2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients: Executive Summary.

Abstract

Document Reviewers: Philip M. Chang, MD, FHRS, FACC; Fabrizio Drago, MD, FAIAC; Anne M. Dubin, MD, FHRS; Susan P. Etheridge, MD, FHRS; Apichai Kongpatanayothin, MD, FAsCC; Jose Manuel Moltedo, MD, FACC; Ashish A. Nabar, MD, DNB, PhD, FISE; George F. Van Hare, MD, FHRS, FACC, FAAP Guidelines for the implantation of cardiac implantable electronic devices (CIEDs) have evolved since publication of the initial ACC/AHA pacemaker guidelines in 1984.1Frye R.L. Collins J.J. DeSanctis R.W. et al.Guidelines for permanent pacemaker implantation, 1984A report of the Joint American College of Cardiology/American Heart Association Task Force on Assessment of Cardiovascular Procedures (Subcommittee on Pacemaker Implantation).Circulation. 1984; 70: 331A-339ACrossref PubMed Google Scholar CIEDs have evolved to include novel forms of cardiac pacing, the development of implantable cardioverter defibrillators (ICDs) and the introduction of devices for long term monitoring of heart rhythm and other physiologic parameters. In view of the increasing complexity of both devices and patients, practice guidelines, by necessity, have become increasingly specific. In 2018, the ACC/AHA/HRS published Guidelines on the Evaluation and Management of Patients with Bradycardia and Cardiac Conduction Delay,2Kusumoto F.M. Schoenfeld M.H. Barrett C. et al.2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society.J Am Coll Cardiol. 2019; 74: 932-987PubMed Google Scholar which were specific recommendations for patients >18 years of age. This age-specific threshold was established in view of the differing indications for CIEDs in young patients as well as size-specific technology factors. Therefore, the following document was developed to update and further delineate indications for the use and management of CIEDs in pediatric patients, defined as ≤21 years of age, with recognition that there is often overlap in the care of patents between 18 and 21 years of age. This document is an abbreviated expert consensus statement (ECS) intended to focus primarily on the indications for CIEDs in the setting of specific disease/diagnostic categories. This document will also provide guidance regarding the management of lead systems and follow-up evaluation for pediatric patients with CIEDs. The recommendations are presented in an abbreviated modular format, with each section including the complete table of recommendations along with a brief synopsis of supportive text and select references to provide some context for the recommendations. This document is not intended to provide an exhaustive discussion of the basis for each of the recommendations, which are further addressed in the comprehensive PACES-CIED document,3Shah M. Silka M.J. Avari Silva J. et al.2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients.Heart Rhythm. 2021; 18: 1888-1924Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar with further data easily accessible in electronic searches or textbooks. The principles in the development of this document are 1) new recommendations or changes to previous recommendations are based on data, when possible; 2) these recommendations are consistent with current ACC/AHA/HRS adult guidelines when reasonable; and 3) all recommendations have been critically reviewed, initially by the writing committee and editors, followed by the PACES executive committee, and subsequently by external HRS, ACCF, AHA, and AEPC representatives. Any revisions or additions to existing recommendations require approval of at least 80% by the members of the PACES writing committee. These recommendations have been developed with standard guideline methodology, i.e., with both a class of recommendation (COR) and a level of evidence (LOE) (Table 1). The class of the recommendation indicates the strength of recommendation, based on the estimated magnitude or certainty of benefit in proportion to risk. The level of evidence rates the quality of evidence based on the type, quantity, and consistency of data from clinical trials and other sources. A recommendation with a Level of Evidence C-EO does not imply that the recommendation is weak. Many of the questions addressed in this (and other) documents either do not lend themselves to clinical trials or are rare disease entities. However, there may be unequivocal consensus that a particular intervention is either effective or necessary.Table 1Class of Recommendation and Level of Evidence Categories* Open table in a new tab Levels of EvidenceTabled 1B-NR: Evidence from nonrandomized studies, observational studies, or registry studiesC-LD: Very limited evidence from observational studies or case series reportsC-EO: Consensus expert opinion, case studies, or standard of care*Adapted from Halperin, et al.4Halperin J.L. Levine G.N. Al-Khatib S.M. et al.Further evolution of the ACC/AHA clinical practice guideline recommendation classification system: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.J Am Coll Cardiol. 