title: Epidemiology, clinical features, and follow-up of patients with syncope and a positive adenosine triphosphate test result.
abstract: OBJECTIVE
  We sought to evaluate epidemiology, clinical features, and outcomes of patients with syncope and an abnormal response to adenosine triphosphate (ATP).
  
  
  BACKGROUND
  Syncope remains of unknown origin in almost 30% of the patients. Injection of ATP induces in some of these patients, but not in control patients, a ventricular pause > or =6 s.
  
  
  METHODS
  Patients with syncope of unknown origin had an intravenous injection of 20 mg of ATP. All patients had a tilt test.
  
  
  RESULTS
  Among 214 patients, 19 (8.9%) had a positive ATP test result. The proportion of positive test results was higher (p < 0.002) in women (14.3%) than in men (2.2%). Ten patients (4.7%) had positive ATP and tilt test results. These patients (exclusively women) were older (p < 0.05) at the time of their fist syncope than the 67 patients with a negative ATP test result but a positive tilt test result. There was a trend for these two test results to be correlated (p = 0.07). Side effects were of short duration and benign. The mean duration of pauses was longer in women (p = 0.009). During a mean period of 31 +/- 14 months, recurrences of syncope were reported in 25% of patients.
  
  
  CONCLUSIONS
  The ATP test is a safe test with an "abnormal" result in <10% of patients with syncope of unknown origin. The profile of these patients is characteristic.
authors.affiliation: Department of Cardiology, Hôpital de la Cavale Blanche, Brest University Hospital, Brest, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Perennes
authors.forename: Marjaneh
authors.initials: M
authors.lastname: Fatemi
authors.forename: Marie L
authors.initials: ML
authors.lastname: Borel
authors.forename: Yves
authors.initials: Y
authors.lastname: Lebras
authors.forename: Corinne
authors.initials: C
authors.lastname: L'Her
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Blanc
mesh_terms: D000255:Adenosine Triphosphate / Q000009:adverse effects; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000139:chemically induced; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D013575:Syncope / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D018667:Tilt-Table Test
chemical_list: D000255:Adenosine Triphosphate