David Hurrell, MD, discusses stress testing.
Welcome to cardiovascular conversations with Minneapolis Heart Institute. Your podcast for the best and cardiovascular content. Cardiovascular Conversations is a new, creative and engaging content source for the latest and greatest in cardiology topics and innovation. Way are your hosts, Fred. Um, use. And I'm Jason Hicks. Enjoy the podcast. Hey, everyone, Thanks for listening to MH Eyes Cardiovascular conversations. We're joined by Dr Dave Hurl, who provides both inpatient and outpatient cardiology care with special interests in several modalities of non invasive cardiology. And he's here today with us to discuss stress testing. Dr. Hurl is also recognized for his interest in integrative and complementary therapies. And he was voted 2019, top doc in Minneapolis ST Paul magazine. Thanks for having me a part of the podcast today. Thank you for joining us. Could you just give us a little history on stress tests And then just sort of an overview of stress tests in general, the father of stress testing was really felt to be Dr Bruce. He developed the Bruce Protocol, and to this day, that is still the standard format for doing a stress test that we used. Um, nuclear imaging came along in the late 19 seventies. The big evolution and stress echo imaging occurred when the concept of digital imaging came along. And once they're able to digitize images that allowed them to do a stress echocardiogram, where you could look at resting images and stress images as if the heart were beating at the same heart rate, even though one heart rate was actually twice as fast as the other, we have pharmacologic agents that we now utilized to do stress testing. That's changed a bit. How we do stress testing and who we do it on. Um, and as you know, with the advent of CT coronary angiography, that's had a huge impact in terms of how we evaluate patients and even cardiac emery. The reality is that you know, a lot of these tests are incredibly complimentary, and that doesn't mean that we do it on every patient by any means. Um, but we still utilize all of these modalities to, to a great degree, with a regular old treadmill exercise study. There's sensitivity of that test is in the range of about 70% 70 75%. Our concern is always that one in four tests is going to be wrong. Um, if you are appropriate for a stress test and have a normal based on E K G. The first test should still be a regular old treadmill exercise study. And there's lots of old data out there that tells us that good performance on a regular stress test still gives you an incredibly good prognosis going forward. Are there other things that you glean out of? The stress test, though, is a cardiologists besides just Yeah, I think you're gonna need to go and have a calf now for some of our individuals were actually evaluating them for symptoms of arrhythmia. However, if we're still looking for coronary disease, there's a lot of aspects of the stress test in and of itself that could be quite helpful from a prognostic standpoint, in terms of looking at how long they exercise, what symptoms they have when they exercise their blood pressure response to exercise. Sometimes we know that the patient has coronary disease. We're just trying to figure out whether or not they're at an acceptable risk toe undergo some type of non cardiac surgery. Um, you know, I think it's been proven with many studies that the CT coronary angiogram cannot be incredibly helpful and efficient in evaluating a patient in the emergency room who presents with a reasonable possibility of underlying Cornyn order disease. So if they have, you know the potential for underlying coronary disease, where you feel it's appropriate for them to have. I be contrast and have a CT scan. I think it's a very efficient way to evaluate a patient. And to be honest with you, it's essentially replaced all of the emergency room based stress testing that we do here at Abbott Northwestern Hospital. Then I think one of my big concerns about C T cornea geography is that it's a an atomic test rather than a functional test. So if you have a patient who shows up with a typical symptoms but say some risk factors, uh, and you do a CT coronary angiogram and you identify that they have a 70% blockage in a small diagonal branch, I think I can confidently say that that's an incidental finding. To convince that patient that it's an incidental finding that does not need to be treated sometimes could be incredibly difficult, and it leads to invasive angiography and even potentially stent placement where it was never proven that there was functional ischemia. Alright, Some cool cases with Dr Hurl coming up next case number one. So the first is a 75 year old woman who presents it atypical and some typical chest pain. She has COPD and arthritis. She has a chronic smoking history and she also has hypertension. Her e k g shows. Um, you know, normal Sinus rhythm, right? Bundle, branch block. She's got some bilateral enlargement. How do we evaluate her? Well, can she? Can she exercise that comes down to the eyeball test many times. You know, you gotta look at him and say, Do I really think they're going to be able to do a good job? Actualize or not? And she