2. Mathewson, F.A.L. and Harvie, F.H: Complete heart block in an experienced pilot. Br Heart J XIX (2): 253-258, 1957. This case history of the RCAF pilot who had been referred for assesssment because of a slow heart rate. At the time he was a flying instructor. All non-invasive assessment was normal including exposure to simulated high altitude. The electrocardiogram showed a relatively normal QRS duration and the heart rate was responsive to a variety of stresses. Follow-up in ten years revealed no new findings, and no symptoms of syncope or pre-syncope were elicited.