Amanda Wilde (Host): A stress test provides valuable insight into your heart health. Dr. Steven Francescone, cardiologist at St. John's Riverside Hospital, is here to break down the purpose, procedure and understanding the results of your stress test.

This is Riverside Radio HealthCast from St. John's Riverside Hospital. I'm Amanda Wilde. Dr. Francescone, you titled this podcast, "My Stress Test is Normal. What now?" What made you come up with that?

Dr Steven Francescone: Thanks, Amanda. Yes, I did. I think it's a very common question that I get from patients after stress testing. And it's very important for them to have a firm understanding of what the results mean moving forward. And I think while it is very good to have a normal stress test, obviously, in some cases, it may not tell the whole story. So, that's why I wanted to put this together and give a little bit more detail into the ins and outs of a stress test and what it may mean for each patient.

Host: So let's back up and describe what a stress test is. What is a stress test?

Dr Steven Francescone: So, a stress test is a functional test or an assessment that we use in cardiology and medicine, which is designed to increase a person's heart rate or thereby increase the demand on your heart. And we can achieve that in a couple of ways. We can elevate the heart rate by physical exercise on a treadmill, which is probably the most common way. Or, for those who can't exercise, we have several medications we use in the process of stress testing that can mimic the effect of exercise to achieve the same end result. And we generally combine that with some form of imaging of your heart, either with ultrasound or with nuclear imaging to capture before and after images of the heart flow or the muscle tissue itself.

Host: So, you're talking about heart flow and how the stress test is an assessment of how your heart functions during physical activity. What does the stress test specifically show?

Dr Steven Francescone: The stress test is actually designed to detect what we call flow-liniting blockages or flow-liniting narrowings. These blockages or narrowings are on the basis of cholesterol buildup over many years. In other words, the stress test is designed to pick up a blockage that prevents blood from freely flowing to normal heart muscle and nourishing it with oxygen.

A flow-liniting blockage requires the artery to be narrowed by generally more than 70%. So, stress tests are designed to pick up those kinds of blockages. Plaque buildup that's less than 70% generally doesn't limit the blood flow, and would most likely show up as normal on a stress test. So, a stress test is a very, very good non-invasive tool that we have, and it's fairly accurate with a sensitivity of about 85% to 90%.

Host: Are there blockages the stress test does not show?

Dr Steven Francescone: Generally not. It would be very rare for that to happen, but there are false negatives that occur. So, in very rare circumstances, a person might have balanced blockages in three vessels all around the heart or,\ blockage of the left main coronary artery, which would, in some instances, show up as normal flow. So, there are very few instances where blockages may be present, either in a balanced fashion the way I just described or a blockage of the left main coronary, where stress testing may indicate normal flow. Generally, though, in those cases, there are other things that are going on symptom-wise where your cardiologist would be able to suspect that there's a problem and perform additional testing where appropriate.

Host: Well, that sort of leads into my next question, which is who should have a stress test? When is it appropriate?

Dr Steven Francescone: So, that's a challenging question to answer. But I'll do my best to sort of give general guidelines. In every case, every patient is different and every circumstance is different, so there are sort of tailored situations. But I'll give you the general ACC AHA guidelines, the American Heart Association, American College of Cardiology.

In general, stress testing is recommended for patients that have symptoms, some form of symptom where it's not entirely clear that it's cardiac. So, there could be potentially a GI component to it, there may be some muscular aspect to it. So, the symptom complex may not be totally clear. In those cases, the use of a stress test is very helpful in helping move the dial one way or another away from or toward a cardiac cause.

In the absence of symptoms, stress testing is generally not indicated with a few exceptions. So if you're a patient who's had prior heart surgery, like open heart surgery or a stent, the guidelines do support performing sort of followup stress testing even in the absence of symptoms after a certain period of time has elapsed and your doctor can guide you on when that's appropriate.

Host: Now, to get to the title of this podcast, what is the followup after I find my stress test is normal?

Dr Steven Francescone: I think to answer that question, we have to go back to one of the questions from before, which is, what does a stress test not show? And I think the whole point of this discussion is to kind of emphasize that stress test is not designed to pick up the presence or absence of any plaque.

for this, you need doctor's intuition, your doctor's skills, and perhaps other diagnostic testing. So, you sort of briefly go over that. There are other diagnostic tests available, which may or may not be appropriate to help someone determine if they have any plaque. There are calcium scores, which have been discussed in other podcasts, which are able to tell us presence or absence of plaque. In other words, yes or no, you have plaque or not. There are coronary CTAs, which are CAT scans with contrast that give a much more detailed visualization of the heart arteries and can give much more information about the characteristics of plaque: soft plaque, hard plaque, perhaps plaque that might be at risk of rupture.

And finally, there's the gold standard test, which is coronary angiography, which is otherwise known as cardiac catheterization. This is a test that is invasive and usually reserved for very, very specific circumstances, acute heart attacks or unstable syndromes. And that really sort of shows us the artery anatomy, exact plaque morphology, and can offer potential therapy in the way of stents, if appropriate.

But in general, if your stress test is normal, it is a generally a good thing and should result in a discussion with your primary care doctor or your cardiologist about managing your other risk factors, your diabetes, your hypertension, your smoking, getting on a good exercise regimen, eating well. And in certain cases, if it's appropriate to flesh out more details about plaque presence, then there are these other diagnostic modalities that are available.

Host: So, a stress test can be an important tool in diagnostics. But it sounds to me like in heart health, the expertise and insight of the doctor is very important. And as an expert in this area, do you have any other thoughts on this discussion before we close?

Dr Steven Francescone: Well, I think if you are considering a stress test, if you think it might be appropriate for you, you should have a discussion with your primary doctor or perhaps consult with a cardiologist who can tailor the recommendation for you.

Host: Thank you so much, doctor, for this insight into stress tests.

Dr Steven Francescone: My pleasure.

Host: That was cardiologist Dr. Steven Francescone. For more information, please call our physician referral service at 914-964-4DOC. That's 914-964-4DOC, or email us at findadoc @riversidehealth.org. If you found this podcast helpful, please share it with others, and you can check out other episodes of Riverside Radio HealthCast online.

This is Riverside Radio HealthCast, the podcast from St. John's Riverside Hospital.