has a couple points against her because of her COPD chronic smoking. So it's 75. She's been doing it for 50 years, and she has arthritis s. So I'm kind of leading you down a path of suggestion. Eso not not a treadmill. Stress test s well, I think you know, sometimes we try to do these bedside echoes in the emergency department. But these are patients that don't always yield very good images. I'm thinking maybe a stress echo wouldn't be our best choice. That is that correct? I think that is fair because there's the strong possibility that you'll have sub optimal image quality. So then it puts us in that chemical. Can I say Lexi scan here? Sure. Alexis can, uh, you know, eyes. Also known as record Dennison. Most people know it as Lexus can. And I think when we were training, we we heard Diaper animal or a dentist. Do you use those agents much anymore? No. Um, well, diapered animal. I had a really long half life, so it's stuck around for a long time, which meant that people felt lousy for a long time and they would come back to clinic and say, I'll never do that taste test again. When a dentist came along, it's very short acting. It was a great drug, except, um, the difference between a dentist scene. And I think the record Dennison is that record. Dennison may even be tolerated a bit better, and it seems to have less uptake from your bowels. So you get a little bit better image quality. So we all have pretty much transition to the Lexus can at this point. So the Reagan Dennison nuclear medicine study So are we right? You're right. Okay. Right on. Alright, well, alright. So we choose. We've chosen this. So we've sent our patient to you. What happens to her now? So she has rest and stress images, Nuclear medicine images, uh, that are taken, um, and the demographic images so that we can basically slice and dice heart Any. Which way that we want to on the standard format is that we do short access images, vertical long access images and horizontal axis images on. Then we compare the rest images to the stress images. So she undergoes resting stress images, stress images being of course with Alexis can on what we're really looking for is we're looking for a change in the profusion from rest to stress. So if we see a decrease in profusion with stress, that would suggest that there is a blockage in that an atomic territory. However, if we see a decrease at rest and a decrease in stress, that would be what we consider a fixed effect and would be more consistent with scar or previous myocardial infarction. the nuclear medicine study and just a quick digression on that because we have both a pet or SPECT study correct right and is one more common than the other. And why would you use one versus the other? Well, the specs study is definitely way more common. Um, it's, uh, technically much more challenging to do the pet studies, and you have to have a reasonably high volume to make it affordable to your clinical practice. It's a nuclear medicine study. So we're gonna doused her with a little radiation here, too, right? Um, which obviously could be a problem for some of our patients. So maybe this wouldn't be the optimal test for, you know, young person. You have a 35 year old coming in that can't exercise, but the 35 I would certainly choose a to be Domenico over. Alexis can just because of the radiation exposure. When you're 75 years old, I'm not as concerned about the cumulative risk, so a normal Lexus can test. Essentially, you're looking at. If a person's test is normal about a 1% incident rate from the test or what, where we look, that's correct. So if they don't have a history of coronary disease. The data would suggest that they have, ah 1% event rate in the next year. Uh, if they do have a history of established corner disease, then it's more like the 2 to 3%. But it's it's still low risk. And if you look at stress echo image ing in that they're all about the same in the patients who have no known history of coronary disease. Where they separate is if you take a patients with established coronary disease and do the same modalities. That's where the nuclear medicine test tends to shine. Better three event rate again being in that 2% range. However, some studies suggested that echo in known corner disease has a much higher event rate. So what you'll see is that cardiologists tend to move much mawr toward nuclear imaging. If patients have established corner disease rather than echo imaging for those that patient group. Okay, okay. And that probably makes sense to in the sense, in the sense that they're likely to have abnormal echoes at rest, too. I mean, would that be one of the other reasons to move away from absolutely because it's so much easier as a reading cardiologists to look at a normal ventricle at Rask and then determine if it becomes abnormal. Then if I start with an abnormal ventricle and I have to determine if it becomes mawr abnormal. So we've done this test on our 75 year old female patient, and it is abnormal. This one's normal. Is there ever a point at which you say I still I'm worried I'm going to do an angiogram. If you say to yourself if this test is normal, I'm going to stop. Good. But if you say if this test is normal, I'm not gonna believe