Effect of treadmill exercise testing on serum enzymes and the resting electrocardiogram.

Fifty-three adult male patients with chest pain underwent treadmill exercise stress testing according to the Bruce protocol. The resting 12-lead electrocardiogram (ECG) and serum concentrations of glutamic oxaloacetic transaminase, lactic dehydrogenase creatine phosphokinase and alpha-hydroxybutyrate dehydrogenase were evaluated before, and at 1 and 20 hours after exercise. Twenty-eight subjects (53 percent) had a normal test result, 10 (19 percent) had ischemic ST -segment changes and anginal pain, and 15 (28 percent) were considered to have equivocal results because of an abnormal baseline ECG or the concurrent administration of cardioactive medication. In contrast to earlier reports, no significant changes in the serum enzyme values were seen in any of the three groups orin any individual subject, nor were ECG changes detected after recovery from exercise. The diagnostic evaluation of the exercise ECG must depend upon the demonstration of ischemic ST -segment changes and not upon changes in concentrations of serum enzymes.