Understanding the patient's goals, interests and fears can help us frame difficult decisions and respond honestly.


Undergraduate Degree

  • Amherst College , 1980 , Amherst , MA

Medical School

  • Boston University School of Medicine , 1985 , Boston , MA


  • Tripler Army Medical Center , 1986 , Honolulu , HI


  • Tripler Army Medical Center , 1988 , Honolulu , HI


  • Boston Children's Hospital , 1998 , Boston , MA

Philosophy of Care

Many patients will need to see us for years. Understanding their goals, interests and fears can help us frame difficult decisions and respond honestly. As children move into adolescence, constantly refocusing care towards the teen is equally critical. Recurrent education about options, anticipated problems and tradeoffs takes longer. Whenever possible, this combination of interest, respect and education lets families make effective choices.

As a general pediatrician earlier in my career, I was constantly frustrated that when I identified a major problem I almost always had to get help to manage it.  Now, after more than 20 years at Boston Children's, I know precisely how to help my patients with a number of major problems.  And I know exactly where to find colleagues, nurses, and technologists with the same level of commitment.  


Following medical school, Dr. Alexander completed a pediatric residency in Hawaii and then served four years as an Army Pediatrician in rural Louisiana. He returned to Boston for a fellowship in pediatric cardiology and completed additional training in electrophysiology, which included serving as Chief Fellow. Since 1996, he has been a director of the Exercise Physiology Program and joined the Arrhythmia Service in 1998. One aspect of his clinical work focuses on arrhythmias in children from fetal life to well into adulthood for those with congenital heart disease. This focus has been part of numerous research papers and presentations on the risks and benefits of therapy. He performs catheter ablations, manages pacemakers and ICDs and assists in balancing therapy options for arrhythmias. A second aspect has been to serve as liaison with neurology, anesthesia and the emergency room in evaluating potential cardiac concerns in patients. This has developed shared expertise in patients with problematic syncope syndromes, Rett’s Syndrome, and congenital central hypoventilation. More recently, Dr. Alexander has been serving on the Institutional Review Board and on the Unexplained Diagnoses Taskforce. He currently directs the New England-wide Systematic Clinical Assessment and Management Program (SCAMP) on syncope.


  • American Board of Pediatrics, General Pediatrics
  • American Board of Pediatrics, Pediatric Cardiology
  • American Board of Internal Medicine, Adult Congenital Heart Disease
  • International Board of Heart Rhythm Examiners


