Long-term follow-up after pacemaker implantation in neonates and infants

Device-related complications in a national pediatric cardiac implantable electronic device cohort stratified after age and implantation technique

BACKGROUND

Cardiac implantable electronic devices (CIEDs) can be implanted epicardially or transvenously in children. Both techniques involve procedure-specific complications, and evidence for the choice of technique in children of different ages is scarce.

OBJECTIVES

The purpose of this study was to characterize a complete national pediatric cohort with de novo CIED implantation and compare the risks and causes of reintervention between transvenous and epicardial CIED recipients.

METHODS

This retrospective nationwide cohort study included all Danish children aged ≤15 years receiving a CIED from 1977 to 2021. Outcomes included time to first reintervention stratified by age and implantation technique. Reintervention was due to either battery depletion or lead or generator complication.

RESULTS

A total of 376 children received an epicardial (n = 131 [35%]) or transvenous (n = 245 [65%]) CIED with median [interquartile range] follow-up of 14 [6-21] years. Median age was 6 [1-11] years. For epicardial recipients, complication-driven reintervention was equal across age groups (P = .10), whereas among transvenous recipients the risk was significantly lower with increasing age (P <.001). Age-specific risk analyses revealed different risks for children aged <1 year, 1-8 years, and 9-15 years (Pinteraction <.001). For children <1 year, a complication-driven reintervention was more frequent for transvenous vs epicardial recipients (P <.001), whereas in children aged 9-15 years, the opposite was observed (P = .02).

CONCLUSION

Transvenous implantation in children <1 year and epicardial implantation in children 9-15 years was associated with higher risk of CIED-related complication leading to reintervention, whereas for children aged 1-8 years, the complication risk was similar between implantation techniques.

Dual- Vs Single-Chamber Ventricular Pacing in Isolated Congenital Complete Atrioventricular Block in Infancy

BACKGROUND

The optimal pacemaker programming strategy for infants with isolated congenital complete atrioventricular block (CCAVB) remains unresolved. Dual-chamber pacing maintains atrioventricular synchrony and physiological heart rate variability but increases the burden of ventricular pacing on a myocardium that may be inherently prone to left ventricular (LV) dysfunction.

OBJECTIVES

This study sought to compare clinical outcomes of dual (DDD)- vs single (VVI)- chamber pacing in infants with CCAVB (DAVINCHI).

METHODS

A multicenter retrospective study (2006-2023) identified infants with CCAVB and pacemaker implant at <1 year, with single-site ventricular pacing and no significant congenital heart disease. Outcome measured were clinically significant LV dysfunction, mortality, and complications.

RESULTS

A total of 109 infants (64% autoimmune CCAVB) were identified, 60.6% had VVI pacing. Over a median follow-up of 5 years, 60 complications occurred in 47 subjects (43.1%). Smaller infants had more complications. Clinically significant LV dysfunction developed in 11 (10.1%) and was more frequent in DDD (21% vs 3%; P = 0.006). LV dysfunction resulted in mortality in 1 patient and 10 patients required a change in pacing mode. Independent risk factors for LV dysfunction were DDD pacing and neonatal implant. Right ventricular pacing lead placement had a higher HR (HR: 2.67) for LV dysfunction but was not statistically significant (P = 0.2).

CONCLUSION

DDD pacing increases LV dysfunction risk compared with VVI in infants with CCAVB. Single-chamber LV apical pacing should be considered in infants with isolated CCAVB who require pacing. There is a high risk of pacing-related complications, particularly with an increased risk of ventricular lead complications in low-weight neonates.

Epicardial pacing outcomes in infants with heart block: Lead and device complications from a multicenter experience

BACKGROUND

Infants with complete heart block (CHB) require epicardial pacemaker (PM) insertion. Prior studies described epicardial pacing outcomes in infants and children, although they were limited by small or heterogeneous populations.

OBJECTIVE

This study aimed to explore patient- and procedure-level associations with device complications in infants with CHB who received a permanent PM.

METHODS

This was a multicenter, retrospective cohort study including infants receiving an epicardial PM between 2000 and 2021 for CHB. The primary outcome was time to device-related adverse event: lead failure requiring revision; pocket infection; exit block requiring increased pacing output; or lead-related coronary artery compression. Time-to-event analysis was performed by the Kaplan-Meier method with a multivariable Cox proportional hazards model.

