Adenosine and the Cardiovascular System

Allison B. Reiss; David Grossfeld; Lora J. Kasselman; Heather A. Renna; Nicholas A. Vernice; Wendy Drewes; Justin Konig; Steven E. Carsons; Joshua DeLeon

Disclosures

Am J Cardiovasc Drugs. 2019;19(5):449-464. 

In This Article

Adenosine, Electrophysiological Effects

Adenosine has potent cardiac electrophysiological effects on the heart[11] (Figure 2). A1, A2A, A2B, and A3 adenosine receptors have been identified in the heart.[42] The A1 receptor on cardiomyocytes mediates inotropic inhibitory actions of adenosine on contractility.[43] Adenosine acts at receptors in the sinus node and atrioventricular (AV) node. Stimulation of specific cell-surface A1 receptors shortens the duration, depresses the amplitude, and reduces the rate of rise of the action potential of AV nodal cells, slowing impulse conduction through the AV node.[44,45] Adenosine decreases spontaneous depolarization in the sinus node and conduction velocity in the AV node. The effect on both the sinus and AV nodes is dose dependent and of very short duration. The rapid negative dromotropic action on conduction speed in the AV node is the basis for the clinical administration of adenosine by intravenous bolus injection as an antiarrhythmic agent for the acute management of paroxysmal supraventricular tachycardia mediated by a reentrant mechanism involving the AV node.[46,47] Adenosine interrupts conduction through the AV node and abruptly terminates the reentry wave as it approaches nodal tissue.[48]

Figure 2.

Electrophysiological effects of adenosine on the heart. Adenosine acts at receptors in the atrium, sinus node, and AV node. The A1 adenosine receptor on cardiomyocytes (a) mediates inotropic inhibitory actions of adenosine on contractility that are opposed by A2 adenosine receptor activation (b). Stimulation of specific cell-surface A1 receptors shortens the duration, depresses the amplitude, and reduces the rate of rise of the action potential of AV nodal cells, slowing impulse conduction through the AV node. Adenosine decreases spontaneous depolarization in the sinus node and conduction velocity in the AV node. AMP adenosine monophosphate, ATP adenosine triphosphate, AV atrioventricular, cAMP cyclic AMP, SA sinoatrial

Adenosine can also be used diagnostically to distinguish a supraventricular tachycardia with aberrant conduction, which may terminate with adenosine, from a ventricular tachycardia, which will not.[49–51] In a study by Flyer et al.,[52] adenosine was used as a therapy to treat supraventricular tachycardia to alter the AV node action potential. In the 80 heart transplant patients treated, none experienced asystole after adenosine administration, with AV block induced in 96% of patients at a dose of 200 μg/kg, indicating that the treatment was both safe and effective.[52]

Adenosine is contraindicated in Wolff-Parkinson-White syndrome with atrial fibrillation because degeneration to ventricular fibrillation can result.[53] During intravenous infusion into conscious humans, adenosine has a number of known side effects such as hypotension and bronchospasm, facial flushing and headache. These occur very briefly due to the short half-life of the medication and resolve upon termination of infusion.[54,55]

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