Tag Archives: adenosine

On the Pharm


As a medic student, just learning the basics of pharmacology, it was cool to see this in action the other day:

Fifty-something year old woman. “Cardiac emergency”.

To be specific, the patient says she’s having an SVT. She knows “it’s SVT”, because it’s happened before. Twice.

Turns out she’s She’s right:


The red lines in the EKG above are time. Five of those bigger boxes is a second. We have her at about 215 bpm:

The medic establishes an IV in the patient’s arm while I hang a bag. The medic pushes Adenosine into the line—with a fluid chaser, because it needs to get to the heart now. (Adenosine only stays potent for five seconds!).

But gets there it does. And what does it do when it’s there? Oh, it only stops the heart and restarts it. That’s all.


Above, you see the Adenosine work real time. First, the wave looks like a normal rhythm—only twice as fast. When the drug hits, the line gets all wacky. (Thats V-Tach: the lower bit of the heart going nuts).

Then the heart stops! For almost two seconds; the heart is not working.

The patient clutches her chest and says, “I don’t feel so good”. For almost two seconds.

Then she’s okay.

And that’s pharmacology.