Yeah, there are some powerful non-farmacologic options. A major one especially for AF and atrial flutter is electrical cardio version, right? Delivering a synchronized electrical shock to reset the heart's rhythm. Modern machines use bifphasic energy which is good because it lets us use lower energy levels making it safer. Now most SVTs apart from AF and flutter often respond well to drugs first but cardioversion is really important when a tacic cardia is causing serious problems. like hemodynamic instability, heart failure symptoms, or anggina, especially if meds aren't working quickly. It's also a useful tool for persistent AF or flutter, maybe before starting long-term meds or considering ablation.

How successful is it?

Initially, pretty good for AF, maybe 70 to 90% success in restoring sinus rhythm right then and there. But here's the catch. Without ongoing anti-riythmic drug therapy, only about 20% of those patients are still in sinus rhythm a year later.

Oh, wow. So, it's often not a long-term fix. on its own

generally not for AF. No, it's more like hitting the reset button. That long-term success rate does improve maybe to 50 65% if you add a drug like amodderone afterwards to help maintain the rhythm. Now, okay, for everyone listening, especially you PBC candidates, this next bit is super important. The rules around anti-coagulation for cardio version,

right? The blood thinners.

Yes. If a patient has AF or atrial flutter that's lasted 48 hours or more, or if they have a CH2 score of two or higher and the arhythmia has been there 12 hours or more

or if they've had a TIA or stroke in the last 6 months, they must be adequately anti-coagulated for at least three weeks before the cardio version.

Three weeks before. And remind us quickly about Chad 2.

Sure. Chad 2 helps estimate stroke risk. C is congestive heart failure. H for hypertension. A for age over 75. D for diabetes. Those are all one point. And S is prior stroke or TIA. That gets two points.

Got it?

Now, if the cardio version is more urgent, there's an alternative. You can start anti-coagulation then do a transissophageal echo cardiogram a te

looking for clots in the atrium

exactly if the tea is clear you can proceed with cardio version sooner but regardless of how you get there anti-coagulation must continue for a minimum of 4 weeks after the procedure

4 weeks after why so long

because the atrium can be stunned after cardioversion it doesn't contract well immediately so the risk of clot formation and stroke is still high during that recovery period

critical safety point okay what other non-drug opt are there.

The other major player is catheter ablation. This is a more invasive procedure where catheters are guided into the heart. Energy usually radio frequency which heats tissue or cryothermal which freezes it is applied very precisely to target the specific heart tissue causing the arhythmia. Essentially you're creating tiny scars to block or eliminate the abnormal electrical circuits. There are even newer techniques like pulse field ablation emerging.

And how effective is ablation?

It really depends on the type of SVT. For those re-entrant tech cardias, AVNRT and AVRT and for focal atrial teacardia, ablation is incredibly effective. We're talking cure rates often in the 90 to 98% range.

Wow. Cure rates.

Yes. With relatively low risk compared to say AF ablation. That's why the threshold to recommend ablation for these is quite low. It's strongly recommended for WPW with fast pre-exited SVT and definitely first lane consideration for anyone with recurrent symptomatic AVRT, AVNRT or focal. For typical atrial flutter, it's also highly successful around 95% with low complication rates. So, it's considered first line for most flutter patients.

Okay. So, verificative for those. What about for AF?

For AF, it's a bit different. Ablation is definitely a strong option for patients who are symptomatic despite trying anti-arithmic drugs or for those who just don't want to be on long-term meds.

It's often not a complete cure in the same way as for AVNRT or flutter, but it can significantly reduce the arhythmia burden, meaning fewer episodes, shorter episodes, less severe symptoms. Success rates tend to be higher for peroxismal AF, the kind that comes and goes.

Are there risks with ablation?

Yes, like any invasive procedure, there are risks. Things like bleeding or bruising at the catheter insertion site, damage to blood vessels, cardiac tamponade, bleeding around the heart, stroke, and a very rare but serious complication called an atrial esophageal fistula.

Fistula.

Yeah. An abnormal connection between the atrium and the esophagus. It can develop maybe two to six weeks after the procedure, often presenting with fever, chest pain, or difficulty swallowing. It's rare, but something we watch for. Often PPIs are prescribed postablation, partly to reduce potential GI irritation.

Good to know. Any other non-drug approaches?

Just briefly, there's perccutaneous left atrial appendage occlusion or LAOO. This involves placing a device to close off a small pouch in the left atrium called the appendage where most stroke-causing clots form in AF. This is really reserved for a very small specific group of patients. Those with AF who are at high stroke risk but have an extremely high irreversible risk of bleeding. That means they absolutely cannot take long-term anti-coagulants. Think recurrent major bleeding like intraraanial bleeds.

So not a common procedure.

No. And the current Canadian Cardiovascular Society guidelines give it a weak recommendation based on lowquality evidence. So it's an option but a niche one.

Okay, that covers the non-farmacologic side really well.

Now let's switch gears to medications. This is often, you know, the cornerstone especially for long-term management of AF and flutter. Let's start with that big question, rate control versus rhythm control. When do we choose which path?

Yeah, this is a fundamental decision. The big firm trial really shaped our thinking here. It showed that for many older patients, especially those who were asymptomatic or had only minimal symptoms from their AF, simply controlling the heart rate was just as good as trying to maintain a normal rhythm in terms of preventing stroke or death.

So, rhythm control isn't always necessary or better.

Exactly. It told us we don't always need to be aggressive about forcing sinus rhythm, particularly if the patient feels fine with rate control. However, there are definitely situations where rhythm control should be the goal. If patients have significant symptoms despite rate control, if they're younger and asymptomatic, or if there's concern about tech cardia related cardiammyopathy where the fast heart rate itself weakens the heart muscle and importantly, the current CCS guidelines actually recommend pursuing rhythm control in patients with recently diagnosed AF defined as within the last year because studies suggest better outcomes including stroke and mortality in that group.

Okay. So if we are aiming for rhythm control what are the main drug options?

We have several classes of anti-arithmic drugs. The class IC agents like fleconide and propifone are options. They can be used acutely for chemical cardioversion or for long-term maintenance therapy. Now listen up PBC candidates. This is absolutely critical. Fleanide and propenone are contraindicated. Do not use them in patients who had coronary artery disease or any any structural heart disease like significant left ventricular hypertrophy or reduced ejection fraction.

Why is that? What's the danger?

The danger is proarythmia. In a structurally abnormal heart, these drugs can actually cause potentially lethal ventricular arhythmias. It's a major safety issue. Also, another key point, if you use a class IC agent for AF or flutter, you must co-prescribe either a beta blocker or a non dihydroparadin calcium channel blocker like diliasm or verapamil.

Why the combo? It's a safety net.

The class IC drugs slow conduction in the atria, which is good, but they can sometimes paradoxically speed up conduction through the AV node if the patient flips into atrial flutter. Adding the AV nodal blocker prevents a dangerously fast ventricular response.

Okay, important pairing. What about other classes?

Then we have the class 3 agents. Amiodarone is probably the best known. It's very effective. Arguably one of the most effective drugs we have for preventing AF recurrences,

but it has downsides

big time. It has a notorious side effect profile. Can affect almost anything. GI upset, skin discoloration, nerve issues, corial deposits, thyroid problems, both hypo and hyperthyroidism, and more seriously, potential lung toxicity, pulmonary fibrosis, and liver dysfunction.

So, lots of monitoring needed.

Absolutely. Regular liver function tests and thyroid function tests, usually every six months, are essential if someone is on long-term amiodone. Another class 3 drug is Donorone. It's structurally related to amiodone, but designed to have fewer side effects particularly thyroid and lung issues. It showed a reduction in cardiovascular hospitalizations or death in trials. However, it's generally less effective than amiodone or the class IC drugs at actually preventing AF episodes and it also has important contraindications particularly in patients with significant heart failure where it can actually worsen outcomes.

Any others for rhythm control?

For acute chemical cardio version there's ibutylide which is IV only and vernicolant another 5v option which is known for working very quickly. Okay, that's a solid overview of rhythm control drugs. Now, what if rhythm control isn't the goal? Say for those patients with persistent or permanent AF, where we're focusing on rate control, what are the go-to meds

for rate control? Assuming the patient has normal left ventricular function. Our first line choices are usually beta blockers, drugs like metoprolol, bisoprolol, or even propernol or the non dihydropiritane calcium channel blockers which are deltasm and verapamill.

