Chapters Transcript Video Navigating Noninvasive Stress Testing: Modalities, Concepts, and Clinical Decision-Making Dr Lynch reviews the various types of noninvasive stress testing modalities and risks and benefits to each. All right, good morning. Thank you all for coming so early. Um, so my talk today is trying to help everyone, everyone navigate through this large field of, um, noninvasive stress testing. And um hold on for one second. Um, so I have no conflicts of interest. In anything, um, in the whole entire medical field actually hopefully um I want to review the various types of non-invasive stress testing modalities, um, the terminology and concept of stress testing, the um understanding of basic indication and contraindication to stress testing and um look at the risk and benefits of various um stress testing modalities. Can everyone actually hear me? Yes. OK, good. There's a lot of background noise, so maybe someone has their um. So not muted if you can um mute your phones, that would be great. Um, so you know the purpose of stress testing is truly to provoke ischemia. Um, we're looking to to detect obstructive coronary disease, um, that are associated and giving the patient chest pain, um, and that's truly what these tests are, um, supposed to show, we cannot detect non-obstructive, um, coronary artery disease. Um, we also are trying to, um, see, um, how patients respond to a medical therapy, um, evaluate if they have any exercise related symptoms. And um in some sorts we assess for chronoobic competence and arrhythmias. Um, And um. Try to see if we can um actually um bring them out during the stress test. So when we choose a stress test, we uh basically um look at three basic questions. What's our pre-test probability of coronary artery disease? Um, are there any conditions precluding um a diagnostic exercise, um, EKG stress test, and can the patient exercise? Um, so in the all fall over Centao system, we have 1% um um of um chief complaint of chest pain, and that doesn't mean that, you know, after a while, you know, we actually see that we can go up to 15% um associated chest pain um symptoms during the visit that are being addressed. Um, there's a ton of variabilities, um, for chest pain. What I always tell my patients is that our brain is not really good at detecting anything, um, or discerning any chest pain between your diaphragm and your neck. So any pain that happens between your diaphragm and your neck, the body, um. thinks it's chest pain. Um, Good. So how to see these patients when they come to the office, um, basically, um, we think about um the chest pain presentation, then we determine the pretest probability, and then we determine the most appropriate chest test modality. So Aina for um being. Um, categorized in typical and atypical, um. Is is a pretty straightforward um assessment if it's typical, so typical andre has a pressure-like comfort behind the mid sternum um that radiates into your left jaw, left shoulder, or left upper arm, um above the elbow. Um, It is brought on by exercise and released by rest, um, or released by nitroglycerin. Um, And um all being brought on not only by exercise but also by emotional stress. Um, so these are our typical chest pain. You usually will see that males will have um a significant higher incidence of typical chest pain. Um, and females have a much higher incidence of atobcal chest pain. So atycal chest pain is, um, anything that doesn't fall in this chest pressure category. Maybe the patient has a little bit of a harder time describing um the pressure. Sometimes um they think it feels like reflux, it's a more sharp burning pain. Um, it could be, um, located on the right side, not mid sternal, um, it could be just in the jaw or just in the shoulder, sometimes it's just in the back, um. What should happen with obstructive coronary disease, that even this atypical chest pain is brought on by emotional or um exertional stress and relieved by rest. Um, So you have to really go back and talk to the patient over the last 3 to 4 months. Have you had any symptoms, you know, say it's just my lower side of my jaw hurts every single time I fold laundry. Over the last 3 to 4 months, have you, um, have you noticed that every time you sit down, it goes away and that comes on when you try to do your laundry, um. Sometimes patients present actually much more advanced, they wake up in the middle of the night or the pain um occurs at rest, which is progression of a severe stenosis above 90%. In this case, you have to actually go back and see was it initially um. With exertion and relief by rest and then it progressed into a resting picture, or has it always been um at rest and randomly? Randomly and at rest does not sound like cardiac pain, but once it um you get the history of it, um, and you always have to go probably back 4 to 5 months. So this is just what I said. Men are definitely at much higher um rate for having typical chest pain, um, women are more atypical. Um, let me look at the pre-test probability. So we want a high pretest probability, um, in order to get a, um. Um, uh, a higher predisposability in order to get an optimal stress test result. Um, When I determine the stress test modality, patients have to um be able to walk more than 2 flights of steps or um 2 blocks um without getting any symptoms, um, you have to document it in the chart in order to get insurance approval um for the exercise and reverse, you have to document in the chart that they can't do so in order to get a pharmacological stress test. We're looking at body habitats, um. Our echo echocardiographers know that um