Adenosine is used to terminate supraventricular tachycardia (PSVT) involving the atrioventricular node by rapidly administering 6-12 mg intravenously over 1-3 seconds. It works in over 90% of cases by activating potassium channels to hyperpolarize cell membranes in the sinoatrial node, atria, and atrioventricular node, indirectly reducing calcium current and blocking the reentrant circuit through the atrioventricular node. Adenosine has advantages over verapamil in being more effective, having an action under 1 minute, avoiding hemodynamic deterioration, and being safer for wide complex tachycardias.

1. AdenosineAdenosine

2. PSVTPSVT

3. • Rapid i.v. 6-12 mgRapid i.v. 6-12 mg
• ATP 10-20 mgATP 10-20 mg
• Do it in about 1-3 secondsDo it in about 1-3 seconds

4. • Adenosine terminates it within 30Adenosine terminates it within 30
sec more than 90% episodes ofsec more than 90% episodes of
PSVT involving the AV nodePSVT involving the AV node

5. MOAMOA
• Acticates Ach sensitive K channels and causesActicates Ach sensitive K channels and causes
membrane hyper polerizsationmembrane hyper polerizsation
• Via A1 ( adenosine receptor) on SA nodeVia A1 ( adenosine receptor) on SA node
AV node,atriumAV node,atrium
Indirectly reduces- Ca current in AV nodeIndirectly reduces- Ca current in AV node
Depression of the re enternt circuit thru AV nodeDepression of the re enternt circuit thru AV node
is responsible for the termination of PSVTis responsible for the termination of PSVT

6. ADVADV
1.1. Efficacy better than verapamilEfficacy better than verapamil
2.2. Aaction lasts< 1 minAaction lasts< 1 min
3.3. No haemodynamic deteriorationNo haemodynamic deterioration
4.4. Safe in wide QRS tachycardia-V is unsafeSafe in wide QRS tachycardia-V is unsafe
5.5. Effective in patients not respon ding toEffective in patients not respon ding to
verapamilverapamil

7. ADVADV
1.1. Efficacy better than verapamilEfficacy better than verapamil
2.2. Aaction lasts< 1 minAaction lasts< 1 min
3.3. No haemodynamic deteriorationNo haemodynamic deterioration
4.4. Safe in wide QRS tachycardia-V is unsafeSafe in wide QRS tachycardia-V is unsafe
5.5. Effective in patients not respon ding toEffective in patients not respon ding to
verapamilverapamil