Adenosine-induced cardiopulmonary arrest in a patient with paroxysmal supraventricular tachycardia—a response
Adenosine-induced cardiopulmonary arrest in a patient with Paroxysmal supraventricular tachycardia—
a response
To the Editor,
We read with interest the case report of Walsh et al in September’s issue of the American Journal of Emergency Medicine, “Adenosine-induced cardiopulmonary arrest in a patient with paroxysmal supraventricular tachycardia” [1] (SVT). We recently found success in using the ?-agonist metaraminol to terminate SVT.
An otherwise fit 64-year-old man underwent a laparotomy and colostomy for Crohn disease and associated malignancy. After an uncomplicated general anesthetic, the patient’s heart rate suddenly increased from 70 to 150 beats per minute. A 12-lead electrocardiogram confirmed an atrioventricular nodal reentry tachycardia with a rate of 150 beats per minute. Carotid massage was performed with no effect. Adenosine 6 mg was given as a rapid bolus followed by a large flush, after which the systolic blood pressure dropped significantly to 70 mm Hg. At this point, we decided to sedate the patient for synchronized electrical cardioversion. However, we first administered an Intravenous bolus of
0.5 mg of metaraminol to attempt to increase the patient’s blood pressure, after which the tachyarrhythmia suddenly terminated and systolic blood pressure returned to 120 mm Hg. A further 12-lead electrocardiogram showed no evidence of ischemia or aberrant pathway, and the patient’s subse- quent recovery was uneventful.
Metaraminol is a sympathomimetic amine, having direct and indirect agonist effects at predominantly ?-adrenorecep- tors, thus causing a vasopressor effect [2]. The use of metaraminol for termination of SVT has previously been described as a subcutaneous regimen [3], and other ?-agonists such as phenylephrine have also been used [4]. The proposed mechanism is that, by raising the blood pressure, they cause stimulation of carotid sinus and aortic baroreceptors with consequent reflex vagal stimulation. It has also been proposed that the increase in blood pressure improves Coronary blood flow, reversing any ischemia that may be causing the arrhythmia [4].
Metaraminol has many properties that may make it preferable to adenosine, including absence of bronchospasm, chest pain, and hypotension. Metaraminol can be given peripherally, has no significant Drug interactions, and has a longer half-life than adenosine, making it easier to administer. In the case reported by Walsh et al [1], metaraminol would have been far less likely to lead to cardiopulmonary arrest. As such, we propose that metaraminol could be
considered as part of the management of SVT, particularly if the patient is hypotensive.
Nigel S. Jenkins MB BS, MA
Department of Anaesthetics
Ysbyty Gwynedd LL57 2PW Bangor, UK
Mark Knights Mb ChB
Department of Anaesthetics
Morriston Hospital Swansea, UK
Carsten Eickmann State Exam Med, DA
Department of Anaesthetics
Ysbyty Gwynedd LL57 2PW Bangor, UK
Mark Payne MB BS
Department of Cardiology
Ysbyty Gwynedd Bangor, UK
doi:10.1016/j.ajem.2010.02.020
References
- Walsh RC, Felice KL, Meehan TJ, Stull BW, Schumann HM, Zautcke JL. Adenosine-induced cardiopulmonary arrest in a patient with paroxysmal supraventricular tachycardia. Am J Emerg Med 2009;27: 901.
- Sasada M, Smith S. Drugs in anaesthesia & intensive care. 2nd ed. Oxford University Press; 1997.
- Bowers D. Metaraminol in the treatment of paroxysmal supraventricular tachycardia. Can Med Assoc J 1968;99:868.
- Jacobson L, Turnquist K, Masley S. Wolff-Parkinson-White syndrome. Termination of paroxysmal supraventricular tachycardia with phenyl- ephrine. Anaesthesia 1985;40(7):657-60.
A response to a letter regarding the case report “Adenosine-induced cardiopulmonary arrest in a patient with paroxysmal supraventricular tachycardia“
To the Editor,
We would like to comment upon the response generated by our original case report, “Adenosine-induced cardiopul- monary arrest in a patient with paroxysmal supraventricular tachycardia.” Although we are grateful for the attention our report has generated, we have some concerns regarding the specifics of the query.
The authors have an excellent case report themselves that likely deserves some consideration to be published on its own and not as part of a letter discussing our report. Not only are the pharmaceuticals involved in both of these cases