Publications powered by Harvard Catalyst Profiles

  1. Care of Children with Supraventricular Tachycardia in the Emergency Department. Pediatr Cardiol. 2021 Jan 04. View abstract
  2. Long-term Effects of an Evidence-based Guideline for Emergency Management of Pediatric Syncope. Pediatr Qual Saf. 2020 Nov-Dec; 5(6):e361. View abstract
  3. Risk Factors for Early Recurrence Following Ablation for Accessory Pathways: The Role of Consolidation Lesions. Circ Arrhythm Electrophysiol. 2020 Nov; 13(11):e008848. View abstract
  4. Value of provocative electrophysiology testing in the management of pediatric patients after congenital heart surgery. Pacing Clin Electrophysiol. 2020 09; 43(9):901-907. View abstract
  5. Establishing a Comprehensive Pediatric Cardiac Fitness and Rehabilitation Program for Congenital Heart Disease. Pediatr Cardiol. 2020 Dec; 41(8):1569-1579. View abstract
  6. Clinical and Genetic Findings in Children Presenting With Ventricular Fibrillation as the First Manifestation of Cardiovascular Disease. J Am Heart Assoc. 2020 05 18; 9(10):e016322. View abstract
  7. Low mortality in fetal supraventricular tachycardia: Outcomes in a 30-year single-institution experience. J Cardiovasc Electrophysiol. 2020 May; 31(5):1105-1113. View abstract
  8. Adverse event rate during inpatient sotalol initiation for the management of supraventricular and ventricular tachycardia in the pediatric and young adult population. Heart Rhythm. 2020 06; 17(6):984-990. View abstract
  9. Ultra-rapid atrial pacing as a form of rate control in postoperative automatic arrhythmias in patients with congenital heart disease. HeartRhythm Case Rep. 2020 Apr; 6(4):215-218. View abstract
  10. Outcomes of catheter ablation of anteroseptal and midseptal accessory pathways in pediatric patients. Heart Rhythm. 2020 05; 17(5 Pt A):759-767. View abstract
  11. Interdigitating Myocardial Tongues in Pediatric Cardiac Fibromas: Plausible Substrate for Ventricular Tachycardia and Cardiac Arrest. JACC Clin Electrophysiol. 2019 05; 5(5):563-575. View abstract
  12. The Real-World Utility of the LINQ Implantable Loop Recorder in Pediatric and Adult Congenital Heart Patients. JACC Clin Electrophysiol. 2019 02; 5(2):245-251. View abstract
  13. Intravenous Amiodarone and Sotalol Impair Contractility and Cardiac Output, but Procainamide Does Not: A Langendorff Study. J Cardiovasc Pharmacol Ther. 2019 05; 24(3):288-297. View abstract
  14. Dual-Site Ventricular Pacing in Patients With Fontan Physiology and Heart Block: Does it Mitigate the Detrimental Effects of Single-Site Ventricular Pacing? JACC Clin Electrophysiol. 2018 10; 4(10):1289-1297. View abstract
  15. Evaluation of left ventricular false tendons in children with idiopathic left ventricular tachycardia. Pacing Clin Electrophysiol. 2018 09; 41(9):1143-1149. View abstract
  16. Incidence and Predictors of Clinically Important and Dangerous Arrhythmias During Exercise Tests in Pediatric and Congenital Heart Disease Patients. JACC Clin Electrophysiol. 2018 10; 4(10):1319-1327. View abstract
  17. Electrocardiograms in Healthy North American Children in the Digital Age. Circ Arrhythm Electrophysiol. 2018 07; 11(7):e005808. View abstract
  18. Utility of incomplete right bundle branch block as an isolated ECG finding in children undergoing initial cardiac evaluation. Congenit Heart Dis. 2018 May; 13(3):419-427. View abstract
  19. Placebo-controlled crossover assessment of mecasermin for the treatment of Rett syndrome. Ann Clin Transl Neurol. 2018 03; 5(3):323-332. View abstract
  20. Cardiac Events During Competitive, Recreational, and Daily Activities in Children and Adolescents With Long QT Syndrome. J Am Heart Assoc. 2017 Sep 21; 6(9). View abstract
  21. Finding the next good thing. J Thorac Cardiovasc Surg. 2017 06; 153(6):1555-1556. View abstract
