Pediatric Cardiology Fellowship

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The Pediatric Cardiology Fellowship Training Program began at the University of Colorado School of Medicine (CU SOM) Department of Pediatrics and Children's Hospital Colorado in 1971. Children's Colorado is a freestanding children's hospital with a full affiliation with the University of Colorado School of Medicine for training pediatric residents and fellows. Children’s Hospital Colorado is a top 10 best children’s hospital in the country and the Heart Institute is consistently ranked within the top 15 best programs in the United States. We serve a diverse population from a large catchment area in addition to Colorado including Wyoming, Montana, North and South Dakota, Nebraska, Kansas, and New Mexico. The fellowship is fully accredited by the American Medical Association, the American Board of Pediatrics, and the Accreditation Council of Graduate Medical Education. The mission of our program is to prepare trainees for careers in academic pediatric cardiology. We accomplish this through a three-year program with substantial exposure to a broad spectrum of congenital and acquired heart defects and extensive time spent in active basic, clinical, translational research. We offer three categorical fellow positions a year with an additional 4th position every other year (Even-year start dates) for candidates who have completed a pediatric critical care fellowship.

We also offer a fourth year of advanced training in:

Please visit the section “Fourth-Year Fellowships of Advanced Training” located to the left of this webpage for more information.

Program Aims

  1. To prepare trainees to provide patient-centered, comprehensive cardiac inpatient and outpatient care for pediatric patients and families, with a focus on promoting patient safety and quality improvement and developing excellent communication skills.
  2. To provide outstanding opportunities in basic science, translational, clinical, educational research and quality improvement methodology that prepare fellows for successful careers in academic pediatrics.
  3. To provide outstanding opportunities in procedural learning in cardiac catheterization, echocardiography, electrophysiology, cardiac intensive care, and cardiothoracic surgery.
  4.  To teach trainees strategies to maintain wellness (of self and others), to build resilience, and to minimize burnout.
  5. To provide trainees with opportunities to individualize elements of their educational program in a way that allows them to explore diverse career options and that aligns with their career goals.
  6. To build and maintain an infrastructure to recruit diverse fellows and provide an inclusive learning environment that promotes and celebrates differences.


Clinical goals of our training program are to provide comprehensive training in all areas of pediatric cardiology practice. Fellows rotate primarily at Children’s Hospital Colorado, but will also spend time at University of Colorado Hospital and Denver Health Medical Center. Under the supervision of a large and diverse faculty, trainees gain exposure to patients with a broad spectrum of clinical problems. Learning from direct patient care is augmented by a comprehensive series of lectures focused on congenital and acquired cardiology. Additional seminars provide training in communication, ethics, and practice administration. Fellows receive ample opportunities to learn the common procedures employed in cardiology.

Scope of Clinical Training

Fellows in our program develop the clinical skills necessary to prepare them to competently and confidently manage the broad spectrum of conditions that fall within the practice of pediatric and adult congenital cardiology. The combination of three clinical sites, each with distinct patient populations, enhances the opportunities to become familiar with a broad range of ages and clinical problems.

Clinical Schedule

Each year is broken down into 13 four-week blocks. Night float primarily occurs during research blocks and consists of Monday-Thursday coverage. Weekend shifts are Saturday and Sunday days (two fellows covering the CICU) and one fellow covering the overnight shift (Friday-Sunday). There are four weeks of vacation all taken during research blocks.

Most clinical activity during fellowship occurs at Children’s Colorado with some time spent at the University of Colorado Hospital during the ACHD and EP blocks, and clinic at Denver Health Medical Center during the outpatient block (also a site for continuity clinic). Each trainee will spend 24 blocks total on clinical service with 15 blocks of research time. There is some flexibility in the apportionment of clinical blocks and modifications to the block schedule can be made on an individualized basis.

All trainees are assigned to a continuity clinic, scheduled for one afternoon per week. Fellows interested in a longitudinal follow-up experience with individual patients are encouraged to schedule those patients in their assigned clinic afternoons. Additionally, trainees are invited to participate in outreach community-based cardiology clinics throughout the state of Colorado as well as Wyoming.


1st-year 2nd-year 3rd-year
Cardiac Progressive Care Unit Consult Team Cardiac Progressive Care Unit
Consult Team Cardiac Intensive Care Unit Consult Team
Cardiac Intensive Care Unit Cardiac Catheterization Cardiac Catheterization
Cardiac Intensive Care Unit Echocardiography Echocardiography
Cardiac Catheterization Heart Failure/Transplant Electrophysiology
Echocardiography Outpatient Cardiology Elective
Echocardiography Adult Congenital Heart Disease Elective
Echocardiography Clinical Elective Research
Electrophysiology Research Research
Heart Failure/Transplant Research Research
Research Research Research
Research Research Research
Research Research Research


Patient Volume

Our Heart Institute is multi-state referral center and one of the large volume surgical centers in the United States. We have 55 pediatric cardiologists on faculty and 3 pediatric cardiothoracic surgeons. Our pediatric congenital heart surgeons perform over 675 surgical cases a year. We perform around 30 stage 1 palliations (Norwood operation) each year, which is one of highest volumes in the country. Our cardiac intensive care unit has 22 beds and has over 5,600 patient admission days each year. Our cardiac progressive care unit (step-down unit) is a 32-bed unit with over 7,500 patient admission days a year.  We are a regional cardiac transplant center and perform between 10-15 heart transplants a year. In addition, we implant between 5-10 ventricular assist devices per year averaging more than 400 patient VAD days a year.  We have a robust ECMO service and are an ELSO (Extracorporeal Life Support Organization) ECMO Center of Excellence Platinum Level.