RESULTS

There were 174 infants who received an epicardial PM (282 bipolar, 39 unipolar leads) for CHB. Median age and weight at PM were 93.5 days and 4.5 kg, respectively. Pacing indication was postoperative CHB in 63% and congenital CHB in 37%. The median follow-up was 2.1 years. The primary outcome occurred in 26 infants at a median time to event of 0.6 year. Age ≤90 days at PM implantation was the most significant risk factor for a device-related adverse event (hazard ratio, 7.02; P < .001), primarily driven by pocket infections. Lead failure occurred in 3% of leads with a 5- and 10-year freedom from failure of 93% and 83%, respectively.

CONCLUSION

Device complications affect 15% of infants receiving a permanent PM for heart block. Age ≤90 days at PM implantation is especially associated with infectious complications. Epicardial lead durability appears similar to previously reported pediatric experiences.

Long-term outcome of permanent epicardial pacemaker implantation in neonates: Experience from an Indian center

Introduction

Permanent pacemaker implantation (PPI) in neonates is challenging with respect to indications, device selection, implantation technique, and long-term outcomes. Complex anatomy, the need for long-term pacing with high rates, and a problematic postoperative period are the major problems.

Methods

We prospectively followed up 22 newborns who underwent PPI below 28 days of life at our institute.

Results

The median age at implantation was 2 days (interquartile range 1-9 days), and 9% were born preterm. The average heart rate before implantation was 46.4 ± 7.2 bpm. Maternal lupus antibodies were positive in 8 (36.4%) neonates, whereas 11 (50.0%) had associated congenital heart disease. Nineteen neonates underwent single chamber (VVI) and three underwent dual chamber (DDD) pacemaker implantation. Over a median follow-up of 46 months (range 2-123 months), the average ventricular pacing percentage was 87.5 ± 24.9%, with a stable pacing threshold. Seven children underwent pulse generator replacement due to battery depletion at a median age of 47 months. Pacing-induced ventricular dysfunction was seen in five children at a median age of 23.6 months, and two underwent upgradation to cardiac resynchronization therapy. Overall mortality was 13.6%, all due to tissue hypoperfusion and lactic acidosis in the postimplantation period.

Conclusions

PPI in neonates has a favorable outcome with excellent lead survival. Overall mortality is 13.6%, which is predominantly in the postimplantation period and related to myocardial dysfunction.

Permanent epicardial pacing in neonates and infants less than 1 year old: 12-year experience at a single center

BACKGROUND

Permanent epicardial pacing is the primary choice for neonates and infants with bradyarrhythmia. We reviewed mid-term outcomes after epicardial permanent pacemaker (EPPM) implantation in this age group.

METHODS

From Dec 1, 2008 to Dec 1, 2019, children who underwent EPPM implantation within the first year of life were included in our study. Patients were followed up for as long as 12 years, until Jun 11, 2021, for all-cause mortality and pacemaker reoperation. Kaplan-Meier and log-rank tests were used for analysis.

RESULTS

Of 31 consecutive patients [18 boys (58.1%) and 2 neonates (6.5%)] included in this study, 30 (96.8%) were discharged alive and assessed at a median follow-up of 3.9 years [interquartile range (IQR) 4.7]. The median age and weight of the patients were 156 days (IQR 217) and 5.3 kg (IQR 3.5), respectively, at the time of their operation. Twenty-five (80.6%) patients had congenital heart disease, and the main indication for pacing was postoperative atrioventricular block (AVB) in 21 (67.7%) patients. During follow-up, 3 (9.7%) patients died and there were a total of 9 pacing lead failures in 7 (22.6%) patients. The median longevity of leads (unipolar steroid-eluting) was 2.9 years (IQR 3.6). Freedom from lead reoperation was 90.3%, 72.0%, 65.5% and 49.1% at 1, 3, 5, and 8 years, respectively. The median longevity of the pacing generators was 3.3 years (IQR 2.8). Freedom from generator reoperation was 90.3%, 75.6%, 52.4% and 43.6% at 1, 3, 5 and 6 years, respectively.

CONCLUSIONS

The mid-term outcome of EPPM implantation in neonates and infants was acceptable. Neonates and infants with EPPM implants face the risk of repeated reoperations and all-cause death. A patient's prognosis can depend on regular follow-up, type of pacing lead and the presence of congenital heart malformations, especially complex congenital heart disease.

