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Rady Children's Specialists




Current Fellows: Dr. Thomas Glenn, Dr. Arpine Davtyan, Dr. Nicholas Dreger, Dr. Peter Guyon, Dr. Jennifer Lehmberg, Dr. Alejandro Borquez

The three-year fellowship in pediatric cardiology is an ACGME-accredited program designed to prepare exceptional clinicians and investigators to become active participants and leaders in academic pediatric cardiology. The clinical training is provided at Rady Children’s Hospital through the UC San Diego School of Medicine.

The program currently accepts two fellows each year and has the potential for additional subspecialty training in interventional catheterization, electrophysiology and cardiac development/genetics. Fellows are trained through extensive experience as supervised primary caregivers for inpatients and outpatients, typically with one-on-one teaching by faculty cardiologists. Additionally, there is an established didactic conference series attended by all fellows.

Conference Schedule

Tuesdays: Regional Patient Management and Surgical Care Conference (2 hours)

Wednesdays: Core Lecture Series or Fetal Echo Case Conference (1 hour)

Thursdays: Cath or CVICU Conference (alternating weeks) and EP Conference (1-2 hours)

Fridays: Echo Conference or Monthly M&M Conference (1 hour)

Faculty and fellows take active roles in each of these conferences, including frequent journal clubs and a wide range of lectures that prepare each fellow for excelling clinically as well as for the pediatric cardiology board examination. There are additional, less frequent conferences (typically once or twice monthly), including the Fellow Research Conference and the Morbidity and Mortality Conference, during which fellows take an active primary role in the presentations.

Below is the typical month by month breakdown of clinical fellow schedules:

3 Year Total Inpatient (6) CVICU (3) Echo (5) Cath (4) EP (2) Elective (2-3) Research (12)
Year 1 3-4 1 2 2 1 1 1-2
Year 2 2-3 1 2 2 1 1 1-2
Year 3 0 1 1 0 0 1 9

Fellows are also involved in all aspects of outpatient care, with each fellow being assigned to a half-day outpatient clinic that is attended each week during all months except for the inpatient service months. In addition, rotations through the heart failure and transplant clinic, exercise physiology laboratory and pulmonary hypertension clinics are included.

The program includes 12 months of dedicated research time, which is spread out during the final two years with a wide variety of opportunities available in both clinical and basic sciences. The faculty actively participates in mentoring for these projects. The program offers flexibility in scheduling in order to maximize both clinical and research experiences for each fellow.

Application Procedure

A specialty match run by the National Resident Matching Program fills positions in the Pediatric Cardiology Training Program. The schedule of dates can be obtained from the NRMP website at

Our timetable for the application process is as follows:

  • Applications and CVs will be reviewed from – July to August.
  • Interviews will be scheduled from September to October.

Applicants apply electronically through ERAS.

Eligibility Criteria

  • Graduate of a medical school located in the United States or Canada, accredited by the Liaison Committee on Medical Education (LCME); or
  • Graduate of a college of osteopathic medicine in the United States accredited by the American Osteopathic Association (AOA); or
  • Graduate of an international medical school located outside the United States and Canada who holds a current, valid certificate issued by the Educational Commission for Foreign Medical Graduates and holds a full and unrestricted license in the State of California to practice medicine or has received written notification from the Medical Board of California of approval to commence training in an accredited program in this state; or
  • Graduate of a medical school located outside the United States who has completed a Fifth Pathway program provided by an LCME-accredited medical school, and who provides evidence of compliance with the licensure laws of the State of California.

Our program requires that applicants have completed three years of an accredited general pediatric training program. All fellows must be eligible to have a California medical license when starting the fellowship.

Program Director:

Paul Grossfeld, M.D.
Rady Children’s Hospital-San Diego
Division of Cardiology
3020 Children’s Way/MC 5004
San Diego, CA 92123
Phone: 858-966-5855
Fax: 858-571-7903

Current Fellows:

Caitlin Heyden, D.O. (4th-Year Interventional Fellow): Caitlin is a native New Yorker and completed all of her training in New York prior to moving to California for 4th-year interventional training. She attended Cornell University for her undergraduate education and New York College of Osteopathic Medicine of NYIT for medical school. Caitlin completed her categorical pediatrics residency and a year as chief resident at Stony Brook University Medical Center on Long Island. Subsequently, she completed a cardiology fellowship at Cohen Children’s Medical Center of Northwell Health in New Hyde Park, N.Y. 

Alejandro Borquez, M.D. (3rd-Year Categorical Fellow): Alejandro grew up in Tijuana, Baja California, and attended Dartmouth College and UC Davis School of Medicine. He completed his residency at Lucille Packard Children’s Hospital at Stanford, then returned to San Diego for his fellowship. His medical interests include international medicine, electrophysiology and critical care.

Peter Guyon, M.D. (3rd-Year Categorical Fellow): Peter is originally from Salt Lake City and earned an undergraduate degree in English at Brigham Young University before attending medical school at the University of Pennsylvania in Philadelphia. He completed his residency in pediatrics at UC San Diego/Rady Children’s Hospital and stayed for his fellowship in pediatric cardiology. His medical interests include interventional cardiology and humanitarian outreach. When not at the Hospital, he enjoys basketball, tennis, biking, hiking and golfing poorly.

Nicholas Dreger, M.D. (2nd-Year Categorical Fellow): Nick hails from a small town in northern Wisconsin. He attended UW-Madison before earning his medical degree from the Medical College of Wisconsin. Subsequently, he completed his pediatrics residency at the University of California Irvine – Children’s Hospital of Orange County. Nick is interested in general cardiology and electrophysiology.

Jennifer Lehmberg, M.D. (2nd-Year Categorical Fellow): Jenn is a native Texan who got her start at the McGovern School of Medicine in Houston but has since been making her way across the country for her medical training. She completed her categorical pediatrics residency at Washington University in St. Louis before coming to UC San Diego/Rady Children’s Hospital for her pediatric cardiology fellowship. Her medical interests within medicine include sustainable global health initiatives, especially in Latin America, and legislative advocacy within the American Academy of Pediatrics.

Arpine Davtyan, M.D. (1st-Year Categorical Fellow): Arpine was born in Yerevan, Armenia, and moved to Los Angeles as a child. She completed an undergraduate degree in biology at Stanford University, and medical school at the University of Toledo College of Medicine. She then completed general pediatric residency at UC Irvine/Children’s Hospital of Orange County before coming to UC San Diego/Rady Children’s Hospital for fellowship in pediatric cardiology.

Thomas Glenn, M.D. (1st-Year Categorical Fellow): Tom is a proud Arizona native who went to the University of Arizona for his undergraduate education (Bear Down!) before moving out of the country and attending St. George’s University in Grenada for medical school. He returned to the U.S. for his clinical rotations and completed his pediatric residency at Rutgers NJMS in Newark, N.J. He is excited about being back on the West Coast with so many outdoor activities to do. He has a strong interest in long-term Fontan outcomes and is heavily involved with the National Pediatric Cardiology QI Collaborative and its efforts to improve the care for single ventricle patients.