Those are the main stays.

Yes, those are your workh horses for slowing the ventricular rate. What about dyoxin? Its role is more limited these days. It's generally considered only if the first line agents aren't getting the rate down enough or perhaps if there's significant LV dysfunction where beta blockers or CCBs might be less desirable or need careful titration. Digin works mainly by increasing veagal tone to slow AV conduction. So, it's often less effective during activity compared to beta blockers.

And amidone for rate control

generally no because of its long-term toxicity potential. We really Try to avoid using amiodarone just for rate control. Its place is primarily in rhythm control if needed.

What rate are we aiming for?

The typical target for resting heart rate is usually 100 beats per minute or less. We used to aim for stricter control, maybe less than 80, but studies suggested a more lenient target of under 100 or 110 was often sufficient and potentially safer. And if medications just aren't cutting it, if the rate stays too high despite drugs,

then what?

Then we might consider a nodal ablation with permanent pacemaker implantation. Basically, you ablate the AV node to completely block the fast signals from the atria getting to the ventricles and then the pacemaker takes over, providing a reliable controlled heart rate.

A more definitive but also more invasive solution.

Exactly. It's reserved for when medical therapy fails or isn't tolerated.

Okay, let's shift to that other absolutely critical piece for AF and flutter patients. Yeah, stroke prevention, anti-coagulation. What are the key messages here for our listeners?

This is arguably one of the most important aspects of managing AF and flutter. Oral anti-coagulants are the standard of care for patients deemed to be at high enough risk of stroke. We use risk scores like the CH8's AS2 score we mentioned or more commonly now the C2 ADS2 VAS score to estimate that risk.

Future Canadian pharmacists studying for the PBC. What are the absolute must know therapeutic tips? The key takeaways.

All right, let's boil it down. Key pearls for you to remember. First, always look for and manage underlying conditions. Hypertension, heavy alcohol use, obesity, sleep apnea. Optimizing these can genuinely improve AF symptoms and treatment success. Don't just focus on the arhythmia itself.

Good point. Holistic approach.

Second rate. versus rhythm control in afflu remember affirm for older minimally symptomatic folks either strategy is reasonable but actively pursue rhythm control in younger patients those with significant symptoms or recent onset AF one year third ablation think first line for typical atrial flutter usually second line for AF after meds fail or aren't tolerated but maybe first line for peroxismal AF in some centers if the patient prefers

and for the other SVTs

for re-entrant tachicardias AVR AV NRT rhythm control is always the goal and catheter ablation is generally preferred because it can be curative. Fourth and I'll say it again because it's that important for safety and exams. Avoid fleconite and propenone in anyone with structural heart disease or coronary artery disease. Major contraindication.

Got it. Bring that one into memory.

Yes. And if using pill in the pocket only immediate release forms. Finally, no one to refer. Indications for ablation. Suspected teacardiac causing cardiammyopathy refer to an electrophysiologist. Difficulty achieving rate or rhythm control, refer to a cardiologist. Recognizing your limits and when specialist input is needed is key.

Fantastic summary. We have covered so much ground today on super ventricular tacoc cardia. From understanding the different types and goals, exploring non-drug options like cardioversion and ablation to diving deep into the pharmacologic strategies for rhythm control, rate control, and crucial stroke prevention, plus those essential therapeutic tips. Hopefully, you feel much clearer and more confident about SVT now. And thinking about all this, especially the rapid advances in ablation techniques and even new drug developments on the horizon, it does make you wonder how will that balance between drugs and procedures continue to shift for managing these complex arrhythmias over the next say 10 years. It's a constantly evolving field.

That's a really interesting thought to leave our listeners with. The landscape is definitely changing. Okay, before we wrap up, let's test your recall with a quick multiple choice question based on our discussion. Which of the following anti-riythmic drugs is contraindicated? in patients with coronary artery disease or structural heart disease despite its effectiveness in rhythm control for some SVTs.

A ammo B soal

C flickenide

D guiltymle that over think back to our key warnings. Thank you so much for joining us for this deep dive. We hope it's been valuable for your learning journey.

Absolutely. Keep learning, keep questioning that critical thinking is what makes a great pharmacist. We look forward to diving into another topic with See you next time.

The higher the score, the higher the risk and the stronger the indication for anti-coagulation.

And which antiquagulants are preferred? Now

the current guidelines including the CCS guidelines clearly recommend the direct oral anti-coagulants, the DOAC's as the preferred agents over warrin for most patients with non-valvular AF.

So drugs like epixaban, dabatran, adaxaban, riveroxaban

precisely. Large clinical trials ally, rocketaf, aristotle, engage f, aptimi48 have shown that these doas are at least as effective as warerin at preventing stroke and generally have a better safety profile particularly regarding the risk of intraanial hemorrhage which is the most feared complication of anti-coagulation.

What about warrin? Is it still used?

Oh yes, warfrain is still used. It's effective. It's been around for However, it's inexpensive. But the DOAC's are generally preferred because they have more predictable dosing, fewer drug and food interactions, and don't require routine blood monitoring like Warfin does with the INR. Warin is still necessary in some specific situations like patients with mechanical heart valves or moderate to severe mitro stenosis,

aspirin, ASA.

ASA alone is significantly less effective than anti-coagulants for stroke prevention in AF. It's generally not considered adequate protection for patients who truly need anti-coagulation based on their stroke risk score.

How do you choose which DOAC?

The choice can depend on several factors. Weal function is a big one as dosing needs adjustment based on kidney function for all the feces. Twice daily versus once daily dosing preferences, cost and formulary coverage, potential drug interactions, and patient coorbidities can all play a role. They are all good options, but nuances might favor one over another in specific individuals. And it's also crucial to address modifiable bleeding risk. factors. Things like uncontrolled hypertension, concurrent use of antiplatlet drugs or NSAs, excessive alcohol managing these can help make anti-coagulation safer.

What about using lower doses of DOAC's?

This is a critical point. Reduced doses of DOACs should only be used when specific criteria related to age, weight, or renal function are met as defined in the product monographs and clinical trials. Using a lower dose inappropriately, just hoping to reduce bleeding risk, can lead to inadequate stroke prevention. You have to use the evidence-based dose for the patient's characteristics.

Very important caution. Okay. Briefly, what about managing those other SVTs longterm? The re-entrant ones like AVNRT, VRT, and focal AT.

Right. As we mentioned for recurrent symptomatic AVRT, AVNRT or focal AT, catheter ablation is really considered firstline therapy because it offers a potential cure. If ablation isn't done or preferred or while waiting for it, chronic medication can be used. Options here include beta blockers, DTI, Verapam. These work by slowing conduction through the AV node. Or you might use class IC agents like fleconide or propaphenone. Again remembering the contration in structural heart disease. Or class 3 agents like sodtool or amiodorone in some cases.

I've also heard of a pill in the pocket approach.

Yes, that's an option for carefully selected patients with infrequent but bothersome episodes usually AVNRT or AVRT. The idea is they take a single larger dose of medication, often a beta blocker or calcium channel blocker. sometimes a class IC agent right when an episode starts to try and terminate it themselves.

Who is that suitable for?

It needs careful selection. The patient needs to understand their arhythmia, be able to recognize it reliably, and have had the drug tested safely under medical supervision first. It's generally not suitable for patients with underlying structural heart disease, significant LV dysfunction or sinus node problems like bradic cardia. And critically, only immediate release forms of the drugs should be used for this approach.

Okay. Well, This has been incredibly detailed. So, let's try to synthesize this for our listeners.

تاکی اریتمی بطنی
Okay, let's unpack this. Imagine you're reviewing a patient's chart and you see ventricular tachurhythmias. Your mind immediately races. Uh, is this critical? What drugs are involved? What's dangerous? Today, we're diving deep into exactly what you as Canadian pharmacist KBC candidates need to know to confidently handle these well complex cases. We know how vital it is to get this complex medical info down into something, you know, concise, easy to follow, and practical for exam success. So, we pulled out the most important bits, therapeutic choices, algorithms, those key tables, and essential tips. Really trying to provide some clarity and maybe some peace of mind. This deep dive is brought to you by the Pharma Board Group, and it's based on the excellent CTC reference materials. Our mission today, distill the core knowledge you need, make sure you don't miss anything crucial.