Pacemaker implantation post congenital heart disease surgical repair: tertiary center experience

This was a retrospective study documenting all pacemaker implantations (PMIs) secondary to postoperative atrioventricular block. A total of 26 patients were included between 2011 and 2020. The incidence rate was 1.8%, with a median follow-up time of 4.5 years. At the time of the initial PMI, the median weight was 5 kg, and the median generator longevity was 45 months. Mean cardiopulmonary bypass and aortic clamp times were significantly longer among surgeries complicated with PMI (P≤ 0.05). Trisomy 21 patients were 4 times more likely to need a PMI (95% CI 1.8-9, P < 0.001). The mean Risk Adjustment in Congenital Heart Surgery and Society of Thoracic Surgery scores were higher in patients with PMI. All initial PMIs were epicardial (18 single chamber). Most patients underwent ventricular septal defect closure (isolated or complex), except for 5 patients who underwent left-sided surgery. Pacing-induced dilated cardiomyopathy occurred in 3 patients. All implanted leads were functional except for 2 leads with high thresholds and another biventricular system infection. There was a 31% rate of pacing reintervention.Conclusion: PMI resulted in significant morbidity but without mortality. The highest risk for PMI was left ventricular outflow tract repair, trisomy 21, prolonged cardiopulmonary bypass, and aortic cross times. What is Known: •Incidence rate for postoperative atrioventricular block requiring pacemaker was at 1.8%, similar to previously published reports. •Longer cardiopulmonary bypass and aortic cross-clamp times were associated with higher risk for developing postoperative persistent atrioventricular block. What is New: •Incidence for persistent atrioventricular block requiring pacemaker was highest among left ventricular outflow tract surgery at 8.6%. •Following all intracardiac repair, Down syndrome patients were 4 times more likely to need a pacemaker implantation compared to the non-syndromic group.

Pacemaker Implantation in Neonates and Infants: Favorable Outcomes with Epicardial Pacing Systems

The implantation of pacemakers (PM) in neonates and infants requires particular consideration of small body size, marked body growth potential, and the decades of future pacing therapy to be expected. The aim of this study is to quantify the complications of implantation and outcome occurring at our center and to compare these with other centers. Retrospective analysis of 52 consecutive patients undergoing PM implantation at a single tertiary care center within the first year of life. PMs were implanted at a median age of 3 months (range 0-10 months). Structural heart defects were present in 44 of 52 patients. During a median follow-up time of 40.4 months (range 0.1-114 months), measurements for sensing, pacing thresholds, and lead impedance remained stable. No adverse pacing effect was observed in left ventricular function or dimensions over time. There were 20 reoperations in 13 patients at a median time of 4.7 years (range 0.05-8.2 years) after implantation, for end of battery life (n = 10), lead dysfunction (n = 3), device dislocation (n = 3), infection (n = 3), and diaphragmatic paresis (n = 1). No PM-related mortality occurred. Epicardial pacemaker implantation in neonates and infants is an invasive but safe and effective procedure with a relatively low risk of complications. Our current implantation technique and the use of bipolar steroid-eluting electrodes, which we prefer to implant on the left ventricular apex, lead to favorable long-term results.

Epicardial Pacemaker in Neonates and Infants: Is There a Relationship Between Patient Size, Device Size, and Wound Complicatıon?

We aimed to investigate the complications after epicardial pacemaker (PM) implantation in neonates and infants and their relationship with factors such as device size and patient size. Between May 2010 and July 2018, 55 patients under 1 year of age who underwent epicardial PM placement were retrospectively evaluated. PM-related complications requiring rehospitalization were determined as wound site problems requiring surgical intervention, battery pocket infection, battery pocket dehiscence without infection, PM removal, relocation of the PM system, and replacement of the PM system with another system. The patients were divided into three groups: < 3 kg, 3-5 kg and > 5 kg. Fifty-five patients underwent PM implantation, 43 (78.2%) because of postoperative atrioventricular block (AVB), 10 (18.2%) because of congenital AVB, and two (3.6%) with diagnoses of c-TGA and AVB. Five (9%) patients incurred 18 complications. No statistically significant difference was observed in complication development between the groups (p > 0.05). Single- or dual-chamber device implantation did not affect complication development (p > 0.05). Despite the role of factors such as low weight, low age, and device volume in the development of wound complications, the relationship between these factors and complications is not statistically significant. Therefore, our results are encouraging in terms of the use of dual-chamber PMs instead of single-chamber ones in heart diseases in which AV synchronization is important.

Neonates and infants requiring life-long cardiac pacing: How reliable are epicardial leads through childhood?

BACKGROUND

In the literature, data is lacking on mid-term results of epicardial pacemaker implantation in neonates and infants. Our aim was to evaluate the mid-term results of epicardial pacemakers implanted in infants under 1 year of age.

METHODS AND RESULTS

We conducted a retrospective review of patients who underwent pacemaker implantation between 2000 and 2017. Pacemaker and lead parameters were reviewed at discharge, 2, 4 and more than 5 years after implantation. A total of 71 patients aged 4 ± 3 months and weighing 4 ± 2 kg were included in the study. Indications for pacemaker implantation were: acquired AV-block (n = 44), congenital AV block (n = 22), sick sinus syndrome (n = 4) and AV block type Mobitz II (n = 1). Median follow-up time was 5 years (range: 1 month-17 years). At 5 years of follow-up, atrial lead energy threshold for pacing decreased significantly (0.72 ± 0.71 μJ to 0.45 ± 0.35 μJ; P < 0.001) but was stable for ventricular leads (0.57 μJ [0.05; 39.47] to 0.64 μJ [0.13; 9.45], P = 0.97). Atrial lead impedance increased significantly (569 ± 137 Ω to 603 ± 134 Ω, P < 0.001), whereas ventricular lead impedance decreased (603 ± 202 Ω to 490 ± 150 Ω, P < 0.001) after 5 years. Repeat operations were required for generator change (n = 55), lead exchange (n = 17) and infection (n = 1). At 2, 5 and 10 years, atrial lead survival was 96%, 91% and 76% and ventricular lead survival was 94%, 82% and 75%, respectively (P = 0.45).

CONCLUSION

Stable pacing thresholds after 5 years indicated that epicardial pacemakers are safe for infants under 1 year of age until at least school enrolment age. However, due to stimulation at higher heart rates in infancy, battery depletion is a frequent occurrence.

Surgical Outcomes of Permanent Epicardial Pacing in Neonates and Young Infants Less Than 1 Year of Age

BACKGROUND

Open surgical implantation of epicardial leads in neonates and infants remains the first option of treatment. We reviewed the long-term outcomes after epicardial pacemaker implantation in neonates and infants.

METHODS

From 1989 to 2016, 48 patients (16 neonates) underwent pacemaker implantation within the first year of life. Their median age and weight were 66.5days (range: 0∼319 days), and 4.2kg (range: 1.9∼9.3kg), respectively, at the time of first pacemaker implantation. The indications for pacemaker implantation were postoperative or congenital atrioventricular block, sinus node dysfunction, and/or myocarditis-induced atrioventricular block. Forty-six (46) unipolar epicardial leads (non-steroid-eluting: 22; steroid-eluting: 24) and two bipolar leads (steroid-eluting) were inserted using a median sternotomy or subxiphoid approach.

RESULTS

The mean follow-up duration was 8.5±7.9years. The most commonly used generator mode at first implantation was VVI (n=24, 50.0%). Eleven (11) generator mode changes from the initial VVI or VVIR to dual-chamber pacing were made at a mean of 7.0±6.2years after the first implantation for better inter-chamber synchrony and ventricular function. Freedom from reoperation for generator change after the first implantation was 95.3, 70.6, and 21.9% at 1, 5, and 10 years. Eighteen (18) lead malfunction events (34.1%) were detected. Freedom from reoperation for lead change was 97.8, 76.2, and 46.3% at 1, 5, and 10 years. The lead replacement rate was significantly higher in patients with non-steroid-eluting than steroid-eluting leads (p=0.045).

CONCLUSIONS

Neonates and infants require more frequent changes in pacemaker generator and leads than the older population. The use of steroid-eluting leads increased lead longevity and reduced the need for surgical re-interventions.

Minimally Invasive Epicardial Pacemaker Implantation in Neonates with Congenital Heart Block

BACKGROUND

Few studies have characterized the surgical outcomes following epicardial pacemaker implantation in neonates with congenital complete atrioventricular block (CCAVB).

