What's a nuclear stress test like? Is it safe?

Lori, thank you for your post. My biggest concern about the scan comes from this note in the Lexiscan prescribing information: "Do not administer LEXISCAN to patients with:
• Second- or third-degree AV block, or
• sinus node dysfunction
unless these patients have a functioning artificial pacemaker [see Warnings and Precautions (5.2)]"

I don't know if I have sinus node dysfunction or not. My doctor told me this was something that would be determined by the scan. But maybe there is some other test that should be performed first?

I should mention that I live in an area classified as "medically under-served." The cardiologists' reception room is almost always standing room only. I think the doctors are doing the best they can with an overwhelming patient load. Still, it is unsettling to be told, "Call if you have any questions," when voice mail may or may not produce a response.

Hi again! After reading the information from the Lexiscan site (5.2 and 5.3) and doing a little more research into your situation, I can see your hesitancy in regards to having this test done with your current symptoms. I misunderstood before. I thought it was regarding the test itself.

You’ve already been diagnosed with Afib and arterial fluttering after wearing the monitor and have tachycardia/bradycardia symptoms, both of which can be complications of sinus mode dysfunction. And that is definitely on the contraindication list of this test, unless those conditions are being corrected with a pacemaker.
If this were me, I’d certainly want reassurance too before going ahead with this.
Digging a little further on various sites, sinus mode dysfunction or, it’s also called sick sinus syndrome is determined with an ECG, an event monitor-ECG which you wear for a few days, a Holter monitor, or an implantable loop recorder that records your heart over a longer period of time if you have irregular episodes of symptoms.

Here’s some information from the Mayo Clinic site on Sick sinus syndrom.
https://www.mayoclinic.org/diseases-conditions/sick-sinus-syndrome/diagnosis-treatment/drc-20377560
In my unprofessional but concerned opinion, it’s in your best interest to get further information from your cardiologists office. I know you’re not very comforted by the fact that they seem overworked. But that should have no bearing on how you should be treated, if nothing else it is all the more reason for you to ask for clarification. Is there a patient portal where you can contact the doctor or a member of his team, Nurse practitioner, to address your concerns?

Hello again, Lori! I am so glad you understand my concern about having the stress test done BEFORE sick sinus syndrome has been ruled out. I will reach out to the cardiologist's office again for more info, as you suggested. Though I filled out a form two weeks ago asking to register for the patient portal, I have yet to receive the e-mail invitation from the office to initiate the registration. (Big sigh.) So to voice mail I will go.

I have this anxious fear of being seen as a "pest," so your encouragement and concern are more comforting to me than you can know! Thank you again!

Lori, thank you for your post. My biggest concern about the scan comes from this note in the Lexiscan prescribing information: "Do not administer LEXISCAN to patients with:
• Second- or third-degree AV block, or
• sinus node dysfunction
unless these patients have a functioning artificial pacemaker [see Warnings and Precautions (5.2)]"

I don't know if I have sinus node dysfunction or not. My doctor told me this was something that would be determined by the scan. But maybe there is some other test that should be performed first?

I should mention that I live in an area classified as "medically under-served." The cardiologists' reception room is almost always standing room only. I think the doctors are doing the best they can with an overwhelming patient load. Still, it is unsettling to be told, "Call if you have any questions," when voice mail may or may not produce a response.

Hello again, Lori! I am so glad you understand my concern about having the stress test done BEFORE sick sinus syndrome has been ruled out. I will reach out to the cardiologist's office again for more info, as you suggested. Though I filled out a form two weeks ago asking to register for the patient portal, I have yet to receive the e-mail invitation from the office to initiate the registration. (Big sigh.) So to voice mail I will go.

I have this anxious fear of being seen as a "pest," so your encouragement and concern are more comforting to me than you can know! Thank you again!

Advocating for your health is in no way being a pest. I second what @callalloo mentioned about, if this were for your child you wouldn’t hesitate to pester a doctor to get the best care. Well, your health is equally important.

So approach this in the perspective that the doctor works for you and is in a partnership with you to keep you healthy. Don’t apologize for asking questions. Knowledge is power. As a patient it’s natural to have questions about your health and the tests being given. In the case of this particular stress test, you see a cautionary red flag considering your symptoms. So be pleasant but remain firm in your resolve to get an answer. Have notes of what you want to say and why you have the concerns.

From experience, a reply for an email invitation to a patient portal is usually pretty quick. So you might want to check into that again as well. But definitely call. Do you ever get to speak with a receptionist or is it always voice mail?

I have sinus nose.now worried.

Your doctor probably just wants to make sure that you don't have any parts of your heart which are damaged and are causing arrhythmia. PVCs are usually benign but with the symptoms you describe your doc is probably just wanting to be cautious and to rule out anything more dangerous.
Nuclear stress tests identify damaged areas in the heart. I haven't had one but they are used to identify areas of the heart that are damaged. These may cause arrhythmia.

I am new to Mayo Connect, posting because I am concerned about a nuclear stress test scheduled for 10 days from now. After wearing a heart recording device I was told the results were "crystal clear" that I have AFib and atrial flutter. Cardiologist told me I needed a Lexiscan nuclear stress test. I asked her if the heart recorder showed any episodes of abnormally low heart rate, and she said no. I know I've had episodes of bradycardia as well as tachycardia. I have a pulse ox monitor for COPD. When I feel faint or out of breath I use this and have seen a number of instances where my oxygen level was fine but heart rate was in 30's and 40's. Yesterday after exertion I felt unwell and pulse rate was between 29-44 for several minutes until I laid down.

I am wondering if the stress test is appropriate when it's not yet been determined whether my problem is one related to electrical activity in the heart? I had the feeling the doctor was not tuned in to what I was trying to say about having had bradycardia symptoms as well. I'd like to hear if anyone else has been through this scenario.

Bay20740