Dr. Marshall specializes in outpatient evaluation and management of infants, children and adolescents with all forms of heart disease or suspected heart disease. He is actively involved in the inpatient management of children with cardiac disease at several hospitals in the San Antonio area, focusing on the perioperative management of children with structural heart disease. Dr. Marshall is passionate about exercise physiology and performs and interprets the cardiopulmonary exercise tests at Methodist Children’s Hospital.

He joined Pediatrix® Cardiology of San Antonio in 2021 and is a member of the Texas Medical Association.

Dr. Marshall was born in Anchorage, Alaska, but quickly found his way to Texas and grew up in the suburbs of Houston. He graduated summa cum laude from Texas A&M University with a bachelor of science degree in biomedical science. He returned to Houston to complete medical school at Baylor College of Medicine. After medical school, he moved to the Midwest for his postgraduate training, completing his pediatric residency at Cincinnati Children’s Hospital, followed by a pediatric cardiology fellowship at the University of Michigan.

Dr. Marshall enjoys travel, movies, exploring San Antonio and the Hill Country with his dog Cooper (his cat is not a fan of exploration). He is a proud Texas A&M alumnus and football season ticket holder.


In-person appointments are not available with all clinicians at every location.

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