title: Bidirectional tachycardia with normal QRS duration.
mesh_terms: D000368:Aged; D001344:Autopsy; D004562:Electrocardiography; D005260:Female; D006801:Humans; D009206:Myocardium / Q000473:pathology; D013610:Tachycardia / Q000175:diagnosis* / Q000473:pathology