There are approximately 1,000 pediatric cardiac catheterizations performed per calendar year in our Heart Institute as well as over 250 electrophysiology cases per year. We are a regional referral center for adult congenital heart disease and have over 2,400 ACHD outpatient visits each year as well as around 60 surgeries, 150 cardiac catheterizations, and 150 electrophysiology cases.  

There are approximately 21,000 outpatient clinic visits per year at Children's Hospital Colorado as well as at our network of care sites and outreach clinics. The network of care sites are located throughout the Denver metro area, and our outreach locations include northern, western, and southern Colorado as well as throughout the state of Wyoming.  More than 25,000 outpatient and inpatient echocardiograms are performed and interpreted annually at Children's Hospital Colorado.

Night Float Responsibilities

As with all aspects of clinical training, the program promotes progressive responsibility and increasing autonomy when covering overnight. All night float shifts during fellowship are in-house and include continuity care of cardiac inpatients, cardiac consultations, and imaging requests overnight. In addition, half of the weekday night float shifts and all weekend night shifts include coverage of the cardiac ICU (The other half of nights are covered by the pediatric cardiac critical care fellows). For weekdays that the cardiology fellow is covering the CICU there is advanced practice provider coverage of the cardiac step-down unit. The number of calls for first year a fellow is approximately 45, second year averages 35 calls, and third year fellows approximately 30. The cardiology fellow schedule is created by the incoming third year fellows and published in the spring prior to the new academic year.  


Four weeks of vacation is allowed per year per ACGME policy. Vacation time is taken during research blocks.


Research training is a major focus of the fellowship training program and fellows are provided substantial protected time throughout their fellowship to engage in rich research experiences. The research program is designed to provide comprehensive scholarly training that prepares all trainees with the background and skills to successfully compete for academic faculty positions and extramural funding at the completion of their fellowship. Although many cardiology fellows are mentored by a faculty member within the Division of Pediatric Cardiology, the program encourages fellows to consider a broad range of potential mentors. The program will assist in identifying potential mentors, both within the Department of Pediatrics and, when appropriate, from across the School of Medicine campus.

Opportunities and Resources

Research opportunities available to cardiology trainees are broad and varied. First year fellows are allotted four research blocks to explore various research opportunities early with the goal to start a project prior to completion of the first year of training. The Exercise Physiology Laboratory, Echocardiographic Laboratory, Electrophysiology Laboratory, Catheterization Laboratory, and Cardiac Intensive Care Unit within the Children's Hospital Colorado are all very well suited for clinical research. In addition to clinical research, there are many opportunities to pursue both translational and basic science research, and our division has several NIH-funded researchers. Research facilities are available throughout Children’s Hospital Colorado and the University of Colorado School of Medicine and include molecular biology laboratories, immunology laboratories, and perinatal research facilities among others.

Several categorical fellows have been successful in receiving funding for their research including grants from the Children's Hospital Colorado Research Institute, the Colorado Clinical Translational Sciences Institute (CCTSI), the NIH, and the American Heart Association.  Finally, we have several full-time research coordinators within the Heart Institute who are available to assist in coordinating patient recruitment and data collection.


During the first block of assigned research time, a trainee will typically meet with several potential mentors to discuss possible research projects and become familiar with different research programs. In the case of a basic science program, the fellow may “shadow” in individual labs in which they are interested. With the help of the Program Director, the goal is for the fellow to choose a mentor and research project by the end of their second research block. Once a research project is chosen, a timeline for research activity is developed by the mentor and the trainee. Broadly, the goal for research projects is for the fellow to have made sufficient progress that they can consider submission of an abstract to a national meeting by the end of their second year. In general, research time during the third year of fellowship should be spent finalizing the project with the ultimate goal for their scholarly work to be presented and a manuscript published.

Colorado Clinical Translational Sciences Institute (CCTSI)

The Colorado Clinical and Translational Sciences Institute is a collaborative enterprise between University of Colorado Denver, University of Colorado at Boulder, six affiliated hospitals and health care organizations, and multiple community organizations with resources to promote research and training that will advance health care and improve the public health. The CCTSI was established in 2008 with funding from the Clinical and Translational Science Award (CTSA) initiative of the National Institutes of Health (NIH). Through the CCTSI, Clinical Translational Research Centers (CTRCs) have been established at several affiliated hospitals, including The Children’s Hospital, University of Colorado Hospital, and Denver Health Medical Center. The CTRCs support research with clinical inpatient and outpatient space, inpatient research beds, nursing and research staff support, and core laboratory and nutrition services. To access CTRC resources, investigators submit a clinical protocol for review by the Scientific Advisory and Review Committee (SARC). The SARC review process gives investigators experience that may improve future COMIRB (Colorado Multiple Institutional Review Board) and grant applications. The CTRC also offers biostatistical collaboration/consultation for study design, including sample size and power calculations, data analysis, and manuscript preparation. To fulfill its mission to train future researchers, the CCTSI offers ongoing comprehensive educational programs in several areas, including Informatics, Biomedical Ethics, Biostatistics, and Study Design. Biostatisticians are also available for consultation on individual research projects through the Colorado Biostatistics Consortium (CBC). For more information, please see

Scholarship Oversight Committees

Each fellow is assigned a Scholarly Oversight Committee (SOC), composed of at least 3 faculty members. The SOC meets every six months to evaluate the fellow’s scholarly progress and to help provide support and direction. At the end of training, the SOC is responsible for determining whether the fellow’s work has met the American Board of Pediatrics requirement for sub-board eligibility.

