Watch Anthony H. Kashou, M.D., a cardiovascular fellow at Mayo Clinic in Rochester, Minnesota, and Adam M. May, M.D., a cardiac intensivist at Washington University School of Medicine in St. Louis, Missouri, discuss the Mayo Clinic ventricular tachycardia calculator, a practical diagnostic solution that does not require a high level of expertise in ECG interpretation.
Welcome to Mayo Clinic's E C G segment Making Waves Continuing Medical Education podcast. Join us every other week for a lively discussion on the latest and greatest in the field of electrocardiography. We'll discuss some of the exciting and innovative work happening at Mayo Clinic and beyond with the most brilliant minds in the space and provide valuable insights that can be directly applied to your practice. Welcome to Mayo Clinic's E C G segment Making Waves. We're so glad you could join us today. We have an exciting episode planned for you as we share the release of our brand new clinical tool called Mayo Clinic, ventricular Takac cardia calculator. We'll have an expert discussant joining us today who will help us better understand this tool and how to use it. So let's get started discriminating between ventricular tachycardia V T and super ventricular wide complex tachycardia and S V T. By means of a 12 DC G is important for achieving appropriate high quality and cost effective care in patients presenting with wide complex tachycardias, critical patient management decisions, rely on accurate and timely wide complex tachycardia differentiation into V T or S V T A. True V T, ventricular tachycardia, misclassified as an S V T can lead to adverse even fatal patient outcomes. Alternatively, a true S V T that's misdiagnosed as ventricular tachycardia might result in the initiation of potentially harmful medications, inappropriate invasive interventions and increase health care expenditures. Several decades of clinical research have brought forth an ever expanding arsenal of ready to use manual E C G interpretation methods for differentiating these wide complex tachycardia. A central limitation of manual methods is their heavy reliance on the E C G interpreter for their proper execution. Hence, despite the availability of numerous manual E C G interpretation criteria and algorithms, accurate differentiation of V T and S V T continues to be problematic, especially among non expert E C G interpreters. The application of existing manual wide complex tachycardia differentiation methods is commonly thwarted by their improper or lack of use in the real-life clinical practice. Now, given the challenges of properly man, applying these manual algorithms in clinical practice. Mayo clinic, investigators sought to create a practical diagnostic solution that does not require a high level of ex expertise in E C G interpretation. Instead a new general liable, accurate and easy to use tool. The mayo clinic V T calculator was created to assist clinicians in successfully achieving this task. And today we're joined by Doctor Adam May to discuss the Mayo Clinic V T calculator. In further detail. Doctor May is a cardiac intensivist and assistant professor of medicine at Washington University School of Medicine in Saint Louis. Doctor May's research interests are related to the discovery development and refinement of innovative processes to enhance the diagnostic capabilities of automated E C G interpretation. More specifically, his work has led to the development of automated methods designed to accurately differentiate wide complex tachycardia including the one we're gonna talk about today. His forthcoming research seeks to leverage the diagnostic capabilities of artificial intelligence techniques to better facilitate accurate rhythm analysis. Doctor May thank you for joining us. Hello, Anthony. The pleasure is all mine. Well, this is uh you know, really, you know, exciting, you know, I've had you on for a number of times and I love having you on because I continue to learn from you and we start to share more of this important problem. But today we potentially have somewhat of a solution. And so maybe, you know, you could start by telling us what is this mayo clinic V T calculator. Yes. Uh Happy to and and indeed, it is a um an exciting time uh to offer up a a new solution for a historically challenging problem. So the Mayo Clinic V T calculator, it is a publicly available web-based and semi automated tools designed to help clinicians differentiate wide complex tachycardia into V T and S V T. It is a new tool designed for clinicians, those who encounter patients with a wide complex tacho card in their clinical practice. Um And I in with its use, clinicians will receive what we describe as a V T probability or a likelihood that a wide complex tacho cardia is actually a ventricular tacho cardia. Now, this is intended to help providers differentiate wide complex tacho cardias for their patients. Now, the calculator does the following following the entry of readily and routinely