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enseignants",{"title":54,"url":55},{"title":57,"url":58},{"title":186,"group":48,"menu":187},"Produit",[188,189,190,191,192,193,194],{"title":38,"url":7},{"title":65,"url":66},{"title":68,"url":69},{"title":71,"url":72},{"title":74,"url":75},{"title":15,"url":77},{"title":195,"url":10},"Tarification",{"title":197,"group":48,"menu":198},"Mentions légales",[199,200,201,202,203],{"title":197,"url":84},{"title":86,"url":87},{"title":89,"url":90},{"title":92,"url":93},{"title":95,"url":96},{"title":205,"group":48,"menu":206},"Service client",[207,208,209],{"title":101,"url":102},{"title":104,"url":105},{"title":107,"url":108},{"content":211,"related":283,"meta":348,"internal":358},{"title":212,"leadIn":213,"category":214,"elements":217,"becomeAnExpert":251,"author":273,"readDuration":281,"readDurationFormatted":282},"Detecting arrhythmias with ICDs","Discover how ICDs detect arrhythmias and prevent cardiac arrest.",{"id":215,"name":216},1,"Course previews",[218,229,234,239,246],{"type":219,"data":220},"video",{"readDurationInSeconds":221,"video":222},271,{"platform":223,"name":224,"url":225,"size":226},"YouTube","Detecting arrhythmias with ICDs.","https:\u002F\u002Fwww.youtube.com\u002Fwatch?v=ovrISeSxyqU",{"width":227,"height":228},200,113,{"type":230,"data":231},"free_text",{"readDurationInSeconds":232,"text":233},9.333333333333334,"\u003Cp>How do ICD's work to detect arrhythmias and prevent cardiac arrest? In this video, you'll find out why having more leads in the heart provides a more accurate picture of the type of rhythm your patient is experiencing and how to decipher the results.\u003C\u002Fp>",{"type":230,"data":235},{"readDurationInSeconds":236,"title":237,"text":238},14.133333333333333,"Join our ICD Essentials course today!","\u003Cp>Want to learn how to recognize and treat ventricular arrhythmias with ICDs? Take our \u003Ca href=\"https:\u002F\u002Fwww.medmastery.com\u002Fcourse\u002Ficd-essentials\">ICD Essentials course\u003C\u002Fa> and confidently deal with ICDs in a clinical setting. Your instructor, Dr Kristian Webb–a board-certified devices specialist, author, and cardiology education enthusiast based in London–will guide you through the fundamentals of ICD use and troubleshooting.\u003C\u002Fp>",{"type":240,"data":241},"cta",{"readDurationInSeconds":242,"text":243,"buttonText":244,"buttonUrl":245},3.466666666666667,"Become a great clinician with our video courses and workshops","Start learning for free","https:\u002F\u002Fwww.medmastery.com\u002Fuser\u002Fregister",{"type":230,"data":247},{"readDurationInSeconds":248,"title":249,"text":250},132.53333333333333,"Video Transcript","\u003Cp dir=\"ltr\">\u003Cstrong>[00:00:00] \u003C\u002Fstrong>So, it's all well and good seeing that these devices are able to see the heart's rhythm and recognize when the patient's having a cardiac arrest. But I really want to drill down into how these devices are able to do this. So, let's start by having a look at the S-ICD. It's able to see what the heart is doing by creating an electrical circuit, which is actually comprised of a shocking coil, \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:00:30]\u003C\u002Fstrong> the cathode in this example, the box itself, the anode but most importantly, some of the heart tissue itself. So, in actual fact, between the cathode and the anodes, any electrical variations are picked up by the device. So, this probably comes from the heart but obviously, you might have some other muscle, subcutaneous muscle working. They could be picked up as well but the majority of information is coming from the heart muscle itself. So, the fluctuations between \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:01:00] \u003C\u002Fstrong>these two electrodes are then depicted as pretty much a surface ECG. So, in an S-ICD, this is the information you're given. But I really want to emphasize what's great about a transvenous ICD device. Now, these devices give you localized electrograms. As opposed to a complete surface ECG, it's giving you a localized electrogram. So, let's have a look. The circuit in this single-chamber ICD \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:01:30] \u003C\u002Fstrong>is comprised of the tip of the lead, which is playing the part of the cathode and the coil itself, which is playing the part of the anode. You can see the heart muscle, this is slightly exaggerated, just so you can see it clearly, but the heart muscle itself is involved in that circuit once more. But it's only the ventricle that's really involved, so that means that the signal, the information we're picking up, is only from the ventricle. Now, what if we have another lead in the atria as well. What happens if we had a second lead \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:02:00]\u003C\u002Fstrong> and we had a dual-chamber ICD? Well, in actual fact, as opposed to a generalized ECG, we get two bits of information, we have the electrical activity from the atria. So, that's picked up this P wave, but that's not showing on the ventricular channel. But we do have the ventricular depolarization on that channel and the T wave, whereas, we don't see that on the atrial lead. Now, it doesn't look as beautiful as this. In most \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:02:30] \u003C\u002Fstrong>examples, we just see deflections. If we have a look here, at this example of what we might get during a VT, you can see the atrial deflections representing atrial activity, most likely intrinsic sinus beats. But here, interestingly, on the ventricular lead, we're picking up multiple depolarizations, some very fast activity coming from the ventricle itself. So, we're getting two bits of information to help us ascertain what that rhythm is.