Acceleration of ventricular response to atrial flutter after intravenous adenosine.

Abstract

Adenosine may be of therapeutic and diagnostic value in the emergency management of arrhythmias. It causes transient atrioventricular nodal block and thus ends paroxysmal supraventricular tachycardias that involve the atrioventricular node. Also, it may uncover underlying atrial arrhythmias by slowing the ventricular response. Its duration of action is brief and serious adverse effects have not been reported. A 12 year old patient with atrial flutter is presented, in whom intravenous adenosine was followed by acceleration of the heart rate to a potentially dangerous arrhythmia. (Br Heart J 1993;69:263-265) Adenosine is an endogenous purine nucleoside that causes atrioventricular nodal block when injected intravenously.' 2 It is effective, therefore, to end paroxysmal supraventricular tachycardias that have a re-entrant circuit that includes the atrioventricular node.Y4 With atrial arrhythmias, such as atrial flutter, adenosine induced atrioventricular nodal block may be of diagnostic value by slowing the ventricular response to show the underlying atrial tachyarrhythmia.3-5 Transient side effects, including chest discomfort, flushing, and dyspnoea, are common, but serious adverse effects of adenosine have not been reported. This may be attributable to its extreme brevity of action because of rapid metabolism and removal from blood.7 We report a case where intravenous administration of adenosine was followed by an increase in the ventricular response to atrial flutter, with a resultant potentially life threatening arrhythmia. Case report A 12 year old boy was admitted to hospital after an episode of syncope. He had a history of Mustard repair of transposition of the great arteries at the age of 10 months. After the repair of an atrial baffle leak one year before the present admission, he had undergone implantation of a permanent ventricular pacemaker (Medtronic "Activitrax II", VVI-R) for symptomatic sinus node dysfunction. He had continued to complain of episodes of dizziness, the aetiology of which was not identified.On admission he was well with no evidence of heart failure. Heart rate was 120 beats/min and he was normotensive, with a blood pressure of 109/58 mm Hg. An electrocardiogram showed a narrow complex tachycardia. To clarify the diagnosis of the tachycardia, and possibly restore normal rhythm, adenosine was given intravenously with incremental boluses of 0 1, 02, and 0-4 mg/kg (4, 8, and 16 mg). Transient symptoms of increasing severity (flushing, non-specific malaise) were reported with each dose. After the 8 mg dose of adenosine, the ventricular rate briefly slowed to 86 beats/min (for four seconds) but then increased to 235 beats/min. This rapid rate persisted for three minutes before settling to 120 beats/min. A further dose (16 mg) was given. This slowed the ventricular rate so that the pacemaker paced the ventricle at 60 beats/min for 10 seconds ( fig IA). During this period of ventricular slowing, underlying atrial flutter waves at 280 beats/min were apparent. The ventricular respons...

Unusual Side Effect of Adenosine Infusion

“…Some authors reported also a dangerous increase of the ventricular rate in atrial flutter patients following the administration of adenosine, with conduction increasing from 2:1 to 1:1 after a brief period of high grade atrioventricular block [11][12][13]. Three of these five reported cases required electrical cardioversion.…”

“…Because the signal transduction pathways activated by adenosine and acetylcholine converge on the same potassium channels to produce similar electrophysiologic effects in the atrial myocardium, adenosine induced and vagus nerve-dependent AF are mechanistically similar. Both adenosine and vagus nerve activation cause spatially and temporally heterogeneous shortening of atrial refractoriness [10].Some authors reported also a dangerous increase of the ventricular rate in atrial flutter patients following the administration of adenosine, with conduction increasing from 2:1 to 1:1 after a brief period of high grade atrioventricular block [11][12][13]. Three of these five reported cases required electrical cardioversion.…”

Paroxysmal supraventricular tachycardia: improving diagnosis and management within the accident and emergency department

“…[11][12][13] A similar response has been described in atrial flutter. [14][15][16] This ''rebound'' phenomenon may result from an increase in sympathetic nerve activity and plasma catecholamine levels. 11 Adenosine induced ventricular arrhythmias including ventricular tachycardia, 17 polymorphic ventricular tachycardia, [18][19][20][21] and ventricular fibrillation 22 have all been described in the literature.…”

A Caveat during Adenosine Challenge

“…2 In this situation, the most dreaded consequence is degeneration of the arrhythmia into ventricular flutter or fibrillation and cardiac arrest. 3 We report an adverse event in a patient who received adenosine in an attempt to clarify the etiology of a supraventricular tachycardia.…”

“…2 In this situation, the most dreaded consequence is degeneration of the arrhythmia into ventricular flutter or fibrillation and cardiac arrest. 3 We report an adverse event in a patient who received adenosine in an attempt to clarify the etiology of a supraventricular tachycardia.A 77 year old female with a history of rheumatoid arthritis presented to our institution complaining of profound fatigue for one day. Her electrolytes, complete blood count, TSH and serial troponins were all within normal limits.…”