Epicardial atrial pacemaker lead placement after multiple cardiac operations

Impact of the axillary approach on epicardial pacing lead durability in children

BACKGROUND

To avoid lead failure and pocket infection in neonates/infants requiring pacemakers, we used the axillary approach of placing the generator in the axilla and the leads in the intrathoracic space. We describe the technical details of the axillary approach and evaluate the efficacy of this method.

METHODS

We assessed 21 patients (7 males) weighing ≤8.0 kg who underwent epicardial pacemaker implantation with the axillary approach between 2004 and 2018. The axillary approach entails (1) positioning the pacemaker generator in the axilla to avoid local skin/pocket complications due to tissue compression by the generator and (2) making a double loop in the pleural space to reduce stress on the pacemaker leads caused by somatic growth. This approach can be combined with median sternotomy for simultaneous intracardiac repair.

RESULTS

The patients' median age at pacemaker implantation was 6.0 months; 16 (76%) patients were aged <12 months. The median body weight was 4.5 kg (interquartile range: 3.0-7.0). In all five patients requiring simultaneous cardiac repair, a median sternotomy was performed to access the heart. Sixteen patients required only pacemaker implantation: left thoracotomy was performed in 10 patients, right thoracotomy in 5, and subxiphoid approach in 1. The 5- and 10-year freedom from pacemaker-related adverse events was 89.4% and 79.5%, respectively.

CONCLUSIONS

The axillary approach using intrathoracic double-loop routing of leads to position the generator in the axilla for pacemaker implantation can be a valuable alternative for neonates/infants weighing ≤8 kg with or without complex congenital heart disease.

Lateral thoracotomy for epicardial pacemaker placement in patients with congenital heart disease

OBJECTIVES

Our institution adopted a lateral thoracotomy approach to epicaridal pacemaker implantation with the objective of avoiding epicardial scar tissue and to achieve adequate lead pacing and sensing. We sought to assess the short-term outcomes of this approach.

METHODS

A single-centre review was conducted in paediatric patients and adults with congenital heart disease or inherited arrhythmia syndromes who underwent a lateral thoracotomy for epicardial pacemaker placement from August 2010 to January 2016. Patient histories were recorded along with outcomes including complications, lead and generator performance.

RESULTS

Twenty-one operations were performed in 20 patients (median age 17 years, range 3 months-49 years), including 19 pacemakers and 2 implantable-cardioverter defibrillators (ICDs). Prior epicardial pacemakers had been placed in 11 (55%) patients, including 3 with multiple pacemakers. Most patients had undergone at least 1 prior cardiac operation, with a mean of 3.2 (range 0-7) prior cardiac operations. Through our lateral thoracotomy approach, 17 of the 19 attempted atrial leads (89%) and 20 of the 20 attempted ventricular leads (100%) were successfully implanted with acceptable pacing thresholds. Complications included 1 (5%) bleeding, 2 (10%) pacemaker pocket revisions and 1 late death at 6 months unrelated to the pacemaker. There were no lead failures at a mean follow-up period of 27.5 months (range of 0.7-56.1 months).

CONCLUSIONS

The lateral thoracotomy is a useful approach for epicardial pacemaker implantation in patients with congenital heart disease or inherited arrhythmia syndromes including those with multiple prior operations.

Long-term follow-up shows excellent transmural atrial lead performance in patients with complex congenital heart disease

BACKGROUND

Many patients with congenital heart disease require permanent pacing for rhythm management but cannot undergo transvenous lead placement. In others, epicardial scarring prohibits adequate sensing and pacing thresholds using epicardial leads. This study describes long-term lead performance using a transmural atrial (epicardial to endocardial) pacing approach in patients with congenital heart disease.

METHODS AND RESULTS

For transmural atrial (TMA) lead access, a bipolar, steroid-eluting transvenous lead was placed from the epicardium via purse-string incision or atriotomy and affixed to atrial endocardium. Records were reviewed for patient data and acute and long-term lead performance for TMA leads placed 1998 to 2004. Forty-two of 48 TMA leads remain active at last follow-up. Two leads fractured, 4 were functional at >5-year follow-up but no longer active. Freedom from lead failure 98% (95% confidence interval, 86%-100%) at mean follow-up 7.8 years. TMA leads gave excellent sensing and pacing characteristics at implant and chronically. Median acute and chronic sensing thresholds were 3 and 2.8 mV, respectively; median acute and chronic pacing thresholds at 0.5 ms were 0.9 and 0.7 V, respectively. TMA leads performed similarly in Fontan patients. Overdrive pacing for intra-atrial re-entrant tachycardia was successful in 7 of 8 patients. One patient with high baseline risk died of stroke 7 years after implant. No lead-associated thrombi were observed.

CONCLUSIONS

TMA pacing leads had excellent longevity, initial, and chronic functional properties and provide an alternative to epicardial leads in patients with congenital heart disease. Patients who cannot receive transvenous leads, have epicardial scarring or have intra-atrial re-entrant tachycardia could benefit most from routine use of this technique.