2016; 67: 1572-1574Crossref PubMed Scopus (116) Google Scholar Open table in a new tab *Adapted from Halperin, et al.4Halperin J.L. Levine G.N. Al-Khatib S.M. et al.Further evolution of the ACC/AHA clinical practice guideline recommendation classification system: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.J Am Coll Cardiol. 2016; 67: 1572-1574Crossref PubMed Scopus (116) Google Scholar The writing committee consisted of members of PACES who were selected by the PACES executive committee. The writing committee members included junior and senior pediatric electrophysiologists as well as allied health professionals and represented diverse genders, countries, and cultures. The writing committee also included external representatives from the ACC, AHA, HRS, and AEPC. Prior to final publication, all committee members were required to verify their specific contributions to this document. Appendix 1 lists writing committee members’ relevant relationships with industry. Following internal review by the PACES executive committee, this document was then reviewed by the PACES writing committee. Following considerations of these comments and approval by an independent PACES reviewer, the recommendations were opened for public comment to PACES members. An official reviewer each nominated by HRS, ACC, AHA, and AEPC provided independent external review. This document was then approved for publication by the PACES executive committee and endorsed by all collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society. Appendix 2 lists reviewers’ relevant relationships with industry. The purpose of this document is to provide guidance to clinicians for the management of pediatric patients who may require a CIED, with a primary focus on the indications for device implantation. The document will be useful to pediatric cardiologists, cardiac surgeons, cardiac intensivists, anesthesiologists, and arrhythmia specialists. This document supersedes the pediatric CIED recommendations made in “ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities”5Epstein A.E. Dimarco J.P. Ellenbogen K.A. et al.ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities.Heart Rhythm. 2008; 5: 934-955Abstract Full Text Full Text PDF PubMed Scopus (533) Google Scholar and “2012 ACCF/AHA/HRS Focused Update of the 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities.”6Tracy C.M. Epstein A.E. Darbar D. et al.2012 ACCF/AHA/HRS focused update of the 2008 guidelines for device-based therapy of cardiac rhythm abnormalities.Heart Rhythm. 2012; 9: 1737-1753Abstract Full Text Full Text PDF PubMed Scopus (90) Google Scholar 1.In patients with isolated sinus node dysfunction (SND), there is no minimum heart rate or maximum pause duration where permanent pacing is absolutely recommended. Establishing a temporal correlation between symptoms and bradycardia is critical in the decision as to whether permanent pacing is indicated.2.Young patients with impaired ventricular function or abnormal cardiovascular physiology may be symptomatic due to sinus bradycardia or the loss of atrioventricular (AV) synchrony at heart rates that do not produce symptoms in individuals with normal cardiovascular physiology.3.Although the average ventricular rate in newborns and infants with congenital complete atrioventricular block (CCAVB) provides an objective measure regarding the decision for pacemaker implantation, additional factors may equally influence the decision/timing of pacemaker implant. These include birth weight (size), congenital heart defects, ventricular function, and other comorbidities.4.In patients with postoperative AV block, a period of observation for at least 7–10 days before pacemaker implantation remains advised; in select cases, earlier pacemaker implantation may be considered if AV block is not expected to resolve due to extensive injury to the cardiac conduction system.5.Atrial pacing with antitachycardia pacing capabilities is reasonable for congenital heart disease (CHD) patients with recurrent intra-atrial reentrant tachycardia when medication and catheter ablation are not effective.6.There is increased