OBJECTIVE

This study sought to assess the long-term outcomes of a minimally invasive epicardial approach using a subxiphoid access for pacemaker implantation in neonates.

METHODS

Between July 2002 and February 2015, 16 consecutive neonates underwent epicardial pacemaker implantation due to CCAVB. Among these, 12 (75.0%) had congenital heart defects associated with CCAVB. The patients had a mean age of 4.7 ± 5.3 days and nine (56.3%) were female. Bipolar steroid-eluting epicardial leads were implanted in all patients through a minimally invasive subxiphoid approach and fixed on the diaphragmatic ventricular surface. The pulse generator was placed in an epigastric submuscular position.

RESULTS

All procedures were successful, with no perioperative complications or early deaths. Mean operating time was 90.2 ± 16.8 minutes. None of the patients displayed pacing or sensing dysfunction, and all parameters remained stable throughout the follow-up period of 4.1 ± 3.9 years. Three children underwent pulse generator replacement due to normal battery depletion at 4.0, 7.2, and 9.0 years of age without the need of ventricular lead replacement. There were two deaths at 12 and 325 days after pacemaker implantation due to bleeding from thrombolytic use and progressive refractory heart failure, respectively.

CONCLUSION

Epicardial pacemaker implantation through a subxiphoid approach in neonates with CCAVB is technically feasible and associated with excellent surgical outcomes and pacing lead longevity.

Risk factors for complications in the implantation of epicardial pacemakers in neonates and infants

BACKGROUND

Complications related to epicardial pacemakers in infants have been reported, though limited data are available on their incidence and associated risk factors.

OBJECTIVE

The hypothesis of the study is that younger, smaller patients and larger devices would be associated with complications in neonates and infants.

METHODS

This is a retrospective study of all patients at a single center receiving an epicardial pacemaker at ≤12 months of age (1996-2015). Patient and device characteristics were obtained. Characteristics of patients with and without complications were compared.

RESULTS

There were 86 patients with a median age of 73 days (interquartile range 13-166 days), of whom 12 (14%) had a complication. Eight (9%) needed surgical intervention, of whom 5 (6%) required explantation. Younger age (9 days vs 89 days; P = .01) and lower weight (2.91 kg vs 4.44 kg; P = .004) at implantation were associated with complications. Device characteristics were not statistically different. Patients ≤3 kg in weight and/or <5 days of age had an odds ratio of 18.1 (3.6-91.2; P < .001) for developing a complication with a negative predictive value (NPV) of 97%. Regardless of weight, patients aged >21 days were found to be at lower risk with an NPV of 96%; and regardless of age, patients weighing >4 kg had an NPV of 98%.

CONCLUSION

Young age and low weight at the time of implantation are risk factors for complications, while device characteristics appear to play a minor role. Reserving pacemaker implantation for patients >3 kg in weight and 5 days of age may predict patients at low risk of developing complications.

Pacing device therapy in infants and children: a review

The number of pediatric pacemakers implanted is still relatively small. Children requiring pacing therapy have characteristics that are distinct from those of adults, including physical size, somatic growth, and cardiac anomalies. Considering these features, long-term follow-up of pediatric pacemaker implantation is necessary. Selection of appropriate generators, pacing modes, pacing sites, and leads is important. Generally, epicardial leads are commonly used in small infants. On the other hand, the use of endocardial leads in children is increasing worldwide because of their benefits over epicardial leads, such as minimal invasiveness, lower pacing threshold, and longer generator longevity. Endocardial leads are not suitable for patients with intracardiac shunts because of the high risk of systemic thrombosis. Venous occlusion is another significant problem with endocardial leads. With the increase in the number of pacing device implantations, the incidence of infection from such devices is also increasing. Complete device removal is sometimes recommended to treat device infection, but experience in the removal of endocardial leads in children is still scarce. This article gives an overview of pacing therapy in the pediatric population, including discussions on new pacing systems, such as remote monitoring systems, magnetic imaging compliant pacemaker systems, and leadless pacing devices.

