Welcome to Dr. Warrick's podcast channel. Warrick is a practicing cardiologist and author with a passion for improving care by helping patients understand their heart health through education. Warrick believes educated patients get the best health care. Discover and understand the latest approaches and technology in heart care and how this might apply to you or someone you love. Hi, my name is Dr Warrick Bishop and welcome to my podcast and videocast station. Today I'm delighted to have with me Dr Alistair Begg, a colleague and cardiologist from Adelaide. Hi Alistair, how are you? Hi Warrick, thanks for having me along. Thank you, thanks for your time. And today I'm pretty keen to talk about some of the monitoring we do when we commence people on medications, whether that's... cholesterol lowering medications or say blood pressure medications or even medications to deal with funny rhythms of the heart. So we do all sorts of stuff to monitor our medications. Let's start off by thinking about perhaps the blood tests we might do in monitoring someone who we've started a medication in. perhaps for lowering cholesterol. How would you go about that, Alistair? Sure, Warrick. Well, look, like all doctors, they want to see what the effects of a drug is, but they also want to see the side effects of it. So what's the unintended consequences of giving a drug? And the way we monitor patients is often with blood tests and cardiology. So we're looking for the effectiveness of the drug, but we're also looking for the side effectiveness of the drug. And there are various drugs that cause problems with either the muscle or the liver, and statins are one of those drugs that need to be monitored periodically. So when you monitor the effectiveness of the drug, you're also looking for side effects. And you can monitor a blood test called the creatinine kinase or the CK. And that's one way of looking for any subtle muscle damage from the drugs. And you can also monitor the LFTs or the liver function tests to look for a side effect or a subtle inflammation of the liver that can sometimes happen with statins. And I stopped a statin this week, actually, on a patient who had a liver function test that were greater than three times the normal range. just in the possibility that that was a side effect of the statins. And I'm going to recheck those blood tests in six to eight weeks just to see if the liver abnormalities have resolved. So you said three times greater liver abnormality and you mentioned a blood test called CK or creatinine kinase. When you're checking these bloods, If they're elevated at all, is that a concern or is there a certain threshold that would trigger your concerns? Well, people can have a slightly elevated CK and not have any symptoms. And sometimes that can just be normal for them. So having a baseline is often a good thing and looking at the changes over time. So going back to see what the baseline CK was. And also... looking at what they've been doing. I mean, if they've been out in the garden or if they've just had a marathon or something like that, then that can cause a CK to go up as well. So there's lots of different causes for CK elevation. If they're particularly dehydrated, the CK may go up due to a problem with dehydration. So there's all different causes for the muscles to get some damage. But if you're on a statin, it potentiates that effect, so it makes it more likely to happen. So in a sort of a mild elevation of the CK, you may just watch the patient because you may assess that the benefits of being on the drug are greater than the risks. And so every time we look at these tests, we have to factor in the benefits and the risks of the drug. Of course. Look, I had, talking about that CK elevation, I actually had a patient who was in his late... 40s towards early 50s in that sort of age range. I'd commenced him on a cholesterol-lying agent, a statin, and had put in place some blood tests down the line to follow up, in fact, on the CK. Well, I got called from the laboratory telling me that this man's CK was nearly 7,000, and to put that into context, normal reference range is less than 250. So this was way, way over the top. And immediately I tracked down this man to find out what was going on and called up and said, how are you going? He said, oh, I'm fine, doc. What's up? Well, first of all, I was pretty pleased to hear he didn't have any problems, pains, side effects or complaints. So a great starting point. I said, well, look, your muscle enzyme tests are up a bit. Have you been doing anything sporting wise or exercise wise? Just like you said, Alistair, it turned out this gentleman had played a very physical game of soccer the day before his blood test and without question was kicked, thumped and exercised, all contributing to his CK going up quite high. I'm pleased to say that subsequently we rechecked without the exercise and all came back down toward normal range. But you're exactly right. These things fluctuate a lot. As you say, not only the number but also the symptoms the patient has with it can be really important. What about the sort of testing or monitoring you do for someone you put on a blood pressure therapy, Alistair? Sure. Well, look, some medications can have unintended consequences. Typically, when we're talking about monitoring of blood tests for patients starting blood pressure tablets, There are certain drugs called the ACE inhibitors that potentially can cause the kidney function to deteriorate. In an older patient where you might be worried about the arteries to the kidney, it's important to check the kidney function periodically, particularly in the early stages of starting these drugs. You can actually get quite a drop in the kidney function with certain drugs. And the other one to watch for is the diuretics. Diuretics can affect your potassium in the blood and they can also make you dehydrate. And the ACE inhibitors can also affect your potassium as well. So there are certain blood tests that need to be monitored with blood pressure drugs independent of monitoring for any side