Correspondence

Enhanced Atrioventricular Conduction during Atrial Flutter after Intravenous Adenosine

N Engl J Med 1994; 330:288-289January 27, 1994

Article

To the Editor:

Adenosine is the treatment of choice for tachycardia with narrow QRS complexes involving the atrioventricular node as part of its reentrant circuit1. It has also been recommended as a diagnostic aid in determining the mechanism of other tachyarrhythmias, but there has been no thorough analysis of its risks and benefits for this use. We report an adverse event associated with adenosine administered for diagnostic purposes to a patient with atrial flutter.

A 53-year-old man came for medical evaluation because of palpitations. An electrophysiologic study previously revealed normal atrioventricular-node function (second-degree atrioventricular nodal Wenckebach block occurred at 360 msec), no evidence of preexcitation, and inducible atrial flutter with 2:1 atrioventricular block. The heart rate on admission was 140 per minute, and the blood pressure was 110/60 mm Hg. In anticipation of therapy, an electrocardiogram was obtained continuously. Figure 1Figure 1Continuous Electrocardiographic-Rhythm Strip Starting 13 Seconds before Adenosine Therapy. shows the rhythm during the next 88 seconds -- transient high-grade atrioventricular block and later prolonged, enhanced atrioventricular conduction. Laboratory analysis revealed normal values for electrolytes, thyroid-function tests, and cardiac enzymes, and no drugs were detectable in the plasma.

Adenosine was probably responsible for the accelerated atrioventricular conduction during atrial flutter. The most plausible mechanism for the rapid ventricular rate in this patient was an increase in sympathetic tone. The sequence of a transient slower heart rate followed by acceleration after the administration of adenosine was probably due to the augmentation of sympathetic-nerve traffic2,3.

Physicians considering the risk-benefit ratio of giving adenosine for a tachyarrhythmia unlikely to be terminated by this agent should recognize its potential complications. Wesley and Turnquest documented torsades de pointes after adenosine was given for diagnostic testing in a patient with a prolonged QT interval obscured by sinus tachycardia4. Rankin et al. reported acceleration of the ventricular response to atrial flutter in a patient with congenital heart disease who was given multiple injections of adenosine “to clarify the diagnosis of the tachycardia, and possibly restore normal rhythm”5. Their patient was given 4, 8, and later 16 mg of adenosine for atrial flutter with 2:1 atrioventricular block. The atrial flutter persisted, and the ventricular response ranged from 60 to 240. The more rapid rate and faster conduction lasted considerably longer (180 seconds) than the high-grade block (4 seconds). The authors' report left unresolved the question whether patients might have accelerated conduction after receiving a standard dose of adenosine. That question is answered here, since the patient was given only 6 mg of adenosine, which resulted in a potentially life-threatening acceleration of the heart rate. Therefore, we wish to warn those considering giving adenosine for tachyarrhythmia not involving the atrioventricular node in its reentrant circuit about the possible adverse effects of this drug.

Michael A. Brodsky, M.D.
Byron J. Allen, M.D.
University of California, Irvine Medical Center, Orange, CA 92668-3298

James A. Grimes, M.D.
Claudia Gold, M.D.
St. Joseph Hospital, Orange, CA 92668-3891

5 References

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Citing Articles (3)

Citing Articles

1. 1

   Cagatay Ertan, İlyas Atar, Oyku Gulmez, Asli Atar, Aliseydi Ozgul, Alp Aydinalp, Haldun Müderrisoğlu, Bülent Özin. (2008) Adenosine-Induced Ventricular Arrhythmias in Patients with Supraventricular Tachycardias. Annals of Noninvasive Electrocardiology 13:4, 386-390
   CrossRef

2. 2

   BARBARA J. DREW, MELVIN M. SCHEINMAN. (1995) ECG Criteria to Distinguish Between Aberrantly Conducted Supraventricular Tachycardia and Ventricular Tachycardia:Practical Aspects for the Immediate Care Setting. Pacing and Clinical Electrophysiology 18:12, 2194-2208
   CrossRef

3. 3

   &NA;. (1994) Adenosine. Reactions Weekly &NA;:488, 4
   CrossRef