Three Part Question
In [adults with supraventricular tachycardia] is [adenosine or verapamil] more effective at [restoring sinus rhythm]?
A 55 year old women presents to A & E with palpitations and shortness of breath. The physician on-call performs an ECG revealing a regular rhythm, with a p-wave distorting the start of the QRS complexes. The patient is diagnosed with atriventricular nodal re-entry tachycardia. Induction of AV block is attempted using both the carotid sinus massage and the valsava manoeuvre unsucessfully. The clinical team considers using either verapamil or adenosine as the next step in the managing this patient's arrhythmia.
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[(exp Supraventricular Tachycardia) OR (exp Tachycardia, Atrioventricular Nodal Reentry) OR (supraventricular tachycardia.mp) OR (narrow complex tachycardia OR narrow-complex tachycardia OR junctional tachycardia.mp.)] AND [(exp Verapamil/) OR (verapamil.mp.)] AND [(exp Adenosine) OR (adenosine.mp.) OR (adenocor.mp.)] limit to (humans and english language)
79 papers were found of which 4 were clinically relevant.
|Author, date and country
||Study type (level of evidence)
|Garrat C. et al|
|20 patients with a history of documented, recurrent, sustained paroxysmal junctional tachycardia referred for electrophysiologic study. All drugs stopped >72 hours before admission, amiodarone stopped >3 months||non-randomized, unblinded crossover clinical trial||sucessful termination of arrhythmia||100% vs 95% (adenosine vs verapamil); p<0.05||treatments were not randomly allocated
criteria for exclusion not explained
statistical methods not explained
possibility for selection bias|
|presence of significant arrhythmias afterconversion||ocurred in 35% with verapamil vs 0% with adenosine; p<0.05|
|unmasking of latent or intermittent preexcitation||0.5% revealed with verapamil vs 100% with adenosine; p<0.05|
|Rankin AC et al|
|43 patients who presented with spontaneous episodes of paroxysmal tachycardia treated with either adenosine or verapamil||retrospective review||restoring sinus rhythm (verapamil vs adenosine)||81% vs 96% (p<0.05)||treatments not randomly allocated
outcomes not assessed blind
sample size not justified
|Di Marco JP et al|
|359 with a tachycardia electrocardiographically consistent with paroxysmal ventricular tachycardia||two prospective,multicentre, double-blind, randomized, placebo controlled, single crossover clinical trials||cumulative efficacy of adenosine vs placebo in conversion to sinus rhythm||91.4% vs 16.1% (p<0.001)||patient bias
exclusion of patients to avoid verapamil side-effects
randomisation not explained
no confidence interval given|
|cumulative efficacy of adenosine vs verapamil in conversion to sinus rhythm||93.4% vs 90.6% (p=NS)|
|Hood MA et al|
|25 patients with narrow complex tachycardia presenting to the emergency room and those whom tachycardia was induced in the electrophysiologic laboratory||Randomized, unblinded, double cross-over trial||termination of PSVT by adenosine vs verapamil||100% vs 73%, p=0.07||outcomes not assessed blind
size of sample not justified
no placebo control
patient numbers small|
|conversion arrhythmias post administration of adenosine vs verapamil||57% vs 50%, p=NS|
Adenosine in doses up to 20 mg is a rapid, safe and effective means in terminating paroxysmal supraventricular tachycardias in patients whose arrhythmia did not responde to vagal manoeuvres. Side-effects are common but generally well tolerated and transient. It should be the treatment of choice in those patients in whom verapamil is known to have adverse effects, including those with hypotension, cardiac failure or who are taking beta-blocker drugs and in those in whom the diagnosis is in doubt (e.g. if the QRS complexes are broad). Verapamil is reserved in those in which adenosine produces severe symptoms, in those where arrhythmias recur or for patients with poor venous acess, patients with bronchospasm or those taking agents that interfere with adenosine action or metabolism like methylxanthines and dypiridamole.
Clinical Bottom Line
Adenosine is the initial drug in the acute management of paroxysmal supraventricular tachycardia after the failure of vagal manoeuvres.
- Garrat C. Linker N. Griffith M Ward D. Camm J. Comparison of Adenosine and Verapamil for termination of paroxysmal junctional Tachycardia The American Journal of Cardiology 1989;64:1310-1316
- Rankin AC. Rae AP Oldroyd KG Cobbe SM Verapamil or Adenosine for the Immediate Treatment of Supraventricular Tachycardia Quarterly Journal of Medicine February 1990; no 274,203-208
- Di Marco JP, Miles W, Akhtar M, Milstein S, Sharma A, Platia E, McGovern B, Sheinman M, Govier W Adenosine for Paroxysmal Supraventricular Tachycardia: Dose ranging and Comparison with Verapamil Annals of Internal Medicine 1990; 113:104-110
- Hood MA, Smith WM Adenosine versus Verapamil in the treatment of supraventricular tachycardia: a randomized control trial American Heart Journal 1992; 123: 1543