Yeah. And what's really fascinating here is just how diverse these arhythmias can be. You know, from sustained ventricular tacocardia right through to life-threatening ventricular fibrillation. Understanding the fundamental definitions and um the immediate goals of therapy is truly foundational for any pharmacist really. We'll be connecting the dots today between diagnosis risk factors and then looking at both non-farmacologic and pharmacologic options with a special focus of course on drug induced QT prolongation. That's a huge area for us.

Okay. So let's start right there with the basics getting our definition straight. What exactly are ventricular tacic cardia VT and ventricular fibrillation VF? Because like you said knowing the difference is pretty crucial for management. Right.

Absolutely. So ventricular teoc cardia VT is essentially when you see uh three or more consecutive ventricular heartbeats on an ECG that's an electroc cardiogram and the rate is faster than 100 beats per minute. Now VT can be quite varied clinically. Sometimes it's asymptomatic maybe not clinically important at all. Other times it can be well rapidly life-threatening. On the other hand ventricular fibrillation or VF, that's a completely different beast. It's a totally disorganized chaotic heart rhythm. You just don't see any recognizable QRS complexes on the ECG. VF is always associated with cardiovascular collapse always. And it's almost invariably fatal without immediate electrical defibrillation. It's like a um a lightning strike to the heart's electrical system. Just chaos.

Wow. Yeah. Big difference there. So, understanding those critical differences, what does this mean for patient care? What are our primary goals when we're faced with VT or VF?

Right. If we connect this to the bigger picture, our goals are uh sort of twofold. The immediate goal is Number one, relieve symptoms and most importantly restore a profusing rhythm as quickly as possible. This is especially true in sustained VT, VF, or you know, cardiac arrest. Every second counts there. Our second major goal, this is more long-term, is to prevent the potentially fatal occurrence or recurrence of sustained VT or VF. So, you're managing the immediate crisis, but also looking ahead. Long-term prevention,

right? Immediate and long-term makes sense. Okay. So, before we can treat, we obviously need to diagnose. For our listeners, the pharmacist preparing for PA. What are the essential investigations they should really be aware of? The things that lead to a VT or VF diagnosis?

Yeah, good question. For pharmacists, understanding this diagnostic pathway helps you anticipate what information is relevant. How to interpret results you might see. It always starts with a careful patient history. Always. You're looking for symptoms like syncopy, that's fainting or presinopy, feeling like you might faint, also important. Anggina, heart failure symptoms, any prior history of an MI, you know, a heart attack or other structural heart disease, it's crucial to ask about symptom correlation with exercise or stress and critically medications, recent medications.

Are they on any anti-urythmics or drugs that might prolong the QT interval? We'll talk more about those. And family history, too. Sudden death, especially under age 65, that might even point towards needing genetic testing.

Okay, history first. What else?

Beyond history, a physical exam can give clues about underlying structural heart disease like cardiammyopathy. And this is a common pitfall. Uh electrolyte assessment is absolutely vital.

The electrolytes, right?

Yes. Specifically, potassium, K, calcium, K, and magnesium. MG imbalances here can trigger arhythmias. And as pharmacists, managing these electrolytes can actually be a frontline defense against some of these arhythmias. Then the 12 lead ECG, that's fundamental. It can show signs of a prior MI, eskeeia, or repolarization abnormalities like a short or prolonged QT interval. Obviously, an ECG that actually captures the VT is extremely helpful.

And imaging,

yes. And cardiogram provides crucial details on heart chamber size and function. Specifically, left ventricular ejection fraction or LVF. That's a key prognostic indicator. There are other tests too. Halter or loop recorders to track a ventricular ectopy, you know, extra beats and correlate with symptoms. Treadmill exercise tests for exercise induced VT or eskeeia. Even things like cardiac MRI to look at heart structure and scar tissue. And here's a crucial diagnostic tip, especially for you as pharmacists interpreting reports. Any wide complex teacardia that means a QR restoration of.12 seconds or more in patients over 50 years old should be considered VT until proven otherwise. In fact, most wide complex tacocardias regardless of age are actually VT. It's just safer to assume VT initially.

That's a really important clinical pearl. Okay, that's quite a workup. So once we have a diagnosis, how do we figure out the clinical significance, the prognosis? Does asymptomatic VT always mean it's benign or are there like hidden dangers?

No, not at all benign necessarily. And this is a critical distinction. the clinical importance and um the subsequent management of VT really depend on two key things. One is it sustained or non-sustained and two and this is especially important is their underlying structural heart disease particularly left ventricular systolic dysfunction a low LVF that's probably the single most important prognostic factor

so LVEF is really key

absolutely so for asymptomatic VT which usually means short episodes non-sustained typically 3 to 10 beats the risk is very low if there's no structural heart disease. However, if there is structural heart disease, especially LV dysfunction, then even asymptomatic non-sustained VT, can signal a significant risk, a risk of future serious symptomatic sustained VT or VF. That's where you need to be vigilant. Review the patient's full cardiac history.

Got it. And what about symptomatic VT?

Symptomatic VT can show up as palpitations, shortness of breath, chest discomfort, presyncopy, even loss of consciousness, or cardiac arrest. But here is a key nuance for you to remember. The severity of the symptoms doesn't always determine the prognostic importance.

Oh, interesting.

Yeah. For instance, even severe symptoms in a patient with non-sustained VT but no structural heart disease. Well, that's often prognostically benign. In those cases, your role as a pharmacist might be more about patient reassurance and education, not necessarily immediate aggressive therapy.

Okay. And the really severe end, cardiac arrest,

right? Most out of hospital cardiac arrests are likely due to VF ventricular fibrillation, which as we said almost always leads to arrest in ly. Sustained VT on the other hand can later collapse but maybe after a variable duration could be minutes. Sustained VT defined as lasting 30 seconds or more or needing immediate intervention is most often linked to structural heart disease. Usually coronary artery disease CAD often with a prior MI. This definitely requires investigation and therapy.

And non-sustained less than 30 seconds.

Non-sustained VT less than 30 seconds generally only needs treatment if the risk of subsequent sustained VT or arrest is high. For For example, if the LVEF is under 35% or if it's associated with marked QT prolongation, which we'll definitely get into. And one more point, VT with a structurally normal heart, that's rarely life-threatening, even if it's sustained, and typically requires no therapy if it's asymptomatic and non-sustained.

Okay, that distinction based on structural heart disease seems absolutely central.

Now, here's where it gets really interesting, I think, and directly impacts daily pharmacy practice.

Drug induced QT prolongation. It's such a huge safety concern. Let's unpack the QT interval and its connection to arrhythmia risk.

Okay. Yeah. Let's dive into the QT interval. It's an ECG measurement rate from the very start of the QRS complex to the end of the T-wave. Think of it as a crucial surrogate measure for the heart muscle's repolarization time. Basically, how long it takes the heart's electrical system to reset after each beat. Measuring it accurately can be tricky. Sometimes it's affected by heart rate. There's variability across different ECG leads. Sometimes U-waves get in the way,

right? And that's why we use the corrected QT. The QTC.

Exactly. Because the raw QT interval changes dynamically with heart rate, we use a corrected QT or QTC to account for this. The Bazette formula is very commonly used. Though interestingly, it can undercorrect at very fast heart rates. For clinical purposes, the American Heart Association defines a prolonged QTC as 470 milliseconds or more in men and 480 milliseconds or more in women. Those are key numbers to remember.

Okay. 470 for men, 480 for women. Why is this so important. What's the danger?

Well, the danger is that prolongation of this repolarization time significantly increases the likelihood of a very specific dangerous type of ventricular arhythmia called torsads deoint or TDP

to de point right

TDP is a form of polymorphic VT. It often stops on its own but it can cause hemodynamic instability or even degenerate into fatal VF. So it's serious and the risk of TDP directly increases as the QTC gets longer. It becomes a major concern when the QTC goes over 500 milliseconds or increases by more than 60 milliseconds from the patient's baseline QTC.

So QTC over 500 or a jump of over 60 milliseconds. Got it. What causes this QT prolongation?

