The sacubital part blocks neprolin which breaks down BMP but NT probnp is fine as still a good marker. Also watch for potential hypotension AR and can lower blood pressure quite a bit. So you might need to adjust diuretic doses and titrate AR and every 2 to 4 weeks. All right moving to beta blockers.

These are obviously huge in HFREF cutting hospitalizations and mortality. Bisoprolol and carvidol are the ones specifically shown to reduce mortality, right?

Exactly. When you start beta blockers, always start very low and titrate up slowly, like every 2 to 4 weeks. This is vital because, and this is a really critical point for your exam and practice, beta blockers should not be started or have their dose increased when a patient is acutely decompensated.

That's such a key distinction. It sometimes feels a bit counterintuitive, maybe since they're so important long term. Can you elaborate just a bit on why starting them during acute decompensation is a no-go?

That's a great question. It really highlights the nuances. So in acute decompensation, the heart's already struggling, right? Beta blockers acutely they reduce heart contractility and heart rate. If you give them, right, then you can actually worsen cardiac output, potentially leading to um severe hemodynamic instability or even cardiogenic shock. We use them for their long-term benefits on heart remodeling, but the patient needs to be stable for that. As pharmacists, you'll monitor blood pressure, heart rate, look for signs of worsening HF. Daily weights are crucial here, and counsel patients. You might feel a bit worse temporar arily when starting or increasing the dose but stick with it the long-term benefits are substantial

then we have the mineral corticoid receptor antagonists or MAS sperolactone epinent rune

yeah they play a big role in HFRF too reducing mortality and morbidity but what are the absolute must know contraindications or monitoring points here

they definitely come with some big warnings mostly around potassium and kidney function you absolutely do not use them if baseline potassium is over 5 millmal or if their creatinine clearance is under 30 mil a minute. Monitoring serum creatinine and potassium is crucial usually at 3 days 7 days after starting or changing dose then monthly for 3 months and then maybe every 3 months once they're stable. And a practical tip if a patient gets gynecomastia breasted enlargement with spironolactone which can happen because of its anti-androgen effects. Eperone is a great alternative. It doesn't have that side effect. And then the relatively newer but really impactful class SGLT2 inhibitors daglyloin and propololis. expert. So, what's the big deal with this class in heart failure? Their impact on reducing bad outcomes has been huge, and this is key. It works whether or not the patient has diabetes.

This has been truly groundbreaking. These are now considered for basically all HFREF patients, unless there's a specific reason not to use them. You do need to be aware they can cause some volume depletion. It's a mild diuretic effect, so you might even need to lower other diuretic doses. Also, expect an initial dip in their EGFR maybe in the first four weeks. That's generally okay if it's less than about 15%. This is a really powerful class every pharmacist needs to be comfortable with for HFREF. Now,

okay, let's quickly touch on a few other important agents for HFREF that aren't part of that core four. First, ivabberdine,

right? Ivdine has a pretty specific uh niche role. It's for patients with an LVEF of 35% or less and a resting heart rate of 77 BPM or more despite being on the best possible beta blocker dose or if they just can't tolerate beta blockers. Very important point. Do not use it if the patient has atrial fibrillation. It only works on the finest node.

Got it. Next. Dyoxin, an older drug in the HF world.

Yeah, dyoxin. It helps with symptoms and reduces hospitalizations, but it's crucial to remember it does not reduce mortality.

It also has a narrow therapeutic window, meaning the difference between a helpful dose and a toxic dose is small. So, you have to carefully monitor serum levels, aiming for that 6 to 1.2 non-mole range to avoid toxicity.

And the combination of nitrates and hydrolysine,

that combo has a specific place. It's useful for patients who can't tolerate ACE inhibitors, ARBs, or ARNIs, maybe because of kidney problems or high potassium. It's also used as an add-on therapy, particularly in black patients, where studies have shown a specific benefit.

Lastly, 5V iron replacement. This one sometimes surprises people.