  22. Pausing With the Gauze: Inhibition of Temporary Pacemakers by Radiofrequency Scan During Cardiac Surgery. Anesth Analg. 2016 11; 123(5):1143-1148. View abstract
  23. Relation of Left Atrial Size to Atrial Fibrillation in Patients Aged =22 Years. Am J Cardiol. 2017 Jan 01; 119(1):52-56. View abstract
  24. Transvenous approach to pacemaker lead implantation for sinus node dysfunction after extracardiac lateral tunnel Fontan conduit placement. HeartRhythm Case Rep. 2016 Nov; 2(6):495-498. View abstract
  25. Pushing back the cliff (but there probably still is a cliff): Arrhythmia, late outcome, and uncertainty in Fontan patients. J Thorac Cardiovasc Surg. 2016 11; 152(5):1364-1365. View abstract
  26. Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias. PLoS One. 2016; 11(7):e0158975. View abstract
  27. Heart block following stage 1 palliation of hypoplastic left heart syndrome. J Thorac Cardiovasc Surg. 2016 Jul; 152(1):189-94. View abstract
  28. Regional Implementation of a Pediatric Cardiology Syncope Algorithm Using Standardized Clinical Assessment and Management Plans (SCAMPS) Methodology. J Am Heart Assoc. 2016 Feb 19; 5(2). View abstract
  29. Exercise Performance in Patients with D-Loop Transposition of the Great Arteries After Arterial Switch Operation: Long-Term Outcomes and Longitudinal Assessment. Pediatr Cardiol. 2016 Feb; 37(2):283-9. View abstract
  30. A Phase 1, Dose-escalation, Double-blind, Block-randomized, Controlled Trial of Safety and Efficacy of Neosaxitoxin Alone and in Combination with 0.2% Bupivacaine, with and without Epinephrine, for Cutaneous Anesthesia. Anesthesiology. 2015 Oct; 123(4):873-85. View abstract
  31. Impact of pacing on systemic ventricular function in L-transposition of the great arteries. J Thorac Cardiovasc Surg. 2016 Jan; 151(1):131-8. View abstract
  32. Pediatric Dilated Cardiomyopathy Patients Do Not Meet Traditional Cardiac Resynchronization Criteria. J Cardiovasc Electrophysiol. 2015 Aug; 26(8):885-889. View abstract
  33. Attention-deficit/hyperactivity disorder treatment: what are the long-term cardiovascular risks? Expert Opin Drug Saf. 2015 Apr; 14(4):543-51. View abstract
  34. Mechanism and ablation of arrhythmia following total cavopulmonary connection. Circ Arrhythm Electrophysiol. 2015 Apr; 8(2):318-25. View abstract
  35. Corrected QT interval changes with atypical antipsychotics. J Am Acad Child Adolesc Psychiatry. 2015 Jan; 54(1):9-10. View abstract
  36. Preoperative electrocardiograms for nonsyndromic children with hand syndactyly. J Hand Surg Am. 2015 Mar; 40(3):452-5. View abstract
  37. Implementing a guideline to improve management of syncope in the emergency department. Pediatrics. 2014 Nov; 134(5):e1413-21. View abstract
  38. Time dependence of risks and benefits in pediatric primary prevention implantable cardioverter-defibrillator therapy. Circ Arrhythm Electrophysiol. 2014 Dec; 7(6):1057-63. View abstract
  39. EHRA/HRS/APHRS expert consensus on ventricular arrhythmias. Europace. 2014 09; 16(9):1257-83. View abstract
  40. EHRA/HRS/APHRS expert consensus on ventricular arrhythmias. Heart Rhythm. 2014 Oct; 11(10):e166-96. View abstract
  41. Safety, pharmacokinetics, and preliminary assessment of efficacy of mecasermin (recombinant human IGF-1) for the treatment of Rett syndrome. Proc Natl Acad Sci U S A. 2014 Mar 25; 111(12):4596-601. View abstract
  42. Perinatal outcome in fetuses with heterotaxy syndrome and atrioventricular block or bradycardia. Pediatr Cardiol. 2014 Aug; 35(6):906-13. View abstract
  43. Utility of preoperative electrophysiologic studies in patients with Ebstein's anomaly undergoing the Cone procedure. Heart Rhythm. 2014 Feb; 11(2):182-6. View abstract
  44. Impact of transcatheter pulmonary valve replacement on biventricular strain and synchrony assessed by cardiac magnetic resonance feature tracking. Circ Cardiovasc Interv. 2013 Dec; 6(6):680-7. View abstract
  45. In-hospital arrhythmia development and outcomes in pediatric patients with acute myocarditis. Am J Cardiol. 2014 Feb 01; 113(3):535-40. View abstract
  46. Transbaffle mapping and ablation for atrial tachycardias after mustard, senning, or Fontan operations. J Am Heart Assoc. 2013 Sep 19; 2(5):e000325. View abstract
  47. The role of cardiac resynchronization therapy for arterial switch operations complicated by complete heart block. Ann Thorac Surg. 2013 Sep; 96(3):904-9. View abstract
  48. The use of an integrated electroanatomic mapping system and intracardiac echocardiography to reduce radiation exposure in children and young adults undergoing ablation of supraventricular tachycardia. Europace. 2014 Feb; 16(2):277-83. View abstract
  49. Chest pain and syncope in children: a practical approach to the diagnosis of cardiac disease. J Pediatr. 2013 Sep; 163(3):896-901.e1-3. View abstract
  50. The electrophysiological characteristics of accessory pathways in pediatric patients with intermittent preexcitation. Pacing Clin Electrophysiol. 2013 Sep; 36(9):1117-22. View abstract
  51. Radiofrequency-assisted transseptal perforation for electrophysiology procedures in children and adults with repaired congenital heart disease. Pacing Clin Electrophysiol. 2013 May; 36(5):607-11. View abstract
  52. Multiple accessory pathways in the young: the impact of structural heart disease. Am Heart J. 2013 Jan; 165(1):87-92. View abstract
  53. Cardiac troponin T as a screening test for myocarditis in children. Pediatr Emerg Care. 2012 Nov; 28(11):1173-8. View abstract
  54. Prospective evaluation of defibrillation threshold and postshock rhythm in young ICD recipients. Pacing Clin Electrophysiol. 2012 Dec; 35(12):1487-93. View abstract
  55. Circulating matrix metalloproteinases in adolescents with hypertrophic cardiomyopathy and ventricular arrhythmia. Circ Heart Fail. 2012 Jul 01; 5(4):462-6. View abstract
  56. Costs and benefits of targeted screening for causes of sudden cardiac death in children and adolescents. Circulation. 2012 May 29; 125(21):2621-9. View abstract
  57. Electrocardiogram screening for disorders that cause sudden cardiac death in asymptomatic children: a meta-analysis. Pediatrics. 2012 Apr; 129(4):e999-1010. View abstract
  58. Attention-deficit/hyperactivity disorder, stimulant therapy, and the patient with congenital heart disease: evidence and reason. Pediatr Cardiol. 2012 Mar; 33(3):394-401. View abstract
  59. Reproducibility of echocardiographic diagnosis of left ventricular noncompaction. J Am Soc Echocardiogr. 2012 Feb; 25(2):194-202. View abstract
  60. Cardiac tumors and associated arrhythmias in pediatric patients, with observations on surgical therapy for ventricular tachycardia. J Am Coll Cardiol. 2011 Oct 25; 58(18):1903-9. View abstract
  61. Exercise, stand up, flip a coin, or just say no: provocative testing in the child with borderline QTc. Circ Arrhythm Electrophysiol. 2011 Aug; 4(4):422-3. View abstract
  62. Marked QT prolongation and ventricular tachycardia of a transient nature in young children with cardiomyopathy. Pacing Clin Electrophysiol. 2012 Aug; 35(8):e247-50. View abstract
  63. The electroanatomic mechanisms of atrial tachycardia in patients with tetralogy of Fallot and double outlet right ventricle. J Cardiovasc Electrophysiol. 2011 Sep; 22(9):1013-7. View abstract
  64. Recovery of oxygen consumption after maximal exercise in children. Med Sci Sports Exerc. 2011 Apr; 43(4):555-9. View abstract
  65. Exercise testing identifies patients at increased risk for morbidity and mortality following Fontan surgery. Congenit Heart Dis. 2011 Jul-Aug; 6(4):294-303. View abstract
