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Video version https://youtu.be/abGsk9x7ax0 Non-Invasive EPS – Fact or Fiction? We’ve already discussed the use of CRM devices to monitor and manage arrhythmias, but what about using the leads to gain more information about the root cause of the problem? We can use the information from the separate leads during, for example, a tachycardic event to analyse and really find out what’s happening to the patient. This is good for the patient as it can mean avoiding further invasive EP studies, and helpful for us because we can make a more informed and timely decision about treatment routes. One of the first things we’re taught when learning to interpret EKGs is not to trust the machine’s report without checking it out for ourselves (STEMI or LVH, anyone?); maybe we should take that a little further and make sure we agree with our CRM devices! <Slide 1 Initiation of Short RP tachycardia> Let’s start with an example – the arrhythmia report here tells us we’re looking at an episode of VT, but we notice that the atrial and ventricular rates are around the same rate – 144/145bpm. The A-sensed lead and V-sensed lead show that we start off with A-paced beats followed closely by V-paced beats… all good so far. Then we see that the episode of tachycardia starts with a premature atrial beat – and we know that VT typically starts with a ventricular premature beat. Is this really VT? Could it be SVT? Then we see a run of atrial premature beats, each followed – eventually – by a ventricular beat. So it looks like we’re seeing an atrial rhythm with a very – VERY – slow pathway. Our atrial premature beat did have a V-paced beat afterwards, but the conduction pathway is so slow… could the premature beat have blocked the fast pathway, forcing conduction through a slow pathway with retrograde fast pathway conduction? So we now have a slow-fast SVT; typical of atrio-ventricular nodal re-entry tachycardia (AVNRT). With AVNRT we have a re-entry circuit going round the AV node Now, this patient has a device with an atrial electrode and a ventricular electrode, and these devices have the capacity to do basic EP studies without any further invasive procedures. So we can use this device alone to further our understanding of the patient’s needs, with none of the risks or costs associated with traditional EPS. Wonderful! <Slide – Use of devices in EP lab (initiaton/termination)> Here we have a report from a St. Jude’s dual chamber pacemaker in a female patient who was admitted to hospital with serious symptomatic palpitations and pre-syncope. We had been unable to catch one of these episodes on a 12-lead EKG, but they were convincingly cardiac, at high risk of causing injury to the patient, and so we really needed to consider treatment. Should we do EP studies with a view to finding a source of arrhythmia and ablating? Traditional EP studies, although generally very safe, are not without their risks. It’s an invasive procedure where we introduce tubes through a blood vessel into the heart. There’s a risk of bleeding at the insertion site, and a risk of trauma anywhere en route to or within the heart. Although they’re done in aseptic conditions we can’t rule out the possibility of infection, and in this case the patient had a known blood-borne virus which always increases the risks to the staff involved in her care. Luckily, we knew that this woman had a dual-chamber pacemaker, with an atrial and a ventricular lead. In this case we were able to use her pacemaker to do an atrial drive at 700milliseconds – we can see two beats conducted from the atrium to the ventricles… then we initiate a premature atrial beat which actually triggered 8 beats of SVT – supra-ventricular tachycardia. At this point the patient confirmed that this had reproduced her symptoms of palpitations and feeling pre-syncopal. So we were able to make a diagnosis, based only on EP studies conducted through her already implanted device, of AVNRT. We can see that her premature atrial beats took a long time to conduct, so we think they’re going down a slow pathway to the ventricle, then with a dual nodal pathology - following a refractory phase - are returning to the atrium via the fast pathway and looping round until terminated. We could also consider the possibility of an atrial tachycardia, but we know that atrial tachycardia doesn’t typically terminate in the atrium unless with an ectopic premature atrial beat. What we have here terminates with an normal atrial beat with a usual morphology complex - unlikely to be an atrial tachycardia. <Slide - entrainment> What could we do in the cath lab to help confirm our diagnosis and plan management? We need to reinduce the tachycardia and try pacing it from the ventricle slightly faster than the atrial tachycardia had been. Once we stop pacing the ventricle, we can see a V-beat… then an A-beat… then a V-beat. Such a V-A-V response, according to Morady in his famous paper is most likely to be AVNRT or AVRT – atrioventricular re-entry tachycardia involving an accessory pathway, such as in Wolff-Parkinson-White syndrome. If we’d been looking at atrial tachycardia we’d expect to see V-A then another A then V. We’d see the drive for the tachycardia coming truly from the atria so we’d see more atrial than ventricular beats sensed. How can we tell from this whether it’s an AVNRT or