Fellowship Educational Conferences

There are daily afternoon lectures (Monday, Wednesday, and Thursday) at 4 pm with the first two months dedicated to our core lecture series (Monday-Friday). Lectures are given by various faculty members and are dedicated to various sub-specialty topics including cardiac catheterization, electrophysiology, imaging, heart failure/transplant, exercise physiology, and outpatient cardiology topics. In addition, the weekly cardiac ICU lecture series occurs on Wednesdays at noon. The Heart Institute’s lecture series occurs on Tuesday afternoon at 4 pm and includes Morbidity and Mortality, Quality Improvement and Outcomes, and other division-wide lectures.

Surgical Case Conference

A weekly pediatric cardiac surgery case conference is held at Children's Hospital Colorado on Friday mornings at 7:30 am. Surgical cases for the upcoming week are presented as well as several discussion cases. The cases are prepared and presented by the cardiology fellows with active input from both cardiac surgery and pediatric cardiology faculty. In addition to the clinical case, relevant imaging studies and cardiac catheterization data are presented and reviewed. Each week, the cardiology fellow presenting is paired with a faculty member who is available for questions and review prior to Friday morning.

Book and Journal Club

Weekly Book Club occurs on Thursdays and is run by the cardiology fellows. Different chapters from Moss and Adams are divided among the fellows at the beginning of the year. A faculty mentor is assigned for each chapter and available for discussion and questions for the fellow preparing the chapter. In addition to book club, several sub-specialties have journal clubs throughout the year often discussed outside of working hours at a faculty’s home.  These are excellent opportunities for the fellows to meet with the staff on an informal basis to discuss pediatric cardiology topics.

Board Review

Board review sessions organized by faculty members occur every 6-8 weeks. These sessions focus on high-yield content and utilize an audience response system with board style questions.

Department of Pediatrics Educational Series

This educational series was developed to address areas of scholarly interest common to all pediatric core fellowships. Fellows attend 5-6 half-day seminars spread across their 3 years of fellowship. Attendance is mandatory and the trainee is excused from clinical responsibilities. In addition to providing core educational material, these sessions allow trainees in different disciplines throughout the department to meet and interact with one another in an informal and collegial environment.

Topics for this curriculum: Pediatric Fellowship Educational Series


Formal introductory instruction in biostatistics is give during the second year of fellowship through a 6-session, 12-hour biostatistics course that is taught by a PhD biostatistician. In addition, fellows have access (in-person or online) to regular biostatistics seminars which are provided by the CCTSI. Trainees who undertake advanced graduate coursework with a biostatistics component (Masters in Public Health or Masters in Clinical Science) may be exempt from the introductory course.

Additional Opportunities

Although not required for completion of the fellowship, some trainees pursue additional graduate coursework during their fellowship. The University of Colorado School of Public Health, which is on the Anschutz Medical Campus, offers a Masters of Public Health. The University of Colorado Denver Graduate School offers a graduate program in clinical science, which awards a Masters of Science in Clinical Science (MSCS). This program provides training in clinical sciences through theoretical and methodological coursework and its application to an individual research project. Funding for additional graduate coursework is not guaranteed, but may be available on an individual basis.

National Meetings

Cardiology fellows are encouraged to attend regional and national scientific meetings throughout their fellowship. Meetings commonly attended by cardiology fellows include American Heart Association, American College of Cardiology, American Society of Echocardiography, International Society for Heart and Lung Transplantation, Pediatric Cardiac Intensive Care Society, and the Western Society of Pediatric Cardiology (WSOPC). To support academic development, the section supports attendance to national meetings for 2nd and 3rd year fellows. Fellows are encouraged to submit at least one abstract per year. In addition, the section supports travel to any national meeting for which the trainee has an abstract accepted.

The University of Colorado’s School of Medicine, the Children’s Hospital Colorado, and the Heart Institute believe that diversity is a value that is central to their educational, research, service and health care missions. We are committed to working towards equity and justice for all. With this goal in mind, the Heart Institute created a Diversity, Health Equity, and Inclusion workface that includes over 40 members and represents every discipline within the H.I. including fellows, faculty, nursing, pharmacy, and research staff. The workforce has 7 subcommittees, including:

  • DHEI data focused on patient outcome reporting/transparency and equitable research
  • DHEI Quality Improvement
  • DHEI awareness and education
  • Underrepresented minority faculty, fellow, and staff recruitment and retention
  • DHEI Family Advisory Council
  • Community engagement, outreach, and legislative action
  • University of Colorado-School of Medicine and Children’s Hospital Colorado liaison and dissemination of information

The vision of the Heart Institute DHEI Taskwork is as follows:

  1. To create actionable changes that will reduce health outcome disparities and remove barriers to equitable care
  2. To build a workforce representative of the community we serve
  3. The ensure a diverse, equitable, and inclusive approach to H.I. research
  4. To provide education and training to our division aimed at increasing cultural competency and awareness of health disparities in the congenital and acquired heart disease population
  5. To celebrate diversity and promote an inclusive environment for patients, their families, and team members with the H.I.

