Gonna have to pass on this one. I am a medic and use adenosine to stop a heart that has SVT or supraventricular tachycardia or a heart beat of 180 or higher being uncontrolled by the AV node. When given IV push it stops the heart for aprox 6 seconds most of the time the heart restarts itself. Most of the time! This is something that I would pass on with any heart problems for sure. Not worth it at all IMO.
When administered intravenously, adenosine causes transient heart block
in the AV node
. This is mediated via the A1 receptor
, inhibiting adenylyl cyclase, reducing cAMP and so causing cell hyperpolarization by increasing outward K+ flux. It also causes endothelial dependent relaxation of smooth muscle as is found inside the artery walls. This causes dilatation of the "normal" segments of arteries; i.e. where the endothelium
is not separated from the tunica media by atherosclerotic plaque
. This feature allows physicians to use adenosine to test for blockages in the coronary arteries, by exaggerating the difference between the normal and abnormal segments.
In individuals suspected of suffering from a supraventricular tachycardia
(SVT), adenosine is used to help identify the rhythm. Certain SVTs can be successfully terminated with adenosine.
This includes any re-entrant arrhythmias
that require the AV node for the re-entry (e.g., AV reentrant tachycardia
(AVRT), AV nodal reentrant tachycardia
(AVNRT). In addition, atrial tachycardia
can sometimes be terminated with adenosine.
Adenosine has an indirect effect on atrial tissue causing a shortening of the refractory period. When administered via a central lumen catheter, adenosine has been shown to initiate atrial fibrillation
because of its effect on atrial tissue. In individuals with accessory pathways
, the onset of atrial fibrillation can lead to a life-threatening ventricular fibrillation
Fast rhythms of the heart that are confined to the atria
(e.g., atrial fibrillation
, atrial flutter
) or ventricles
(e.g., monomorphic ventricular tachycardia
) and do not involve the AV node as part of the re-entrant circuit are not typically converted by adenosine. However, the ventricular response rate is temporarily slowed with adenosine in such cases.
Because of the effects of adenosine on AV node-dependent SVTs, adenosine is considered a class V antiarrhythmic agent
. When adenosine is used to cardiovert
an abnormal rhythm, it is normal for the heart to enter ventricular asystole
for a few seconds. This can be disconcerting to a normally conscious patient, and is associated with angina-like sensations in the chest.