When vagal maneuvers fail to terminate stable narrow-complex SVT, the primary medication of choice is adenosine. For the unstable patient with a regular and narrow QRS complex, adenosine may also be considered prior to synchronized cardioversion.
Adenosine is the primary drug used in the treatment of stable narrow-complex SVT (Supraventricular Tachycardia). Now, adenosine can also be used for regular monomorphic wide-complex tachycardia.
When given as a rapid IV bolus, adenosine slows cardiac conduction particularly affecting conduction through the AV node. The rapid bolus of adenosine also interrupts reentry (SVT causing) pathways through the AV node and restores sinus rhythm in patients with SVT.
When injected into the body, adenosine is rapidly absorbed by red blood cells and blood vessel endothelial cells and metabolized for natural uses throughout the body. In light of this adenosine should be administered by RAPID intravenous bolus so that a significant bolus of adenosine reaches the heart before it is metabolized.
A change from the 2010 guidelines now has adenosine given up to two times rather than three.
Dosing
The first dose of adenosine should be 6 mg administered rapidly over 1-3 seconds followed by a 20 ml NS bolus. If the patient’s rhythm does not convert out of SVT within 1 to 2 minutes, a second 12 mg dose may be given in a similar fashion. All efforts should be made to administer adenosine as quickly as possible.
A lower initial dose of 3mg should be used for patients taking dipyridamole or carbamazepine as these two medications potentiate the effects of adenosine.
Also, prolonged asystole has been seen with the use of normal doses of adenosine in heart transplant patients and central line use. Therefore, the lower dose (3mg) may be considered for patients with a central venous line or a history of heart transplant.
Precautions
Some side effects of adenosine administration include flushing, chest pain/tightness, brief asystole or bradycardia.
Make sure that adenosine is not used for irregular, polymorphic wide-complex tachycardia and unstable VT. Use in these cases may cause clinical deterioration.
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Faiz says
If adenosine failed to revert SVT, what is our next option? Do we give amiodarone or ccb?
Jeff with admin. says
Amiodarone would be the next option within the tachycardia algorithm. Procainamide or sotalol are also options.
If the patient is stable, consultation with a cardiologist would be recommended.
Kind regards,
Jeff
Nino says
First of all, thank you <3
"Make sure that adenosine is not used for irregular, polymorphic wide-complex tachycardia and unstable VT. Use in these cases may cause clinical deterioration". what do you meen?
Jeff with admin. says
Use of adenosine will not be effective for polymorphic wide complex ventricular or unstable VT and its use will delay proper treatment. Adenosine can also further compromise the condition of the myocardium when certain conditions such as long QT syndrome are present.
Kind regards,
Jeff
Caitlin says
Can you clarify when to use adenosine vs. cardioversion? I am gathering that most often, you’d try adenosine prior to cardioversion–is there a reason? Is there a situation (outside of polymorphic tachycardia and unstable VT) that we would cardiovert and skip adenosine? For some reason, it’s just not sticking well in my head so any clarification would be amazing.
Jeff with admin. says
The typical of adenosine for the treatment of narrow complex stable superventricular tachycardia. Adenosine may even be considered in some unstable situations if dealing with regular narrow complex SVT.
It is also acceptable to use adenosine with
stable wide complex tachycardia if the rhythm is regular and monomorphic. This is because there may be a bundle branch block that is making the QRS complex wide.
Cardioversion should not be used for any type of sinus tachycardia. Sinus tachycardia is the result of a physiologic response to extrinsic factors. Identify the extrinsic factor and treat that.
If a patient is STABLE with tachycardia and no other interventions seem to be helping then expert consultation should be received prior to further treatment.
If tachycardia of greater than 150/minute is present and the patient is unstable and no other interventions have been helpful then cardioversion should be considered. Keep in mind that if a patient is seriously ill or has underlying cardiovascular disease, symptoms may be present at a lower rate than 150.
Hope that helps. Please let me know if you have any other questions.
Kind regards,
Jeff
alea says
Just looking for clarity – is adenosine contraindicated in rapid afib/aflutter because of the possibility of a bypass tract (may cause actual ventricular conduction 1:1) I can’t seem to find consistent rationale for this. I’ve read elsewhere it being used sometimes to help “diagnose” a rhythm.
Jeff with admin. says
Adenosine is not contraindicated for rapid atrial fibrillation and atrial flutter. Adenosine will not correct problem, but they may be able to slow the ventricular rate down enough to identify the underlying atrial arrhythmia.
Kind regards,
Jeff
Joy Boyd says
Just crammin’ and jammin’ all this info into my head
Al Faidi says
does adenosine works on Sinus Tach?