It can be congenital. There are genetic long QT syndromes. Patients with these conditions absolutely must avoid QT prolonging drugs their whole lives. So that patient history is vital again. But for us as pharmacists, acquired causes are far more common. These include things like bradic cardia, slow heart rate, electrolyte abnormalities, especially low pot. potassium, low calcium, low magnesium hypothermia, myioardial eskemia, and medications. By far the most common culprit, both anti-arithmic drugs and many, many non-cardiac medications can prolong the QT interval. They mainly do this by acting on a specific potassium channel called IKR. This is really where pharmacists are the frontline defenders. For a comprehensive, up-to-date list of QT prolonging drugs, you should always refer to reputable resources like credible meds. It changes frequently.

That's a huge list. I know. For our PBC candidates listening, can you maybe highlight some of the most critical drug classes or specific drugs that pharmacists absolutely need to be watching out for, the high yield ones for TDP risk?

Absolutely. Let's spotlight the really high impact ones for your exams. Among the anti-riythmics themselves, amuterone, sodalol, quinadine, proanomide are key. Amuterone is interesting. It very frequently prolongs the QT interval, but it's actually infrequently associated with TDP, possibly due to its broader antiorythmic effects blocking multiple channels. Sodtool, however, is a different story. It marketkedly prolongs QT. It shows something called reverse use dependence, meaning its effect is more pronounced at slower heart rate.

Reverse use dependence. Okay.

Yeah. And it's actually the drug most often associated with QT prolongation in registry studies. There is a nearlinear relationship between the sodalol dose and QT prolongation. The risk really jumps at doses higher than 320 milligs per day. So, sodtool is a big one.

Okay. Sodalol is key. What about non-cardiac? drugs

right beyond anti-riythmics certain antibiotics are notable think macrolytes like aithramycin chloriththramycin eriththramycin also floricquinolones like cyproloxicin we also see it with some anti-depressants like cyopram especially at higher doses and the older tricyclic anti-depressants antimedics like andatetron some ozole antifungals many typical and atypical antiscychotics even the opioid methadone it's not just cardiac drugs it's a really wide range

wow it really is everywhere

it is is but what's also crucial is understanding the actual risk. The risk of prohibia with most of these non-cardiac QT prolonging drugs is actually quite low. Unless the uncorrected QT interval is already quite long, say over 500 to 520 milliseconds. The probability of TDP significantly depends on the patients individual risk factors. Think of these as compounding effects. Things like female sex, older age, bricardia, low potassium or magnesium, higher drug dosage, using multiple QT prolonging drugs together, and medical conditions. is affecting drug metabolism like heart failure or sepsis. These things multiply the risk.

So it's not just the drug, it's the drug plus the patient context.

Makes sense. Okay. So connecting all this once a patient is diagnosed. What about non-farmacologic interventions both immediate and chronic? What's vital there?

Right. For immediate therapy, if a patient has sustained monomorphic VT and they're unstable, meaning hypotension, angina, heart failure, severe symptoms, then synchronized cardioversion is the way to go. That's a precisely timed electrical shock. But for polymorphic VT or VF, it's different. It's an immediate non-synchronized shock defibrillation. You don't wait to synchronize with the chaotic rhythm. You just shock immediately. Repeat every 2 minutes if needed. Maybe increasing the shock energy if the first attempts fail. This immediate action is absolutely life-saving.

Okay. Shock therapy first for emergencies. What about long-term prevention? Non-drug approaches.

When it comes to chronic therapy, preventing recurrence, the implanted cardioverter defibrillator or ICD is incredibly effective. It detects VT or VF and delivers a shock internally to terminate it. Current guidelines strongly recommend an ICD as the preferred treatment for patients with a history of cardiac arrest, VF, or sustained VT that isn't due to some reversible cause. Studies like the AVID trial showed significant mortality benefits compared to drug therapy alone.

So, ICDS are really the gold standard for prevention in high-risisk patients.

For secondary prevention, yes. However, it's important for pharmacists to understand this distinction. While ICDs terminate events, they don't necessarily prevent the arhythmias from happening again long term. They're a safety net, not a cure for the underlying tendency.

That's a good point. Any other non-drive strategies?

Yes, catheter ablation is another key option. It involves mapping the heart's electrical pathways and using energy, usually radio frequency, to destroy the small area causing the arhythmia. It's often considered first line for patients with structurally normal hearts who have BT, and it's also used for selected patients with eske. cardiammyopathy often combined with beta blockers. Ablation is generally comparable in efficacy to amadronone actually superior to sodtool and often more effective than just escalating drug therapy if VT keeps recurring despite medications. There's also something called stereotactic cardiac radio ablation using focused radiation. It's still investigational really a last resort for truly refractory VT that hasn't responded to anything else.

Okay, ICDS and ablation are major players.

Now let's turn back to the ological toolbox. We've touched on QT issues, but what are the key medications used for immediate and chronic management of VTVF? What should our PBC candidates specifically focus on?

Right, the drugs for immediate therapy and sustained VT or VF, introvenous amodderone is uh moderately effective. It rarely terminates VT immediately, but it's particularly useful in preventing early recurrence, especially in what we call an electrical storm, multiple VTVF episodes close together or in shockresistant VF. F doses typically involve an IVA bololis maybe a second bolus followed by an infusion. As pharmacists you need to watch for hypotension low blood pressure especially with rapid administration.

Okay around the fourth what else?

Procanomide also given introvenously it's mainly for monomorphic VT not polymorphic VT like torsods and again you need careful blood pressure monitoring due to hypotension risk. Magnesium IV magnesium sulfate. This is the treatment of choice for torsodin very important. It can also be useful in myioardial esia but remember it has no benefit in regular monomorphic VT

magnesium for torsods. Got it.

Yes. Then intravenous beta blockers like metoprolol or propranolol. These can prevent VT or VF especially in the setting of an acute MI or electrical storm. Interestingly some evidence suggests propranolol might be superior to metoprolol specifically in electrical storm. Lastly licane. It's only occasionally effective in sustained monomorphic VT maybe less than 20% of cases respond. It might increase the rate of return of spontaneous circulation ROC and shockresistant VF, but watch for CNS side effects like confusion or seizures at higher doses.

Okay, that covers the acute drugs. What about chronic therapy? Preventing recurrence with meds.

For chronic therapy preventing recurrence, it's absolutely paramount for pharmacists to understand this. ICD implantation is superior to drug therapy for preventing sudden death in high-risisk patients both for secondary prevention and for primary prophylaxis in patients with low LVEF drugs are often adjuncts or for patients who aren't ICD candidates.

So drugs are often secondary to ICDs in high-risisk cases.

In many cases, yes, but medications still play a huge role. Beta blockers are a cornerstone. They're recommended for pretty much all patients if tolerated. They suppress arhythmias and they reduce mortality in heart failure or postMI patients. They're excellent for exercise, stress or eskeeia induced VT. Metaprolol, a tennol, bicopolar are common choices there. Emiodarone and sodalol taken orally are effective in preventing VTBF recurrence. But remember they are less effective than ICDs in preventing sudden death and overall mortality in those high-risisk patients. They can however be used as a really important adjunct to ICD therapy to reduce the frequency of painful shocks from the ICD. That improves quality of life significantly.

Using drugs to reduce shocks makes sense. Are there other drug options?

Yes, but they're less common now. Class Agents like meine or sometimes quinadine. These are typically last resort addition. ions maybe for electrical storm that's resistant to beta blockers and amiodorone or if amioderone isn't tolerated or effective used very cautiously quinodine notably is only available in Canada through health Canada's special excess program

okay so mainly beta blockers emioderone sodalol with ICDs being primary for high-risisk prevention now this brings up a critical practical question for pharmacists given everything we've said about drug induced QT prolongation how should we approach patients who need these potentially problematic medications especially if they're already at high risk. What's our framework?

Yeah, this is where your clinical judgment as a pharmacist really shines. It's a balancing act. I recommend a step-wise approach. First, always verify, is this medication actually on a known QT prolonging drug list. Is it associated with TDP? Use resources like credible meds.

Second, clarify the patients history, personal or family history of ventricular arhythmias, congenital long QT syndrome, unexplained syncopy, sudden death. If a patient has known congenital LQT syndrome. It's generally best to avoid QT prolonging medications entirely if possible.

