Nicolas Leth Madsen, MD $$

Pediatric Cardiologist

Associate Professor at UT Southwestern Medical Center

Languages Spoken:


UT Southwestern Pediatric Group


Nicolas Madsen, M.D., is the Co-Director of The Heart Center and Chief of Cardiology at Children’s Health℠. He is also an Associate Professor of Cardiology at UT Southwestern. As a pediatric cardiologist, he cares for children who have congenital and acquired heart conditions and adult patients who have congenital heart disease. 

He earned his medical degree at University of Washington School of Medicine, where he also completed his residency training in pediatrics and his fellowship training in pediatric cardiology. Prior to his arrival at Children’s Health, Dr. Madsen was the Medical Director of the Heart Institute at Cincinnati Children’s Hospital.

I can think of no greater profession than pediatric cardiology.
Dr. Madsen

“I can think of no greater profession than pediatric cardiology. The opportunities for positive and lasting impact are evident everywhere and across the lifespan. It is a privilege to provide the most advanced clinical care for the benefit of newborns with congenital heart disease. It is inspiring to assist patients and families as they navigate the complex journey from child to adult. It is with deep gratitude that I recognize the privilege of being a pediatric cardiologist.”

Dr. Madsen is a nationally recognized leader and researcher who works to improve the quality of life for children with congenital heart disease. He co-founded the Pediatric Acute Care Cardiology Collaborative (PAC3) and serves as Executive Director. The goal of this organization is to help children hospitalized with heart conditions achieve better outcomes through traditional research and quality improvement science. His dedication to children’s heart health has previously earned him the Heart Hero Award from the advocacy group Conquering Congenital Heart Disease and the Clinical Care Award from Cincinnati Children’s Hospital.

Dr. Madsen enjoys spending time with his family, discovering new trails, and searching for the world’s best breakfast burrito. In addition to English, he speaks Danish.

Education and Training

Medical School
University of Washington School of Medicine (2005)
University of Washington (2008), Pediatrics
University of Washington (2012), Pediatric Cardiology
Graduate School
University of Washington School of Public Health (2011)
Board Certification
American Board of Pediatrics/Pediatric Cardiology

Departments and Programs