it. And I'm going to still do something else. Then why do we? Oh, there it is. There it is. Okay, Case number two. So it's a 47 year old man who was atypical chest pain. I called a Canadian kind of angina class to which means that, um, if you think that's the Canadian Cardiovascular Society scale goes from 04 with zero being no chest pain, one occurring with only, you know, really heavy exertion and then to being, you know, a bit lighter exertion, but still exertion That's kind of where he seems to fit. He's got risk factors smoking, hypercholesterolemia, hypertension, um, his e k g at rash, normal sized rhythm with electrical hypertrophy. Do you use any scoring system, or is it mostly gestalt from all the years of knowledge under you're referring to the heart score. I'm referring to Grace, um, referring to Timmy. I'm referring to the heart score, and I mean, I'm not like I said, I'm not trying to box you in here, but it just Is there a mortgage stall for you guys? It is at this point time. It is mortar shell. We don't use the scoring systems that you refer to, like the heart score. The heart score, I think, can be valuable working out of the emergency department. Um, but not so valuable in a clinical practice. So just a quick question about the Canadian Angela class when your patient comes in and they're discussing their chest pain and they say, What's this chest pain, all the boat? Are you more inclined? Thio? Give them a Canadian rating. That would have been funny, except that Minnesotans sound just like Canadians. It seems like this is the kind of guy who could, Who could have some image ing to? Maybe not just a treadmill stress test, but I'm thinking maybe a stress echo with him. But I've always wondered about the Bruce Protocol. I know there's a doctor, Bruce. So what does that exactly mean? Because there's a modified Bruce and Bruce. Then there's a Naughton. I don't not right. What about the Bruce? Protocol, again developed in the mid 19 fifties, really refers to a standardize a time interval, standardized gradation or elevation and a standardized speed. It's been established, is very predictive of determine underlying corner disease. And because we do the same protocol with every patient, it means a great deal to us When somebody says, Oh, they did seven minutes on a bruise is very different than saying they did 12 minutes on a bruise. So this guy, you're thinking stress Eckel for him. I'm kind of thinking white. We can't just put him on. Just put him on the treadmill, let him rip. So, Dr Girl question for the car. Is there a chance we could just put him on a train on? Let him rip what I'm trying to point out with The fact that I say that he's got normal Sinus rhythm with electric car purchase is that he has an Emam electrocardiogram likely reflective of that and left a car. Perch V is one of the classics it causes false positive S T depression in the lateral leads when you exercise, and so it's likely that he's going to have a false positive e k g. Is there ever a hard stop like the Tech lays the camera on this patient's heart and decides how we can't proceed with this? What? What are we looking for before actually starting the test? The classic is aortic valve stenosis. Eso if the tech looks and says, Hey, this patient really have superiority valve stenosis. I think that's why they've got left to go hypertrophy. The second one is, if you think about a guy like this, he's kinda coming in expecting to have a normal left ventricle at rest. And if the tech looks at the heart says, Oh, no, we're starting out with an admirable. Either there's regional wall motion abnormalities or there's global left tackle Hypo Genesis, we might say, I think we're dealing with something completely different, and we need to go in a different direction. You get the resting and then you finally stress them. And then the tech looks at that little stress features and says, How are you? Determine if it's a It's a positive test tonight. So assuming they start out with a normal left ventricle at rest, if you see an abnormal left ventricle with exercise that is in a regional fashion generally. But it could be a cardiomyopathy worth more global. But if it's a regional type almost and Mellie, then you say, Look, that's That's an abnormal test Now, At the same time, we're looking at all those other variables that we would look at on a Bruce Protocol. And that's the E K G. The heart rate response of blood pressure response, Of course. The symptoms. How did he dio? He did awesome. He passed this test with flying colors. You know, it's interesting as we're no doctor. Heralded. Awesome. But how did our patient dio? Well, it it sounds like he's gonna he's gonna do. Okay, we got him to quit smoking. Case number three. All right, you guys 60 60 year old male with prior inferior infarction is admitted with chest pain in the setting of acute bronchitis and active wheezing. He has COPD a barrel chest with limited exercise capacity. Past medical history again is notable for Prime Mark Carney infarction. Ah, family history, diabetes and a former smoker. Alright, well, this one s so I got an e k g. And he's got a normal Sinus rhythm. It looks like he's had an old in fear of my And might I just