Dr. Mark W. Sheehan returns to South Denver Cardiology Associates after originally joining the practice in 1981. Mark was born and raised in Staten Island, New York. He received his bachelors degree from Ohio State University with the distinctive of Cum Laude; he then received his medical degree from Baylor College of Medicine in Houston also being honored with the distinction of Cum Laude. He did his residency at Baylor Affiliated program in Houston, Texas and his fellowship in general and interventional cardiology at the University of Colorado School of Medicine in Denver. Awards include: Phi Beta Kappa, 1971; Alpha Omega Alpha, 1974; Hospital Affiliates Inc., Outstanding Graduating Senior Award, Baylor College of Medicine, 1974; Outstanding Young Men of America, 1982; American Heart Association-Denver Metro Division Medical Volunteer of the Year; Henry M. Porter Honoree-Porter Hospital Foundation; Named one of 5280 Magazine's Best Doctors. He is board certified in Interventional Cardiology and Internal Medicine.

Mark and his wife Linda have two grown children. Mark is a co-founder of the Christian Medical Ministry to Cambodia/Jeremiah's Hope where they bring medical services to the people of Cambodia. Mark currently leads numerous mission trips to Cambodia and has hopes of one day opening a hospital to serve the people of Cambodia.