an AVRT’s accessory pathway? We need to measure the PPI – the post-pacing interval. If we take the time between the last paced beat in the ventricle to the next beat in the ventricle and subtract it from the tachycardia cycle length (TCL) we’ll see the distance our entrainment location is from the tachycardia. The distance of this PPI minus TCL tells us more about what we’re seeing: if it’s less than 110 milliseconds, it’s most likely an accessory pathway – the ventricle is involved in the tachycardia, close to the circuit in the accessory pathway. However if its above 110milliseconds, it’s likely to be AVNRT; we’re further from the tachycardia circuit as the circuit is within the atria/AV node so when we pace from the ventricle we’re waiting for the impulse from our pacemaker-initiated ventricular beat to penetrate the atrial-nodal circuit. In this example we have a PPI of 541, minus a TCL of 360 – well above the 110, and far away from the tachycardia circuit. When we paced from the ventricle we were entraining the tachycardia, but we were pacing from a point in the conduction system far away from the tachycardia initiation point. We also used a few other techniques to help our diagnosis: we did incrementally faster pacing from the ventricle, and also from the atrium, and we saw that the conduction from the atrium to the ventricle, and the conduction from the ventricle to the atrium, as we increased the speed, was decremental; both the AV delay AND the VA delay grew longer. This indicates that the patient is unlikely to have an accessory pathway – in an accessory pathway the conduction is not decremental as it’s the AV node that slows down the conduction from the atria to the ventricle and vice-versa. There are some other pathways which could be considered, and we’ll discuss these another time. This is a great example of getting some really sophisticated EPS and making a clear diagnosis using already-implanted dual chamber devices. We followed this with a typical AVNRT ablation which ended up being a really simple procedure based on the information we already had from her pacemaker. It’s uncommon, in our experience, to use already-implanted devices to perform fully diagnostic EP studies. Does your department use this method? If you have any experience or comments about this, if you have any thoughts about the benefits or limits of these methods, we’d love to hear from you! Here at EPme.me we love feedback; our aim is to help you learn so please do get in touch with ideas for sessions you’d like to see. Whether you work in electrophysiology, devices, both or neither, we want to hear from you. Follow our YouTube channel to keep up to date with leading cardiac electrophysiology from around the world. Sign up for our newsletter to receive our free ECG cheatsheet — you’ll wonder how you did without it. COMING UP: Next few weeks, we’re gonna be talking some great EP cases’ Fresh from the EP lab Part 1 - “4th time lucky”. Some really interesting case studies from the EP lab. Thank you so much! Website: https://epme.me/ Instagram: http://instagram.com/cardiac_electrophysiology Twitter: https://twitter.com/EPmedotme Facebook: https://www.facebook.com/EPme.me/ Pinterest: https://www.pinterest.com/epmedotme/ YouTube channel:https://www.youtube.com/channel/UCism4RgECx2HYcn4x_IWhbA?sub_confirmation=1

Video version https://youtu.be/AKOdaRQe5zg VT or not? Cardiac Rhythm Management (CRM) devices are widely used to address heart rhythm disorders thanks to sophisticated algorithms. But can we always trust them? Let’s have a look at an interesting case study from our clinic. New_Fig1_event This is an event that happened to a 52-years old male patient with a defibrillator. What type of tachycardia could it be? Was it: · a ventricle tachycardia (VT)? · an atrial tachycardia (AT)? · an accessory pathway (AVRT)? · an AV node re-entry tachycardia (AVNRT)? Patient’s CRM device algorithm recognized it as a VT event. CRM device recognition: · a ventricle tachycardia (VT) · an atrial tachycardia (AT) · an accessory pathway (AVRT) · an AV node re-entry tachycardia (AVNRT) But can we trust this result? A closer look at the case As we can see in the case report, an average Atrial rate was faster than average Ventricle rate. However, the criteria for VT event is the opposite, isn’t it? And what about EGM? There are equal atrial and ventricle rates occurring in the event and the device recognizes it as VT in the marker channel. In consequence on this recognition, the device provides anti-tachycardia pacing (ATP) therapy in the ventricle to override the VT and stops it without having to give a shock to our patient. It helped, but was it really VT? How it started After an A sensed and V sensed beat we can see a premature ventricular complex (PVC) that is correctly labeled in the marker channel as well. This premature ventricular beat is followed by an A paced and V paced beat, so obviously the premature ventricular beat had no connection/effect to the tachycardia. Nevertheless, the next A sensed beat is conducted down to the ventricle and THAT seems to be the start of the tachycardia. This is followed by a second A beat that goes down to the ventricle. And what is more interesting – AV delay changed! But VT doesn’t start with an atrial event! That means it was probably not VT and the CRM device was not right. New_Fig2_avg_rates_channels_PVC_start_ AV_delay Was it: · a ventricle tachycardia (VT)? · an atrial tachycardia (AT)? · an accessory pathway (AVRT)? · an AV node re-entry tachycardia (AVNRT)? Tachycardia morphology What’s more, if we have a look at the shock EGM, we can see a wide complex QRS representing a contraction of the ventricle. A premature V beat has a very different shape from the tachycardia beat. That brings another point against VT because of the QRS morphology of the tachycardia looks like a normal sinus rhythm beat. VA interval Not only did the tachycardia morphology prove that it’s probably not VT. A short VA interval could direct us to an AVNRT. A typical AVNRT generally conducts from the atrium to the ventricle down the slow pathway and back up the fast pathway. In other words, we can’t confirm it’s AVNRT, but it’s a likely option. Termination The event is terminating through ventricular pacing (ATP). The ventricles are being paced at a faster rate than the tachycardia and the tachycardia is still running in the atrium at its own rate, at the same time. That confirms it’s not an accessory pathway (AVRT) because otherwise, it would be running at the V pacing rate, as AVRT by definition involves both the A and V. New_Fig3_ channels_shape_shortVA_termination It has already been proven that it’s not a VT and it’s not an accessory pathway. Was it: · a ventricle tachycardia (VT)? · an atrial tachycardia (AT)? · an accessory pathway (AVRT)? · an AV node re-entry tachycardia (AVNRT)? The tachycardia terminated by itself. And it didn’t terminate in the ventricle but in the atrium. As you can see in the following strip from a similar event in the same patient (also recognized as VT). New_Fig4_term_inA It’s very unlikely it was an atrial premature beat and it’s also unlikely that it is an atrial tachycardia because it wouldn’t just stop on an atrial beat if the atrium was running. Was it: · a ventricle tachycardia (VT)? · an atrial tachycardia (AT)? · an accessory pathway (AVRT)? · an AV node re-entry tachycardia (AVNRT)? Don’t trust solely in devices Boston Scientific devices know how to detect the difference between SVT and VT. How does the devices work? The device reading is based on rhythm ID algorithm that correlates to the morphology. However, since the device is counting only what’s happening on the ventricular channel and not on the atrial channel, as it's marked in the Ventricle blanking period (the sensed atrial beats are recorded in brackets), that’s why it’s detecting the event as VT and not SVT. Thanks to the device our patient received a VT treatment and it helped him, even though it wasn’t a VT. We found out that the event was an SVT, most likely an AVNRT. Therapy treatment for this diagnosis is a simple ablation. Whereas the type of treatment for VT or AVNRT would be totally different. New_Fig5_key_factors In this case, the patient has undergone a successful SVT ablation in the EP lab, because he was symptomatic with this SVT, and we wanted to avoid more of these events being wrongly recognized as VT by mistake. In the future, his defibrillator might not just give him anti-tachycardia pacing, but an inappropriate electric shock. And that’s what we certainly didn't want. Diagnosing In order to recognize heart rhythm disorders correctly, it’s important to constantly train our electrophysiology skills. Even though we work with modern devices, the algorithms are sometimes not reliable enough. With this in mind, there is a final key point to remember–when the device recognizes a VT event, always ask: is it really a VT or not? Here at EPme.me we love feedback; our aim is to help you learn so please do get in touch with ideas for sessions you’d like to see. Whether you work in electrophysiology, devices, both or neither, we want to hear from you. Follow our YouTube channel to keep up to date with leading cardiac electrophysiology from around the world. Sign up for our newsletter to receive our free ECG cheatsheet — you’ll wonder how you did without it. COMING UP: Next few weeks, we’re gonna be talking about using devices in arrhythmia diagnosis. Some really interesting case studies from devices, to explore further the effects and use of devices in EP. Thank you so much! Website: https://epme.me/ Instagram: http://instagram.com/cardiac_electrophysiology Twitter: https://twitter.com/EPmedotme Facebook: https://www.facebook.com/EPme.me/ Pinterest: https://www.pinterest.com/epmedotme/ YouTube channel:https://www.youtube.com/channel/UCism4RgECx2HYcn4x_IWhbA?sub_confirmation=1

Video version https://youtu.be/0IvTueu2wyg Here I am, back with my third blog post. I must mention it was heartening (pun intended) to receive a plethora of feedback on my last post. The post was about heart monitoring devices and explored the role of implantable loop recorders (ILRs) and ECG machines in arrhythmia diagnosis. Feedback means people are listening, watching and reading. That’s a good feeling. Speaking of feedback, my post today dwells on remote home monitoring devices and if their feedback capabilities can and are being optimally utilized in the world of EP. Over the years, the capabilities of implanted heart devices have grown exponentially, both in their therapeutic and diagnostic functions. However, this has translated into an increased burden on device clinics, as there is a large quantity of data being captured, which needs