title: Occurrence of ST segmental electrical alternans during exercise test.
mesh_terms: D000788:Angina Pectoris, Variant / Q000503:physiopathology*; D003329:Coronary Vasospasm / Q000503:physiopathology*; D004562:Electrocardiography; D005080:Exercise Test; D006321:Heart / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged