In 1972, Tajik was appointed as a consultant in Cardiovascular Diseases at
Mayo Clinic. Between 1980 and 1992, he served as the Director of the Echocardiography Laboratory, and, from 1993 to 2002, he was Chairman of the Cardiovascular Division. In 2010, he joined
Aurora Health Care. He was later President of Cardiovascular Services at
Aurora St. Luke's Medical Center. In addition to clinical work, Tajik teaches at Mayo's cardiovascular center and has won multiple teaching and mentorship awards. His research focuses include adult
congenital heart disease,
hypertrophic cardiomyopathy,
valvular heart disease,
Marfan syndrome, aortopathies,
pericardial disorders, and
diastolic heart failure. He has written more than 600 articles and book chapters, and has co-authored seven books. He is a member of the
American Heart Association (AHA),
American College of Cardiology (ACC), American Society of Electrocardiography (ASE), International Society of Cardiovascular Ultrasound, and Heart Valve Society of America. He served as the Chairman of Electrocardiography Committees for both the AHA and ACC, and was the Chairman of the ACC's International Committee from 2001 to 2006. He is also on the editorial boards of several cardiology journals. He holds several U.S. patents on ultrasound catheter-based technology. In 2020, he was the driving force behind a countywide preventative cardiology project called Cardiovision 2020 in Olmsted County, Maryland. An annual Tajik-Seward Echo Lectureship was established in 2006 by Mayo colleagues, and the annual A. Jamil Tajik Young Investigator Award was started by the Japanese Society of Echocardiography in 2008. He has been director/co-director of cardiology courses both in the United States and abroad, including the ACC's Heart House and 50 American College of Cardiology/American Society of Echo extramural courses. He also hosted the tele-education program
Cardiology Today and Tomorrow in the 1990s. ==Awards==