An alternate technique to pacing in complex congenital heart disease: assessment of the left thoracotomy approach

BACKGROUND

Pacing in children with congenital heart disease often requires alternate approaches to standard transvenous pacing. The surgical approach used to implant the pacemaker leads has been shown to impact lead survival. There is a paucity of pediatric literature describing the experience using a left thoracotomy approach.

OBJECTIVES

To report on short- and mid-term experiences with pacemaker implant via the left thoracotomy approach in children with complex congenital heart disease.

METHODS AND RESULTS

Data were abstracted retrospectively from patients' hospital charts. To date, the left thoracotomy technique has been used in 11 patients with complex heart disease, with a median of three prior cardiac operations. The median patient age was five years (range of two months to 23 years of age). The pacing indications were acquired postoperative atrioventricular block (n=5), sinus node dysfunction (n=5) and long QT syndrome (n=1). There were no intraoperative complications or long-term complications from this approach. The pacing thresholds at implant and follow-up were acceptable in all patients. One patient died in follow-up for reasons unrelated to the pacemaker or arrhythmia.

CONCLUSIONS

The placement of epicardial pacemaker leads via the left thoracotomy approach is a safe and effective alternative to transvenous pacing in pediatric patients with complex congenital heart disease.

Endocardial Atrial Pacing Lead Implantation and Midterm Follow-Up in Young Patients with Sinus Node Dysfunction After the Fontan Procedure

The purpose of the study was to investigate the results of endocardial lead implantation, lead performance, and follow-up in young patients after the Fontan procedure. A retrospective study was conducted with patients who had endocardial atrial pacing for SND and intact AVN function after Fontan from two pediatric centers. Patient demographics, pacing, and sensing data of endocardial atrial leads were analyzed at the time of pacemaker implantation and follow-up visits. Fifteen patients (weight 42.6 +/- 35 kg) had transvenous endocardial atrial lead implantation at an average age of 11.4 +/- 6.5 years. Active-fixation leads were used in all patients and steroid elution was present in 12 (80%) patients. Adequate P wave sensing was obtained in patients with sinus rhythm (n = 10); the remaining four patients had junctional rhythm without measurable P waves. Lead failure was not observed in any patient during the follow-up period of 2.9 +/- 2.1 years. The energy threshold at implantation was 1.46 +/- 1.5 microJ, 1.54 +/- 0.75 microJ at 3 months, 0.62 +/- 0.45 microJ at 1 year, 0.72 +/- 0.65 microJ at 2 years, 0.75 +/- 0.55 microJ at 3 years, and 0.8 +/- 0.85 microJ at 5 years postimplant. The lead impedance was 648 +/- 298 omega at implantation, 714 +/- 163 omega at 3 months, 744 +/- 195 omega at 1 year, 734 +/- 198 omega at 2 years, 800 +/- 142 omega at 3 years and 830 +/- 200 omega 5 years postimplant. Anticoagulation therapy (aspirin n = 5, warfarin n = 8) was continued by 13 patients. Complications consisted of a pneumothorax at implantation and a transient ischemic attack in one patient 4 years after pacemaker implant. Endocardial atrial leads offer low energy thresholds and can be implanted relatively safely in Fontan patients.

Pacemaker Syndrome in the Young:. Do Children Need Dual Chamber as the Initial Pacing Mode?

The aim of this study was to determine if single chamber rate responsive ventricular pacing (VVIR) predisposes growing children to develop pacemaker syndrome (PS), and if so, what are determining factors and/or clinically useful predictors. PS is a constellation of symptoms that result from the lack of consistent AV sequential filling due to atrial contraction against closed AV valves. PS has not been commonly reported in the young. Data from all patients with pacemakers with congenital complete atrioventricular block (CAVB) with normal anatomy, and those with congenital heart disease (CHD), and surgically acquired CAVB were reviewed. Inclusion criteria were normal ventricular function by cardiac ultrasound and 100% VVIR pacing. Of 89 patients with VVIR pacemaker implants, 33 met these criteria. Of these, 19 developed PS. For statistical analysis, chi-square and independent samples t-test was used with significance defined at P < or = 0.05. No consistent association was found between cardiac anatomy, type of CAVB, or age at implant with development of PS. However, PS did correlate with duration of pacing (P = 0.02). The exercise stress test showed significant differences between 100% VVIR-paced patients with and without PS, in terms of work rate (P = 0.002) and measured oxygen consumption (P = 0.01). This study shows that PS appears to be a time related event in younger children with normal ventricular function who are 100% ventricular paced. Thus, this supports VVIR pacing as an adequate and cost-effective initial therapy for symptomatic bradycardia due to CAVB.

Indications and techniques of pediatric cardiac pacing

There are special challenges associated with the use of transvenous pacemakers in children. For example, a child's chest cavity or vascular dimensions could be too small to host the generator and leads available or required. If leads are implanted, they may stretch as the child grows. This increases the risk that the leads will later dislodge or fracture. Moreover, children requiring pacemakers often have coexisting congenital heart defects and the structural abnormalities of those could hinder easy placement of the pacing system. This article will first review the indications for permanent pacing in children and will then describe the unique challenges associated with such use.