Adenosine for wide-complex tachycardia: efficacy and safety.
OBJECTIVE
: To determine whether adenosine is useful and safe as a diagnostic and therapeutic agent for patients with undifferentiated wide QRS complex tachycardia. The etiology of sustained monomorphic wide QRS complex tachycardia is often uncertain acutely.


METHODS
: A retrospective observational study.


METHODS
: Treatment associated with emergency visits at nine urban hospitals.


METHODS
: Consecutive patients treated with adenosine for regular wide QRS complex tachycardia between 1991 and 2006.


METHODS
: Treatment with adenosine infusion.


RESULTS
: Measured outcomes included rhythm response to adenosine, if any, and all adverse effects. A positive response was defined as an observed change in rhythm including temporary atrioventricular conduction block or tachycardia termination. A primary adverse event was defined as emergent electrical or medical therapy instituted in response to an adverse adenosine effect. A rhythm diagnosis was made in each case. The characteristics of adenosine administration as a test for a supraventricular as opposed to ventricular tachycardia were determined, and the adverse event rates were calculated. A total of 197 patients were included: 104 (90%) of 116 (95% confidence interval, 83%-95%) and two (2%) of 81 (95% confidence interval, 0.3%-9%) supraventricular tachycardia and ventricular tachycardia patients demonstrated a response to adenosine, respectively. The odds of supraventricular tachycardia increased by a factor of 36 (95% confidence interval, 9-143) after a positive response to adenosine. The odds of ventricular tachycardia increased by a factor of 9 (95% confidence interval, 6-16) when there was no response to adenosine. The rate of primary adverse events for patients with supraventricular tachycardia and ventricular tachycardia was 0 (0%) of 116 (95% confidence interval, 0%-3%) and 0 (0%) of 81 (95% confidence interval, 0%-4%), respectively.


CONCLUSIONS
: Adenosine is useful and safe as a diagnostic and therapeutic agent for patients with regular wide QRS complex tachycardia.
Marill
Keith A
KA
Department of Emergency Medicine (KAM), Massachusetts General Hospital, Boston, MA, USA. kmarill@partners.org
Wolfram
Sigrid
S
Desouza
Ian S
IS
Nishijima
Daniel K
DK
Kay
Darren
D
Setnik
Gary S
GS
Stair
Thomas O
TO
Ellinor
Patrick T
PT
D000241:Adenosine / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013610:Tachycardia / Q000175:diagnosis* / Q000188:drug therapy*
D000889:Anti-Arrhythmia Agents; D000241:Adenosine