you know, the, the larger the upper thorax and the larger the um breasts are, the harder it is to get um pictures on um on these patients, um, and same thing actually with nuclear stress testing as well. And then we have limits on our um weight limits on our tables um that we have to um be aware of as well. So what kind of methods can we do? We can do exercise, treadmill, and bicycle. Biye is actually the primary stress modality in Europe. I was very surprised when I came to America several decades ago that um treadmill was used um and now I'm very surprised about the bicycle in Europe. So both um modalities work really, really well. I think Santera only has the treadmill options. And then we have the vasodilator pharmacological stress agents with ri adenozine, adenosine and the irriamol um that we can use um for our echocardio um stresses we have to buttamine. That was um for the last year, um, not available and is now more available we're still caution to use. Um, and that was due to manufacturing issues, um, we can, um, use electrocardiography, echocardio echocardiography, myocardial perfusion spec imaging, and magnetic resonance perfusion imaging to, um, detect ischemia. Um, so, Ischemic findings on the stress testing we're looking for signs and symptoms, reproduction of chest symptoms, um, chest pain symptoms or blood pressure changes in response to stress, ST segment elevation or depression on EKG, regional bone motion abnormalities on echocardiography, um, and perfusion defects on myocardial perfusion imaging. So what are our complications? And that's when we choose the stress test, we always, you know, I always assume worst case scenario. What is my risk of that the patient basically falls off the treadmill um. Hurts himself, um, do they have the coordination or the mental um stability to exercise? Um, how well is the hypertension controlled? Um, how is the um probability of that the patient will develop arrhythmias? What do I think, um, well, um, and is the risk of developing an MI and then stroke or death, um. Actually my first ever stress test conducted as a fellow. My patient was exercising on a treadmill, went into ventricular tachycardia and needed to be resuscitated, so it taught me to be humble. It never happened since, but I think it was just a sign to be humble in what you wanted to order on your exercise stress test. Um, absolute contraindications to stress testing is an acute myocardial infarction within 2 days, elevated troponin levels, and I think um I had. So far in our system, um, our, um, stress test, um, uh, colleagues are really good in looking at troponin and discussing this with the physician, um, ongoing unstable anginal symptoms, the patient is having active pain um before the stress test, absolute contraindication. If this active pain is from a plaque rupture and if you have a 90% lesion, you obviously do not want to cause more stress on the heart. Um, higher risk pretest probability of um. Unstable angina and uncontrolled cardiac arrhythmias, so this patient has a history of ventricular tachycardia that was um induced on the last stress test. You probably not want to um stress this patient again, so good thorough history with that. Decompensated heart failure patients who cannot lie flat, um, who have significant um fluid on board, um, also not. Um, an indication symptomatic severe aortic stenosis, um, and that's why, um, we require an echocardiogram for most of our nuclear stresses so that we can see this, um, and a good history, um, before you put someone on a treadmill, acute pulmonary embolism, um, acute myocarditis or pericarditis, and um the risk of an acute aortic dissection aneurysm or an active dissection. All absolute contraindications. Um, relative contraindications are known obstructive left main coronary artery stenosis, moderate to severe aortic stenosis, um, with tachy arrhythmias, um, and acquired high degree of complete heart block. Um, hypertrophic cardiomopathy with a severe resting gradient, and then again your cognitive impairment, um, and risk of not being able to cooperate. Um, and another one is, um, resting blood pressure above 200, um, systolic and 110 diastolic. So stress testing and pregnant patient, so, um, you, you might all have heard about Ventera's new Cardi B program, uh, where we see our um high risk um cardI B patients. That means they have an underlying um heart condition. I'm just gonna skip forward, um. And then backwards, so, um, when I see patients in my cardio B clinic, um, we are looking um sometimes to um to check these patients, so why do we do this? Because we're trying to come up with a delivery plan that's healthiest for the mother as well as the baby. Um, there's several modalities of delivering these patients, all of the modalities have different type of stresses to the mother and the baby. So what we usually do, we look at a carpa score on these patients um and calculate um a risk score. Um, the car score has, um, a predictor of prior cardiac events, um, heart failure, the history of a mechanical valve, ventricular dysfunction, decreased ejection fraction, um, or left ventricular a shart obstruction, pulmonary hypertension, history of coronary artery disease, uh, high risk erotopathy, that's your alodelos patient, um. And um then takes an account um if the patient had any intervention on what they had before or how late they arrived to us in pregnancy. We usually try to conduct the stress tests around 32, 30 to 32 weeks, sometimes a little bit earlier um because um they might need to be delivered earlier. Once we assign points to the patients, um, anything above