Diversity in Denver

Training at the University of Colorado provides the opportunity to care for an incredibly diverse population of patients and families. As the regional referral center for the Mountain West, Children’s Hospital Colorado and the Heart Institute regularly serves children from urban and rural areas in multiple states including Colorado, Wyoming, Montana, New Mexico, Nebraska, Kansas, and North and South Dakota.

The Denver Metro Area is home to a diverse and vibrant array of people from all racial, ethnic, socioeconomic, religious, and cultural backgrounds. Denver is one of the fastest-growing cities in the United States with a city population of over 700,000 and over 3 million in the metropolitan area. Approximately 1 in 6 Denver residents was born in a country other than the United States and over 40% of children in Denver speak a language other than English at home. The population of Denver is approximately 1% Native American, 5% Asian, 12% Black, 50% non-Hispanic White, and 32% Hispanic/Latinx. In the three-zip-code region surrounding the Children’s Hospital Colorado, 77% of residents belong to racial and ethnic minorities. In addition, Denver ranks among the top 10 cities in the United States for the highest proportion of residents who identify as LGBT.

University of Colorado and Children’s Hospital Colorado DEI Resources:

The CU Anschutz LGBTQ+ Hub

Repurposes the Women and Gender Center formerly at CU Anschutz.  On this website you will find information about services and resources provided by the LGBTQ+ Hub. 

You can also visit us in our physical space (shared with the Oasis Space) Mondays, Wednesdays, and Fridays, located on the second floor of the Education 2 North Building, room 2101.

Here is the website link: 

1st Year Fellows


Hannah Hollon, MD

  • Medical School: Medical University of South Carolina
  • Residency: Children's Hospital of Richmond at VCU
  • Email:

Why did you decide to pursue pediatric cardiology?

I always wanted to go into cardiology but fell in love with pediatric cardiac physiology in medical school and quickly learned that I love working with kids. I have a special interest in pediatric obesity prevention and treatment and completed a pediatric obesity medicine fellowship at the Children's Hospital of Richmond and plan to ultimately specialize in preventive cardiology.

Why did you choose to train at Children’s Hospital Colorado?

I'm not sure yet, but I am looking forward to working with an incredible group of people, including leaders in the preventive cardiology field!

What are your hobbies and what do you like to do in your spare time?

I love to do anything outside. I own 3 bikes and keep adding to the collection for commuting, cycling, and mountain biking. I also love running, hiking, camping, wildflower hunting, gardening, and cooking. I am really looking forward to finding new wildflowers in Colorado!



Umakanthan Kavin, MD 

  • Medical School: Charles E. Schmidt College of Medicine at Florida Atlantic University
  • Residency: Internal Medicine/Pediatrics at the Medical University of South Carolina
  • Email:

Why did you go into pediatric cardiology?

The advancements made in the field of pediatric cardiology have been so impressive. Patients are provided better treatments and interventions, affording them an increasingly higher quality of life, which is incredibly gratifying to us as providers. Each individual patient's congenital heart disease is unique, and I love being a part of the multi-disciplinary, team-based approach to determine the best solution for each particular case. Lastly, the relationships you establish with patients and their families are so special and can be lifelong. 

Why did you choose to train at Children’s Hospital Colorado?

It was clearly evident on interview day that not only was I going to be a part of an excellent Heart Institute, but that I was also going to be working with a supportive faculty that was passionate about fellow education and that would push me to become the best cardiologist I could be.

What are your hobbies, and what do you do in your spare time?

I love all things basketball, exploring new restaurants, and finding the best places for trivia night!



Aidan Reid, MD

  • Medical School: Rocky Vista University
  • Residency: Medical College of Wisconsin
  • Email:

Why did you go into pediatric cardiology? 

I fell in love with pediatric cardiology because of the ability to take care of infants and children across a broad range of acuities and clinical settings. The complex anatomy and physiology are fascinating and truly lead to caring for each patient as an individual. No two cases of congenital heart disease are identical, nor are the needs of two different patients or their families. Providing care with an emphasis on addressing unique needs is one of my favorite aspects of the field. 

Why did you choose to train at Children’s Hospital Colorado? 

There are so many reasons I chose to train at Children's Hospital of Colorado but some of the standouts are the focus on fellow education/professional development and the down to earth nature of the faculty I met with. Everyone is so dedicated to helping fellows achieve their personal goals in the setting of a high-volume program with a huge catchment area and complex patient population that provides an outstanding base for all fields of cardiology. 

What are your hobbies, and what do you do in your spare time?

My ever-growing list of hobbies includes mountain biking, skiing, golfing, fly fishing, backpacking and hiking with our dog, cheering on the Brisbane Lions, and searching for the perfect beer garden.


 2nd Year Fellows


Nadia Chaudhry-Waterman, DO

  • Medical School: Edward Via College of Osteopathic Medicine-Virginia Campus
  • Residency: Inova Children's Hospital's Pediatric Residency 
  • Email: Nadia.Chaudhry-Waterman

Why did you go into pediatric cardiology?

I chose to go into pediatric cardiology because of the diverse pathology we treat and because of the team-based environment in which we work. No matter what field within cardiology you choose to specialize in, you are never working alone. A heart center is comprised of surgeons, interventionalists, electrophysiologists, intensivists, and general cardiologists, all working together for the good of their patients. I love working in a team environment and that really drew me to this specialty. 

What are the best parts of training as a cardiology fellow at Children’s Hospital Colorado?

