtful planning. Review of current guidelines with assessment of risk/benefit must be performed along with planning on a case-by-case basis in order to achieve maximal success and reduce risk in this specialized population of patients that is rapidly increasing in size.

RECENT FINDINGS

Guidelines for pacing in pediatric and congenital heart disease patients span many years. Most recent consensus and summary guidelines address pacing in adult patients with or without congenital heart disease. Pediatric recommendations from prior documents must be included in current decision-making. Pacing in pediatric and congenital heart disease patients is important therapy. Creation of an individualized plan of care with attention to risk/benefit decision-making regarding when and how to pace is critical in this population to maximize beneficial outcome.

Pacing therapy in children with isolated complete atrioventricular block: a retrospective study of pacing system survival and pacing-related complications in a national cohort

AIMS

To evaluate pacing system survival and complications to pacemaker (PM) therapy in children with isolated complete atrioventricular block (CAVB).

METHODS AND RESULTS

We performed a nationwide retrospective study of children diagnosed before 15 years of age with isolated CAVB and PM treatment. Between 1983 and 2012, 127 patients underwent PM-implantations at 3.2 (0-17) [median (range)] years and were followed for 11 (0.6-19) years. An endocardial or epicardial PM system was implanted in 72 and 55 patients, respectively. A total of 306 pacing leads (76% steroid-eluting) were implanted. Pacing system survival was significantly affected by age, with a higher risk of a new intervention for children aged <1 month at first implantation. Lead survival of the steroid-eluting leads at 5 and 10 years was 90 and 81%, respectively, with no difference between epicardial and endocardial systems. Complications leading to revision of the pacing system occurred in 24% of the patients. Patients aged <1 month at first PM implantation had a five-fold increased risk for a complication to occur. Dividing the cohort according to year of first procedure showed that those who had their first implantation ≥2002 had fewer complications and also lead- and pacing system survival was better in the later cohort.

CONCLUSION

Pacing system survival and complications to PM therapy in young patients with isolated CAVB were significantly affected by age, with low age at PM implantation constituting a risk factor. Endocardial and epicardial pacing systems showed no significant differences in performance.

Transvenous pacing in complex post-operative congenital heart disease guided by angiography: A case report

Transvenous pacing in patients with postoperative complex congenital heart disease (CHD) can be challenging and pose technical challenges to lead placement because of the complex anatomy, distortions produced by the surgical procedures, and the altered relationship of cardiac chambers. We describe the utility of angiography for transvenous dual chamber pacemaker implantation in a post-operative complex congenital heart disease.

Longitudinal Outcomes of Epicardial and Endocardial Pacemaker Leads in the Adult Fontan Patient

Placement of an epicardial pacemaker system is often preferred over an endocardial system in patients who have undergone a Fontan operation, but data are limited on how these two systems perform over time in patients with Fontan palliation. We performed a retrospective review of adults with Fontan palliation who had pacemaker implantation and interrogation data at Mayo Clinic from 1994 to 2014. Lead parameters, pacing mode, and polarity were collected at the earliest device interrogation report. Clinic notes and device interrogation reports were reviewed at implantation, 6 months, and yearly after implantation to determine impedance, capture threshold (CT), and energy threshold (ET). There were 87 patients with 168 leads in the study cohort. The mean follow-up time was 7.7 years (6 months-19 years). There were 143 epicardial leads (57 atrial and 86 ventricular) and 25 endocardial leads (20 atrial and 5 ventricular). There was no difference in the baseline lead parameters between epicardial and endocardial leads for impedance (610 ± 259 versus 583 ± 156 Ω, p = 0.93), CT (2.0 ± 1.3 versus 1.8 ± 1.3 V, p = 0.28), or ET (7.1 ± 12.5 versus 6.8 ± 18.1 µJ, p = 0.29). Compared to endocardial leads, ventricular epicardial leads were associated with temporal decrease in impedance and increase in ET. Regarding clinical outcomes, epicardial leads had higher rates of failure but similar generator longevity in comparison to endocardial leads. Ventricular epicardial leads were associated with temporal decrease in impedance and increase in ET. Epicardial leads had a higher rate of failure but similar generator longevity compared to endocardial leads.

Predictors of electrocardiographic screening failure for the subcutaneous implantable cardioverter-defibrillator in children: A prospective multicenter study

BACKGROUND

Subcutaneous implantable cardioverter-defibrillator (SICD) shows promise for select patients at risk of sudden cardiac death. However, patients need to pass an electrocardiographic (ECG) screening (ECG-S) test before they can receive an SICD. Predictors of ECG-S failure in children are unclear.

