Welcome, my name is Dr. Warrick Bishop. I'm a cardiologist, an author and a keynote speaker. I'm CEO of the Healthy Heart Network. I'm all about trying to help people live as well as possible for as long as possible. Heart disease is huge in Australia. Every 20 minutes someone suffers a heart attack. Most of these could probably have been avoided if only we knew what to do. This podcast is all about helping you understand blood pressure, weight, cholesterol for better health. If you enjoy this podcast, I would be honored for a five-star review. You can share it with your family and friends. It may well save someone you love. Hi, my name is Dr. Warrick Bishop and welcome to my podcast and videocast station. And thanks so much for taking the time to listen. I really do appreciate it. Today I'd like to talk about some of the diagnostic testing that we use in cardiology. Let's start with the simple ones like physical examination, where we check the pulse and blood pressure. Pretty straightforward. We also listen to the heart. If you don't remember, that's called auscultation, and that can give us clues about how the valves are working, how the heart's working, and can tell us about fluid in the lungs. ECG which stands for electrocardiograph which is the electrical representation of the function of the heart. Combined with that we can sometimes get ECGs that last for 24 hours or longer. These are called halter monitoring and we would use these when people have funny heartbeats and we want to capture one of those funny heartbeats and document what it is. Pretty routinely, we would get a chest x-ray if we saw someone in accident and emergency with possible heart-related issues. This would show us the size of the heart, but also any fluid in the lungs. And then, importantly, we would get an echocardiogram. This is an ultrasound assessment of the heart and really gives us wonderful structural and functional detail of how the heart's working, compression of the ventricle, the main pumping chamber of the chest, of the heart, but also how the valves are functioning. Then when we think about further testing, we can break it down into what are we looking to evaluate? And I've sort of thought about that in terms of evaluating risk, evaluating symptoms, and evaluating heart function. Well, when it comes to risk, we would of course measure things like cholesterol, blood test, blood pressure, inflatable cuff in the consulting room, but we can also do 24-hour blood pressure monitors, which are incredibly valuable for giving us an idea of what a 24-hour blood pressure impacting the heart is like. We might also check things like fasting blood sugar level to assess for diabetes. Again, we're thinking about risk and risk factors. One of the tools. One of the tests that I'm very passionate about is cardiac CT imaging, and this is a way that we can literally scan the arteries and look for evidence of problems. So risk could be dealt with with those tests I've just discussed. Well, what if we're thinking about symptoms, symptoms of shortness of breath on exertion, or just pain on exertion? Well certainly if we're getting symptoms that occur on exertion often is the case that we want to repeat that exertion and evaluate how the heart performs. We would call that a stress test, putting someone on a treadmill and making them run. And when we do a stress test we monitor the heart several different ways. We would put dots on the chest. and those dots would be a continuous ECG or electrocardiogram, because the ECG or electrocardiogram changes if the heart's not getting enough blood. Why does it change? Well, if a cell is not receiving enough blood, enough energy, then it starts to fail. And the way it fails is that the electrical current over the cell membrane is not maintained. And as you change the electrical current over the cell membrane, and that's in an entire territory or region that's perhaps affected by a blocked artery, then that will impact the ECG. we might combine stress testing with an echocardiogram. That's where we take images of the heart at rest and then repeat them when the patient has exercised. And when we look at the post-exercise images, we're looking to see if the heart function has improved as it should or whether there's a problem with it, which could point to an underlying problem with the arteries. We can also do what's called a perfusion or nuclear medicine scan and we can use isotopes that when we stress people and then inject the isotope, the isotope is then detected by special detectors which show how that isotope is distributed throughout the heart and therefore whether there's areas or regions of the heart that are not being appropriately perfused, i.e. The isotope is not distributing in those areas as it should, and so there's a relative lack of blood flow, pointing again to an underlying problem with one of the arteries. Interestingly, we've got the option of giving people drugs to simulate exercise. If you can't, for whatever reason, because of arthritis for example, walk on a treadmill, We can infuse drugs that replicate and give us an idea of what's going on. And during the infusion of those drugs, we can undertake the ECG, echo or perfusion evaluation that I've just talked about. There's also fascinating technology that is being used fairly... regularly in the United States, less so here in Australia, but this is where you can take a comprehensive CT with contrast of the heart with its arteries and then apply technology to evaluate if there's areas of flow limitation. This is very interesting and I think we will see more and more of this into the future as that technology becomes more and more available. Absolutely fascinating space. Then the other area of evaluation that I've included is evaluating the heart and its function. Well of course echocardiography is our workhorse for evaluating cardiac function and this gives us beautiful images of how the heart squeezes and how the valves are working. But we do have other testing. We can use a blood test which evaluates for proteins that are released by the heart when the heart's under strain. proteins or fractions of proteins are referred to as brain natriuretic peptides or atrial natriuretic peptides and they're released when the heart is under particular load. So these being present in increased numbers or increased amounts in a blood test would support the premise of the heart not working properly. A really valuable test if you're trying to evaluate shortness of breath in an individual who may have, for example, asthma or lung-related smoking-related lung disease, and you might be worried about their heart. A brain natriuretic peptide would point towards their shortness of breath either being lung-related or heart-related. resonance imaging and when we talk about magnetic resonance imaging in the cardiac setting we call it CMR for cardiac magnetic resonance CMR. This is an exquisite test and incredibly sensitive at giving us so much information but it's not easy, it's fairly time consuming and there's a limited rebate in Australia for achieving it but a great test to bear in mind. Lastly, very occasionally and only as a last resort for diagnostic purposes we can do biopsy of the heart and that can be done by a puncture through the neck into one of the big veins in the neck which would be called the jugular vein and then a wire with a clamp or biopsy device at the end can be passed into the heart and small samples of the heart can be taken. Well, that's a whole lot about the diagnostic tests that we use in cardiology and it's possible I've even forgotten some of them. But these are really powerful ways that we can start to evaluate the heart and understand exactly what's going on. Remember we talked about simple tests in the clinic, echocardiography as a fairly standard tool in so much of our cardiac assessment these days. We talked about... the tests for risk, the tests for symptoms, and the tests that we might undertake if someone's heart function were in review. Well, I hope you found that informative and interesting. If you have any queries or questions, drop us a note at info at drWarrickbishop online. And if you've got any ideas for future podcasts, you can let us know as well. For now, I'm going to wish you the very best. Again, I really do thank you for taking the time to listen. I hope you live as well as possible for as long as possible. Take care and bye for now. Did you know that coronary artery disease kills one in four people? So most of us are likely to carry some risk or know someone who does. If you're interested in finding out more about how to evaluate that risk, check out www.virtualheartcheck.com. It will give you information about risk and what else can be done to be even more precise.