Jeff with admin. says
o, adenosine does not work for sinus tachycardia. Adenosine would be contra indicated with sinus tachycardia. Sinus tachycardia occurs as a normal reaction to things like infection, exercise, and increased metabolic demand.
Want to make sure to treat the cause of sinus tachycardia and not simply the rhythm. When you correct the cause, the sinus tachycardia will self correct.
Kind regards,
Jeff
Rhm says
Is there a study on adenosine that its potency will be lost when we loaded/aspirated the adenosine into a syringe from its vial? I was told that its potency will be lost in just less than 10 seconds once removed from its vial.
Jeff with admin. says
This is incorrect. Removing the adenosine from the vile has nothing to do with the loss of potency.
The adenosine will remain fully effective until it is injected into the patient.
Adenosine is metabolized very rapidly once it enters the bloodstream because every cell in the body is able to metabolize adenosine. The half-life of the adenosine once it has entered the body is 10 seconds.
Kind regards,
Jeff
Sean says
The issue is not removing it from the vial, the issue is that the body converts adenosine to ATP, which is used as cellular energy currency, so we give it hard and fast and hope some ends up at the heart.
Amy says
Say your patient is in svt, and has an implanted (on demand) pacemaker. Pacemaker only kicks in if rate drops below 70. What happens to the rythm once the pt Brady’s down or goes into brief asystole? Does the pacemaker override that response?
Jeff with admin. says
The pacemaker would fire once the heart rate dropped and this would not be a problem.
Kind regards,
Jeff
Harrell Guy Graham says
Will ATP work in this situation? Is the word ‘adenosine’ being used loosely to also refer to ATP? (I realize the two are distinct but I’ve seen researchers use the terms interchangeably when referring to treatments for certain tachycardias. Whereas the medicine used by doctors is labeled ‘Adenosine’)
Harrell Guy Graham says
Reason I am asking is because one patient swears to me he got “ATP” for his tachycardia.
Jeff with admin. says
ATP (adenosine triphosphate) is typically a reference to the organic chemical that is produced in biological systems and not the synthetic chemical typically labeled as adenosine that is structurally nearly identical to ATP.
There are molecular differences which I do not understand, but the patient would have received synthetic adenosine.
ATP would be a reference to the organic biologically produced chemical which is not available as a product. It is only produced within biological systems.
The person you were referring to was probably misinformed by someone like most of us who did not understand the chemical differences between ATP and adenosine.
Kind regards,
Jeff
See Thao says
Can adenosine be use on a patient example: came to the hosp for asthma exacerbation and then have a monomorphic ventricular tachycardia?
Jeff with admin. says
In the literature there are four case reports of patients with asthma or chronic obstructive airway disease developing bronchospasm following treatment with intravenous adenosine.
The case reports have their limitations and there is not a direct contraindication for the use of adenosine. However, care and caution should be used if a patient has any type of ongoing underlying condition that may affect the outcome of the administration of adenosine.
Kind regards,
Jeff
RAAZIZ says
Correct sir
Alvin Cachuela says
Adenosine is the primary drug used in the treatment of stable narrow-complex SVT (Supraventricular Tachycardia). It can now also be used for regular monomorphic wide-complex tachycardia. What does it means? does it means adenosine can be used for regular monomorphic VTACH? thanks
Jeff with admin. says
Yes that is correct. It can be used for regular monomorphic ventricular tachycardia with the pulse.
Kind regards,
Jeff
Richard says
I’ve had several SVT episodes – Two received EMS adenosine IV treatment and short ER visit – since then I’ve had several SVT events but have waited them out at home – is there any self-administered treatment that can be used? (like adenosine pill?)
Jeff with admin. says
SVT and its treatments can have serious side effects and should most likely be handled in the presence of healthcare professionals. I would encourage you to ask your provider the question you asked here.
Kind regards,
Jeff
Tracy says
I have a follow up question from Katharine. If adenosine was given to VT with a pulse in order to discern between VT & SVT, would the rhythm still go into asystole? OR would there be no effect at all– meaning, VT would remain on the monitor the whole time after adenosine administration?
Jeff with admin. says
Not always does the rhythm completely go to asystole. You will see a pause and then the rate will be much slower until the adenosine is metabolized over 30 to 60 seconds.
This is true for both VT and SVT.
Kind regards,
Jeff
Katharine says
Oh wait, you could give it for monomirphoc regular V Tach , too, I suppose.
Joel says
adenosine works by stopping AV nodal impulses. In ventricular tachycardia the impulse is from the ventricle. adenosine would have no effect on ventricular impulses. That is a shockable rhythm.