OBJECTIVE

The purpose of this study was to identify the incidence and predictive factors for failure of ECG-S in children.

METHODS

Patients 18 years and younger with a preexisting ICD underwent ECG-S for SICD. ECG and demographic data were analyzed for factors predictive of failure.

RESULTS

Seventy-three patients (mean age 14.2 ± 3.3 years; range 5-18 years) with hypertrophic cardiomyopathy (n = 24, 33%), long QT syndrome (n =18, 25%), other inherited arrhythmia syndromes (n = 20, 27%), congenital heart disease (n = 9, 12%), and miscellaneous conditions (n = 2) with an existing transvenous ICD underwent prospective ECG-S. Nineteen (26%) failed ECG-S. Failed patients had a longer corrected QT (QTc) interval (457 ms vs 425 ms; P = .03), a longer QRS duration (120 ms vs 98 ms; P = .04), and a lower ratio of R-wave to T-wave amplitudes (R:T ratio) in lead aVF (4 vs 5; P = .001). Multivariable logistic regression identified QTc interval (odds ratio [OR] 4.31; P = .04), QRS duration (OR 4.93; P = .03), R:T ratio in lead aVF (OR 3.13; P = .08) as predictors of failure. A risk score with 1 point each for QTc interval >440 ms, QRS duration >120 ms, and R:T ratio <6.5 in lead aVF was associated with probability of failure of 15.4% (1 point), 47.4% (2 points), and 88.6% (3 points), respectively.

CONCLUSION

ECG-S failure for SICD occurred in 26% of children, which is higher than the reported incidence in adults. Factors predicting ECG-S failure included longer QTc interval, longer QRS duration, and lower R:T ratio in lead aVF.

What endocardial right ventricular pacing site shows better contractility and synchrony in children and adolescents?

AIMS

Right ventricular (RV) apical (RVA) pacing can induce left ventricular (LV) dyssynchrony, remodeling, and dysfunction in children with complete atrioventricular block (CAVB). We compared the functional outcome of RVA with RV alternative pacing sites (RVAPS), including para-Hisian, septal, and outflow tract sites.

METHODS

This is a single-center, retrospective study. Data were collected before pacemaker implantation (transvenous leads), postoperatively, at 6 months, and at 1-2-3-4 years. Electrocardiogram evaluation included QRS duration, axis, QTc/JTc, and QTc dispersion. Echocardiographic evaluation included 2-D/3-D assessment of ventricular dimensions (Z-score of LV end-diastolic dimension), function (ejection fraction), and synchrony.

RESULTS

From 2009 to 2015, 55 patients with CAVB, aged 3-17 years, with or without other congenital heart defects, underwent RVAPS (30 patients, median age 11 years) or RVA (25 patients, median 12 years). All leads were positioned into the septum. Before implantation, no significant differences in parameters were observed, except for higher Z-score in RVAPS than in RVA. After implantation, at a median follow-up of 2.5 (range 1-6) years, the two groups showed no significant differences in LV dimensions, contractility, and synchrony. QRS intervals of RVAPS were significantly shorter than RVA. Clinical status was good and contractility/synchrony indexes were normal or adequate in all patients.

CONCLUSIONS

In pediatric patients, RVAPS and RVA showed no significant differences in LV dimensions, contractility, and synchrony. Preimplantation dilated patients showed LV reverse remodeling. RVAPS demonstrated shorter QRS intervals. Therefore, septal pacing sites, either RVA or RVAPS, seem to determine good contractility and synchrony at a mid-term follow-up.

Long-term outcome of transvenous pacemaker implantation in infants: a retrospective cohort study

AIM

Evaluation of long-term outcome of transvenous pacemaker (PM) implantation in infants.

METHODS AND RESULTS

A retrospective analysis of all transvenous PM implantations in infants <10 kg between September 1997 and October 2001 was made. Indications for PM implantation, age at implantation, and determinants of long-term outcome including cardiac function, PM function, and PM (system) complications were noted. Seven patients underwent transvenous VVI(R) PM implantation. Median age at implantation was 3 days (range: 1 day to 14 months), median weight 3.5 kg (range: 2.3-8.7 kg), and median follow-up 14 years (range: 12.3-16.3 years). Pacemaker indications were congenital complete atrioventricular block (n = 4), long QT syndrome with heart block (n = 2), and post-operative complete atrioventricular block with sinus node dysfunction (n = 1). No procedural complications were noted. Today all patients are alive and symptom free with good PM and cardiac function. Two patients underwent PM generator relocation for imminent skin necrosis and skin traction. Two patients suffered from asymptomatic left subclavian vein occlusion and developed thrombosis on the PM electrode. Three patients were converted to an epicardial PM system, due to atrial perforation after upgrading procedure (n = 1), syncope with need for implantable cardioverter defibrillator implantation (n = 1), and systolic dysfunction with development of dilated cardiomyopathy, which normalized under cardiac resynchronization therapy pacing (n = 1). Two patients needed atrioventricular (AV) valve repair for severe insufficiency. Two patients underwent repositioning of dysfunctional PM leads. In five patients, transvenous leads were removed. Indications were elective lead replacement (n = 1), atrial perforation (n = 1), and switch to an epicardial system (n = 3).