recognition of the need for pacemaker implantation in conditions such as Kearns-Sayre syndrome or certain neuromuscular disorders due to the unpredictable progression of conduction disease.7.The cause of sudden cardiac arrest (SCA) remains undefined in nearly 50% of pediatric survivors. ICD implantation is recommended provided completely reversible causes have been excluded, other treatments that may be beneficial are considered, and meaningful survival is anticipated.8.The decisions for implantation of an ICD for primary prevention in cardiac channelopathies or cardiomyopathies remain guided by limited and, at times, conflicting data. Consideration of patient-specific factors and shared decision-making are critically important.9.In pediatric patients with nonischemic dilated cardiomyopathy (NIDCM), primary prevention ICD implantation for left ventricular ejection fraction (LVEF) ≤35%, in the absence of other risk factors, is not clearly supported by published data.10.In patients with indications for implantation of a CIED, shared decision-making and patient/family-centered care are endorsed and emphasized. Treatment decisions are based on the best available evidence and patient’s preferences. The most common indications for permanent pacemaker implantation in children, adolescents, and patients with CHD are 1) symptomatic sinus bradycardia, 2) advanced second- or third-degree AV block, and 3) pacing for the prevention or termination of tachyarrhythmias.5Epstein A.E. Dimarco J.P. Ellenbogen K.A. et al.ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities.Heart Rhythm. 2008; 5: 934-955Abstract Full Text Full Text PDF PubMed Scopus (533) Google Scholar Many indications for pacemaker implantation in adolescents are similar to those in adults.2Kusumoto F.M. Schoenfeld M.H. Barrett C. et al.2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society.J Am Coll Cardiol. 2019; 74: 932-987PubMed Google Scholar However, in infants and young children, there are important differences. For example, criteria for normal heart rates are an age-dependent variable; whereas a heart rate of 45 bpm is normal in an adolescent, the same rate in a newborn or infant indicates profound bradycardia. In addition, young patients with impaired ventricular function or abnormal physiology may be symptomatic due to sinus bradycardia or loss of AV synchrony at heart rates that do not produce symptoms in individuals with normal cardiovascular physiology.7Hernández-Madrid A. Paul T. Abrams D. et al.Arrhythmias in congenital heart disease. A position paper of the European Heart Rhythm Association, Association for European Paediatric and Congenital Cardiology (AEPC), and the European Society of Cardiology (ESC) Working Group on Grown-up Congenital Heart Disease.Europace. 2018; 20: 1719-1753Crossref PubMed Scopus (118) Google Scholar,8Khairy P. Van Hare G.F. Balaji S. et al.2014 PACES/HRS expert consensus statement on the recognition and management of arrhythmias in adult congenital heart disease.Heart Rhythm. 2014; 11: e102-e165Abstract Full Text Full Text PDF PubMed Scopus (378) Google Scholar Hence, the indications for pacemaker implantation in young patients need to be based on the correlation of symptoms with relative bradycardia rather than absolute heart rate criteria. Significant technical challenges may complicate device and lead implantation in small patients or those with abnormalities of venous or intracardiac anatomy. Epicardial lead placement and innovative use of device technology may be needed to provide pacing or defibrillation in young patients. Furthermore, as device leads may need to be utilized for multiple decades, consideration of the potential consequences from lead failure plays a major role in implantation of pediatric devices. Tabled 1CORRecommendationsLOEReferencesIsolated Sinus Node DysfunctionIPermanent atrial or dual-chamber pacemaker implantation is indicated for SND when there is correlation of symptoms with age-inappropriate bradycardia.B-NR5Epstein A.E. Dimarco J.P. Ellenbogen K.A. et al.ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities.Heart Rhythm. 2008; 5: 934-955Abstract Full Text Full Text PDF PubMed Scopus (533) Google Scholar,9Albin G. Hayes D.L. Holmes Jr., D.R. Sinus node dysfunction in pediatric and young adult patients: Treatment by implantation of a permanent pacemaker in 39 cases.Mayo Clin Proc. 1985; 60: 667-672Abstract Full Text Full Text PDF PubMed Scopus (30) Google Scholar,10Gillette P.C. Shannon C. Garson Jr., A. et al.Pacemaker treatment of sick sinus syndrome in children.J Am Coll Cardiol. 