to be analyzed. This means specialists need to allocate more time to clinic patients. The increased longevity of patients, while a desired outcome, also means, that the device clinic must allocate more resources per patient over the years. Thankfully, with the advent of remote monitoring for implanted devices, the workload of routine analysis at physical clinics has begun to plateau. Such devices provide periodic telemetric transmission of patient’s heart readings via the internet to a secure cloud server. These readings can then be assessed by medical teams located at ‘virtual clinics’. They allow for early diagnosis of conditions and scheduling of physical visits, only when necessary. Over a period, this helps dodge acute complications in several cases. However, I think, the medical community is not completely prepared for a totally remote management of cases via such devices. To support my thought, I will present the case of a very close patient of mine. CASE STUDY A 72-year-old male with ischemic cardiomyopathy and severely reduced global systolic function, the ejection fraction or the capability of the heart, to pump out blood to the rest of the body, was reduced to 19%. To reduce the load on his heart and to synchronize the pumping of blood through his system, the patient was fitted with a CRT-D, a resynchronization therapy where the device functions as a cardiac pacemaker and doubles up as a defibrillator. In this case. His CRT-D also includes home monitoring; the overlying topic for this blog post. Additionally, the patient is on a daily dose of amiodarone (brand name: Procar), which helps lower heart rate & the number of ‘tachycardic’ events. Do note, the patient is 100% dependent on the pacemaker in order to have an underlying rhythm and pump blood. The patient presented on our “virtual clinic” with three days of reduced CRT pacing, manifesting physically as weak and unable to carry out tasks previously capable of, like walking up the stairs. On the analysis of the home monitoring data, we noted, only a reduced CRT pacing, which didn’t give away much. Here’s a look at the graph extracted from the Biotronik home monitoring system. Biotronik Graph Analysis The two-axis represents the percentage being paced and the time. Grey circles denote atrial pacing; blue is for right ventricle pacing and the fuschia triangles denote left ventricle pacing. The reduced CRT pacing appears to be a dangerous situation because this means the patient isn’t being paced 100% of the time, especially as he is a patient who is known to be pacing dependant. However, I cross-checked with his arrhythmic events diary to find a probable cause but there wasn’t any occurrence during these pacing drops. To investigate further, we called him in to for a device analysis and ECG. Biotronik ECG Report As we read the ventricle marker channels, we noticed sense events in left as well as right ventricle. In the third line, we saw a wide complex signal, not a standard normal signal. Now if you study the atrial signals below and compare it to ventricle signals, we know that there are more ventricle signals compared to the atrial signals. Getting to our basics, we know that when V is greater than A, it’s a ventricular tachycardia (VT). Now the question came up, why didn’t his defibrillator pick up on this slow VT and treat it accordingly? It could have been either of the two reasons 1) the defibrillator was not reading the signal 2) it could not diagnose it. But we saw that there were signal readings on the marker channels which implies that the lack of diagnoses was the issue. Just looking squarely at the VT reading, it is about 90 beats per minute. That VT is under the VT cut-off and not just Biotronik but no other implanted defibrillator device can diagnose such a reading. While 90 beats per minute is not as dangerous as say 180 beats per minute, it is terrifying for a patient with just 19% pumping capacity. A minor activity such as a flight up the stairs, during such an episode, can lead to worsening of the situation. Treatment The patient was called into the clinic and treated with aggressive Anti-Tachycardia Pacing (ATP). To explain simply, an ATP is a form of localized stimulated pacing used to treat tachyarrhythmia, by pacing faster than the arrhythmia. It can be executed using an implanted device. How does it work? Well, if the VT is at 120 beats per minute, we pace the ventricles at 140 beats per minute, aiming to break the re-entry cycle. In the case of this patient, we manually paced him at 110 beats per minute and broke the cycle. Post this event, and owing to repeated events that were reported, we admitted him and gave him a VT ablation using 3D mapping. It has now been three years and the patient has been free of any episodes. Food for Thought As we come to the end of this post, I would like to leave you with food for thought. We spoke about virtual clinics. But who exactly is monitoring the remote readings at such clinics? The case discussed above was a yellow alert event for the device, despite it being of an urgent nature. Typically, these messages would arrive at the virtual clinics only the next day. We were successful in this case because we could manually diagnose this, in a timely manner by knowing our patient and carefully analyzing two different reports and making the connection. Now imagine, usually, there are