The best part about training at Children’s Hospital of Colorado has definitely been the people! All of my co-fellows and attendings have been so welcoming and willing to help as I adjust to working and learning within a new system. The diverse pathology we get to see and the patients who travel from far away places to be treated here is also a huge learning opportunity and I know I will be learning enough in the next 3 years to become a more than competent and confident pediatric cardiologist. 

What are your hobbies and what do you like to do in your spare time ?

These days I am loving taking day trips to the mountains, hiking, and exploring new restaurants in the Denver area! I just moved here from the east coast, so having a new place to explore has been a great! I also enjoy running in City Park after work.



Kelsey Guerins Iguidbashian, MD

  • Medical School: Creighton University School of Medicine
  • Residency: University of Colorado Pediatric Residency 
  • Email: Kelsey.Iguidbashian

Why did you go into pediatric cardiology?

Growing up with a grandfather that was a pediatric cardiologist definitely gave me an early introduction and interest in the field. I enjoy cardiology because of the interesting physiology, the incredible progress that is constantly being made in the field, and the long-term relationships built with families both in and outside of the hospital. Within cardiology, I currently have an interest in preventative/exercise rehab.

What are the best parts of training as a cardiology fellow at Children’s Hospital Colorado?

As a resident here at Colorado, I was able to see how friendly, approachable and education-focused so many of our Heart Institute faculty and fellows are, which was a major part of wanting to stay for fellowship. The program is high-volume and has a large catchment area, serving children from all over and allowing us to see a wide array of pathology. It doesn't hurt to train in a city where it is sunny year-round with the mountains nearby!

What are your hobbies and what do you like to do in your spare time ?

Outside of the hospital, I enjoy spending time with my husband, John, doing anything outdoors, running/walking in many of Denver's great parks, skiing, brewery hopping, cheering on the Gonzaga bulldogs (Go Zags!) and watching sunset from Rockies’ games. 



Benjamin A. Olsen, MD

  • Medical School: Creighton University School of Medicine
  • Residency: University of Colorado Pediatric Residency 
  • Email: Benjamin.Olsen

Why did you go into pediatric cardiology?

Trying to understand and then treat the complex pathophysiology in cardiology is an exhilarating experience. Pediatric cardiology then adds a whole new level of complexity and variability. I chose pediatrics in general because I feel my greatest sense of fulfillment and purpose when working with this patient population and their families.

What are the best parts of training as a cardiology fellow at Children’s Hospital Colorado?

This program has the right amount of patient volume and variety with a balance of very complex and some more typical cardiac pathologies. This institution also attracts down-to-earth individuals that create a safe learning environment. Lastly, the family culture within the fellowship program made me feel as if I would always be supported.

What are your hobbies and what do you like to do in your spare time?

All things soccer! Also, running, hiking, mountain biking, and skiing. I also enjoy trying my hand at brewing and cocktail mixing. And of course, spending time with my wife, daughter, and dog is most important.



Lauren M. Zager, MD

  • Medical School: University of Wisconsin School of Medicine
  • Residency: University of Utah Pediatric Residency 
  • Fellowship: Michigan (pediatric critical care)
  • Email: Lauren.Zager 

Why did you go into pediatric cardiology?

I went into pediatric cardiology because I enjoy the long term relationships we are able to make with patients and families and I am fascinated by manipulating different physiologies at bedside in the cardiac ICU

What are the best parts of training as a cardiology fellow at Children’s Hospital Colorado?

Some of the best things about training at Children’s Hospital Colorado are the great co-fellows, supportive attendings and vast patient catchment area.

What are your hobbies and what do you like to do in your spare time?

Outside of work I enjoy hiking with my dog, cooking, exploring all the breweries and restaurants Denver has to offer, and cheering on the Green Bay Packers!


3rd Year Fellows


Samantha Ann Kops, MD

  • Medical School: University of Arizona College of Medicine 
  • Residency: University of Arizona College of Medicine
  • Email: Samantha.Kops

Why did you go into pediatric cardiology?

I went into pediatric cardiology because I love the anatomy and physiology of this patient population. This field is always evolving and every patient requires an individualized approach.

What are the best parts of training as a cardiology fellow at Children’s Hospital Colorado?

The best part about training at Children's Hospital of Colorado is the great people we get to work with. Everybody is dedicated to teaching, and it has been a great place to train.

What are your hobbies and what do you like to do in your spare time?

I really enjoy spending time with my dogs and husband. I love being outdoors and going hiking and exploring all the great things Denver has to offer!



Jeffrey Michael Shuler, MD

  • Medical School: University of Missouri School of Medicine
  • Residency: Cincinnati Children's Hospital
  • Email: Jeffrey.Shuler

Why did you go into pediatric cardiology?

The thing that drew me most to pediatric cardiology was not only the intellectual challenge of understanding congenital heart disease, but also the challenge of then being able to effectively teach families and guide them through the management of difficult and complex diagnoses. Helping a parent finally achieve a sense of true understanding about something that was initially only terrifying and confusing is an incredibly rewarding part of this job.

What are the best parts of training as a cardiology fellow at Children’s Hospital Colorado?

Training at Children’s Hospital Colorado is fantastic for many reasons, but one particular highlight is getting to work with all the amazing people here in the Heart Institute. Every member of this gigantic multidisciplinary team plays an incredibly important role, and there is a strong sense of comradery and commitment to learning that permeates the whole community.

What are your hobbies and what do you like to do in your spare time?