a car park score of 5%, if I have um the suspicion that the patient has exercise intolerance, um, we'll get an exercise um stress test and sometimes an exercise stress echo. Um, if you look at, um, the carpasto, um, everyone's confused sometimes of the prior cardiac events or arrhythmia, so any history of heart failure with prior pregnancy, um, or any kind of cardiac history within their lifetime, um, counts as 3 points, which already shows you that, um, your predicted risk of primary cardiac event during your pregnancy is 15%, pretty high risk. Um, So Stress pain usually is very similar to in pregnant patients very similar to um the patients and the non um pregnant patients um with uh um one caveat that um the patient should not be in active labor or should not have any contractions prior to the stress testing, um, so what you wanna ask the patient is um. How are you feeling? Um, do you have any contractions? Do you have any abdominal pain? Um, if they answer that with yes, um, they do not exercise and the stress test is canceled. Um, I need at least 4 minutes of exercise to make a diagnostic test. Um, labor is slightly longer, as our females know, um, and we need to reassure that we reproduce some of the symptoms, so they need to stay on that treadmill for more than 4 minutes. Dubutamine is contraindication and obviously is radiation and pregnancy, so our only options are treadmill stress testing and um stress echocardiography. Um, So you will see most of the time um the history of heart disease um women who have had prior cardiomyopathy during their pregnancy, severe eclampsia or severe um preeclampsia with severe features, um, or a history of pulmonary hypertension, um, women who develop gestational diabetes or gestational hypertension during the pregnancy, and then the grunt of it is gonna be. Unexplained atypical chest pain symptoms or worsening shortness of breath that um has to be investigated further. Shortness of breath is a very difficult complaint during pregnancy. Pregnancy by itself is associated with increased shortness of breath. Um, it should never occur when you or never worsen when you mildly exercise, and if the patient comes to me with complaints of worsening, exertional shortness of breath during mild exercise, um, and I cannot find a cause for this, um, I usually order um a treadmill stress test. And the 3rd trimester. So, what we um actually, you know, just talked about exercise should always be the preferred method of stress regardless of what imaging motality we choose um it provides us physiological data including heart rate response, blood pressure response, and heart rate recovery, um, which again is extremely important for our pregnant patients um and it allows us for evaluation of exercise induced arrhythmias. Um, contraindications again, um, mental, um. Cognitive decline and significant orthopedic issues, unsteady gait, um, and those who are unlikely to achieve 85% of their maximum predicted heart rate. Um, if that is the case, we can use vasodilators, um, um, and, um, can create with a steel phenomenon in stenosis vessels that then will produce ischemic finding on imaging. contraindication to ra adenoso is severe reactive every disease and serious for arrhythmias, um, with AV conduction defects. Um, they can have, um, caffeine prior to the procedure, so we try to do it 24 hours, no caffeine prior to the procedure. Um, I think current guidelines are. Get me wrong, 6 hours. Um, prior to the procedure, but if someone knows different, you can totally interrupt me or share with us later. Um, it makes sense, you know, the half-life time of caffeine is, is, is clearly shorter than 8 hours, so, um. But just for patient safety, we should say 24 hours. Dubutyine um is my least favorite uh modality of stress. It's extremely unpleasant to the patient. Um, I had a dum and stress test in the past and since then have been a nice converter not to use it anymore. It stimulates your cardiac beta adrenano receptors and results in increased heart rate and contraction, which makes you feel absolutely lousy, and it has to be told to the patient prior because they get very scared during this period. Um, they must hold the beta blockers, um, prior to the procedure, depending on the beta blocker, you have to see how long you have to hold it, usually 3 half-lifetime, um. And it can cause some significant um ventricular arrhythmias. Um, So methods on detecting ischemia now um we can use EKG um with our physiologic data, um, but we cannot really um with the EKG localize um or the distribution or um assess the extent of myocardial ischemia, we can basically just say um there's myocardial ischemia. Present, it has a pretty high positive rate in women just because our diaphragm doing exercise um moves differently than in men, and we also have some significant um breast um changes. So with that, um, women have a significant um higher false positive rate. Contradications to EKG stress testing of the funnel. Left bundle bench block, um, left ventricular hypertrophy with repolarization changes, digoxin therapy, ventricular pace rhythm or WPW. Um, so with the exercise stress test measure, we look at heart rate response, blood pressure symptoms, and our exercise capacity. Um, maximum heart rate is predicted at 220 minus 8 in years. Um, an adequate stress test has 85% to 100% of maximum heart rate, um, and a suboptimal stress test is less than 85% and will be deemed as non-diagnostic. Um, measuring a functional capacity is um done in Mets. Um, so one met is watching television, 4 mets is light household work, 10 mets is a competitive soccer, or let me