Adenosine
 

For others who have been given IV adenosine, what was your experience like?

I call it the big ball of death, and it's definitely a peculiar and psychologically unpleasant sensation, but I never found it to be painful per se. And it only lasts maybe 5 seconds. AND it's certainly better than my heart beating out of my chest for no reason.

There was a segment on Untold Stories of the ER that involved giving adenosine, and the actor playing the patient groaned and writhed on the table like he was having a spinal tap or something. But my astute wife pointed out that others may experience it differently.

Halibut, I've had adenosine more than once for a sustained heart rate of 260+/minute; not a pleasant experience. I'm at the age where I am used to severe hot flashes and, like you said, the short response from the medication sure beats the feeling of your heart beating out of your chest!