very well educated nurses manning these “virtual clinics”. However, are they equipped enough to make advanced diagnoses like we just did? That is something, we need to think about. Here at EPme.me we love feedback; our aim is to help you learn so please do get in touch with ideas for sessions you’d like to see. Whether you work in electrophysiology, devices, both or neither, we want to hear from you. Follow our YouTube channel to keep up to date with leading cardiac electrophysiology from around the world. Sign up for our newsletter to receive our free ECG cheatsheet — you’ll wonder how you did without it. COMING UP: Next few weeks, we’re gonna be talking about using devices in arrhythmia diagnosis. Some really interesting case studies from devices, to explore further the effects and use of devices in EP. Thank you so much! Website: https://epme.me/ Instagram: http://instagram.com/cardiac_electrophysiology Twitter: https://twitter.com/EPmedotme Facebook: https://www.facebook.com/EPme.me/ Pinterest: https://www.pinterest.com/epmedotme/ YouTube channel:https://www.youtube.com/channel/UCism4RgECx2HYcn4x_IWhbA?sub_confirmation=1

Video version https://youtu.be/26Fai7FQWG8In my previous post, I looked a little at the history of medicine — starting in medieval times, when medicine began to be the remit of scholars and we saw the nascent emergence of evidence-based practice. Compare that with early surgery, purely physical procedures performed often by barbers and butchers… anyone with a big knife, really. As medics learned more about the structures and functions within the body, surgery and medicine became more closely aligned, eventually enabling specialization within disciplines based on the systems of the body. Now surgery and medicine are distinct but allied parts of the same profession, and nowhere is there more crossover than in cardiac electrophysiology.I explored some of the pros and cons of the increasingly specialized and sub-specialized — sometimes sub-sub-specialized — nature of medicine in general, and cardiology, electrophysiology, and devices in particular.Now let’s look at some of the benefits of professional specialization into electrophysiology: starting with the ever-growing array of implantable devices we have to help us diagnose and manage arrhythmias, starting with Implantable Loop Recorders — ILRs.ILRs are devices implanted under the skin which recognize and record heart rhythms. The implantation of an ILR is a quick, minimally invasive, almost painless and very safe procedure, with a tiny incision usually done as a day case and with only local anesthetic. It can be done in aseptic conditions in procedure rooms or even at the patient’s bedside.Here we have the Biotronik Biomonitor 2; the Abbott’s (St. Jude) Confirm Rx; and the Medtronic Reveal LINQ. They’re all very small so once they’re implanted the patient shouldn’t have any discomfort or even much awareness of them. The insertion site heals as quickly as any other small superficial wound, with minimal, usually barely visible scarring.So, when do we decide to implant an ILR?When someone comes into your clinic with symptoms that could be related to a heart rhythm disorder, such as palpitations, pre-syncope or syncope, the first thing you’ll do is get a 12-lead ECG. A 12-lead can give us a lot of information about the electrical conduction system of the heart, and there may be underlying problems that a 12-lead shows clearly. The problem is, an ECG taken in the clinic is only a snapshot of that moment in time.What we often need is to have our patient attached to a monitor for a longer period of time. We want to see our patients’ heart rhythm when they have the symptoms they’re reporting. It might be that they only get the symptoms when they’re up and about, so having a heart monitor that allows the patient to get on with their normal life is ideal. Sometimes a patient’s symptoms are serious enough or worrying enough that they’ll need to be admitted to hospital for monitoring, but it’s clearly better, both for the patient and for the allocation of clinical resources, if they can go home while they’re monitored.The next step, then, is a Holter monitor: a 3-lead or 12-lead ECG attached externally that can monitor the patient for up to 72 hours. Some Holter monitors have a button that the patient can press when they have symptoms, or it can be useful to ask your patient to keep a diary of their activities and symptoms.What, then, if your patient comes back into the clinic, has a 72-hour recording of their heart behaving perfectly normally, and no symptoms throughout the recording period? What if they have problematic, even potentially harmful symptoms which sound convincingly like a heart rhythm disturbance, but which only happen, say, every few months? We can’t dismiss a convincingly cardiac-sounding syncope in a patient who’s likely to go home, fall down and break a hip just because we haven’t YET got evidence of their arrhythmia. So, we need to monitor them for longer.Enter “The ILR”.Implantable Loop Recorders can monitor your patient for up to three years from insertion (and they’re improving all the time). They can detect a wide variety of arrhythmias, fast, slow, regular, irregular, regularly irregular, and pauses. You can set specific parameters according to the needs of your patient — useful when one patient has a comfortable