Mark Alexander, MD

Director, Exercise and Sports Cardiology; Senior Cardiologist, Department of Cardiology

Associate Professor of Pediatrics, Harvard Medical School

Phone 617-355-2079

Fax 617-730-0000

NPI 1013907666

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Mark Alexander, MD

Director, Exercise and Sports Cardiology; Senior Cardiologist, Department of Cardiology

Associate Professor of Pediatrics, Harvard Medical School

Medical Services

Languages

English

Education

Undergraduate School

Amherst College

1980

Amherst

Medical School

Boston University School of Medicine

1985

Boston

Internship

Tripler Army Medical Center

1986

Honolulu

Residency

Tripler Army Medical Center

1988

Honolulu

Fellowship

Cardiac Electrophysiology

Boston Children's Hospital

1998

Boston

Certifications

American Board of Pediatrics (General)

American Board of Pediatrics (Cardiology)

American Board of Internal Medicine (Adult Congenital Heart Disease)

International Board of Heart Rhythm Examiners

Professional History

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.

Approach to 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.

Publications

Implementing Sudden Cardiac Death Risk Screening within a Pediatric Primary Care Network. View Abstract

Efficacy and safety of early postoperative ablation in patients with congenital heart disease. View Abstract

Exercise testing in clinical context: Reference ranges for interpreting anaerobic threshold as an outcome for congenital heart disease patients. View Abstract

Comparative utility of omnipolar and bipolar electroanatomic mapping methods to detect and localize dual nodal substrate in patients with atrioventricular nodal reentrant tachycardia. View Abstract

Limited Relationship Between Echocardiographic Measures and Electrocardiographic Markers of Left Ventricular Size in Healthy Children. View Abstract

Pediatric ECG-Based Deep Learning to Predict Left Ventricular Dysfunction and Remodeling. View Abstract

Aortic arch shape after arch repair predicts exercise capacity: a multicentre analysis. View Abstract

Medical cardioversion of atrial fibrillation and flutter with class IC antiarrhythmic drugs in young patients with and without congenital heart disease. View Abstract

Socioeconomic Factors Influencing Pediatric Peak Oxygen Consumption Prediction. View Abstract

Biking More With Congenital Heart Disease: Stratifying Risk in the New Generation of Adult Patients. View Abstract

Retroflexed catheter course reduces the risk of right free wall accessory pathway recurrence. View Abstract

Ventricular arrhythmias after fibroma resection: Are patients still at risk? View Abstract

FORCE Risk Stratification Tool for Pediatric Cardiac Rehabilitation and Fitness Programs. View Abstract

Radiofrequency Catheter Ablation for Pediatric Atrioventricular Nodal Reentrant Tachycardia: Impact of Age on Procedural Methods and Durable Success. View Abstract

AMEN and ALARA-Remembering the dangers of the (new) technology of lesion formation. View Abstract

Brain-based measures of nociception during general anesthesia with remifentanil: A randomized controlled trial. View Abstract

Supraventricular Tachycardia in Infants With Congenital Diaphragmatic Hernia: Prevalence, Associations, and Outcomes. View Abstract

Success with caution: Forty years of congenital complete atrioventricular block. View Abstract

Assessment of Exercise Function in Children and Young Adults with Hypertrophic Cardiomyopathy and Correlation with Transthoracic Echocardiographic Parameters. View Abstract

Activity During the COVID-19 Pandemic in Children with Cardiac Rhythm Management Devices. View Abstract

Pediatric T-wave memory after accessory pathway ablation in Wolff-Parkinson-White syndrome. View Abstract

Pacemaker use for the treatment of reflex-mediated syncope: 40-year experience at a single paediatric institution. View Abstract

Electrocardiogram as a Lyme Disease Screening Test. View Abstract

Vo2peak in Adult Survivors of Hodgkin Lymphoma: Rate of Decline, Sex Differences, and Cardiovascular Events. View Abstract

Accessory pathway ablation in Ebstein anomaly: A challenging substrate. View Abstract