available, computerized E C G interpretation measurements. Six total three from the wide complex taca cardia E C G and then three from the baseline uh E C G of the patient, you can get a result of it being V T probability or likelihood that the Y complex tachycardia is indeed ventricular tachycardia fascinating. And you know, before we, you know, I want to ask you about the inspiration, but can you just give me, you know, we talk about the Y complex Tayar E C G, the one presenting in front of us, how, what is considered a baseline E C G just for our audience? Perfect question. So for the sake of uh using the uh Mayo clinic V T calculator, a baseline E C G, it can be defined as the most approximate or nearest baseline E C G obtained before or after the recorded y complex techo cardio event. It's really, really important and I I think you highlight that the, the model can be applied after the event to help facilitate management thereafter. Now, you know, what would you say was the inspiration for creating the Mayo clinic V T calculator. Yeah, absolutely. So, Anthony, you covered this quite well in the introduction. But uh the bottom line is is why complex tacho cardia differentiation is very hard to do um accurate. Why complex taca cardia differentiation is historically difficult with many pitfalls. These pitfalls are mostly related to deficits and E C G interpreter competency in using the available manual methods such as the Brigada algorithm or the VA B. Our algorithms. Also, in most cases, the available computerized E C G interpretation software algorithms that are currently embedded in uh products that we use today do not attempt to differentiate wide complex taca cardias into V T and S V T. They usually just provide a generic term of it being a wide complex Takac cardia which provides limited value for uh the user. So we wanted to come up with an accurate solution that overcomes those barriers and a solution that can be easily applied to almost any uh E C G uh that is encountered in in clinical practice, independent of E C G interpreter competency. Yeah. And, and I I think you hit it on the head. It it's a problem, you know, existing computerized software struggle with this, right? And don't help us differentiate it. So clinically, it hurt and then just the competency, the proficiency of the E C G interpretation skill amongst professionals, you know, continues to, you know, wane or or doesn't meet this and yet this is one of uh one of the most difficult tasks uh to perform. So let's get right to it. How do we actually use this Mayo clinic V T calculator? So great. This is a perfect question. So it basically can be broken down into a three step process. First and foremost, you actually need the 12 lead E C G S. This can't be applied to a single lead tracing specifically. You need two E C G recordings that being the Y complex Taca Cardia and also a baseline E C G. As we discussed, this baseline E C G could be the most approximate before or after. Uh the Y complex taca cardia is actually second, you need to visually identify and then manually enter three routinely available E C G measurements. These measurements are Q restoration Q S A access and T wave axis from both the Y complex taca card E C G and also the base line E C G. You input these values into the web based calculator and then you can get your calculated V T probability. And then third, uh perhaps the most important step is that you need to assimilate and integrate this resultant V T probability into your overall clinical interpretation and analysis. So if the V T calculator says that the V T probability is high, that essentially is a communicating that there's a high likelihood that the uh wide complex tao cardia is actually a ventricular tacho cardia and thereby should increase your suspicion. That white complex tacho cardia is actually a uh a V T in my clinical experience with this uh uh calculator. Anything that uh assigns a, a V T probability greater than 90%. It's, it would be highly unusual for that rhythm, not to be a wide conflict or, or a uh ventricular tachycardia. Now, in the event that the calculator provides a low V T probability, this essentially communicates that there's a low likelihood that the wide complex tachycardia is actually a V T and thereby it should decrease your suspicion that the Y complex is a Y complex Takac cardia E C G is actually a ventricular tactic cardia. And again, in my experience with this calculator, anything that the calculator uh assigns a V T probability less than 10%. Uh It would be highly unusual for it not to be a super uh super ventricular tach cardia or um A S V T. Yeah. And, and, and this is really interesting. So what I'm hearing is that, you know, so long, you know, the manual methods will be applied. But for this one, you're taking three values from two E C G s and you're simply entering them. So you're looking at them and entering them manually, you know, you don't actually have to apply any algorithm and then