effects and checking the blood pressure as well. Look, I do exactly the same, Alistair, for those blood pressure agents, the ACE inhibitors and the angiotensin-2 blockers. And I also... particularly for blood pressure, I also like to do some monitoring of blood pressure to check the results. So I'm a very frequent user of 24-hour blood pressure monitoring so that we get beautiful averages over a 24-hour period and get a real sense of what a person's blood pressure is like through the day. So I tend to repeat 24-hour blood pressure monitors as well as track the bloods to get that feel for the effectiveness of our therapies. And good news, actually, as an aside, I believe that we may see a Medicare item number for blood pressure monitoring sometime in the near future. So I don't know if you use them a fair bit. I guess you do. Yeah, I find them particularly useful for the early stages in working out whether someone has what's called a white coat syndrome or a white coat hypertension. And, in fact, in the UK, I believe that before starting a blood pressure tablet, you actually have to prove that the patient has elevated blood pressure on a 24-hour blood pressure monitor. They believe very strongly in the cost effectiveness of doing these tests. And, of course, if you can stop someone having a tablet they don't actually need, it's going to save money in the long run as well. And reduce side effects. Sure. Well, sometimes... People get side effects because they don't actually need the tablet. Yeah, yeah, absolutely. Our monitor will provide you with much better starting point for that patient. It sounds like a very sensible English thing to do. So, look, we'll talk briefly about rhythm management and monitoring around rhythm management. Is there anything in particular that jumps? into mind for you there, Alistair? We're talking atrial fibrillation or VT or just funny heartbeats that we've settled down with something. Is there anything you'd keep an eye out for there in terms of monitoring? Sure. Well, once again, I mean, like similar to the blood pressure story, you're obviously monitoring the patient's heart rhythm to see that the heart rhythm medication is effective. So that might just be monitoring symptoms, monitoring pulse, doing periodic ECGs. looking for side effects on the ECG, for instance. Some of these rhythm tablets can actually make the ECG look a bit worse, and that might be a reason to change to a different one. Some of the rhythm tablets have specific side effects, so they may need blood test monitoring. They may need to have the blood test levels checked for the drug. And also some of them can affect your thyroid function or your liver function. Amiodarone is one that comes to mind when you mention atrial fibrillation. And periodic checks on the thyroid function and liver function tests are done to monitor for side effects on that drug. Some of the drugs can affect the ECG, as I mentioned before, and there are certain drugs such as Socolol where the ECG needs to be monitored to make sure that the patient's not going to get a nasty side effect on the heart rhythm. So there's an interval called the QT interval that needs to be monitored on the ECG for those drugs. So every drug has a particular thing that needs to be watched for that particular type of drug. And that's where your cardiologist should be able to put you on the right pathway to taking the drug safely. It's true. Look, one of the agents I use a fair bit of is fleconide, again, an atrial fibrillation drug. As you mentioned, with sodolol, which is used often for atrial fibrillation, flecainide toxicity can also be picked up on the ECG through a different change in characteristic to sodolol, but nonetheless, one that can be picked up on ECG. And my practice is to see people either six-monthly or 12-monthly for a standard ECG if they've got a history of atrial fibrillation that's managed on flecainide therapy. plenty we can do in amiodarone. For those who are listening, cordarone, amiodarone, do make sure that that thyroid is checked and those liver functions are checked. Alistair's quite right. In Tasmania, the incidence of thyroid abnormality on amiodarone is around 25% of the population taking amiodarone will have some thyroid effect. Well, I'm going to pretty well wrap up the monitoring interview now, Alistair, unless there's anything burning you wanted to offer? Look, I think the main thing is that people are aware that at the end of the day, we always make that decision based on risk and benefit. And we discuss the benefits and the relative benefits and risks with the patient. So involving the patient in the decision making. I find engages them and they've got more buy-in and more likely to be happy to take the medication. Yeah, of course. Look, by way of quick summary, we need to look for the things that can go wrong with medications, which might be blood tests, as Alistair alluded to, but could be showing up in something else like the ECG. But we also need to look for evidence of efficacy or effectiveness of these medications. So that might be rechecking. the cholesterol level, rechecking the blood pressure, rechecking rhythm irregularities. And so we're constantly testing the effectiveness of our therapy and looking for potential side effects. I'm going to wrap it up there. I think it was a really useful insight into what we think about as we're dealing with patients who are on medications long-term. I hope you've learned something from it. Alistair, thank you so much for joining me today and sharing. Pleasure, Warrick. Thanks for having me along. For anyone listening who has any queries or questions, drop us a note at info at drorichbishop.online. If you've got any suggestions for future podcasts, let us know. Please join us next time. For now, however, thank you for joining us today. Take care and please don't die from a heart attack. Goodbye. You have been listening to another podcast from Dr. Warrick. Visit his website at drWarrickbishop.com for the latest news on heart disease. If you love this podcast, feel free to leave us a review.