1983; 1: 1325-1329Crossref PubMed Scopus (25) Google ScholarIPermanent pacemaker implantation is indicated in patients with symptomatic SND secondary to chronic medical therapy for which there is no alternative treatment.C-EOIIaPermanent pacemaker implantation (with rate-responsive programming) is reasonable in patients with symptoms temporally associated with observed chronotropic incompetence.C-LD11Reybrouck T. Vangesselen S. Gewillig M. Impaired chronotropic response to exercise in children with repaired cyanotic congenital heart disease.Acta Cardiol. 2009; 64: 723-727Crossref PubMed Scopus (15) Google ScholarIIbPermanent pacemaker implantation may be considered in patients with SND and symptoms that are likely attributable to bradycardia or prolonged pauses without conclusive evidence correlating the symptoms with bradycardia following a thorough investigation.C-EOIIINo BenefitPermanent pacemaker implantation is not indicated in patients with asymptomatic SND.C-EOIIIHarmPermanent pacemaker implantation is not indicated in patients with symptomatic SND due to a reversible cause.C-EO Open table in a new tab Recommendation-Specific Supportive Text Sinus node dysfunction (SND) refers to physiologically inappropriate atrial rates, either due to sustained bradycardia or abrupt pauses in the intrinsic cardiac rhythm. In patients with isolated sinus bradycardia without symptoms due to cerebral or systemic hypoperfusion, there is no minimum heart rate or maximum pause duration where permanent pacing is recommended.2Kusumoto F.M. Schoenfeld M.H. Barrett C. et al.2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society.J Am Coll Cardiol. 2019; 74: 932-987PubMed Google Scholar Establishing a temporal correlation between symptoms and age-related bradycardia is of paramount importance when determining whether permanent pacing is needed. In symptomatic patients with SND, atrial-based pacing is generally recommended over single chamber ventricular pacing.12Gillette P.C. Wampler D.R. Shannon C. et al.Use of atrial pacing in a young population.Pacing Clin Electrophysiol. 1985; 8: 94-100Crossref PubMed Scopus (21) Google Scholar Tabled 1CORRecommendationsLOEReferencesIsolated Congenital Complete Atrioventricular BlockIPermanent pacemaker implantation is indicated for patients with CCAVB with symptomatic bradycardia.B-NR13Jaeggi E.T. Hamilton R.M. Silverman E.D. et al.Outcome of children with fetal, neonatal or childhood diagnosis of isolated congenital atrioventricular block.J Am Coll Cardiol. 2002; 39: 130-137Crossref PubMed Scopus (298) Google Scholar,14Baruteau A.E. Fouchard S. Behaghel A. et al.Characteristics and long-term outcome of non-immune isolated atrioventricular block diagnosed in utero or early childhood: A multicentre study.Eur Heart J. 2012; 33: 622-629Crossref PubMed Scopus (48) Google ScholarIPermanent pacemaker implantation is indicated for patients with CCAVB with a wide QRS escape rhythm, complex ventricular ectopy, or ventricular dysfunction.B-NR2Kusumoto F.M. Schoenfeld M.H. Barrett C. et al.2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society.J Am Coll Cardiol. 2019; 74: 932-987PubMed Google Scholar,13Jaeggi E.T. Hamilton R.M. Silverman E.D. et al.Outcome of children with fetal, neonatal or childhood diagnosis of isolated congenital atrioventricular block.J Am Coll Cardiol. 2002; 39: 130-137Crossref PubMed Scopus (298) Google ScholarIPermanent pacemaker implantation is indicated for CCAVB in asymptomatic neonates or infants when the mean ventricular rate is ≤50 bpm. Ventricular rate alone should not be used as implant criteria, as symptoms due to low cardiac output may occur at faster heart rates.C-LD13Jaeggi E.T. Hamilton R.M. Silverman E.D. et al.Outcome of children with fetal, neonatal or childhood diagnosis of isolated congenital atrioventricular block.J Am Coll Cardiol. 2002; 39: 130-137Crossref PubMed Scopus (298) Google Scholar,15Karpawich P.P. Gillette P.C. Garson Jr., A. et al.Congenital complete atrioventricular block: Clinical and electrophysiologic predictors of need for pacemaker insertion.Am J Cardiol. 1981; 48: 1098-1102Abstract Full Text PDF PubMed Scopus (89) Google ScholarIIaPermanent pacemaker implantation is reasonable for asymptomatic CCAVB beyond the first year of life when the mean ventricular rate is <50 bpm or there are prolonged pauses in ventricular rate.B-NR2Kusumoto F.M. Schoenfeld M.H. Barrett C. et al.2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society.J Am Coll Cardiol. 2019; 74: 932-987PubMed Google Scholar,5Epstein A.E. Dimarco J.P. Ellenbogen K.A. et al.ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities.Heart Rhythm. 2008; 5: 934-955Abstract Full Text Full Text PDF PubMed Scopus (533) Google Scholar,16Dewey R.C. Capeless M.A. Levy A.M. Use of ambulatory electrocardiographic monitoring to identify high-risk patients with congenital complete heart block.N Engl J Med. 1987; 316: 835-839Crossref PubMed Scopus (94) Google ScholarIIaPermanent pacemaker implantation is reasonable for CCAVB with left ventricular dilation (z score ≥3) associated with significant mitral insufficiency or systolic dysfunction.C-LD17Udink ten Cate F. Breur J.M. Cohen M.I. et al.Dilated cardiomyopathy in isolated congenital complete atrioventricular block: early and long term risk in children.J Am Coll Cardiol. 2001; 37: 1129-1134Crossref PubMed Scopus (155) Google ScholarIIbPermanent pacemaker implantation may be considered for CCAVB in asymptomatic adolescents with an acceptable ventricular rate, a narrow QRS complex, and normal ventricular function, based on an individualized consideration of the risk/benefit ratio.C-LD2Kusumoto F.M. Schoenfeld M.H. Barrett C. et al.2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society.J Am Coll Cardiol. 2019; 74: 932-987PubMed Google Scholar Open table in a new tab Recommendation-Specific Supportive Text The average ventricular rate in neonates and infants with isolated CCAVB provides one objective parameter regarding the decision for pacemaker implantation. However, additional factors including birth weight (size), ventricular dysfunction, and other co-morbidities may equally influence the decision. Therefore, an average heart rate of ≤50 bpm is recommended for infant pacemaker implantation when overt symptoms related to low cardiac output are not present. Beyond the first year of life, permanent pacemaker implantation is generally indicated in symptomatic patients. Natural history studies have demonstrated progressive LV dysfunction and mitral insufficiency with cardiovascular mortality in the 4th or 5th decade in CCAVB patients who did not undergo pacemaker implantation.18Michaëlsson M. Engle M.A. Congenital complete heart block; an international study of the natural history.Cardiovasc Clin. 1972; 4: 85-101PubMed Google Scholar Tabled 1CORRecommendationsLOEReferencesAtrioventricular Block: Other ConsiderationsIPermanent pacemaker implantation is indicated in patients with clinically significant ventricular tachycardia (VT) that is pause dependent or associated with severe bradycardia; ICD implantation may be considered as a reasonable alternative.C-LD19Gladman G. Davis A.M. Fogelman R. Hamilton R.M. Gow R.M. Torsade de pointes, acquired complete heart block and inappropriately long QT in childhood.Can J Cardiol. 1996; 12: 683-685PubMed Google ScholarIPermanent pacing is indicated in symptomatic patients with idiopathic advanced second- or third-degree AV block not attributable to reversible causes.C-LDIIaPermanent pacemaker implantation is reasonable for any degree of AV block that progresses to advanced second- or third-degree with exercise in the absence of reversible causes.C-LD20Yandrapalli S. Harikrishnan P. Ojo A. Vuddanda V.L.K. Jain D. Exercise induced complete atrioventricular block: Utility of exercise stress test.J Electrocardiol. 2018; 51: 153-155Crossref PubMed Scopus (11) Google ScholarIIbPermanent pacemaker implantation may be considered for patients with intermittent advanced second- or third-degree AV block not attributable to reversible causes and associated with minimal symptoms that are otherwise unexplained.C-LDIIIHarmPermanent pacemaker implantation is not indicated for asymptomatic first-degree AV block or asymptomatic second-degree Mobitz type I.C-LD2Kusumoto F.M. Schoenfeld M.H. Barrett C. et al.2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society.J Am Coll Cardiol. 2019; 74: 932-987PubMed Google Scholar,5Epstein A.E. Dimarco J.P. Ellenbogen K.A. et al.ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities.Heart Rhythm. 2008; 5: 934-955Abstract Full Text Full Text PDF PubMed Scopus (533) Google Scholar Open table in a new tab Recommendation-Specific Supportive Text Advanced AV block diagnosed during childhood or adolescence may be congenital, related to infiltrative diseases or remain idiopathic. At times, late-onset AV block may be paroxysmal and difficult to document. Exercise testing may be useful regarding the significance of AV block. When progressive AV block occurs during exercise, conduction disturbance within the His-Purkinje system is suspected and is associated with a poor prognosis.20Yandrapalli S. Harikrishnan P. Ojo A. Vuddanda V.L.K. Jain D. Exercise induced complete atrioventricular block: Utility of exercise stress test.J Electrocardiol. 