Okay. Verify their drug. Check the history. Then

then review the patients other medications and their medical conditions. Look for those high-risisk features we talked about. Electrolyte imbalances, brady cardia, female sex, older age, interacting drugs, conditions affecting drug metabolism. Are there multiple risk factors present for patients identified as high risk or those already on multiple QT prolonging meds? Really assess the indication for the new drug. Is it absolutely necessary? Can it be safely replaced with a nonQT prolonging alternative? This is your chance to intervene to suggest safer options.

Proposing alternatives. Good point. What if the drug is deemed necessary?

If the medication is truly necessary after that careful risk benefit assessment, then start with the lowest effective dose. Now, ECG monitoring. It's not always mandatory for all QT drugs, but some recommend getting a baseline ECG and maybe a follow-up, especially if the baseline QT interval is already prolonged or if multiple risk factors exist. If you do monitor Repeating the ECG after about five drug half- livives or after any dosage adjustment is reasonable. And remember those crucial thresholds, a QTC interval over 500 milliseconds or a QTC prolongation by more than 60 milliseconds from the patient's baseline. Both of those warrant immediate careful reassessment. Those are your big red flags. Stop and reevaluate.

QTC 500 or increase 60 m.

Exactly.

Also, educate patients. Tell them to report new symptoms like palpitations, dizziness, shortness of breath. Remind them about conditions that can lead to low PAC. ium like gastroenterteritis or starting a new diuretic. And for those on multiple therapies known to affect electrolytes or QT, consistently monitoring serum potassium and magnesium is key. We need to manage those electrolytes actively. Now, here's a really vital insight, something that often causes perhaps undue fear. In practice, using two or more QT prolonging medications, even in high-risisk patients, doesn't automatically mean further QTC prolongation or that arhythmias will happen.

Oh, yeah. Studies have shown pretty inconsistent results. For example, one large study looked at over 3,400 patients and found no cases of TDP, even when multiple QT prolonging drugs were used concurrently, even with hypocalemia present sometimes. So, the takeaway is if a QT prolonging medication is clinically indicated, we shouldn't necessarily withhold it based entirely on fear of QT prolongation, especially if alternatives aren't suitable. It's about careful risk assessment, individualized management, monitoring, and mitigation, not absolute avoidance based on the list alone. That's a very important nuance. Risk assessment, not just avoidance. Okay, great. Now, to bring all this together for our PBC candidates studying, the source material, the CTC reference, provides excellent algorithms and a really comprehensive drug table. How can these tools be best used for practical insights and ultimately exam success?

Oh, these are truly invaluable study aids. The management algorithms like figure 1 for non-sustained VT and figure two for long-term management of sustained VT or VF. They provide a clear visual roadmap for decision making for non-sustained VT. The algorithm nicely guides you based on whether structural heart disease is present or absent and crucially the patients LVF for the long-term management of sustained VT, VF, or resuscitated cardiac arrest. Figure 2 really emphasizes the primary role of an ICD, but it also shows where catheter ablation fits in and where pharmicotherapy comes in. Always guided by the underlying cause like CAD or LV dysfunction, it consistently reinforces that key message.

An ICD is the preferred therapy for for most patients with sustained VT and structural heart disease. That's a major takeaway for exams.

So, the algorithms provide the framework. What about the drug table?

Then there's the comprehensive drug therapy table, table four. This is gold for quick recall on your exam. It summarizes the key classes, beta blockers, class IA like quinadine, class IB like meatine, and class 3 like sodalol and amioderone. For each drug, it hits the critical details you need for PBC. Common dosages, notable adverse effects, especially TDP risk for those QT prolonging ones. Key drug interactions are listed in crucial comments. For instance, for sodalol, it'll remind you about the significant TDP risk, the need for dose adjustment and renal dysfunction, and the fact it has both beta blocking and class 3 anti-arithmic properties. For amuarone, it highlights that extremely long half-life can be months and its wide range of potential non-cardiac toxicities like thyroid or pulmonary issues and those critical drug interactions like needing to reduce warerin or dioxin doses. The table also points out important context like the fact that class AI agents generally have limited long-term benefit in reducing mortality compared to ICDs when structural heart disease is present. Use this table to really drill down on dosages, adverse effects, interactions, and those key clinical pearls. It's high yield stuff.

Excellent. Sounds like focusing on those algorithms at the drug table is key study strategy.

Okay. And now to put all this fantastic knowledge to the test, here's a quick question. Just the kind of thing you might see on your PBC exam. Ready? Which of the following medications is most frequently associated with prolongation in registry studies due to its potassium channel blocking activity and reverse use dependence.

Mhm.

Is it a a zithramycin b amiodarone c sodalol d f fl fleckenine

h okay let's think we talked about several of these aithramy can amiodarone does but tdp is less common fleonide is class I see the one really noted for frequent QT prolongation in registries and that specific reverse use dependence the answer is c sodalol As we discussed, while many drugs prolong QT, sodtool really stands out in registry studies for this risk, especially at higher doses, and that unique reverse use dependence mechanism makes it a key drug to monitor very closely.

See, sodtool is correct. Nicely explained. We really hope this deep dive into ventricular tachy has given you a clear, concise, and maybe confidence boosting summary for your PBC preparations. Remember, understanding these complex interactions, the diagnostic pathways, the treatment strategies, both drugs and devices. It's all key to becoming a well-informed and effective pharmacist. Keep learning, keep questioning, and thanks for joining us on the deep dive.

Absolutely. And until next time, continue to critically evaluate the information you encounter. Apply it to your patient scenarios. Because in pharmacy, there's always more to learn, always more context to consider. Good luck with your studies.

تروبوآمبولی وریدی
Welcome to the deep dive. We're your shortcut to well getting really well informed.

Yeah. We cut through the noise and get straight to what matters

and deliver it right to you. So today we're doing something a bit special actually.

A custom deep dive. It's specifically for you, our Canadian pharmacist PDC candidates.

That's right. We're zeroing in on a really core area of practice.

Venus thrombbo emolism, VTE for short.

Exactly. Which, you know, covers deep vein thrombosis. DVT. and pulmonary embolism or PE.

And this is uh definitely a high yield topic for your exams.

Clarity and accuracy are key here.

Absolutely. And we should mention this deep dive is brought to you by the farmerboard group.

Correct. And all the insights, everything we're discussing, it's drawn straight from the authoritative CTC reference.

So our mission today, it's really to distill down those key details from the VTE chapter in the CTC.

Yeah. We want to focus on um therapeutic choices, those medication algorithms that guide you.

The key tables too. They simplify things so much. they do

and those essential tips that can really make a difference. Basically, we want to give you some peace of mind.

Summarize the critical stuff concisely. Make sure you don't miss anything vital for the exam

or you know, more importantly for your future patients.

Okay, let's get into it then. Let's unpack this and start right at the foundation. What exactly is VTE?

So, like we said, it's DVT and PE

and why is it such a big deal for us?

Well, it's the third most common cardiovascular disorder. That's huge.

Wow. And it affects up to what 5% of the population in their lifetime.

That's the figure. And think about PE specifically. The annual incidence is about 1.29 per 10,000 people.

And you mentioned it climbs sharply with age.

It really does, which makes sense. You know, more risk factors as we get older. It just underscores how common this is.

So, as pharmacists, our radar needs to be up, especially with older patients.

Definitely. And the link between the two is critical. The most common way a PE happens

is from a DVT breaking off and traveling. An embleization.

Exactly. An embleization of a DVT. So stopping DVT or catching it early is paramount for preventing PE.

And the impact isn't just about how common it is. It's severe, too.

Oh, absolutely. VTE is a cause of death for uh up to 10% of hospitalized patients.

10%. That's significant.

It is. Now, there's a bit of difference in the stats for mortality after diagnosis. Some registry studies show up to 17% dying within 3 months. Randomized trials show a lower figure.

Yeah, closing to 2%. Yeah, that's an important distinction. Probably reflects different patient populations or a closer monitoring in trials.

And it's not just about the acute event, is it? There are long-term problems too.

Big time. Post thrombotic syndrome PTS that can affect up to 40% of DVT patients.