resting heart rate of 47bpm, and another patient hits the floor when they drop below 60bpm.The ILR automatically detects and records heart rhythm disturbances, and transmits information and alerts through wireless technology ( Abbott(St. Jude), Biotronik, or the Medtronic). The information transmitted and stored is secure and compliant with international and local data privacy legislation. The ILR transmits information using a wireless device usually kept at the patient’s home; this device also allows patients to report symptomatic episodes. This can be incredibly useful, allowing the team analyzing the data to match symptoms to heart rhythm disturbances and work out the root cause of the problem.ILRs are purely diagnostic devices: they record but they don’t treat arrhythmias. Once we’ve worked out the exact cause of the patient’s symptoms we may have a few treatment options, so let’s look at some case studies.Case Study 1:Here’s a report received from a Abbott (St. Jude) Confirm Rx device.We have a single ECG lead, so we can start to have a closer look and analyze the rhythm. Firstly, we can see P waves. We’re only looking at a single lead, so we’re not going to worry about whether our complexes are positive or negative. Where we can see P waves we can also see that they’re closely followed by QRS complexes and that the QRS complexes are nice and narrow. We can see a T wave after the QRS, so we’ve got a good idea of the heart rhythm and can work out intervals within the complexes.In this report, the device has identified this as an episode of bradycardia. At 49bpm, it’s on the edge of normal limits — this is where we need to think about what the patient was doing at the time. If they were climbing a flight of stairs, their heart rate didn’t increase to meet demand, and they felt dizzy, then we’ve got an answer. If, on the other hand, they’re asleep or resting, and if they were asymptomatic while their heart rate was arguably slightly slow, then maybe we can call that normal for this patient, and we can re-programme the monitor to only alert us of bradycardia at less than, for instance, 45bpm. This is where it’s really useful to be able to find out how the patient felt at the time.We can also see from this report that it is basing its rate on ventricular sensed beats — VS — and it also tells us the number of milliseconds between each beat. We can use this to judge pauses and to work out the patient’s heart rate more accurately, and this is especially useful in irregular heart rates. There are a thousand milliseconds in a second, so a rate of 1000 milliseconds is one beat per second or a heart rate of 60bpm. Our patient has an RR interval — the gap between one R wave and the next — of 1074 milliseconds. So, just slightly less than 60bpm. A little further on it records an 1102 millisecond RR interval — so we’re on our way down towards around 52–54bpm.So, is it bradycardia, or is it normal sinus rhythm? Well, this case is a good reminder that everybody’s different, and all we can say, without associated symptoms, is that it seems to be normal for this patient.Case Study 2:Our next case is a recording from a Medtronic Reveal LINQ device. There are a few differences in the interface of different devices, but they all give us the same information. We have our ECG rhythm strip, we can see that it’s labeled VS, for ventricular sensed events, and we can see the RR interval in milliseconds.So what are we looking at here? It’s not bradycardia, although there are some RR intervals of 1790 milliseconds, and it’s not tachycardia, although there are some RR intervals of only 570 milliseconds. The patient actually marked this as a symptomatic episode, so we need to know what’s going on.Firstly, is this an atrial originating rhythm? The discerning eye might spot a P wave before each NARROW QRS, so we know this is an atrial based beat. It has a P wave, it’s a nice narrow QRS complex, it’s following the right pathways in the heart’s conduction system. On this slide, we start off with 3 narrow QRS complexes, with associated P waves and, although a little slow, they’re regular. However, after our third normal QRS complex, we have an early beat. This has a much wider morphology than our previous QRS and is followed by what we call a compensatory pause. This means that the next normal-looking P-wave driven QRS complex falls in about where it would if there’d been another normal beat preceding it, instead of this bizarre early complex. Then we have the same pattern repeated, a narrow complex beat followed by an early broad complex beat and then a compensatory pause. We call this bigeminy — ‘two twins’.Every part of the conduction system in the heart, even down to every cell, has the ability to initiate a heartbeat. The heart works best when the beats originate from the SA node, at the top of the conduction system, and travel through the normal pathways: the AV node, bundle of His, the bundle branches and the Purkinje fibers and through every cell of the heart muscle. These pathways give us a synchronized, coordinated heartbeat, with everything happening at exactly the right time. As we work our way down through the conduction system, we find that every part has its own intrinsic rhythm that will kick in as a safeguard if there’s no signal from above. More on this in another episode!Why do we think this patient has bigeminy? We know that the patient’s normal QRS complexes are narrow, and the premature complexes are wide, taking up almost 200 milliseconds, and so we might assume that the early beat originates from the ventricles. It’s not following the normal conduction pathways, it’s less synchronized than this patient’s normal sino-atrial beat, so we get a broader QRS. All the premature beats have the same shape, the same morphology, and so we know that they originate in the same place in the heart. We can get an idea of where the premature beat originated by the shape of the QRS c