Care of Children with Supraventricular Tachycardia in the Emergency Department. View Abstract

Long-term Effects of an Evidence-based Guideline for Emergency Management of Pediatric Syncope. View Abstract

Risk Factors for Early Recurrence Following Ablation for Accessory Pathways: The Role of Consolidation Lesions. View Abstract

Value of provocative electrophysiology testing in the management of pediatric patients after congenital heart surgery. View Abstract

Establishing a Comprehensive Pediatric Cardiac Fitness and Rehabilitation Program for Congenital Heart Disease. View Abstract

Clinical and Genetic Findings in Children Presenting With Ventricular Fibrillation as the First Manifestation of Cardiovascular Disease. View Abstract

Low mortality in fetal supraventricular tachycardia: Outcomes in a 30-year single-institution experience. View Abstract

Adverse event rate during inpatient sotalol initiation for the management of supraventricular and ventricular tachycardia in the pediatric and young adult population. View Abstract

Ultra-rapid atrial pacing as a form of rate control in postoperative automatic arrhythmias in patients with congenital heart disease. View Abstract

Outcomes of catheter ablation of anteroseptal and midseptal accessory pathways in pediatric patients. View Abstract

Interdigitating Myocardial Tongues in Pediatric Cardiac Fibromas: Plausible Substrate for Ventricular Tachycardia and Cardiac Arrest. View Abstract

The Real-World Utility of the LINQ Implantable Loop Recorder in Pediatric and Adult Congenital Heart Patients. View Abstract

Intravenous Amiodarone and Sotalol Impair Contractility and Cardiac Output, but Procainamide Does Not: A Langendorff Study. View Abstract

Dual-Site Ventricular Pacing in Patients With Fontan Physiology and Heart Block: Does it Mitigate the Detrimental Effects of Single-Site Ventricular Pacing? View Abstract

Evaluation of left ventricular false tendons in children with idiopathic left ventricular tachycardia. View Abstract

Incidence and Predictors of Clinically Important and Dangerous Arrhythmias During Exercise Tests in Pediatric and Congenital Heart Disease Patients. View Abstract

Electrocardiograms in Healthy North American Children in the Digital Age. View Abstract

Utility of incomplete right bundle branch block as an isolated ECG finding in children undergoing initial cardiac evaluation. View Abstract

Placebo-controlled crossover assessment of mecasermin for the treatment of Rett syndrome. View Abstract

Cardiac Events During Competitive, Recreational, and Daily Activities in Children and Adolescents With Long QT Syndrome. View Abstract

Finding the next good thing. View Abstract

Pausing With the Gauze: Inhibition of Temporary Pacemakers by Radiofrequency Scan During Cardiac Surgery. View Abstract

Relation of Left Atrial Size to Atrial Fibrillation in Patients Aged =22 Years. View Abstract

Transvenous approach to pacemaker lead implantation for sinus node dysfunction after extracardiac lateral tunnel Fontan conduit placement. View Abstract

Pushing back the cliff (but there probably still is a cliff): Arrhythmia, late outcome, and uncertainty in Fontan patients. View Abstract

Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias. View Abstract

Heart block following stage 1 palliation of hypoplastic left heart syndrome. View Abstract

Regional Implementation of a Pediatric Cardiology Syncope Algorithm Using Standardized Clinical Assessment and Management Plans (SCAMPS) Methodology. View Abstract

Exercise Performance in Patients with D-Loop Transposition of the Great Arteries After Arterial Switch Operation: Long-Term Outcomes and Longitudinal Assessment. View Abstract

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. View Abstract

Impact of pacing on systemic ventricular function in L-transposition of the great arteries. View Abstract

Pediatric Dilated Cardiomyopathy Patients Do Not Meet Traditional Cardiac Resynchronization Criteria. View Abstract

Attention-deficit/hyperactivity disorder treatment: what are the long-term cardiovascular risks? View Abstract

Mechanism and ablation of arrhythmia following total cavopulmonary connection. View Abstract