suggest that these air, like some of the hardest patients Fred, I Can you talk with me about this little boy? I would love to talk to you about this guy. This guy is not straightforward. I don't feel like he is a He is. He falls in that stress category. So we're moving over the chemical or the nuclear side of it. He can't exercise way determined. Looks like he's gonna be able to exercise. So then the record Dennison regularly test is probably not the right test for this gentleman because he's actually coming in with acute bronchitis with active wheezing because not active wheezing. We could get away with it or not get away with it. Right? Because remember, we had our 75 year old lady earlier who had COPD but she wasn't coming in after bronchitis reason, but But you're picking up on the key point of the history is that this particular gentleman is coming in with active wheezing. And he's the kind of individual that you don't want to give Lexus can Thio they see. Oh, not a good idea. See how he hurled a curveball at us like that? Yeah. All right, so we're going to go with a We're going to go with a debuted. I mean, picking w I mean, you get one point for that, but now you have to tell me what imaging modality you put with it. Well, I'll tell you what I feel like I'm learning at a rapid, an accelerated rate here. He has a barrel chest. He's a big seop, dear, I don't feel like I'm going to get good images with an echo. So I'm gonna go with a nuclear medicine. Yeah, you're absolutely right. But you know, a lot of people don't recognize that you can do a w to me nuclear stress test, and you really can, and it it's uncommon test on. That's why I had to add so much history and on this particular patient so that I can narrow it down, that this person didn't fit with anything but a w to me nuclear stress test. So that is the right the right choice. And I put this example in because I think that there this is a common group where a guy has all the risk factors for coronary disease. He comes into the emergency department talking about his short of breath. His chest feels tight. They frequently the Copts who use that word tight. Generally, what we'll do is you know what Say Well, listen, you know, treat the COPD, and if you feel uncomfortable sending them home before we evaluate them further, I would say the debate I mean, nuke study would be appropriate if you become very confident with the diagnosis, just COPD exacerbation, and maybe we can avoid it. And sometimes that proponents can help us there. But as you can imagine, this guy probably is the one that shows up with the abnormal proponents. So now you're uncomfortable. What can we do? The debate, Aminu, because the right way. So if he actually does have a little bump of a troponin. Are we worried that we're going to exacerbate that lesion or that collusion by giving them w you? You do have to be careful. So I mean, I would not stress somebody who you really thought was coming in with unstable angina. That would be the wrong thing to Dio. How did he dio? Well, he did have evidence of his inferior infarct, but it appeared that this was purely a COPD exacerbation and did not represent corner ischemia because that deficit or that defect rather matched the one that he had arrested that restaurant stress images were identical. Demonstrate a fixed, inferior defect to be consistent within factor scar. Is there anything that's going to give us a false positive test on these patients with the nuke studies? Absolutely. So the classic understanding is that in man with a big guts, they're gonna have inferior wall motion, are not almost animals. They're gonna have a profusion defect along the inferior wall which is really due to attenuation. So you have attenuation artifact across the bottom of the heart in women do the breast attenuation you many times we'll see the same thing, but on the anterior side of the heart. It should be a fixed defect, you know, because the belly doesn't move of the breast should move. But everyone, even those move a little bit. And so, as a result, you know, you may see a bit of a shifting attenuation defect, but it should be fixed. And one of the things that we used to help us determine whether or not it's consistent with attenuation artifact is if it's a fixed, let's say, pick into your defect. It should have a wall motion abnormality associate with it. On the other hand, if it looks like breast attenuation and you have very normal wall motion, then it would speak against it being an infarct. Okay, okay, function Very good. Case number four. So the next patient is not showing up to the emergency room, but it's a 72 year old woman with atypical chest pain who is awaiting hip replacement for degenerative joint disease, has a history of hypertension, family history, smoking, EKGs, rash shows, normal Sinus rhythm with some non specific STT wave changes. So now we're getting into kind of that preoperative clearance. How do you feel about this test for quote unquote clearing patients or just that phrase in general, you get council to do that. We don't really like. I don't really like that way. I'm setting you up way Don't necessarily like it either. But I do think that it's it's really important to recognize