And that's chronic swelling pain affects quality of life

hugely. And then after PE about 1 to 4% can develop chronic thrombomolic pulmonary hypertension, CTAP,

which is really serious. is lifelimiting

very much so. So yeah, the stakes are high, short and long-term.

Okay, so given that serious impact, what are we actually aiming for with treatment? What are the goals of therapy?

Right? So for DVT, the goals are pretty clear. First, prevent a major PE. That's number one.

Makes sense.

Then stop the thrombus, the clot from getting bigger. Prevent it extending.

Okay.

Also try to prevent or mitigate that postthrombotic syndrome we just talked about

and reduce the immediate problems, the morbidity of the acute event itself.

Exactly. For PE the goals are even more well critical prevent death

the ultimate goal

prevent it happening a recurrent throbo embolism

and prevent that long-term complication CTEF

those are the core objectives

all right so before we jump into treatments let's quickly touch on initial investigations what does a pharmacist need to know

good point because the signs and symptoms you know the classic swelling or pain for DVT

or shortness of breath chest pain for PE

they're actually quite insensitive and non-specific You really can't hang your hat on symptoms alone.

So if symptoms aren't reliable, what do we rely on?

We use validated clinical prediction rules, things like the well score or the modified Geneva score

applied after the initial history and physical.

Yes, exactly. After the basics, and then if the pre-est probability comes back as low or moderate or unlikely,

that's where D- dimer comes in.

Precisely. The D-dimer test is incredibly useful there. A negative result, especially using an age adjusted threshold. can reliably rule out VTE without needing imaging.

In many cases, yes, it avoids unnecessary imaging, which is great.

But if VTE isn't excluded by DD- dimer,

then imaging is the next step. Absolutely crucial. Usually ultrasound for suspected DVT

like B mode compression or color duplex.

Yep. And for suspected PE, it's usually a CT, pulmonary angography, a CTPa.

Got it. And a quick note, you mentioned on distal DVT, clots in the calf veins.

Right. If symptoms aren't severe, sometimes initial anti coagulation isn't started immediately,

but close monitoring is needed. Repeat imaging

absolutely you need to watch closely to see if it extends proximally further up the leg. If it does, then treatment is definitely needed.

And one last point on investigations screening for thrombophilia.

Yes, important for a specific group. Patients under 40, particularly if they have recurrent VTE or a strong family history.

Identifying those underlying clotting disorders can change long-term management

significantly. Yes. Helps the duration and maybe even the type of therapy.

Okay. Diagnosis and risks covered. Let's pivot to the core therapeutic choices. The pharmacologic heartbeat as you called it,

right? But first, some general measures. These sometimes get overlooked

like the fact that many patients can be treated outpatient.

Yeah. Most DVT patients and even about half of PE patients if their heart and lung function isn't compromised.

That relies on good outpatient support systems, though.

Of course, safe discharge planning is key. And pain management starts simple with a opioids if needed.

Yes. And NSADs. They work for pain, but we have to be cautious

because of the bleeding risk with anti-coagulants. Big counseling point there.

Huge. Definitely flag that interaction.

And for DVT specifically, moving around early. Ambulation is preferred now.

Often, yes. Seems to help resolve pain and swelling faster than strict bed rest used to. And elevating the leg helps with edema, too.

For PE, it's more about supportive care initially. Oxygen, fluids, Exactly. Oxygen if they're hypoxic. 5V fluids if hypotensive or dehydrated. Vasopressors if they're in shock. Stabilize first.

Okay. Now, non-farmacologic choices, elastic stockings, compression bandages.

Right. So, they do help acutely. They improve the edema, the swelling, and the pain.

But, and this is a big butt, isn't it? They don't prevent postroomotic syndrome.

That's the key takeaway from the evidence, particularly the SOX study. A large well done trial.

Placeboc controlled showed no difference in PTS rates. between active and placebo stockings.

Virtually identical around 14% in active versus 13% in placebo. No significant difference.

So we should be careful about promising PTS prevention with stockings long term.

Absolutely. Manage expectations based on the evidence. Acute symptom relief, yes. Long-term prevention, no.

What about IVC filters? Inferior vanava filters?

Very niche. Really reserved for patients where anti-coagulants have failed

despite being on the right dose.

Yes. Or if anti-coagulants are absolutely contraindicated, like an active major bleed, you can't stop.

And retrievable filters are preferred now.

Strongly preferred.

Mhm.

The idea is to remove them once the acute risk period is over or if anti-coagulation becomes possible again.

Avoid long-term filter complications.

Makes sense. All right, let's dive into the main event, pharmacologic choices, the drugs we use. The CTC reference has a great table on this table two.

It does. And the direct oral anticoagulants, the DOAC's are front and center now. A Pixaban, Dabagatran, a Docaban, Riveroxan. working either as direct throbin inhibitors

that's debagran

or factor zats inhibitors

which is the other three a pixabin a doxan river oxiban

and their advantages are pretty clear right quick onset

yeah rapid onset usually within hours

short half- livives relatively speaking

fixed dosing no routine monitoring usually

big plus for patients and fewer drug and food interactions compared to say warerin

represents a major step forward in convenience

definitely but there's a really crucial distinction in how you start Start them. This is vital for the exam.

Okay. What's that?

Aixabiban and riveroxaban can be used as monotherapy. Meaning you start them directly. No need for hepin first.

Just the tablet from day one

essentially. Yes. Though often at a higher initial dose for a short period. But dabagatran andoxiban

they need that leadin period.

Correct.

Yeah.

They require 5 to 10 days of a parental anti-coagulant first like LMW. Then you switch.

So a pixabana river oxiban potentially offer for a simpler start, maybe easier discharge.

That's often the case.

Yeah.

Also, important note on kidney function. Most trials excluded patients with creatinine clearance below 30 millm.

But there's some newer data.

Yeah. Particularly for a Pixaban, there's growing evidence supporting its use down to a CLCR of 15 lmmen, though caution is still needed.

And what about bleeding? Reversal agents exist now.

They do, which is reassuring. The Dard seesmab for Davagatran and Dexanet alpha for the factors A inhibitors

though and Dex is quite expensive still.

It can be yes but having specific reversal agents is a big safety advancement and overall the direct inhibitors show lower risks of major bleeds compared to VKAs.

Good to know okay what about the heperins low molecular weight hepins LMW's

like deltaarin and oxiparin tensiparin key advantage more predictable response than unfractionated hepin

so dosing is simpler weight-based

usually weight adjusted fixed doses given subcutaneously longer Halflife often allows for once or twice daily dosing. Great for outpatient use.

And you mentioned one review suggesting tinsiparin might be better than VKAs for reducing PTS.

Yes, that was an interesting finding in one systematic review. Needs more research, but suggestive

dosing details are in the reference materials. Usually units per kg or milligram per kg,

right? With specified maximum daily doses sometimes. Main side effect is bleeding of course,

but less hit and less osteoporosis than UFH.

Correct. Better facy profile in those aspects, which is a plus for longerterm use if needed. Now unfractionated hepin UFH mostly 4V infusion

most commonly. Yeah. Adjusted based on monitoring usually APTT or sometimes anti levels

aiming for that therapeutic range 1.5 to 2.5 times control for APT.

Exactly. Subcutaneous injection is possible but may be less common for treatment now and depends on concentration availability.

And the big complication to watch for is hit induced thrombocytoenia.

Serious though thankfully rare. If you suspect HIT, stop all hepin immediately. No question.

And you had a clinical pearl about SC Heperin in certain patients.

Ah, yes. Avoid subcutaneous UFH or LMW in patients with massive edema, anarcha or those on vasopressors

because absorption is unreliable.

Very unreliable. Compromised peripheral circulation means you might not get therapeutic levels. IV is safer in those situations.

Got it. Okay. The classic vitamin K antagonists, VKAs, warferin

still very much in use. Requires that careful INR monitoring. targeting two to three.

And the monitoring frequency is intense at first, right? Daily, then every few days.

Yeah.

Then weekly, then eventually maybe every two to four weeks or even up to 12 weeks in some stable patients, but it takes effort to get there.

Sounds like managing warerin is still well a bit of an art form. Needs pharmacist involvement.

