title: The value of the clinical history in the differentiation of syncope due to ventricular tachycardia, atrioventricular block, and neurocardiogenic syncope.
abstract: BACKGROUND
  The present study was undertaken to identify and quantitate the symptoms associated with neurocardiogenic syncope, syncope due to ventricular tachycardia, and syncope resulting from atrioventricular block.
  
  
  METHODS
  Eighty patients referred for evaluation of syncope in whom a diagnosis of neurocardiogenic syncope, atrioventricular block, or ventricular tachycardia was established were studied. Each patient was interviewed using a standard questionnaire. The clinical histories were then compared to identify which variables best differentiated the cause of syncope.
  
  
  RESULTS
  The clinical histories of patients with syncope due to ventricular tachycardia and atrioventricular block were similar. Only age, the duration of prodromal symptoms, diaphoresis prior to syncope, and fatigue following syncope differed. In contrast, the clinical history in patients with neurocardiogenic syncope differed greatly from that obtained in patients with syncope due to atrioventricular block or ventricular tachycardia. Features of the clinical history that were predictive of syncope due to atrioventricular block or ventricular tachycardia were male sex, age > 54 years, < or = 2 episodes of syncope, and a duration of warning of < or = 5 seconds. Features of the clinical history predictive of syncope not due to ventricular tachycardia or atrioventricular block were palpitations, blurred vision, nausea, warmth, diaphoresis, or lightheadedness prior to syncope, and nausea, warmth, diaphoresis, or fatigue following syncope.
  
  
  CONCLUSIONS
  The results of this study identify and compare the features of the clinical history obtained in patients with syncope due to ventricular tachycardia, atrioventricular block, and neurocardiogenic syncope and demonstrate that the clinical history is of value in distinguishing patients with these three causes of syncope.
authors.affiliation: Department of Cardiology, University of Michigan, Ann Arbor, USA.
authors.forename: H
authors.initials: H
authors.lastname: Calkins
authors.forename: Y
authors.initials: Y
authors.lastname: Shyr
authors.forename: H
authors.initials: H
authors.lastname: Frumin
authors.forename: A
authors.initials: A
authors.lastname: Schork
authors.forename: F
authors.initials: F
authors.lastname: Morady
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001342:Autonomic Nervous System Diseases / Q000150:complications / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006327:Heart Block / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D013575:Syncope / Q000209:etiology* / Q000503:physiopathology; D017180:Tachycardia, Ventricular / Q000150:complications / Q000175:diagnosis*