Corrected QT interval changes with atypical antipsychotics. View Abstract

Preoperative electrocardiograms for nonsyndromic children with hand syndactyly. View Abstract

Implementing a guideline to improve management of syncope in the emergency department. View Abstract

Time dependence of risks and benefits in pediatric primary prevention implantable cardioverter-defibrillator therapy. View Abstract

EHRA/HRS/APHRS expert consensus on ventricular arrhythmias. View Abstract

Safety, pharmacokinetics, and preliminary assessment of efficacy of mecasermin (recombinant human IGF-1) for the treatment of Rett syndrome. View Abstract

Perinatal outcome in fetuses with heterotaxy syndrome and atrioventricular block or bradycardia. View Abstract

Utility of preoperative electrophysiologic studies in patients with Ebstein's anomaly undergoing the Cone procedure. View Abstract

Impact of transcatheter pulmonary valve replacement on biventricular strain and synchrony assessed by cardiac magnetic resonance feature tracking. View Abstract

In-hospital arrhythmia development and outcomes in pediatric patients with acute myocarditis. View Abstract

Transbaffle mapping and ablation for atrial tachycardias after mustard, senning, or Fontan operations. View Abstract

The role of cardiac resynchronization therapy for arterial switch operations complicated by complete heart block. View Abstract

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. View Abstract

Chest pain and syncope in children: a practical approach to the diagnosis of cardiac disease. View Abstract

The electrophysiological characteristics of accessory pathways in pediatric patients with intermittent preexcitation. View Abstract

Radiofrequency-assisted transseptal perforation for electrophysiology procedures in children and adults with repaired congenital heart disease. View Abstract

Multiple accessory pathways in the young: the impact of structural heart disease. View Abstract

Cardiac troponin T as a screening test for myocarditis in children. View Abstract

Prospective evaluation of defibrillation threshold and postshock rhythm in young ICD recipients. View Abstract

Circulating matrix metalloproteinases in adolescents with hypertrophic cardiomyopathy and ventricular arrhythmia. View Abstract

Costs and benefits of targeted screening for causes of sudden cardiac death in children and adolescents. View Abstract

Electrocardiogram screening for disorders that cause sudden cardiac death in asymptomatic children: a meta-analysis. View Abstract

Attention-deficit/hyperactivity disorder, stimulant therapy, and the patient with congenital heart disease: evidence and reason. View Abstract

Reproducibility of echocardiographic diagnosis of left ventricular noncompaction. View Abstract

Cardiac tumors and associated arrhythmias in pediatric patients, with observations on surgical therapy for ventricular tachycardia. View Abstract

Exercise, stand up, flip a coin, or just say no: provocative testing in the child with borderline QTc. View Abstract

Marked QT prolongation and ventricular tachycardia of a transient nature in young children with cardiomyopathy. View Abstract

The electroanatomic mechanisms of atrial tachycardia in patients with tetralogy of Fallot and double outlet right ventricle. View Abstract

Recovery of oxygen consumption after maximal exercise in children. View Abstract

Exercise testing identifies patients at increased risk for morbidity and mortality following Fontan surgery. View Abstract

Clinical, pathological, and molecular analyses of cardiovascular abnormalities in Costello syndrome: a Ras/MAPK pathway syndrome. View Abstract

Nonfluoroscopic imaging systems reduce radiation exposure in children undergoing ablation of supraventricular tachycardia. View Abstract

Lead extraction in pediatric and congenital heart disease patients. View Abstract

Malnutrition and hemodynamic status in adolescents hospitalized for anorexia nervosa. View Abstract

Needle in a haystack: modeling the incidence of sudden cardiac arrest in healthy children. View Abstract

System survival of nontransvenous implantable cardioverter-defibrillators compared to transvenous implantable cardioverter-defibrillators in pediatric and congenital heart disease patients. View Abstract

Permanent atrial pacing lead implant route after Fontan operation. View Abstract

Lyme carditis in children: presentation, predictive factors, and clinical course. View Abstract