CONCLUSION

Transvenous PM implantation in infants (<10 kg) is associated with a high incidence of vascular occlusion, thrombosis, and severe atrioventricular valve regurgitation during long-term follow-up. We advocate an epicardial approach for PM implantation in small children.

Late Outcome and Predictors of Adverse Events Related to the Implantation of a Permanent Pacemaker in Patients with Isolated Congenital Atrioventricular Block

Isolated congenital atrioventricular block (ICAVB) is a rare, and pacemaker implantation is the only effective treatment. We sought to identify the predictive factors of adverse events related to pacemaker implantation in ICAVB. This is a cohort study of patients diagnosed with ICAVB who underwent pacemaker implantation from 1980 to 2014 in a single center. During the studied period, a total of 647 patients underwent implantation of their first permanent cardiac pacemaker before 30 years of age. Of these, only 62 (9.5 %) were diagnosed with ICAVB. This condition was diagnosed in utero in 15 (24.2 %) cases, 5 (8.1 %) in the neonatal period, 32 (51.6 %) during childhood, and 10 (16.1 %) during adolescence and young adulthood. The presence of autoantibodies (anti-Ro/SSA) was observed in 41 % of mothers who underwent serological evaluation. Age at the time of the initial pacemaker implant was 9.8 ± 9 years. During a mean follow-up time of 15 years, 1 (1.7 %) death occurred due to infectious endocarditis. Complications related to pacemaker implant were reported in 24 patients (38.7 %). The number of complications was significantly higher in the group with an epimyocardial implantation site (HR 6; CI 2.45-14.95). Ventricular dysfunction occurred in 6 (11.7 %) patients; however, we were not able to identify any predictors of it. Our results showed a low mortality rate after permanent therapy. However, these patients exhibited high morbidity related to the pacemaker system, and the epimyocardial implant site was an independent predictor of complications. Predictors of left ventricular dysfunction were not found in the present study.

Congenital and childhood atrioventricular blocks: pathophysiology and contemporary management

Atrioventricular block is classified as congenital if diagnosed in utero, at birth, or within the first month of life. The pathophysiological process is believed to be due to immune-mediated injury of the conduction system, which occurs as a result of transplacental passage of maternal anti-SSA/Ro-SSB/La antibodies. Childhood atrioventricular block is therefore diagnosed between the first month and the 18th year of life. Genetic variants in multiple genes have been described to date in the pathogenesis of inherited progressive cardiac conduction disorders. Indications and techniques of cardiac pacing have also evolved to allow safe permanent cardiac pacing in almost all patients, including those with structural heart abnormalities.

CONCLUSION

Early diagnosis and appropriate management are critical in many cases in order to prevent sudden death, and this review critically assesses our current understanding of the pathogenetic mechanisms, clinical course, and optimal management of congenital and childhood AV block.

WHAT IS KNOWN

• Prevalence of congenital heart block of 1 per 15,000 to 20,000 live births. AV block is defined as congenital if diagnosed in utero, at birth, or within the first month of life, whereas childhood AV block is diagnosed between the first month and the 18th year of life. As a result of several different etiologies, congenital and childhood atrioventricular block may occur in an entirely structurally normal heart or in association with concomitant congenital heart disease. Cardiac pacing is indicated in symptomatic patients and has several prophylactic indications in asymptomatic patients to prevent sudden death. • Autoimmune, congenital AV block is associated with a high neonatal mortality rate and development of dilated cardiomyopathy in 5 to 30 % cases. What is New: • Several genes including SCN5A have been implicated in autosomal dominant forms of familial progressive cardiac conduction disorders. • Leadless pacemaker technology and gene therapy for biological pacing are promising research fields. In utero percutaneous pacing appears to be at high risk and needs further development before it can be adopted into routine clinical practice. Cardiac resynchronization therapy is of proven value in case of pacing-induced cardiomyopathy.

Pacing and Defibrillators in Complex Congenital Heart Disease

Device therapy in the complex congenital heart disease (CHD) population is a challenging field. There is a myriad of devices available, but none designed specifically for the CHD patient group, and a scarcity of prospective studies to guide best practice. Baseline cardiac anatomy, prior surgical and interventional procedures, existing tachyarrhythmias and the requirement for future intervention all play a substantial role in decision making. For both pacing systems and implantable cardioverter defibrillators, numerous factors impact on the merits of system location (endovascular versus non-endovascular), lead positioning, device selection and device programming. For those with Fontan circulation and following the atrial switch procedure there are also very specific considerations regarding access and potential complications. This review discusses the published guidelines, device indications and the best available evidence for guidance of device implantation in the complex CHD population.

Results of remote follow-up and monitoring in young patients with cardiac implantable electronic devices

BACKGROUND

Remote monitoring is increasingly used in the follow-up of patients with cardiac implantable electronic devices. Data on paediatric populations are still lacking. The aim of our study was to follow-up young patients both in-hospital and remotely to enhance device surveillance.

METHODS

This is an observational registry collecting data on consecutive patients followed-up with the CareLink system. Inclusion criteria were a Medtronic device implanted and patient's willingness to receive CareLink. Patients were stratified according to age and presence of congenital/structural heart defects (CHD).

RESULTS

A total of 221 patients with a device - 200 pacemakers, 19 implantable cardioverter defibrillators, and two loop recorders--were enrolled (median age of 17 years, range 1-40); 58% of patients were younger than 18 years of age and 73% had CHD. During a follow-up of 12 months (range 4-18), 1361 transmissions (8.9% unscheduled) were reviewed by technicians. Time for review was 6 ± 2 minutes (mean ± standard deviation). Missed transmissions were 10.1%. Events were documented in 45% of transmissions, with 2.7% yellow alerts and 0.6% red alerts sent by wireless devices. No significant differences were found in transmission results according to age or presence of CHD. Physicians reviewed 6.3% of transmissions, 29 patients were contacted by phone, and 12 patients underwent unscheduled in-hospital visits. The event recognition with remote monitoring occurred 76 days (range 16-150) earlier than the next scheduled in-office follow-up.

CONCLUSIONS

Remote follow-up/monitoring with the CareLink system is useful to enhance device surveillance in young patients. The majority of events were not clinically relevant, and the remaining led to timely management of problems.

Low incidence of complications after cephalic vein cutdown for pacemaker lead implantation in children weighing less than 10 kilograms: A single-center experience with long-term follow-up

BACKGROUND

Only a few studies on the cephalic vein cutdown technique for pacemaker lead implantation in children weighing ≤10 kg have been reported even though the procedure is widely accepted in adults.

OBJECTIVE

The purpose of this study was to prove that cephalic vein cutdown for pacemaker lead implantation is a reliable technique with a low incidence of complications in children weighing ≤10 kg.

METHODS

The study included 44 children weighing ≤10 kg with an endocardial pacemaker. Cephalic, subclavian, and axillary vein diameters were measured by ultrasound before implantation. The measured diameters were used to select either an endocardial or epicardial surgical technique. Regular 6-month follow-up visits included pacemaker interrogation and clinical and ultrasound examinations.

RESULTS

Two dual-chamber and 42 single-chamber pacemakers were implanted. Mean weight at implantation was 6.24 kg (range 2.25-10.40 kg), and mean age was 11.4 months (range 1 day-47 months). In 40 children (90.1%), the ventricular leads were implanted using the cephalic vein cutdown technique, and implantation was accomplished via the prepared right external jugular vein in 4 of the children (9.9%). The atrial leads were implanted using axillary vein puncture and external jugular vein preparations. Mean follow-up was 8.9 years (range 0-20.9 years). Only 1 pacemaker-related complication was detected (a lead fracture near the connector that was successfully resolved using a lead repair kit).

CONCLUSION

The cephalic vein cutdown technique is feasible and reliable in children weighing ≤10 kg, which justifies the application of additional surgical effort in the treatment of these small patients.

Device therapy in children with and without congenital heart disease

Device therapy in children has undergone several changes over the last few years due to developments in technology as well new approaches to preservation of ventricular function in paediatric pacing, novel data on pacing lead survival, inclusion of cardiac resynchronisation therapy and accumulating experience with the implantable cardioverter-defibrillator. Despite these developments device therapy in children is still associated with significant complications mainly due to patient size, growth and underlying structural heart disease. The amount of available data on therapy outcomes is much smaller than in their adult counterparts and prospective randomized studies are completely missing. Thus device therapy has to be cautiously tailored to individual patient needs having in mind the specific situation of expected decades of treatment. Avoidance of complications and potential harm precluding successful therapy continuation in the future should be one of the main principles.