Video version https://youtu.be/9_1HN16mS-A What's the best way to start an educational platform for electrophysiology, is really working out, what are we doing?Why am I asking this?Nowadays, as electrophysiology is growing and growing, and the number of devices, pacemakers, defibrillators are growing and growing, people are slowly subspecializing into electrophysiology and into devices. Therefore, before we start and start discussing in future episodes about different cases about electrophysiology or devices, I constantly ask myself are we breaking this up too much? Is this a sub-subspecialism?Now before that, when did the whole idea of subspeciality really come about? So all of this comes actually way back when to the medieval times where medicine and surgery were divided up into two different subjects.Medicine was performed by the learned professional and surgery was actually performed by the bonesetters and carried out by tradesmen and barbers. It was more of a vocation rather than medicine, which was about curing people through diseases from diseases through medicines and through therapies. So already back in the medieval times, we were divided into medicine versus surgery. But really, the subspecialty as we know it today came about in the early 20th century in the USA. Where did it happen? It happened in ophthalmology, the eyes, and pediatrics, children, where they had their own examination boards and their own methods of studying and specialty in those particular fields of medicine.Now I'm talking about electrophysiology. So what do we have?We have medicine,we have a specialty in internal medicine,we have a subspecialty in cardiology,and now we have sub-subspeciality in electrophysiology.How far should this go? How far should we really be breaking this down?Should we be going further and having a sub-sub-sub into devices and electrophysiology?Where does it end? So let's look at the pros and the cons of subspecializing.So when it comes to subspecializing, let's start with a positive side.Below you can see the slide of the Pros.-So if we look at it in the education context, well, whilst we're striving for excellence and studying and subspecializing, we're actually hoping to gain control in something and maybe dare I even say “mastery” in the body of knowledge that we're subspecializing in. Whether it's devices, whether it's ablations and electrophysiology, whether it's EKGs, we're trying to gain control. What does that allow us?1. Academic Progress:In a world where the niche is key, where you don't just go to a restaurant to have a cup of coffee, you go to a coffee shop and you have specialized niche coffee shops. So when the niche is key, if someone is subspecialized in devices, they'd be able to progress academically within that field.2. Scientific Progress:In the field where the industry has a tight grip on progress. It allows you to push forth scientifically and maybe control the industry and have a doctor maybe decide where, or point the industry in which way it should go by our own personal scientific progress through a niche and subspecializing, understanding of the field.Well, not only does it affect us educationally, but also economically. If we're subspecializing, we're being able to focus on performing procedures that are maybe more lucrative. For example, if we are being able to perform certain specialized implantations of devices, and we get a high level of proficiency in it 'cause we're subspecialized or sub-subspecialized in it, well then we're being able to work at it at a higher level and maybe even also quicker, therefore it can be more lucrative. In another way though, we can also have pay based on performance health system. Believe it or not, the Portuguese health system, I've heard, have a pay based on performance depending on how well doctors perform in procedures or in the field of medicine is their pay grade. Well, therefore, there's definitely a pro to subspecializing because your performance will be better at what you do better, at what you're subspecialized in. And then again, also in the economic field is discussing accountability. Nowadays, accountability is key. Malpractice insurance, damage settlements, they are all key to people working in the medical system, and to the patients they treat. They wanna know that their doctor performing the procedure is specialized in that procedure. If the doctor isn't subspecialized in the procedure, well, is it possible that he could lay vulnerable to being sued?Now let's look at the pros of subspecializing from the patient. Well with the patient, he can guarantee that he's getting the best of care, 'cause he's going to a specialist in it. It's also better for the team. Think about it. Within the hospital team, you have one person specialized in devices and one person specialized in ablations and another one specialized in heart failure. You're offering a complete service with specialists. Isn't that better for the patient? And then think about the location. Well, wherever you are, wherever you're giving your service, well if you're rural, you're filling a need by being a specialist. In certain rural locations, they lack specialists in devices so they'll be able to fill a need. And if you're living in the more urban site, well if you've got specialists, that's a top-notch specialist with the best experience, hey, it's more attractive. He can offer the best quality of service. All of this is the pros of subspecializing. It sounds great!So tell me, are there any negative sides to it? Well, of course, there is.Below you can see the slide of the Cons.