DOLATOWSKI, ROSEMARY P., RAY W. SQUIRES, MICHAEL L. POLLOCK, CARL FOSTER, and DONALD H. SCHMIDT. Dysrhythmia detection in myocardial revascularization surgery patients.Med. Sci. Sports Exerc., Vol. 15, No. 4, pp. 281–286, 1983. In order to document the type and prevalence of significant dysrhythmias in myocardial revascularization surgery patients, cardiac electrical activity was recorded during graded exercise testing, 24-h ambulatory electrocardiography, and electrocardiographic-monitored exercise training. Patients participated in a cardiac rehabilitation program that began approximately 2 wk post-surgery, and attended three monitored exercise sessions per week for 12 consecutive weeks. Graded exercise testing and 24-h ambulatory electrocardiography were administered in the second and eighth weeks of the study (weeks 1 and 6 of the exercise program) post-surgery. Eighty-eight percent of the patients exhibited significant dysrhythmias. A greater number of significant dysrhythmias were found during the second 6 wk of the study in comparison with the first 6 wk. Graded exercise testing was not as effective as ambulatory electrocardiography and monitored exercise training in dysrhythmia detection. Not all dysrhythmias were detected by any one technique, thus a combination of methods may be best for optimal surveillance and detection.