Florida State Paramedic Practice Exam

What is the primary action of adenosine in the treatment of tachycardia?

1. Increases heart rate

2. Slows conduction through the AV node

3. Enhances contractility of the heart

4. Reduces preload on the heart

The correct answer is: Slows conduction through the AV node

The primary action of adenosine in the treatment of tachycardia is to slow conduction through the AV node. Adenosine works by temporarily interrupting conduction within the atrioventricular (AV) node, which can help restore a normal rhythm in cases of supraventricular tachycardia (SVT). This effect is achieved by hyperpolarizing the nodal tissue, which reduces the number of impulses that can propagate from the atria to the ventricles, effectively resetting the heart's electrical activity. This mechanism is crucial in managing certain types of tachycardia, as it directly addresses the abnormal rapid heart rates that often involve reentrant circuits involving the AV node. The ability to slow down the heart rate through this targeted action makes adenosine a valuable medication in acute settings where rapid intervention is necessary for patient stabilization.