title: Acute treatment of paroxysmal tachycardia by adenosine.
abstract: BACKGROUND
  Adenosine has proven efficacy in clinical trials and in the electrophysiological laboratory for the treatment of paroxysmal tachycardia.
  
  
  OBJECTIVE
  To evaluate the efficacy and safety of adenosine administered in a clinical setting by non-consultant staff.
  
  
  METHODS
  Incremental doses of adenosine were administered intravenously to five children and 32 adults during 39 episodes of paroxysmal tachycardia in a clinical setting. Structural heart disease was present in 43% of patients.
  
  
  RESULTS
  Of 35 episodes of narrow complex tachycardia, adenosine terminated 26 of 28 episodes of supraventricular re-entrant tachycardia (SVRT), one episode of ectopic atrial tachycardia, and induced transient atrioventricular block to reveal atrial arrhythmias in four. Termination of SVRT occurred at a mean (SD) dose of 9.2 (4.0) mg in adults and 0.09 (0.04) mg/kg in children, but two patients had later spontaneous reinitiation of SVRT. Two patients with narrow complex tachycardia who failed to respond to adenosine were subsequently found to have ventricular tachycardia. Adenosine was therapeutic or diagnostic in three of four episodes of broad complex tachycardia. Overall, by intention to treat by the clinician, adenosine was therapeutic or diagnostic in 34 of 39 episodes (87%). Breathlessness (26%), chest tightness (18%) and flushing (18%) occurred transiently. There were no episodes of hypotension. Adenosine was given safely to 15 patients in whom verapamil was considered contraindicated.
  
  
  CONCLUSIONS
  Adenosine is a safe treatment for both narrow and broad complex tachycardias; usually effective for the former and diagnostic for the latter.
authors.affiliation: Cardiology Department, Green Lane Hospital, Auckland, New Zealand.
authors.forename: K Y
authors.initials: KY
authors.lastname: Ho
authors.forename: N J
authors.initials: NJ
authors.lastname: Wilson
authors.forename: W M
authors.initials: WM
authors.lastname: Smith
mesh_terms: D000208:Acute Disease; D000241:Adenosine / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D000075202:Contraindications; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D013614:Tachycardia, Paroxysmal / Q000145:classification / Q000175:diagnosis / Q000188:drug therapy*; D014700:Verapamil
chemical_list: D014700:Verapamil; D000241:Adenosine