Electrocardiography in the selection of Royal Canadian Air Force aircrew.

The electrocardiograms of 5000 healthy adult male applicants for aircrew training have been reviewed. Abnormalities were observed in the tracings of 158 subjects and these were further investigated. T-wave abnormalities occurred in 95 applicants, prolongation of the QRS (including the Wolff-Parkinson-White syndrome) in 28, prolongation of the P-R interval in 23, and miscellaneous changes in a group of 12 men. In many instances the apparent abnormality could be explained as a variation of normal on repeat study (including multiple lead electrocardiograms). In 27 men (0.54 per cent), 15 of whom revealed some associated clinical cardiovascular findings, a significant abnormality persisted and these were considered as unfit for pilot training.