\u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:03:00]\u003C\u002Fstrong> Now, because there's more ventricular events than atrial events, we can be really confident in saying that this is a ventricular arrhythmia and that's key, that essentially, the more leads you have in the heart, the more information you're able to gain, and that's really useful in determining exactly what rhythm a patient is in. I'm just going to end with a real-life example of a VT from an electrogram and this is more like you'll see if you print out information from a device \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:03:30] \u003C\u002Fstrong>or you're looking at information from a device, using the monitor itself. Here, we have the atrial marker, we can see, okay, they're not regular, so maybe there's a few ectopics going through or something else happening but they're not regular. But if we look at the ventricular channel, we can see that they're more numerous. And again, more ventricular events than atrial events, suggestive of a VT. 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Author and cardiology education enthusiast.","\u002Fteachers\u002Fkristian-webb",[259],163,"3m",[284,311,329],{"id":285,"title":286,"text":287,"image":288,"author":296,"path":304,"readDuration":305,"readDurationFormatted":306,"internal":307},1351,"Starting statins as first-line therapy for hyperlipidemia","Starting statins: how to choose the right agent for your patient, match statin intensity to cardiovascular risk, and monitor effectively after initiation.",{"alt":289,"title":290,"size":291,"location":293},"Healthcare provider discussing starting statins with a patient and reviewing a medication bottle","",{"width":292,"height":292},660,{"bucket":294,"key":295},"public-drupal-medmastery-assets-production","\u002F2026-05\u002FC121(2)_magazine image.png",{"id":297,"title":298,"relativeURL":299,"image":300,"professionLong":301,"profession":302,"weight":262},1563,"Franz Wiesbauer, MD MPH","\u002Fteachers\u002Ffranz-wiesbauer-md-mph","https:\u002F\u002Fmedmastery-backend-prod-kjbeds.s3.eu-west-1.amazonaws.com\u002Fmedia\u002Fimages\u002F9c43cef0-41ee-4005-9e4a-d8711c816401","Franz is the founder and CEO of Medmastery. He is an internist with a specialization in cardiology and a master’s in public health from Johns Hopkins University.",{"name":303},"Internist","\u002Fmagazine\u002Fstarting-statins-first-line-therapy",238,"4m",{"created":308,"updated":309,"published":310},1778960150,1779196374,1778961827,{"id":312,"title":313,"text":314,"image":315,"author":321,"path":323,"readDuration":324,"readDurationFormatted":282,"internal":325},1350,"How to recognize INOCA (ANOCA) on an exercise stress test ","Angina, abnormal stress test, clean coronaries—that's INOCA (or ANOCA), and it carries real risk. Learn to recognize and report it with exercise stress ECG.",{"alt":316,"title":290,"size":317,"location":319},"Illustration of the heart's coronary vasculature showing large coronary arteries and the extensive network of smaller vessels affected in INOCA (ischemia with nonobstructive coronary arteries).",{"width":318,"height":318},1200,{"bucket":294,"key":320},"\u002F2026-05\u002FC17(1)_magazine image_0.png",{"id":297,"title":298,"relativeURL":299,"image":300,"professionLong":301,"profession":322,"weight":262},{"name":303},"\u002Fmagazine\u002Fexercise-stress-ecg-inoca",141,{"created":326,"updated":327,"published":328},1778115738,1778799792,1778118255,{"id":330,"title":331,"text":332,"image":333,"author":339,"path":341,"readDuration":342,"readDurationFormatted":343,"internal":344},1348,"Hyperlipidemia screening: who, when, & what to measure","Testing for hyperlipidemia can help you mitigate your patients' cardiovascular risk. Learn who to screen and when, which measures to request, and how to stratify risk.",{"alt":334,"title":290,"size":335,"location":337},"Lipid panel blood sample tubes used to test for hyperlipidemia in a laboratory setting",{"width":336,"height":336},600,{"bucket":294,"key":338},"\u002F2026-04\u002FC121_magazine image.png",{"id":297,"title":298,"relativeURL":299,"image":300,"professionLong":301,"profession":340,"weight":262},{"name":303},"\u002Fmagazine\u002Ftest-for-hyperlipidemia",246,"5m",{"created":345,"updated":346,"published":347},1777403036,1777572381,1777412421,{"seo":349,"og":351},{"title":350,"description":213},"Detecting arrhythmias with ICDs | Medmastery",{"title":350,"description":213,"image":352},{"alt":290,"title":290,"size":353,"location":356},{"width":354,"height":355},475,281,{"bucket":294,"key":357},"\u002Fmigrated-images\u002FScreen Shot 2018-03-06 at 2.19.48 pm.png",{"id":359,"created":360,"updated":361,"published":360},195,1520342500,1655189586]