with a lot of this, uh, stratification that while these modalities have been clearly identified to help risk stratify patients, um, doing any type of coronary intervention has never been shown to decrease their risk. Uh, going forward, Which is kind of amazing when you think about it, because you think if I step the right corner and now they're going to do fantastic was like, Well, it doesn't work that way It does risk stratify between the high risk patients and the low risk patients. But doing intervention, whether it be bypassed or stent placement doesn't really change the outcomes. Eso unless you're having a stem e really Right, Right. But But But for all this other stuff, no, right. I mean, so in this case, So she she comes into her doctor and says, Oh, I'm assuming, like review of systems. Yeah, I've been having this chest pain off and on Well, we should probably talk to the cardiologists about what to do about that. I feel like that. Well, I've had chest pain on and off for 10 years when you know when I do X, Y and Z is Does that, you know, Is that still a fixed lesion that needs to be assessed? Or can this person go to surgery? That kind of stuff, So, yeah, but that might be the example again, as I said earlier, where if you say to yourself, Look, I think at some point we need to establish whether or not this person have coronary disease, and therefore we should do a stress test. Keep in mind. In this particular case, this lady's number one complaint was, Doc, you gotta clear me because I need a new A and then you dig a little deeper and you start to find out they're having some chest pain, which is different than their first complaint being. I've got chest pain. So we decided on the stress test. Okay. And we're gonna go with, um wti mean echo versus could do a nuclear medicine sitting on her, too. Yeah. This is a nice example of where you could go either way. Assuming that you would expect her to have a normal left ventricle and there's no radiation associate with the deputy manacle, I'd probably just do the deputy manacle gives us a functional test. Yeah. So unfortunately, in her case, she ends up with a high rate stress test with positive e k g multiple wall motion abnormalities. She's off the angiography and, um, no history. Yeah, right. You have this abnormal test. What exactly are you seeing on the on the rhythm strip? This is what I wanted to ask before when I asked about rhythm strip. What are we looking for on that with an abnormal test? What would you expect in this situation? Is that because she has some non specific S t two F changes, you're gonna watch the e k G. But you have to be very careful that you don't over interpret it. So let's say she's got some non specific to f changes and you give her the department and she drops her s t segments. Two millimeters. You know, I've got to tell you that that's a that's a non diagnostic stress test from an E K G. perspective, and some individuals will call that abnormal, and it's not. You have to start with normal s t segment normal s T segments. I've fair enough s so it's not gonna not gonna yield as much there. Alright, we're batting. Maybe 300 right now. 50. Case number five. Okay, next up with 7 70 year old man who has corn er disease. The prior stent was left Inter descending corny artery. And he is now awaiting elective abdominal aortic aneurysm. Uh, surgery. His risk are smoking hypertension, family history, E k G. At rest is a left bundle branch block and normal Sinus rhythm. This is a stress test talk, and I'm assuming he's going to get a stress test of some sort. But does this guy need a stress test? This is really a tough one. There's probably, um, gnome or stressful surgery on the heart than an abdominal aortic aneurysm. Open reception. Alright. So choices here, I I see already that this is gonna be a problem for us in terms of doing something that's a little lower on the ladder. Uh, yeah, they like the like, So stress Echo, Bruce, treadmill. All those air out the window. So those are I feel like those air for, um, or low, low risk or moderate risk individuals who have less co morbidity and less risk factors. So he's got coronary artery disease. We're gonna push him automatically into the new. Probably looks bad already. Yeah. So, no, no echo. We're gonna push your medicine nuclear medicine. But I think he probably benefit from, uh, Lexie scanning my Yeah, in my opinion, um, just because I think we'll get better information. We just lean into it. E think we're gonna lean into that one record. Dennison Nuclear medicines. Final answer. Yeah, but you guys got the right answer for some of the wrong reasons. The key factor that you should have picked up on is that this guy has a left bundle branch block, and you don't even have to think you're going to go straight to Alexey. Um, if somebody has a left bundle branch block and just to give you a few pearls pearls on why I feel that way, um, you know, think about from an echo perspective. If you have a left under branch block, you've got very abnormal looking contraction. Now, you may have an overall normal ejection fraction, But it's gonna be a very dissing Quintus contraction. Now, on the nuke side, which you have to keep in mind is