I love to spend my spare time exploring all the best parts of Colorado with my wife, my two-year-old son, and our three other furry animal children. We love to explore all the outdoor activities, great food, and fantastic weather that this amazing part of the country has to offer.



Charles Thomas Simpkin, DO

  • Medical School: Rocky Vista University of Osteopathic Medicine
  • Residency: University of Colorado Pediatric Residency
  • Email: Charles.Simpkin

Why did you go into pediatric cardiology?

For me, pediatric cardiology combines everything that made me interested in medicine in the first place. Being able to think about complex anatomy and physiology to take care of patients from infancy through adulthood helps keep every day interesting and makes me excited to go to work in the morning.

What are the best parts of training as a cardiology fellow at Children’s Hospital Colorado?

There are so many great things about training here - but one that I have really appreciated is the focus on fellow education. Between our almost daily scheduled lectures from experts in their field, to teaching on-the-fly during the day - there is no shortage of learning opportunities for fellows.

What are your hobbies and what do you like to do in your spare time?

I love to do all the usual "Colorado things" like hiking, fly-fishing, and complaining about traffic on I-70 - but my favorite thing to do is to go paddle-boarding with my wife and our dog Finn (check out @rockymtnfinn on instagram for pictures of a corgi in a lifejacket!)

4th Year Fellows Advanced Pediatric Cardiology Fellows


Shannon Murray, MD - : Adult Congenital Heart Disease

  • Medical School: University of Wisconsin School of Medicine and Public Health
  • Residency: Medical College of Wisconsin and Affiliated Hospitals
  • Email: Shannon.Murray

Why did you go into pediatric cardiology?

I enjoy working in cardiology because abstract or complicated concepts like “heart failure” can be described with pictures and broken down into logical problems: a series of causes and effects. As such, cardiac pathology lends itself to being explained and demystified, and I really enjoy connecting with patients and their families by helping them better understand the problems at hand and the corresponding solutions.

What are the best parts of training as a cardiology fellow at Children’s Hospital Colorado?

I feel fortunate to be training at a program with a large catchment area that allows us to see “rare” pathology which is actually quite common around here. I’m also glad we commonly see and manage adults with congenital heart disease in our children’s hospital as well.

What are your hobbies and what do you like to do in your spare time?

In my free time I play club ultimate frisbee, hike, bike, cook, and hang out with family and friends.



Senta Furman, MD – Cardiac Intensive Care

  • Medical School: University of Illinois
  • Residency: St. Louis Children’s Hospital
  • Cardiology Fellowship: Seattle Children’s
  • Email: TBD 

Hello! My name is Senta, and I am joining CHCO as a cardiac critical care fellow this year. I completed all of graduate school in Chicago, followed by pediatrics residency at St. Louis Children's Hospital, cardiology fellowship at Seattle Children's Hospital, and nearly two years as a hospitalist in the CICU at Children's Hospital of Philadelphia. Now it's time to finish my training in a mountain state! Outside of work in Philly, I play piano, practice kundalini yoga (I am a certified instructor), cook lots of veggies, and I'm learning to bonsai. In Denver, I plan to revisit the activities I grew up with, including horseback riding, hiking, skiing, and more veggie cooking. I'm also excited to discover many new adventures, as time allows. Last, I should mention that my research interests are centered on the autonomic nervous system, its regulation of cardiorespiratory rhythms in development and trauma, and its role in predictive analytics. If anyone would like to collaborate, please let me know!



Connor Merritt, MD – Cardiac Intensive Care

  • Medical School: Creighton University School of Medicine
  • Residency: Cincinnati Children’s
  • Critical Care Fellowship: Cincinnati Children’s
  • Email: Conor.Merritt

Why did you pursue pediatric cardiology?

I am drawn to cardiac physiology, which feels elegant in its simplicity. Despite its simplicity a failing cardiac system is some of the most challenging physiology to manage at the bedside. I am drawn to that complex interplay of failing cardiac physiology and its impact on the rest of the body. While I truly love pediatric critical care, I find myself wanting to care for the most critically ill patients, particularly those with severe heart disease. I am particularly interested in the ability to follow a patients changing cardiac physiology, the multi-organ system effects, and the longitudinal relationships that can be formed with families and staff through the care of a patients within the CICU.

What made you decide to come to Children's Hospital for your advanced fellowship?

I have been fortunate to see firsthand the incredible training that Colorado Children’s Hospital CICU trained physicians like Katja Gist and Adam Carlisle have received, and importantly the care they are able to provide for the most critically ill patients. I aspire to be able to care for and teach complex cardiac physiology to a similar caliber as they do. Most importantly I decided to continue my training here at Colorado Children's Hospital in order to learn from the excellent clinicians, providers and educators that are a part of the cardiac institute.

What are your hobbies and what do you like to do in your spare time?

In my free time I like to spend time with friends and family. I like to do anything outdoors, traveling, biking, hiking, and rafting. Or finding a new world to immerse myself in, either through a new book or a new movie/tv show.



Natalie Soszyn, MD - Interventional Cardiology

  • Medical School: University of Melbourne
  • Residency: Royal Children’s Hospital, Melbourne, Australia
  • Cardiology Fellowship: Royal Children’s Hospital, Melbourne, Australia and Starship Children’s Hospital, Auckland, New Zealand
  • Emial: Natalie.Soszyn

I am one of the two cath fellows. I was inspired to train in pediatric cardiology after doing research with the team in Melbourne looking at antenatal diagnosis rates of children with CHD when I was a medical student. I really enjoyed the diversity of patients you see in pediatric cardiology from very well to very unwell. Additionally, I still find anatomy and physiology of congenital heart disease fascinating.  I haven’t been here long but I think the best parts of training in Colorado as a fellow is the people – everyone is friendly and approachable and keen to teach. Hobbies – when I do have spare time – I am an avid tennis player and enjoy sailing (if I get the time). As a true Australian, the beach is my second home and I love to try to get there as much as I can.



