John O. “Jack” Parker made a positive difference in Canadian medicine and cardiology. His contributions to cardiovascular medicine and to Queen’s University are internationally recognized and will long be remembered.

A prize-winning medical graduate of Queen’s in 1954, Jack undertook further training at Queen’s and then spent a two-year research fellowship in the cardiopulmonary laboratory of the Nobel laureate Andre Cournand. Thereafter, Jack received a McLaughlin travelling fellowship that permitted him to complete a final year of training in Paris and London at the National Heart Hospital.

He returned to Queen’s University as he was appointed Assistant Professor of Cardiology in 1962 and he rapidly rose through the academic ranks becoming the Chair of the Queen’s Division of Cardiology (1972-1988). Ultimately Jack’s leadership had national and international impact. He served as President of the Canadian Cardiovascular Society (1986-1988) and then became a Trustee of the American College of Cardiology (1988-1993).

Jack pioneered coronary angiography in Canada in the early 1960s after visiting the laboratory of Mason Sones at the Cleveland Clinic, where it was first developed. Invasive cardiology was then in its infancy and Jack soon began a series of elegant studies of the pathophysiology of angina pectoris and coronary artery disease that garnered international recognition after they were published in the premier cardiac journal Circulation. This work was followed by thematic studies exploring the most common therapy for angina at the time, namely nitroglycerin and its various formulations; these then guided physicians towards a better approach to nitrate use.

His investigative work led to international recognition and invitations to not only lecture around the world but also numerous requests from other investigators to visit Queen’s and establish new collaborations.

An inspired and energetic clinician scientist, Jack was one of the few Canadians to be honoured by election to the American Society of Clinical Investigation. He achieved this in recognition of his pioneering work in coronary angiography and physiology.

An accomplished, skilled and insightful physician Dr. Parker had a large clinical practice. His ward rounds were memorable for their inspired blend of clinical care, learning, and probing of unsolved clinical issues. House staff under his watch were expected to dress and behave professionally and were promptly excused if his exacting standards were unmet.

He was a gifted teacher who taught generations of medical students and young doctors the principles of cardiovascular medicine. Dr. Parker’s influence on a host of cardiovascular trainees is legendary.  His enthusiasm, work ethic, curiosity, clarity of thought, impatience for change, and willingness to push the envelope in the search for new knowledge created an exciting laboratory in which to work and explore clinically relevant questions.

In return for their hard work his trainees received generous guidance and career support that paid lasting dividends. Many of his trainees went on to academic positions in Canada and around the world after being transfected with the “Parker gene” for clinical investigation.

It was my privilege to serve as his trainee between 1967-1969 and later as his colleague at Queen’s between 1972-1984.

In an era when the “triple threat” is thought to have disappeared, John Parker represented what was rare but possible… if you were talented, dedicated, tenacious and curious. His career accomplishments brought honor to himself and to Queen’s. 

Paul Armstrong is Professor of Medicine in the Division of Cardiology at the University of Alberta and Director of the Canadian VIGOUR Centre. He is Director of TORCH  a Strategic Training Program Initiative in cardiovascular research.