It absolutely does. The biggest challenge, the sheer number of drug and food interactions

like ASA and NSA day, they don't change the INR,

but they hammer the stomach lining and platelets, right? So bleeding risk skyrockets.

Critical counsel point and herbals too.

Yes, things like ginko, jinseng, St. John's word can interact significantly. Patients need clear advice on these.

Okay. Lastly, thrombolytics, altiplas used less often.

Much less often less than 10% of VTE patients reserved for the really severe cases

like PE with hypotension, hemodynamic instability.

Exactly. Or maybe patients who are initially stable but then deteriorate rapidly if they have a low bleeding risk.

And for DBT even rare

very rare maybe life or limbthreatening clots like massive ilophemeral DVT with no contraindications

catheter directed lis is sometimes considered

but the bleeding risk is high very high especially intraanial hemorrhage it's always a major risk benefit calculation and remember altois isn't actually health Canada approved for PE it's used off label based on guidelines

good point for the exam okay we have the drugs now the crucial question how long duration of anti-coagulation This depends heavily on recurrence risk. Your reference likely has an algorithm like a figure one to guide this.

So if it's a first VTE clearly caused by something temporary like major surgery.

Typically 3 months of treatment is enough. The provoking factor is gone. Risk drops.

But it's not always that simple. What about minor risk factors?

Right? Other transient things like maybe prolonged travel, immobilization, postpartum period. But even persistent minor risks like IBD, heart failure, obesity

might need longer than 3 months. maybe 6 months or even longer.

It often warrants consideration for extended therapy beyond that initial 3 6 months. It needs individual assessment.

And what about unprovoked VTE? No clear cause.

That's where indefinite or long-term treatment often comes into play. The risk of recurrence is significantly higher and often lifelong.

But you have to balance that against bleeding risk

always. That's the constant equation. There are scoring tools like ET predict or the CH shape score that can help estimate both recurrence and bleeding risk to guide that conversation. And for distal DVT, you mentioned three months is preferred over six weeks.

Yes, guidelines generally suggest three months now for distal DVT as well.

The source mentions males having a higher recurrence risk.

It does statistically, but again, the emphasis is always on the individual patients overall risk profile, not just one factor.

And for long-term therapy choice, DOAC is often preferred.

Generally, yes, for convenience and safety profile. VKAs are an option, especially if CLCR is under 30 or the are interaction issues

and LMW alone

might be used if oral options aren't suitable particularly in some active cancer patients like those with GI cancers where LMW has shown benefit

okay we've covered treatment thoroughly but prevention prophylaxis is just as vital right

absolutely preventing VTE in the first place especially in hospitalized patients is a huge focus risk varies a lot though

and recommendations depend on the situation like type of surgery

exactly high-risisk orthopedic surgery like hip or knee replacement, major general surgery. Those patients usually need prophylaxis details often in tables like table one in your reference.

And it's not just surgical patients. Medically ill patients too.

Yes, acutely ill medical patients think severe infection, heart failure, exacerbation, respiratory failure. They often benefit from prophylaxis too if immobilized.

How long does prophylaxis usually last?

Often 10- 14 days or until mobility improves, but sometimes longer.

Extended prophylaxis is beyond discharge, especially after a hip or knee replacement.

What about CO 19? Any specific recommendations?

Yeah, the guidelines evolved. Critically ill COVID patients generally get standard dose prophylaxis. For moderately ill patients, not in ICU, therapeutic dose heperin might be considered if bleeding risk is low,

but not intermediate doses.

No. Studies didn't really support intermediate dosing.

And the goals of prophylaxis pretty similar to treatment goals

essentially, yes, but focused on prevention. Prevent DVTP, reduce mortality, Prevent PTS. Prevent CEPH. Stop it before it starts.

What about non-farmacologic prophylaxis stockings, compression devices?

Graduated compression stockings, intermittent pneumatic compression, IPC devices, they do reduce risk,

but less effective than drugs

generally. Yes. Pharmacologic prophylaxis is usually more effective. So, these mechanical methods are often reserved for patients at very high risk of bleeding where drugs are just too dangerous. Neurosurgery is a classic example.

Okay, let's talk pharmacologic. is for prophylaxis. Again, your reference probably has a table like table three LMWs.

Yep. LMWs like Daltaparin and Oxiparent Tinsiparin are main stays used at lower fixed daily doses for prophylaxis

and still have that lower risk of hit and osteoporosis compared to UFH. Correct. UFH for prophylaxis

still used usually 5,000 units subcutaneously two or three times a day. Generally considered effective mainly for moderate risk procedures.

Fondiparent arra that's 2.5 milligrams daily subcutaneously. It's specifically approved for high-risisk orthopedic patients. A good option there.

Now, this is interesting. Aspirin, ASA, for prophylaxis.

Yes. Specifically in the context of hip or knee replacement surgery after an initial course of a more potent anticoagulant like LMW or a DOAC.

Switching to lowdose aspirin like 81 milligram daily.

Exactly. Studies have shown is pretty much as effective and safe as continuing the LMW or DOAC for extended prophylaxis in that specific setting. A simple cheaper option for some.

That's a really practical point. And doc's for prophylaxis

definitely used especially after elective hip and knee replacement. A Pixaban 2.5 milligram B riveroxaban 10 milligrams daily. Debbie getran has a specific posttop initiation regimen

and effective

very as effective as LMW and in fact a pixaban riveroxaban have shown superiority over anoxiparin in some major orthopedic trials.

Wow superiority that's significant.

It is it really reinforces their role in orthopedic prophylaxis

in cancer patients. Prophylaxis important there too.

Very important. Cancer itself increases VTE risk significantly. Prophylaxis is often recommended especially for ambulatory patients starting chemotherapy who have a high corona score.

Options include LMW or DOAC's like a Pixaban.

Yes, a Pixaban showed good results in the AVERT trial for ambulatory cancer patients. LMW is also a standard option. Important area for pharmacist intervention.

Okay, loads of great info on treatment and prophylaxis. Let's shift to some special considerations and therapeutic tips. Pregnancy and breastfeeding first. This is critical.

Absolutely critical. VTE is a major cause of maternal morbidity and mortality. The risk just skyrockets during pregnancy and postpartum.

Like 7 10 times higher before birth and 15 35 times higher after.

Those are the numbers. It's a massive increase compared to non-pregant women of the same age.

And it links back to Virgow's triad again

perfectly. You get venous stasis from hormones in the is pressing on veins, you get potential vessel injury during delivery and pregnancy itself creates a hypercoagulable state.

A perfect storm for clots

indeed.

So managing VTE during pregnancy, what's the approach?

LMW is the anti-coagulant of choice. Deltaarin and Noxiparin.

Why LMW?

Crucially, they don't cross the placenta, so they're safe for the baby. UFH also doesn't cross, but LMW is generally preferred.

Less bone loss, too.

You mentioned

Yes. Less risk of heper induced osteoporosis compared to long-term UFH.

And treatment duration, minimum 3 months.

Minimum 3 months total and it must include at least 6 weeks postpartum because the risk stays high after delivery. Full treatment doses initially.

What drugs must be avoided in pregnancy?

Warin is the big one. Terraogenic effects especially first trimester. Avoid

docs

also generally avoided. Not enough safety data. They do cross a placenta and they get into breast milk.

Fond paranex.

Only if you absolutely have no other choice like a severe LMW. ology very limited data

and delivery planning is complex for women on LMW

very needs careful coordination between the obstitrician hematologist anesthesiologist to plan when to hold and restart the LMW around delivery to balance clotting and bleeding risks sometimes a retrievable IVC filter is even considered if anti-coagulation is has to be stopped near term

what about postpartum and breastfeeding management

for that postpartum period up to 6 weeks warrin seuf or LMW are all considered safe options for continued treatment or secondary prevention

and breastfeeding safe with those agents.

Yes, Warin, UFH, LMW safe during breastfeeding. They don't pass into milk in significant amounts or aren't absorbed by the baby.

But DOAC safety in breastfeeding is still unknown,

not established. So generally avoided or used with extreme caution and specialist advice if breastfeeding.

Okay, last key area, therapeutic tips for managing hit. Hepin induced thrombocytoenia. Rare but serious.

Very serious. If it happens, you need to switch anti-coagulants immediately to something non- heepin.

What's approved in Canada for HIT?