Ernesto Mejia, MD - Interventional Cardiology

  • Medical School: Foreign Medical Graduate
  • Residency: SUNY Downstate, Brooklyn
  • Cardiology Fellowship: Rainbow Babies and Children’s Hospital
  • Email: Ernesto.Mejia

Ernesto is originally from Cali, Colombia. He completed his pediatric residency at SUNY Downstate in Brooklyn, NY before completing his pediatric cardiology fellowship at Rainbow Babies and Children’s Hospital in Cleveland, OH. Ernesto’s wife, Maria, is also at Children’s undergoing a fellowship in pediatric bone marrow transplant. They come to Denver with their daughter Valentina and two dogs, Doc and Blu. They love spending time outdoors, going for long hikes and walks, and especially watching soccer on the weekends.



Nick Holzemer, MD - Adult Congenital Heart Disease

  • Medical School: University of Minnesota
  • Residency: Michigan (Medicine-Pediatrics)
  • Cardiology Fellowship: Children’s Hospital Colorado
  • Email: Nicholas.Holzemer

I completed my Med-Peds training at University of Michigan, recently finished pediatric cardiology fellowship at CHCO. I’m very excited to join the ACHD team. My wife, Jena, and I enjoy taking our 1-year-old daughter, Quinn, on adventures around town and in the mountains. In my free time I also like to do all the stereotypical CO activities, hiking, skiing, biking, brewing beer, and playing with our two dogs, Frank and Ruth.



Jason Cole, MD

  • Medical School: University of Nebraska Medical Center
  • Residency: Nationwide Children’s Hospital  
  • Cardiology Fellowship: Nationwide Children’s Hospital
  • Email: Jason.Cole

Why did you pursue pediatric cardiology?

I was always interested in cardiac anatomy and physiology before entering medical school. After completing my pediatric cardiology rotation during the 3rd year of medical school education I knew that I had found a specialty that matched my interest of complex cardiac pathology and working with children and their families. In pediatric cardiology you also build lifelong relationships with patients and their families and have the privilege of walking alongside your patients through some of the most difficult moments imaginable. In my mind the paramount example of this is heart failure and transplant when you get to treat some of the sickest patients and see them thrive.  

What made you decide to come to Children's Hospital for your advanced fellowship?

In addition to being one of the top heart centers in the country, the heart failure and transplant program here in Colorado is one of the most established programs in the country. They are a large volume transplant center and have a long history of excellent outcomes in transplant and mechanical circulatory support. The exposure to such a large volume of patients coupled with tremendous faculty mentorship and education provides exceptional training in heart failure and transplant. I feel very fortunate gain my advance training and be a part of the team here in Colorado  

What are your hobbies and what do you like to do in your spare time?

In my spare time you will likely find me with my wife and three kids either skiing, hiking, riding bikes, or at one of our kids many sporting events. I’m an avid Nebraska Cornhusker and Denver Broncos fan and enjoy cheering them on during fall weekends. Otherwise, I enjoy cooking, grilling and trying new food at the many great restaurants here in Denver.  



Krista Young – Advanced Imaging

  • Medical School: UT San Antonio
  • Residency: University of Arizona
  • Pediatric Cardiology Fellowship: University of Iowa
  • Email: Krista.Young

Why did you pursue pediatric cardiology?

I observed my first fetal heart visit as a fourth-year medical student.  Cardiac anatomy/physiology was intriguing, but the counseling and forming of the intense doctor-family relationship before the fetus was born to me was beautiful. 


What made you decide to come to Children's Hospital for your advanced fellowship?

Initially, I was interested in Children’s because I had heard wonderful things about their fetal program. During the interview I learned more about Children’s fetal outreach with telemedicine and opportunities to work with underserved rural areas, even in neighboring states. I had also watched a few presentations given by Children’s on their fetal MRIs and was very interested. Meeting everyone during the interview and seeing how nice they were sealed the deal.


What are your hobbies and what do you like to do in your spare time?

I enjoy spending time outdoors (hiking, biking, and skiing) with my husband and 2 dogs, listening to live music, and trying new foods.

Card apply

The Application Process

Our pediatric fellowships will be conducting virtual interviews for this upcoming interview season.  We will be interviewing to fill four categorical fellowship spots for the 2024 academic year. We look forward to sharing our programs with you and getting to know more about you.  We will send interview offers out mid-August as well as a list of interview dates in September, October, and early November. These will be filled on a first-come, first-serve basis.

If you have questions about the application process, please feel free to reach out to our program coordinator! (Amanda Keith: )

We particularly hope to attract applicants who are motivated and self-directed learners who want to develop academic careers based on excellence in research, scholarship, and clinical pediatric and adult congenital cardiology. To be considered for admission to our program, applicants must have successfully completed training in a 3-year ACGME-accredited residency program in Pediatrics. The Pediatric Cardiology Fellowship utilizes ERAS -  Electronic Residency Application Service (ERAS).