-Well, let's divide it up also starting with education. With education, doctors are nowadays, because of these subspecializing, have to maintain specific board certifications. Each board certification has different requirements, and for different insurance companies, you'd need different board certifications and you need to renew those requirements and those exams. Yes, there's a positive side to that. However, rather than practicing medicine, doctors are having to invest time and money into all these different board certifications. Is it really that necessary? Should they be spending more time going to courses and doing exams than treating patients? Beyond that, when it comes to education, you're limiting yourself and your knowledge base. If you're subspecializing, all you do every day is ablations of atrial fibrillation or implantations of pacemaker and defibrillator devices, well you're limiting yourself into a set knowledge base.You're a doctor.You studied medicine.Years ago, you knew more. You knew dermatology, you knew ophthalmology, you knew the basics. Well, the more you're subspecializing and daily, and day to day, just limiting yourself to your subspecialty, well you're limiting yourself and your knowledge. You're deciding for yourself, potentially at the age of 20, 30, what you're gonna be doing when you're 60 years old. Is that something that you want to limit yourself to? Is that limited knowledge base good for patients? We'll get to that shortly.If we look at the economic side, more and more team members are necessary for treating the same patient. It's costing the medical systems.“How many different cardiologists do you need to treat the same patient?”One is a specialist in devices, one is a specialist in arrhythmia, one is a specialist in heart failure, one is an interventional cardiologist, and that's just cardiologists. These are complicated, complex patients, they have to have specialists in internal medicine and nephrology maybe or diabetes or neurology. How many team members are needed to treat the same patient, costing the medical system? And then go to the next stage, we've got duplication of these providers/services and tests in the community medicine versus the hospital medicine because they've got their device specialists or the cardiologists in the community. And then when they have an acute flare-up of whatever they're going through, they've got their specialists in the hospital. What's the communication like between all these doctors and these team members?Let's look at it from the patient side.Who does he turn to?Who can he turn to because he knows what he's feeling, but does he know is that because of my heart failure? Is that because of my heart rhythm? Is that because of my diabetes? Yes, I'm feeling dizzy, I'm feeling lightheaded. Do I turn to a neurologist? Do I turn to a cardiologist? Where do I go? The bigger the team members, the bigger the teams, I don't know where to turn to as a patient. Now also, maintaining communication between all these different medical providers. Who is it? Is it the family doctor, the general practitioner that tries to keep this group of doctors that treat individual patients together communicating? Is it the patient that's to make sure that his doctors are kept up to date with the different medicines that each doctor's providing? And then look at their location. Well, if someone lives rurally, how many clinics does he have to be a member of to get his complete picture? He's a person. He has many different systems that need treating, especially the older he is. How many different clinics does he have to be attending because he lives rurally to get the complete picture treated? And if he lives urban, who does he choose? Which is the best? Is this urban center, the best for devices, and this one's best for heart failure?Subspecializing isn't that clear-cut as being great for the patients and not necessarily for the doctor maintaining all these certifications and limiting himself potentially, and certainly not for the medical system.I say we've got over-fragmentation of care with over-specializing. Where is the limit?So let's see. Are there benefits?Here’s a clinical study that happened, not from cardiology but in pediatric urology.”The increased pediatric subspecialization is associated with decreased surgical complication rates for inpatient pediatric urology procedures.”They decided to take over 71,000 patients, a nationwide sample based on pediatric urology patients, and they want to see who had the better surgical outcomes. They checked the and pre- and postoperative