title: Sinus tachycardia masquerading as ventricular tachycardia.
abstract: We describe here a 87-year-old male who came to the emergency room with the chief complaints of dyspnea and chest pain. His electrocardiogram showed a wide QRS tachycardia with a heart rate of 140 beats/min, a left bundle branch block pattern and low voltage in leads I, aVL, V5 and V6. A long strip showed a premature ventricular complex, and the sinus beat just after the extrasystole showed P waves which were positive in leads I, II, III and a VF similar in shape to those in sinus rhythm. Therefore, a diagnosis of sinus tachycardia with tachycardia dependent left bundle branch block was made. The low voltage in the left lateral leads was ascribed to pneumothorax of the left lung. When a wide QRS tachycardia is encountered in an emergency situation, marked sinus tachycardia with coexistent bundle branch block or aberrant ventricular conduction should be taken into consideration.
authors.affiliation: Department of Internal Medicine, School of Medicine, Tokai University, Kanagawa, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kanemoto
authors.forename: H
authors.initials: H
authors.lastname: Atsumi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002037:Bundle-Branch Block / Q000175:diagnosis; D003937:Diagnosis, Differential; D004562:Electrocardiography; D006801:Humans; D008297:Male; D013610:Tachycardia / Q000175:diagnosis*; D013616:Tachycardia, Sinus / Q000175:diagnosis*