We participate in the National Residency Matching Program (NRMP)  and do not offer any positions outside of the match. The application should include a copy of your curriculum vitae, at least 3 letters of reference (maximal of 4), a personal statement highlighting why you wish to become a pediatric cardiologist, and your USMLE or COMLEX score reports. In addition, please have your letter writers fill out the Pediatric Cardiology Fellowship Evaluation Form and attach it to the end of their letter of recommendation. If you are not a US citizen, include a copy of your ECFMG report with ERAS. Please bear in mind that you would need to acquire a J1 visa if selected as a candidate for our program. Incomplete or late applications will not be considered. It is your responsibility to ensure all required information has been received.


ERAS Application Timeline

Monday, May 31, 2024ERAS 2024 season ends at 5 p.m. ET.
Wednesday, June 5, 2024ERAS 2025 season begins at 9 a.m. ET.
Thursday, June 5, 2024EFDO will release tokens to fellowship applicants.
Wednesday, July 3, 2024July cycle fellowship applicants may begin submitting applications to programs at 9 a.m. ET.
Wednesday, July 17, 2024July cycle fellowship programs may begin reviewing applications at 9 a.m. ET.
May 31, 2025    ERAS 2023 season ends at 5 p.m. ET.


NRMP Fall Match Timeline

Dates Activity
Wednesday, August 21, 2024Match Opens 
Wednesday, September 25, 2024Ranking Opens
Wednesday, November 6, 2024Quota Change Deadline
Wednesday, November 20, 2024Rank Order List Certification Deadline
Wednesday, December 4, 2024MATCH DAY


Salary and Benefits

The University of Colorado offers salary and benefits packages that are competitive with other fellowship programs across the country. Current salary levels can be found at the School of Medicine - Graduate Medical Education Stipends.


The Mile High City is nestled at the eastern base of the Rocky Mountains and is the largest city in the region with a population of over 2.7 million. Denver enjoys one of the best climates in the country, with 300 days/year of sunny skies. Although it snows in the winter, the snow melts quickly and temperatures are usually moderate. Hot summer days give way to cool summer evenings. The city is the home to dozens of highly rated restaurants and a vibrant nightlife. The city attracts many outdoor enthusiasts with its extensive system of hiking and bike trails and the largest city park system in the country. The Denver Center for the Performing Arts is the largest performing arts complex under one roof in the country and attracts many of the top national theater tours each year. Red Rocks Amphitheater, a natural amphitheater in the foothills west of town, attracts the nation’s top touring musical talent throughout the summer.

Denver is home to the Denver Broncos (NFL), the Denver Nuggets (NBA), the Colorado Rockies (MLB), the Colorado Avalanche (NHL), the Colorado Rapids (MLS) and the Colorado Outlaws (MLL). The University of Colorado, the state flagship school and a world-class educational institution, is based in nearby Boulder. In addition, Denver is the gateway to the Rocky Mountains, which offer abundant recreational and sightseeing opportunities year round. The state of Colorado is home to over 20 major ski areas, many of which are within 2 hours of the city.

Virtual Interviews

In accordance with the University of Colorado Anschutz Medical Campus, we will be conducting our 2023 interviews virtually over zoom. We are so excited to meet you (virtually!) and help you get to know our program. Below you will find the schedule for your interview day. In addition, we hope you will be able to attend one of the virtual “happy hours” with the fellows to learn more about our program and fellows in a more informal setting. (You will receive a separate email from the fellows about this)

Virtual Interview schedule:

9:00-9:45 am Program overview with Dr. Scahill & Dr. SooHoo
9:45-9:55 am Break
10:00-11:35 am
10:00-10:20 am
10:25-10:45 am
10:50-11:10 am
11:15-11:35 am
Four 20-minute interviews with faculty
11:35-12:15 pm Lunch break
12:15-1:00 pm
12:15-12:35 pm
12:40-1:00 pm
Two 20-minute break-out sessions with the fellows
1:00-1:10 pm Break
1:10-2:45 pm
1:10-1:30 pm
1:35-1:55 pm
2:00-2:20 pm
2:25-2:45 pm
Four 20-minute interviews with faculty
2:45-3:00 pm Closing remarks


We hope our interview day is comprehensive and displays the expertise and scope of our Heart Institute, emphasizes our excellent faculty and fellows, and highlights the facets of our training program that are unique to Colorado. We are very proud of the quality of our fellowship program and fellows that we train - and we hope it shows! If you have further questions that arise after your interview day or are curious about specific opportunities at our program – please reach out to Carly, Megan, or Amanda! Our intent is to match well-suited candidates and provide exceptional training with the goal to graduate future leaders in pediatric cardiology. Good luck this interview season!

Additional Questions

Please contact with questions:

Amanda Keith, Fellowship Program Coordinator at (720)-777-2940 or

Carly Scahill, Program Director:

Megan SooHoo, Associate Program Director:

Well-Being / Resilience

Be well

By embracing wellness and improving personal resiliency, physicians can reconnect with the meaning of their work and fend off stress. Reducing or eliminating burnout also has practical implications for the entire department such as improving patient safety, student advancement, and the overall campus environment. 

Visit our Pediatric Well-Being and Resilience website...

Diversity / Equity / Inclusion


We are committed to creating a diverse environment for students, residents, fellows, and faculty. We believe that an environment of inclusiveness and respect promotes excellence and that a setting where diversity is valued leads to the training of physicians who are prepared to practice culturally effective medicine and meet the needs of the various populations we serve. Visit our Diversity, Equity, and Inclusion webpage for more....

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