Rescue of an epicardial left ventricular pacing lead without explantation in a patient with CRT-D pocket infection: mission possible

Device pocket infections in patients with permanent pacemakers and implantable defibrillators are a common complication, requiring explantation of the entire system if involvement of the leads is evident. We report on a patient with a pocket infection of a cardiac-resynchronization therapy defibrillator (CRT-D), in whom the left ventricular epicardial pacing lead was saved without explantation of the lead.

Discovery and management of diaphragmatic hernia related to abandoned epicardial pacemaker wires in a pregnant woman with {S,L,L} transposition of the great arteries

Epicardial pacemaker leads placed during childhood are often not removed when transvenous systems are placed later in life. The risk of complications related to retained pacemaker leads and generators is not clear but is generally considered low. We report the case of a 23-year-old pregnant woman who presented with left upper quadrant pain at 20 weeks gestation. The patient was born with {S,L,L} transposition of the great arteries and had high-grade conduction disease in infancy compelling epicardial pacemaker placement. A standard transvenous pacemaker was placed at age 9 years, without removal of the epicardial system. The patient's abdominal pain was attributed to herniation of abdominal contents through a diaphragmatic defect at the site of the abandoned epicardial pacing wire. Her pain improved spontaneously but worsened later in pregnancy leading to repair of the diaphragmatic hernia via anterolateral thoracotomy at 30 weeks gestation. The procedure was well tolerated by mother and fetus. At 38 3/7 weeks gestation, the patient underwent uneventful delivery by cesarean section for breech presentation. This case illustrates the importance of multidisciplinary collaboration in the care of women with congenital heart disease.

Pediatric pacemakers and ICDs: how to optimize perioperative care

An increasing number of pediatric patients with permanent pacemakers and implantable cardioverter defibrillators (ICDs) require cardiac and noncardiac surgery. It is critical that the anesthesiologist caring for these patients understands the management of the device and the underlying heart disease. Children with these devices are more vulnerable to lead failure and inappropriate shocks compared with the adult population. Preoperative assessment and appropriate reprogramming of the device, in addition to minimizing sources of electromagnetic interference, are keystones in the perioperative care of these patients. Prior consultation with qualified programmers is recommended to enable timely optimization of the device. Magnets may be used in emergency situations but it is important to appreciate the limitations of magnet use on different models of pacemakers and ICDs. Safe and successful perioperative care is dependent upon a well-organized and coordinated multidisciplinary team approach.

Controversies in the therapy of isolated congenital complete heart block

Controversies in the therapy of congenital complete heart block are reviewed in terms of the timing of pacemaker implantation, the type and complications of pacing and its role in the presence of myocardial dysfunction. Drug treatment may be useful in selected cases in the presence of pleural effusions, ascites and hydrops of the fetus, but have no effect on complete heart block. Administration of fluorinated steroids in anti-Ro antibody-positive mothers with the aim of preventing complete heart block has given controversial results. Because of the variety of the clinical presentations, especially in regard to pacing therapy, it is mandatory to refer patients with congenital complete heart block to specialized centers with adequate resources and experienced personnel.

Intra-diaphragmatic pacemaker implantation in very low weight premature neonate

Implantation of a pacemaker (PM) in very low weight premature neonates can be a challenging procedure because of the actual dimension of generators. Ideal placement of the PM is still controversial. We describe a technique of intra-diaphragmatic PM implantation in a 1.3 kg neonate.

An epicardial pacing safety net: an alternative technique for pacing in the young

Epicardial pacing is the standard approach for permanent pacing in small children and patients with functionally univentricular physiology. The longevity of epicardial leads, however, is compromised by increased occurrences of exit block and lead fractures. We report our experience with a technique of placing a second ventricular lead, and attaching it to the atrial port of a dual chamber pacemaker to prevent the need for early re-operation in the event of failure of the primary epicardial lead. A retrospective review showed that, over the period from 2001 through 2007, epicardial ventricular pacemakers had been placed in 88 patients. In 6 of these, we had placed 2 ventricular leads, their median weight being 8.0 kilograms, with a range from 4.2 to 31.8 kilograms. Fracture of a lead occurred in 1 of the patients (17%) 8 months after placement, requiring reprogramming to pace from the atrial port. This possibility avoided the need for repeated emergent surgery. At a median follow-up of 1.5 years, with a range from 0.3 to 4.4 years, there have been no complications. During the same time period, overall failure of epicardial leads at our institution was 13%. Placement of a second ventricular epicardial pacing lead, attached to the atrial port of a dual chamber pacemaker, therefore, may provide a safe and effective means of ventricular pacing in the setting of epicardial lead failure, and may obviate the need for repeat, potentially urgent, pacemaker surgery.