that with the left bundle branch block, they have a bit of an altered profusion of their coronaries, which can lead to a false, positive Antero septal defect. So and, uh, if you do, Alexis can, which does not appreciably affect heart rate. Um, you don't get that false positive finding. And so if you look at all our stress modalities, this is the one to go, and I think that it's worth mentioning why not a treadmill in and of itself? Because he has a very non diagnostic electrocardiogram to begin with the left bundle branch block. So you know what you're gonna do imaging and you're gonna do Alexis can Stress is the best choice. E should have known that because I've seen that I've done that with the left on a branch block and pace rhythms, right? Should get Lexus, too, for the same reason, you know. So that was a man idiot. But we knew that we knew that going into this and all right, I'm right there. with you, Fred Going back to a comment I made earlier. If you have somebody who gets on the treadmill and let's say they're exercising and they get typical angina and they have an abnormal E k g. And they have normal imaging And if I'm clearly worried that I may have a false negative stress imaging study, then I would go on to a CT coronary angiogram. This sensitivity of this test is 90% eso You know, you're gonna miss some. And so I do think about that. So he was. He was fine person in his case. Eso his led sand was okay. You could go on to get his Triple A repair. Okay, Case number six way Have a 58 year old man with a recent year visited as atypical chest pain. But prior right? Coronary artery stent. He's obese, hypertensive in smokes. Pain occurs with emotional stress and exertion based on E K G. So some tea way flattening. What can I ask something? If there was something a little bit different about his history, let's say he doesn't complain pain with exertion, and it's just every time I get worked out every time I get stressed out, I get this pain in my chest and you have these abnormalities. Do you? Do you go down the road with him too? I had a great example that a few months ago who got really stressed out at work and we get chest pain. Hey, is now a few weeks following his bypass, you know, and another thing to just keep in mind. And unfortunately, this is too prevalent in our society. But there's a lot of individuals that the most stressful thing they do is their emotions. It's not physical. His e k g. That shows some flattening. Well, I'm going to say I'm just gonna go for broke here. I'm going to say we need to do, Ah, stress echo on this guy. I can't really say that a stress echo is the wrong answer, because it's not, Um, but on the other hand, the little hint I put in here that would kind of fall within my algorithm is that he has an established history of coronary disease. And that's where cardiologists tend to lean more toward the nuclear stress test over the stress echocardiogram, but could certainly go either way. But I still think that the sensitivity, the treadmill and established corners he's a bit better. Okay, so we do get the stress echo on him, and it shows us. Oh, he's normal. We're happy with that. Were reassured. Is there a time in the near or distant future where the CT coronary angiography route? I mean, is it going to replace stress testing? No, Andi. And I think that that goes back to an earlier point I was trying to make about functional versus an atomic. You know, I discuss the risk and benefits of corner intervention all the time, and I frequently tell individuals there is a risk of 1% of stroke, heart attack and death. So I like the functionally the functional testing tells me a lot about Is there a clinically significant lesion that I now have toe anatomically investigate? All right, Dr. Dave Carroll, thank you so much for your time today. I appreciate it. Remember, the Minneapolis Heart Institute has an app for that. Don't go it alone and shoot from the hip when it comes to ordering the right test. The MH I app includes many awesome clinical tools along with their stress test algorithm. So look for this wherever you download your phone. APS thanks again to Dr Hurl for his time and expertise. Thistles. Jason Hicks, along with Fred Um, use Take care. Thanks for listening to cardiovascular conversations with Minneapolis Heart Institute. If you haven't already done so, be sure to subscribe to the podcast. And for lots of excellent clinical tools, be sure to check out the APP for Minneapolis Heart. For more information, please also visit Minneapolis Heart Institute at Minneapolis heart dot com. That's mpls heart dot com and don't forget to review us a swell. This is Jason Hicks, and I'm Fred Meuse signing off until next time. See you soon. Use a reproduction of cardiovascular conversations is forbidden without the express written consent of Minneapolis Heart Institute or Align a Health. Cardiovascular conversations should not be used for legal purposes, and it does not take advertising money. The content is informational only and is not to be used as a substitute for medical decision making or as medical advice. Some of the opinions of the hosts and guests are their own and not those of Minneapolis Heart Institute or align a Health