tell you this, our fishermen are also at 10 mets of activity or our construction. Workers when they um work outside in the heat, um, especially our concrete things, so you kind of have to like think about, you know, what your patient does on a regular basis and I always compare it to like a light jog or run, um, your patient should probably go above 7 that has some significant um um predictability if they. Can go above 10, even better predictability, so we should always push our patients if we can to do as much of um functional capacity assessment as we can. Once we get above 10 meds, it has a very good predictability, um, and you see us very happy once we see the 10 meds assessment. Um, positive exercise stress and is defined as more than 1 millimeter of horizontal or down slipping STs measure after the J point, um, and I, um, showed you in that 123, 4th, um. And first picture, um, where you see these ischemic changes happening, there's a lot of false positive uh or equi equivocal um EKG responses that um come with this, and in the setting, as you can see, um, stress is interpretation of an exercise EKG is sometimes very difficult, especially if you don't have a clear baseline because the patient is breathing harder or the EKG leads are not staying on the right wing. We calculated Duke's um treadmill score, which is extremely helpful for predictability. Um, it's exercise time minus 5 times maximized segment deviation in millimeter minus 4 times treadmill and index. Um, with this, we get a low risk, um, moderate risk and a high risk, um, calculating the score. High risk patients have a very poor prognosis um and definitely should be um referred for direct cardiac um angiography, you're moderate risk, um, we should uh add imaging to this. Um, echocardiography, uh, I was so, um, so funny when I this is widely available, everyone knows how hard it is these days to get an echocardiogram, um, it's at intermediate cost and, um, has no radiation, um, or, um, side effects to the patient, um, and, um. Can help us to distribute um the extent of coronary artery disease and distribution of coronary artery disease due to one motion abnormalities. Um, we look at, um, pre-imposes of left ventricle wall motion. We are not looking at valve problems, so you know, when the primary care physicians get the stress test back and say, oh, the stress echo was normal, I'm like, yeah, but you didn't look for valvular issues or any other um um anatom. Like valvar findings um on the echocardios you still have to order full to the echocardiogram um in addition to your exercise stresses if you're looking for any anatomical or functional problems, um, obstructive coronary disease results in regional low motion abnormalities, um. It does require a very fast transfer from the treadmill to the exam table, so the patient has to be able to be agile and get off the treadmill onto the um bed, which poses some significant problems and is limited by body habitats, lung disease, and breast implants. We have a dubutamine stress uh um echocardiogram and and stress stress protocol in um patients who cannot exercise, it comes with um acceleration of doses and dubutamine um it's easier for the patient to go um um to to have the stress images done, but it comes with significant discomfort of the patient. Oh, myocardial effusion spec imaging, um, is the underlying principle that under conditions of stress, disease, myocardium receives less blood flow than normal myocardium. It uses utilizes radioactive isotopes that is absorbed and retained by viable cardiac tissue, um, and it reveals. The distribution of this radioisotope and therefore the relative blood flow to the different regions of the myocardium, and what we do is we compare stress images to images and look at basically color changes that are produced by the program. As you can see here, we are looking at um the collages of the um inferior wall um from orange to purple and well we think there's a profusion defect in that segment. Um, this is a picture of a myocardial perfusion imaging stress test. So who's the optimal patient, um, someone who's unable to perform a treadmill stress test, underlying left bundle bench block, pacemaker dependent patients, obese patients with caution, and um someone who has very poor acoustic windows on echocardiography. It's expensive, it's time consuming, um, it comes with significant radiation exposures and it can cause significant artifacts from breast tissue, diaphragm interference and extra cardiac traer uptake. Um So the sensitivity of nuclear imaging is 87 to 90%. Stress echocardiogram is 70 to 100%. The specativity is and the stress echo is much more wider, between 50 to 100%, and much less wide in the nuclear imaging stress test. As you can see actually the exercise stress test doesn't do so super bad in this sensitive and sitivity issue either. Um, how do we make these better? We make this better by calculating pretest probability so that we can increase our sensitivity and decrease our sensitivity. Um Again, we're looking at pre-test probability of coronary artery disease in order to choose the right test, um, we're looking at conditions that are precluding exercise stress testing testing. And um. We are basically choosing between all these different um modalities, um. Um, monitoring the risk and the benefits for the patient. And that was my talk. I hope I'm exactly at 30 minutes. Any questions um. For a commons. Published August 6, 2025 Created by Related Presenters Petra Lynch, M.D. CardiologySentara Cardiology Specialists View full profile
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