Transvenous pacing in children weighing less than 10 kilograms

Pacemakers are used in small children with increasing frequency for the treatment of life-threatening bradyarrhythmias. The epicardial approach is generally preferred in these patients, to avoid the risks of vessel thrombosis. We examined the feasibility and safety of transvenous pacemaker implantation in children weighing <10 kg, via subclavian puncture, using a 4 Fr sheath introduced after a venogram was performed to evaluate the vein diameter. Progressive dilation with 5, 6, and 7 Fr sheaths preceded the insertion and placement of the endocardial lead. A subaponeurotic pocket was created in the abdominal or pectoral regions, depending upon the patient's size. Between 2001 and 2007, we treated 12 patients (median age = 16 months; range 1-32; median weight = 7.9 kg; range 2.3-10.0; 7 males), of whom four weighed <5 kg. Indications for permanent pacing included postsurgical complete atrioventricular block (n = 8), sinus node dysfunction (n = 2), congenital atrioventricular block (n = 1), and long QT syndrome (n = 1). Single-chamber pacemakers were implanted in 10, and dual-chamber pacemakers in two patients. The patients were evaluated at 48 hours, 10 days, and at 3 and 6 months. The mean follow-up was 31.8 +/- 23.5 months. There were no procedural complications. Lead dislodgment occurred in one patient and required replacement of the ventricular lead. One patient died from septicemia. Endocardial pacemaker implantation was feasible and safe in children weighing <10 kg. This procedure is less invasive than the standard epicardial approach.

Pacemaker and defibrillator therapy in pediatrics and congenital heart disease

Pacemakers and defibrillators have a growing use in pediatrics and in patients with congenital heart disease, but they present unique problems and implications for their implantation and follow-up. Congenital and surgically acquired rhythm disturbances are common, but the efficacy of device therapy is not well established in these patient groups. The diversity and complexity of pediatric patients and congenital heart disease make device management a highly individualized art. There are technical issues related to device implantation that have necessitated novel approaches to using leads and device that were not designed with children specifically in mind. The current guidelines and indications for implantable device therapy for children and congenital heart disease are reviewed, as well as some of the specific limitations and problems encountered.

Equivalent performance of epicardial versus endocardial permanent pacing in children: a single institution and manufacturer experience

BACKGROUND

Children requiring permanent pacing have a lifelong need for follow-up. Epicardial leads have traditionally fared worse than endocardial counterparts. We tested the hypothesis that steroid-eluting epicardial and endocardial leads had equivalent outcomes.

METHODS

We reviewed medical records of 148 children, mean age 8.2 +/- 4.8 years, in whom a dual-chamber pacemaker system with steroid-eluting leads from a single manufacturer was implanted. Primary outcome was mortality. Secondary outcomes included freedom from lead failure and pacemaker system reintervention. Loss of capture-sensing, lead displacement-fracture, exit block, and high thresholds constituted lead failure. Reintervention included need for lead revision or generator change.

RESULTS

There was no early mortality. Late mortality occurred once (0.5 +/- 0.5 deaths/1,000 patient-months) and eight times (3.4 +/- 1.2 deaths/1,000 patient-months) in the endocardial and epicardial groups, respectively. The relative hazard of endocardial versus epicardial site for lead failure was 0.408 (p = 0.038) and for reintervention was 0.629 (p = 0.002). Endocardial and epicardial groups differed in important ways: concomitant cardiac surgery 5% (3 of 61) versus 27% (27 of 99); congenital heart disease 33% (20 of 61) versus 90% (89 of 99); single ventricle physiology 13% (8 of 61) versus 52% (51/99); and age (10.5 +/- 4.5 years vs 5.5 +/- 5.2 years). Adjusting for these covariants, the relative hazard for freedom from lead failure for endocardial versus epicardial leads was 0.546 (p = 0.360). The adjusted relative hazard for freedom from reintervention was 0.157 (p = 0.045).

CONCLUSIONS

Technologic advances attenuate important differences in lead failure rates between endocardial and epicardial steroid-eluting pacing leads and thus bridge the performance gap between these fixation modes.