Richard A. Clark, M.D.   Assistant Projessor of Medicine   Medical Director of The Cardiac Center at Columbus         Dr. Clark graduated with his medical degree from Creighton University and completed his Internal Medicine Residency and Cardiovascular Fellowship at Creighton, as well.  Dr. Clark is the medical director of The Cardiac Center at Columbus, a clinic that provides consultation to out-state physicians on an ongoing basis.  Dr. Clark is the first Creighton cardiologist to live and work in Columbus, Nebraska.  Dr. Clark is board certified in Internal Medicine and Cardiovascular Diseases and specializes in noninvasive cardiology.  He also has an interest in diagnostic cardiac catheterization.