Aratrobin, a direct thrombin inhibitor and danapareroid which is a hepoid.

Are there other options used?

Yes, based on evidence though maybe less data are not officially indicated by villerudin phiparinex even riveroxaban have been used successfully

and expert consensus often leans towards

often fondarex is considered a good choice. It's effective seems seems to have low crossreactivity risk with the hit antibbody and has predictable dosing.

Great practical tip. So to wrap up, we've really done a deep dive into VTE today.

We have covered the definition, the serious impact, the treatment strategies, drugs, non-drug options, duration,

prophylaxis measures which are so important

and those critical considerations for pregnancy and managing HIT. We look at DOAC's, hepins, warfin, the whole landscape

and understanding all these choices, the doses the patient factors. It's absolutely essential for the PBC exam.

Paramount, but more than the exam, it's fundamental for safe, effective patient care in your pharmacy practice going forward.

Definitely. Now, for a final provocative thought to leave you with, with DOAC's becoming so widespread, how do you think this will continue to shift VTE management long term, especially around say monitoring needs or the role and cost of reversal agents?

That's a really interesting question. The reduced need for routine monitoring is a huge shift, but maybe complacent. is a risk and access to reversal agents.

Yeah,

it's changing the game, but cost is still a factor. Definitely something to keep thinking about.

Absolutely. Okay, time to test your knowledge with a quick multiple choice question based on our discussion.

Ready? Which of the following direct oral anti-coagulants, DOAC's can be initiated as monotherapy for the treatment of acute venus throboism without requiring an initial parental anti-coagulant?

Is it a dabatran, b docaban, c riverox? man D fondarin

think about which ones don't need that hepin and leadin we'll provide the answer and a brief explanation in the accompanying materials

we really hope this deep dive has given you clarity accuracy and practical insights for VTE

and remember this deep dive was brought to you by the Pharma board group drawing directly from the CTC reference keep learning keep asking questions

and you'll absolutely continue to deepen your expertise thanks for joining us on the deep dive

فشار خون بالا
Are you a Canadian pharmacist examining board candidate, a PBC candidate? Then you definitely know that um unique stress of trying to keep up with constantly evolving guidelines, especially when the stakes are high like well your upcoming exam, welcome to the deep dive, your shortcut to staying well informed and hopefully gaining that crucial edge. Our mission today, it's a really crucial one. We're taking a deep dive into the 2025 Canadian hypertension guidelines. We'll highlight the key details you absolutely need to know and Crucially, we'll compare them directly to the uh the 2020 guidelines. We'll unpack therapeutic choices, medication algorithms, essential tips, all designed to give you clarity, accuracy, and practical insights for exam success and, you know, peace of mind, too. This deep dive is brought to you by the Pharma Board Group, and we're leveraging insights from the CTC reference. We understand that many of you listening are not native English speakers, so we'll be taking our time. We want to make sure every crucial detail is easy to follow.

That's absolutely right. And as pharmacists, our role in hypertension management in Canada is well it's vital. We've actually seen some um declining trends in hypertension treatment and control across the country recently. So these new 2025 guidelines they really aim to improve populationwide control especially within primary care. They offer a new pragmatic kind of two-part approach. Understanding these updates isn't just about passing an exam. It's really critical for your practice.

Okay, let's really dive into this then. One of the biggest shifts it seems in the 2025 guidelines is how we actually define hypertension. This feels like a fundamental change, right? Right at the diagnostic threshold.

Precisely. Yeah. If you look back at the 2020 guidelines, the diagnostic thresholds, they actually varied a bit. It depended on how the blood pressure was measured. For automated office blood pressure, A OBP, a mean systolic of 135 or diastolic of 85 was considered high. But for the standard office blood pressure measurement, OBPM, it was a higher threshold, 140 over 90.

Okay, so that's the history. Now, bring us up to date. How different is 20 25. What's the new number?

The 2025 guideline simplifies this quite significantly. It recommends a uniform definition. Blood pressure equal to or greater than 130 over 80 millg. That's when measured with a validated device under optimal conditions. Of course, this new lower threshold um it really reflects this growing body of evidence associating cardiovascular risk with lower BP levels than we maybe previously thought.

Wow. 130 over 80. That's a big change. That lower threshold probably means more people will be diagnosed, right? Mhm.

So, how does the guideline make sure we're accurate with this uh lower number prevent overdiagnosis?

That's a really key point. This new definition absolutely emphasizes accurate blood pressure measurement. It's critical. The 2025 guidelines, they actually prefer validated automated ocelometric devices over the old oscultatory spigo monometers. They're just easier to use, less prone to human error, and seem to have better reproducibility. And they recommend a very standardized protocol, a one to five minute rest and three measurements a minute apart. And you average all the val values. Consistency is key.

Okay. Consistency, automated devices. And what about measuring outside the office like at home?

Right. Out of office BP assessment. So 24-hour ambulatory monitoring, ABPM or home BP monitoring, HBPM. That's strongly recommended now to confirm the diagnosis. It's especially important to rule out things like white coat hypertension.

There it's high in the office but normal otherwise.

Exactly.

And also masked hypertension, which is the opposite normal in the office but high outside for Home monitoring the standard is measuring BP in duplicate twice a day for a week and importantly you shouldn't count the first day's readings they tend to be higher these out of office measurements they just correlate more closely with actual cardiovascular events so they're very valuable

okay so diagnosis is clearer more rigorous let's shift gears once diagnosed how do the treatment targets compare between 2020 and 2025

yeah another area of change the 2020 guidelines had while varied targets depending on patient risk in coorbidities. For example, low-risk patients, the target was less than 140 over 90. But for high-risisk patients, say with existing cardiovascular disease or older adults, they aimed for more intensive systolic targets, sometimes less than or equal to 120 based on AOBP. Patients with diabetes had a specific target, systolic less than 130, diastolic less than 80. And for non-diabetic chronic kidney disease, targets were kind of individualized. If they were sprint eligible, they aimed for systolic less than 120.

Seems a bit complex. to track all those variations. So, what's the 2025 approach to targets? Is it simpler?

Much simpler. The 2025 guideline really streamlines this. It's a single consistent target for most adults. Basically, achieve a systolic blood pressure less than 130 millm or HG as long as the treatment is well tolerated. This simplified approach, it's really about ease of implementation, making it clear though it does acknowledge, you know, patient specific factors like frailty or fall risk might need individualization. maybe a slightly higher systolic target and interestingly there's no specific diastolic target recommended now they note that cardiovascular risk is pretty low when the systolic is below 130 anyway

okay single target less than 130 systolic for most now the big one for pharmacists initial phicotherapy what's changed here this sounds critical

this is another major major shift the 2020 guidelines they primarily recommended starting with monotherapy or maybe a single pill combination SPC from a list of firstline choices beta lockers, for instance. They could be first line, but generally only for younger patients.

Okay, here comes. This sounds like where things get really interesting for 2025. What's the new approach?

The 2025 guidelines strongly recommend lowdose combination therapy as the initial treatment right from the start and ideally as a single pill combination and SPC. This involves drugs from two of these three main classes. An ACCE inhibitor or an ARB, a thioide or thioid like diuretic and a long acting dihydropodian calcium channel blocker or CCB. And here's a key point. Beta blockers are no longer recommended as first-line therapy for just hypertension. Not unless there's a specific clinical reason like heart failure, anggina, or maybe postiocardial infarction.

Wow. Straight to combination therapy.

Yeah.

Why the big shift away from starting with one drug? What's the rationale?

Well, the evidence really points this way now. Combining lower doses from different classes gives you additive BP lowering effects, but importantly, it often minimizes adverse effects compared to maxing out one drug. drug better tolerability and SPC's single pill combinations. They significantly improve BP control compared to monotherapy. They also enhance adherence. People are more likely to take one pill than two and persistence, plus potentially cost savings down the line.

Makes sense. Get more bang for your buck pharmacologically and it's easier for patients. So, what if BP isn't controlled with those two drugs? What's step three?

Good question. If BP is still above target despite that two drug combo, the 2025 guideline recommends adding a third firstline agent. So you'd pick from the remaining class. You'd end up with say an ACI or ARB plus a thazide diuretic plus a long acting dihydropodine CCB.

Okay, triple therapy with the main classes.