  66. Clinical, pathological, and molecular analyses of cardiovascular abnormalities in Costello syndrome: a Ras/MAPK pathway syndrome. . 2011 Mar; 155A(3):486-507. View abstract
  67. Nonfluoroscopic imaging systems reduce radiation exposure in children undergoing ablation of supraventricular tachycardia. Heart Rhythm. 2011 Apr; 8(4):519-25. View abstract
  68. Lead extraction in pediatric and congenital heart disease patients. Circ Arrhythm Electrophysiol. 2010 Oct; 3(5):437-44. View abstract
  69. Malnutrition and hemodynamic status in adolescents hospitalized for anorexia nervosa. Arch Pediatr Adolesc Med. 2010 Aug; 164(8):706-13. View abstract
  70. Needle in a haystack: modeling the incidence of sudden cardiac arrest in healthy children. Circulation. 2010 Mar 23; 121(11):1283-5. View abstract
  71. System survival of nontransvenous implantable cardioverter-defibrillators compared to transvenous implantable cardioverter-defibrillators in pediatric and congenital heart disease patients. Heart Rhythm. 2010; 7(2):193-8. View abstract
  72. Permanent atrial pacing lead implant route after Fontan operation. Pacing Clin Electrophysiol. 2009 Jun; 32(6):779-85. View abstract
  73. Lyme carditis in children: presentation, predictive factors, and clinical course. Pediatrics. 2009 May; 123(5):e835-41. View abstract
  74. Orthostasis, the autonomic nervous system, and abdominal pain in children: is there a relation between postural orthostatic tachycardia and recurrent abdominal pain? J Pediatr Gastroenterol Nutr. 2008 Nov; 47(5):696-700. View abstract
  75. Reexamining the emperor's new clothes: ambiguities in current cardiac screening recommendations for youth with attention deficit hyperactivity disorder. Circ Cardiovasc Qual Outcomes. 2008 Nov; 1(2):134-7. View abstract
  76. Ascending aortic dilation in patients with congenital complete heart block. Heart Rhythm. 2008 Dec; 5(12):1704-8. View abstract
  77. Cardiac resynchronization therapy (and multisite pacing) in pediatrics and congenital heart disease: five years experience in a single institution. J Cardiovasc Electrophysiol. 2009 Jan; 20(1):58-65. View abstract
  78. The longitudinal course of cardiomyopathy in Friedreich's ataxia during childhood. Pediatr Cardiol. 2009 Apr; 30(3):306-10. View abstract
  79. Atrioventricular nodal reentrant tachycardia with 2:1 block in pediatric patients. Heart Rhythm. 2008 Oct; 5(10):1391-5. View abstract
  80. Results of a multicenter retrospective implantable cardioverter-defibrillator registry of pediatric and congenital heart disease patients. J Am Coll Cardiol. 2008 Apr 29; 51(17):1685-91. View abstract
  81. Cardiac risk after craniopharyngioma therapy. Pediatr Neurol. 2008 Apr; 38(4):256-60. View abstract
  82. Digital music players cause interference with interrogation telemetry for pacemakers and implantable cardioverter-defibrillators without affecting device function. Heart Rhythm. 2008 Apr; 5(4):545-50. View abstract
  83. How revealing are insertable loop recorders in pediatrics? Pacing Clin Electrophysiol. 2008 Mar; 31(3):338-43. View abstract
  84. Impact of transvenous ventricular pacing leads on tricuspid regurgitation in pediatric and congenital heart disease patients. J Interv Card Electrophysiol. 2008 Jan; 21(1):65-8. View abstract
  85. Microvolt t-wave alternans with exercise in pediatrics and congenital heart disease: limitations and predictive value. Pacing Clin Electrophysiol. 2006 Jul; 29(7):733-41. View abstract
  86. Inaccuracy of Wolff-Parkinson-white accessory pathway localization algorithms in children and patients with congenital heart defects. J Cardiovasc Electrophysiol. 2006 Jul; 17(7):712-6. View abstract
  87. Age, size, and lead factors alone do not predict venous obstruction in children and young adults with transvenous lead systems. J Cardiovasc Electrophysiol. 2006 Jul; 17(7):754-9. View abstract