you insert those numbers and it provides a V T probability just on demand. And the other important thing I heard is that, you know, you have the probability and you mentioned that the high likelihood and the low likelihood, but you also want to uh include potentially other algorithms to help confirm your diagnosis and clinical suspicion. Is that right? Is you wanna also include some other, you know, uh things as you're assessing this. Absolutely. I think uh this uh tool is best used in the context of other tools that are available to clinicians. I would say that this tool uh does a lot in terms of getting clinicians closer uh to the actual underlying diagnosis. However, in I think it needs to be supported by other clinical variables um such as history of myocardial infarction or uh a history of structural heart disease as well as other algorithms uh such as the Regatta algorithm, Lyn lead algorithm for E A V R A algorithm. Mhm Yeah. It's kind of using everything and this is an extremely helpful data point to get you started at least. Now, I I wonder how does this tool actually perform? Yeah. So great question. Uh So overall, I can say that this tool uh performs pretty darn good. Uh So we conducted original research on this issue. Uh And what we determined is that there is strong overall diagnostic performance with good sensitivity and specificity for identifying D T uh on a separate validation cohort. Uh We found that uh the area under the curve or A U C was 0.90. And this was featured in our uh recent paper uh entitled V T prediction model. Um We also observed that there were strong performance metrics across a wide variety of uh V T probability cut points. In subsequent research, we actually found that the algorithm actually helps clinicians in wide complex tacho cardia E C G interpretation. So we found that the tool enhances both clinicians interpretation accuracy as well as their confidence in wide complex techo cardia differentiation. And lastly, we have yet to be published data that will demonstrate that the V T calculator or the V T prediction model uh will compare favorably to existing manual methods including the Brigada algorithm, Brei A V R algorithm and the V T score. It, it it's incredible and I I know this has been, you know, years of work. And finally, you know, this is now available, a tool that clinicians can freely use um to actually improve their accuracy and confidence. And you know, our work together has shown that, you know, with residents and cardiology fellows, it does enhance their ability to do that. And you know, some may say two E C G s. Well, what if I don't have one? And I know there's a lot of work coming and that's already been published to show that's not always needed, but this is a step in the right direction. So what do you recommend for users of the mayo clinic? V T calculator. Great. So um I think users should use the V T calculator results as another data point to influence their final conclusion on what the wide complex tacho cardia actually. Is that being V T or S V T users should use this result with other information that can increase or decrease the post test probability that V is actually present. So this does include, as I mentioned other algorithms uh such as the limb lead algorithm, Brigada algorithm, et cetera. Uh It also should be incorporated with other information uh such as clinical variables. Do they have a history of E T? Do they have a history of uh myocardial infarction? These are important clinical variables that you can add to the overall uh likelihood that A V T is actually present. Bottom line is is that users should use this tool as a device that will assist them in differentiating. Why complex tachycardia not as a tool that replaces their clinical judgment entirely. Why complex tachycardia differentiation is not an easy task? Accurate discrimination is important because it affects the way we manage our patients. While many Manuel approaches help us to discriminate why complex tachycardia they have limitations and heavily rely on the expertise of the E C G interpreter. The Mayo Clinic V T calculator offers a simple, easy to use tool to help clinicians arrive at an accurate diagnosis. We're excited to share that it is now publicly available and you can now access it by visiting mayoclinic dot org and searching mayoclinic V T calculator. Try it out the next time you encounter a Y complex tach cardia and let us know how it performs. Doctor May. Thank you for sharing the mayo clinic V T calculator. I'm so excited to see this tool in practice now released and to see the potential value it adds to clinicians on behalf of our team. Thank you for taking the time out of your day to join us. It's always a true pleasure to have you. You're very welcome, Anthony. It was a pleasure. Thank you for joining us today. We invite you to share your thoughts and suggestions about the podcast at CV education dot mayo dot E D U. 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