How bad does it really feel to have a chemically-induced stress test?

March 23, 2009 7:33 PM

How bad does it really feel to have a chemically-induced stress test? Concerned about the "feeling of impending doom" associated with the administration of adenosine.

A friend of mine recently had a treadmill stress test with thallium that, while the cardiologist present at the test said looked fine, the family doctor didn't like the results of. Since she just had surgery and can not run on the treadmill, now they've scheduled her for a chemically-induced stress test.

They'll be using adenosine to speed up her heart. The thing is, we've read online that for 2-10 seconds after being injected with adenosine intravenously, there is a sensation of "impending doom," or feeling like you're about to die. However, we've also read that the adenosine is pushed in over 4 minutes... does the impending doom feeling happen every time they push more medication in? My friend already has a severe anxiety disorder for which she takes Xanax, and she's really nervous about this effect of adenosine.

Those of you who have had it, how bad is it and how fast do the effects wear off? Is it worse than a panic attack? At the end of the stress test, will they give her something to counteract the adenosine, or will they just let it filter through her system?

posted by IndigoRain to health & fitness (5 comments total)

My 82 year old father had one of these tests last week as part of preparing for lung surgery. He described no distress or feeling of impending doom. The staff giving the procedure told him when the started administering the drug, commented when they were pushing more dosage into his IV, etc. His heart rate, which is slow at rest, was brought up to over 150 beats per minute. The drug deteriorates rapidly after they stop administering it, and the heart rate returns to normal within a few minutes.

He did not seem to find it terrifying or psychologically bad at all. No counteractive agent was used.
posted by longsleeves at 7:59 PM on March 23, 2009

I've never had an adenosine stress test, but I schedule them, and chat with the roughly 4-8 patients per week I schedule them for. I try to ask people how the test went so I have a better idea of what to tell the next patient about how it's going to go.

Most people have told me they felt "uncomfortable" but not necessarily upset. My post-menopausal patients have said it felt similar to a hot flash. A couple have told me they've had a "sinking feeling" which I guess is the impending doom thing. So there you go with the "feeling" part of my answer- it's different for different people.

From what the techs tell me, the adenosine is more of a steady thing, so I gather once you're feeling uncomfortable/hot/sinking, it is a steady feeling throughout. The techs also tell me they do a saline flush when it's over, so the feeling is over pretty quickly.

My advice to your friend is to talk to the doctor who is admistering the test. Ask if a friend can sit in the room while the test is being done. Ask if she can take a Xanax ahead of time (she probably will be allowed to). She should try to talk to the tech, if she can. Most of the techs I know care about their jobs and want the patient to be as comfortable as possible.

And please tell your friend I hope eveything comes out well!
posted by dogmom at 8:09 PM on March 23, 2009

The adenosine infusion during most stress tests tends to run for about 4-6 minutes. I actually haven't seen it done first hand, though I have had the fortune of pushing the full equivalent dose of adenosine and then some rapidly (seconds) into probably over a hundred patients. They uniformly tell me it feels "weird," most get a flushing sensation, and some do have a sense of impending doom. The nice thing about the drug is that by the time they even have a chance to describe what it's like, it's totally worn off. The symptoms may well be different during the stress test though (and likely even milder). Adenosine is metabilized directly, and quite rapidly in the blood. The half-life of this drug is on the order of several seconds, which means that when they stop injecting it, its effects will clear incredibly rapidly. This also means that should your friend not tolerate the infusion, all she has to do is tell them to stop (or scream bloody murder) and they'll stop the process immediately. So if she's anxious already maybe that will ease her concerns.
posted by drpynchon at 9:20 PM on March 23, 2009

I've helped translate for some old patients who had the test, the tech warns the patients before he/she injects the adenosine that they will feel some chest discomfort/pressure. During the test, I've asked patients how they are feeling and if they have any chest pain, which is abnormal and will trigger them to stop the test immediately. Usually the patients will respond back that they have a "heavy" feeling in their chest, that they are a little short of breath, and fatigued.

Right after the infusion, the patients have a seat and immediately feel better within one or two minutes.

I agree with dogmom, talk to the nuclear tech before hand. They will thoroughly answer any questions/concerns your friend may have. Chances are, the tech will call you the day before anyways to go over some last minute things (like no caffiene 24hours prior.)

On preview, if she's really _really_ anxious, her pre-test resting ECG might be abnormal and they might not even proceed with the test.
posted by aGee at 9:42 PM on March 23, 2009

What you have been reading about the feeling of 'impending doom' was likely related to the use of adenosine in supraventricular tachycardia (SVT). For SVT, we push 6 or 12 mg of adenosine - that is, we inject it quickly and flush with saline so the patient receives the whole amount over a few seconds. This has the effect of transiently blocking the AV node and can cause the heart to stop beating momentarily causing this terrible feeling. When adenosine is used for stress tests, it is given as an infusion over 4-6 minutes (as mentioned above). At this rate, the adenosine has the effect of dilating blood vessels as opposed to blocking the AV node. Therefore the heart continues to beat and there should be no feeling of 'doom'. Your friend may, of course, experience some shortness of breath or chest pain during the stress test just as she may on a treadmill. I hope this gives some context to what your friend has been reading on the web.
posted by madokachan at 2:29 PM on March 24, 2009