  88. Transient prolonged corrected QT interval in Lyme disease. J Pediatr. 2006 May; 148(5):692-7. View abstract
  89. Complex regional pain syndromes in children and adolescents: regional and systemic signs and symptoms and hemodynamic response to tilt table testing. Clin J Pain. 2006 May; 22(4):399-406. View abstract
  90. Ablation of nonautomatic focal atrial tachycardia in children and adults with congenital heart disease. J Cardiovasc Electrophysiol. 2006 Apr; 17(4):359-65. View abstract
  91. Cryoablation for accessory pathways located near normal conduction tissues or within the coronary venous system in children and young adults. Heart Rhythm. 2006 Mar; 3(3):253-8. View abstract
  92. Entwining electrical and hypertrophic cardiomyopathies. Heart Rhythm. 2005 Dec; 2(12):1369-70. View abstract
  93. Comparison of modern steroid-eluting epicardial and thin transvenous pacemaker leads in pediatric and congenital heart disease patients. J Interv Card Electrophysiol. 2005 Oct; 14(1):27-36. View abstract
  94. Prospective trial of electroanatomically guided, irrigated catheter ablation of atrial tachycardia in patients with congenital heart disease. Heart Rhythm. 2005 Jul; 2(7):700-5. View abstract
  95. Transvenous pacing in infants: a faith based initiative? Pacing Clin Electrophysiol. 2004 Nov; 27(11):1463-5. View abstract
  96. Radiofrequency catheter ablation of ventricular tachycardia in children and young adults with congenital heart disease. Heart Rhythm. 2004 Sep; 1(3):301-8. View abstract
  97. Fainting freshmen and sinking sophomores: cardiovascular issues of the adolescent. Curr Opin Pediatr. 2004 Aug; 16(4):350-6. View abstract
  98. Patient, procedural, and hardware factors associated with pacemaker lead failures in pediatrics and congenital heart disease. Heart Rhythm. 2004 Jul; 1(2):150-9. View abstract
  99. Relation of right ventricular pacing in tetralogy of Fallot to electrical resynchronization. Am J Cardiol. 2004 Jun 01; 93(11):1449-52, A12. View abstract
  100. Value of programmed ventricular stimulation after tetralogy of fallot repair: a multicenter study. Circulation. 2004 Apr 27; 109(16):1994-2000. View abstract
  101. Modification to the Fontan procedure for the prophylaxis of intra-atrial reentrant tachycardia: short-term results of a prospective randomized blinded trial. J Thorac Cardiovasc Surg. 2004 Mar; 127(3):721-9. View abstract
  102. Implications of implantable cardioverter defibrillator therapy in congenital heart disease and pediatrics. J Cardiovasc Electrophysiol. 2004 Jan; 15(1):72-6. View abstract
  103. Radiofrequency catheter ablation of septal accessory pathways in the pediatric age group. Am J Cardiol. 2003 Oct 15; 92(8):947-50. View abstract
  104. Efficacy of atrial antitachycardia pacing using the Medtronic AT500 pacemaker in patients with congenital heart disease. Am J Cardiol. 2003 Oct 01; 92(7):871-6. View abstract
  105. Incident cases of heart failure in a community cohort: importance and outcomes of patients with preserved systolic function. Am Heart J. 2003 Jul; 146(1):115-20. View abstract
  106. Cardiology participation improves outcomes in patients with new-onset heart failure in the outpatient setting. J Am Coll Cardiol. 2003 Jan 01; 41(1):62-8. View abstract
  107. Circadian and seasonal variation of malignant arrhythmias in a pediatric and congenital heart disease population. J Cardiovasc Electrophysiol. 2002 Oct; 13(10):1009-14. View abstract
  108. Management of ventricular arrhythmias in diverse populations in California. Am Heart J. 2002 Sep; 144(3):431-9. View abstract
  109. Influence of patient factors and ablative technologies on outcomes of radiofrequency ablation of intra-atrial re-entrant tachycardia in patients with congenital heart disease. J Am Coll Cardiol. 2002 Jun 05; 39(11):1827-35. View abstract