Orthostasis, the autonomic nervous system, and abdominal pain in children: is there a relation between postural orthostatic tachycardia and recurrent abdominal pain? View Abstract

Reexamining the emperor's new clothes: ambiguities in current cardiac screening recommendations for youth with attention deficit hyperactivity disorder. View Abstract

Ascending aortic dilation in patients with congenital complete heart block. View Abstract

Cardiac resynchronization therapy (and multisite pacing) in pediatrics and congenital heart disease: five years experience in a single institution. View Abstract

The longitudinal course of cardiomyopathy in Friedreich's ataxia during childhood. View Abstract

Atrioventricular nodal reentrant tachycardia with 2:1 block in pediatric patients. View Abstract

Results of a multicenter retrospective implantable cardioverter-defibrillator registry of pediatric and congenital heart disease patients. View Abstract

Cardiac risk after craniopharyngioma therapy. View Abstract

Digital music players cause interference with interrogation telemetry for pacemakers and implantable cardioverter-defibrillators without affecting device function. View Abstract

How revealing are insertable loop recorders in pediatrics? View Abstract

Impact of transvenous ventricular pacing leads on tricuspid regurgitation in pediatric and congenital heart disease patients. View Abstract

Inaccuracy of Wolff-Parkinson-white accessory pathway localization algorithms in children and patients with congenital heart defects. View Abstract

Age, size, and lead factors alone do not predict venous obstruction in children and young adults with transvenous lead systems. View Abstract

Microvolt t-wave alternans with exercise in pediatrics and congenital heart disease: limitations and predictive value. View Abstract

Complex regional pain syndromes in children and adolescents: regional and systemic signs and symptoms and hemodynamic response to tilt table testing. View Abstract

Transient prolonged corrected QT interval in Lyme disease. View Abstract

Ablation of nonautomatic focal atrial tachycardia in children and adults with congenital heart disease. View Abstract

Cryoablation for accessory pathways located near normal conduction tissues or within the coronary venous system in children and young adults. View Abstract

Entwining electrical and hypertrophic cardiomyopathies. View Abstract

Comparison of modern steroid-eluting epicardial and thin transvenous pacemaker leads in pediatric and congenital heart disease patients. View Abstract

Prospective trial of electroanatomically guided, irrigated catheter ablation of atrial tachycardia in patients with congenital heart disease. View Abstract

Transvenous pacing in infants: a faith based initiative? View Abstract

Radiofrequency catheter ablation of ventricular tachycardia in children and young adults with congenital heart disease. View Abstract

Fainting freshmen and sinking sophomores: cardiovascular issues of the adolescent. View Abstract

Patient, procedural, and hardware factors associated with pacemaker lead failures in pediatrics and congenital heart disease. View Abstract

Relation of right ventricular pacing in tetralogy of Fallot to electrical resynchronization. View Abstract

Value of programmed ventricular stimulation after tetralogy of fallot repair: a multicenter study. View Abstract

Modification to the Fontan procedure for the prophylaxis of intra-atrial reentrant tachycardia: short-term results of a prospective randomized blinded trial. View Abstract

Implications of implantable cardioverter defibrillator therapy in congenital heart disease and pediatrics. View Abstract

Radiofrequency catheter ablation of septal accessory pathways in the pediatric age group. View Abstract

Efficacy of atrial antitachycardia pacing using the Medtronic AT500 pacemaker in patients with congenital heart disease. View Abstract

Incident cases of heart failure in a community cohort: importance and outcomes of patients with preserved systolic function. View Abstract

Cardiology participation improves outcomes in patients with new-onset heart failure in the outpatient setting. View Abstract

Circadian and seasonal variation of malignant arrhythmias in a pediatric and congenital heart disease population. View Abstract

Management of ventricular arrhythmias in diverse populations in California. View Abstract

Influence of patient factors and ablative technologies on outcomes of radiofrequency ablation of intra-atrial re-entrant tachycardia in patients with congenital heart disease. View Abstract

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