2018; 51: 153-155Crossref PubMed Scopus (11) Google Scholar With the exception of infiltrative or inflammatory causes, the criteria for pacemaker implantation are similar to those for CCAVB. Tabled 1CORRecommendationsLOEReferencesPostoperative Atrioventricular BlockIPermanent pacemaker implantation is indicated for postoperative advanced second- or third-degree AV block that persists for at least 7–10 days after cardiac surgery.B-NR21Weindling S.N. Saul P.J. Gamble W.J. et al.Duration of complete atrioventricular block after congenital heart disease surgery.Am J Cardiol. 1998; 82: 525-527Abstract Full Text Full Text PDF PubMed Scopus (151) Google Scholar,22Romer A.J. Tabbutt S. Etheridge S.P. et al.Atrioventricular block after congenital heart surgery: Analysis from the Pediatric Cardiac Critical Care Consortium.J Thorac Cardiovasc Surg. 2019; 157: 1168-1177Abstract Full Text Full Text PDF PubMed Scopus (22) Google ScholarIPermanent pacemaker implantation is indicated for late-onset advanced second- or third-degree AV block especially when there is a prior history of transient postoperative AV block.C-LD23Villain E. Ouarda F. Beyler C. et al.Predictive factors for late complete atrio-ventricular block after surgical treatment for congenital cardiomyopathy.Arch Mal Coeur Vaiss. 2003; 96: 495-498PubMed Google ScholarIIbPermanent pacemaker implantation may be considered for unexplained syncope in patients with a history of transient postoperative advanced second- or third-degree AV block.C-LD24Aziz P.F. Serwer G.A. Bradley D.J. et al.Pattern of recovery for transient complete heart block after open heart surgery for congenital heart disease: Duration alone predicts risk of late complete heart block.Pediatric Cardiol. 2012; 34: 999-1005Crossref PubMed Scopus (22) Google Scholar,25Gross G.J. Chiu C.C. Hamilton R.M. et al.Natural history of postoperative heart block in congenital heart disease: Implications for pacing intervention.Heart Rhythm. 2006; 3: 601-604Abstract Full Text Full Text PDF PubMed Scopus (82) Google ScholarIIbPermanent pacemaker implantation may be considered at <7 postoperative days when advanced second- or third-degree AV block is not expected to resolve due to extensive injury to the cardiac conduction system.C-EOIIbPermanent pacemaker implantation may be considered in select patients with transient postoperative advanced second- or third-degree AV block who are predisposed to progressive conduction abnormalities (see text).C-EO Open table in a new tab Recommendation-specific supportive text Postoperative AV block complicates 3-8% of congenital heart surgeries, with 1-3% of patients requiring permanent pacemaker implantation for persistent postoperative AV block.22Romer A.J. Tabbutt S. Etheridge S.P. et al.Atrioventricular block after congenital heart surgery: Analysis from the Pediatric Cardiac Critical Care Consortium.J Thorac Cardiovasc Surg. 2019; 157: 1168-1177Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar A very poor prognosis has been established for CHD patients with permanent postoperative AV block who do not receive permanent pacemakers. Among patients who regain AV conduction following transient AV block, ≥85% have recovery of AV conduction by post-operative day 7 and ≥95% AV conduction by postoperative day 10.21Weindling S.N. Saul P.J. Gamble W.J. et al.Duration of complete atrioventricular block after congenital heart disease surgery.Am J Cardiol. 1998; 82: 525-527Abstract Full Text Full Text PDF PubMed Scopus (151) Google Scholar,22Romer A.J. Tabbutt S. Etheridge S.P. et al.Atrioventricular block after congenital heart surgery: Analysis from the Pediatric Cardiac Critical Care Consortium.J Thorac Cardiovasc Surg. 2019; 157: 1168-1177Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar Although patients who regain AV conduction have a favorable prognosis, there is a small risk of late-onset complete AV block in transient postoperative AV block patients.23Villain E. Ouarda F. Beyler C. et al.Predictive factors for late complete atrio-ventricular block after surgical treatment for congenital cardiomyopathy.Arch Mal Coeur Vaiss. 2003; 96: 495-498PubMed Google Scholar Permanent pacemaker implantation may be considered for transient postoperative third-degree AV block that reverts to normal AV node conduction in patients with forms of CHD which may develop progressive AV block such as discordant AV connections, AV septal defects and heterotaxy syndromes. Tabled 1COR