It's really important for HFREF patients who are iron deficient, and this is key whether they have anemia or not. Studies show IV iron improves their exercise ability, quality of life, and cuts down hospitalizations. And another key point. Oral iron isn't recommended for this specific reason in heart failure. It just doesn't seem to be absorbed or used effectively in the same way.

Expert, just to wrap up HFREF, what's on the pharmacist's danger zone list? Which drugs should we really avoid or use with extreme caution in these patients?

Knowing what to avoid is just as important. Generally, avoid non-dihydropodine calcium channel blockers dilazasmapl because they can weaken the heart's contraction negative inotropic effects. Most Antiarythmics are also generally not recommended except maybe amodderone for very specific reasons as they don't reduce mortality. Statins are a bit different. If a patient is already on one for coronary artery disease, you generally continue it, but you wouldn't start a statin just for the heart failure itself.

Okay, let's shift gears now to heart failure with preserved ejection fraction or HFPF. You mentioned earlier the treatment landscape here has historically been well pretty challenging.

Yeah, traditionally treating HFTPF was mostly about managing the underlying conditions. hypertension, diabetes, aphib controlling fluid volume and trying to improve quality of life. The big challenge was finding drugs that actually reduced mortality unlike the clear wins we saw in HFREF.

But you hinted that this is where things are really starting to change. What's the big news in HFPF treatment?

This is really exciting actually. The SGLT2 inhibitors specifically in pagaloploin are the only drug class right now that has definitively shown improvement in HFPF in the large trials. They mainly work by reducing heartfield your hospitalizations. That's a huge step forward. Also, MRAs like spironolactone should definitely be considered for symptomatic HFPF patients as long as their potassium and kidney function, EGFR, are okay.

Now, let's tackle a really complex highstakes area. Heart failure during pregnancy and breastfeeding. It sounds like it needs very careful navigation.

Oh, absolutely. It's like walking a tight rope. Pregnancy itself puts a lot of strain on the cardiovascular system, which is risky for someone with existing heart failure. We have to constantly balance the mom heart health needs against the potential risks to the baby because yeah a lot of standard HF meds are territogenic. So during pregnancy itself several drugs are definite no-go. ACC inhibitors, ARBs, RNIs, MRAS, IV and SGLT2 inhibitors either not enough data or known harm but some meds can be used cautiously. Beta blockers especially the beta 1 selective ones like metopol are generally preferred. Furismide can be used carefully to manage fluid but you have to avoid dehydration. Dioxin seems safe though doses might need adjusting and hydrollazine combined with nitrates is another option but with any of these you need really close monitoring of the baby. Then for breastfeeding the picture is still evolving for some. Beta blockers like metoprol seem okay. Fioamide and spironolactone also seem to have minimal transfer into milk. Some ACE inhibitors inpro fosynopril quinappil ramiprol are generally thought to be compatible. However, you generally want to avoid arbs aonizabdine and sgt2 inhibitors while breastfeeding.

just because there isn't much data on their safety.

Expert, this is where theory meets practice for our listeners. Let's boil down some final crucial therapeutic tips. Those practical bite-sized nuggets for daily work and naturally for the PBC exam.

Okay, first off, remember the approach to diuretics is basically the same regardless of HF type. Always aim for the lowest effective dose and constantly reassess their fluid status. Now, if you see hypotension or worsening kidney function when starting or upping the dose of an ACE inhibitor, AR B, RNI or SGLT2 inhibitor. That often signals you need to back off the diuretic dose. It's also really important to realize that sometimes worsening kidney function in HF is actually a sign of congestion and it can often get better once you get rid of the excess fluid with proper diuresis. For HFREF, remember that quadruple therapy goal, but the initiation order is flexible. Tailor it to the patient. The big goal is get all four started and optimize target or best tolerated dose within about 3 to 6 months. And you don't have to max out one before starting the next. You can overlap and titrate together. Specifics: ivabberdine, don't start it unless the beta blocker is already optimized. Max that out first and no ivabberdine if they have aphib. If blood pressure is an issue, maybe try staggering the doses of their anti-hypertensives throughout the day instead of all at once. That cough could be HF getting worse, not just the ACE inhibitor. Always evaluate carefully. Electrolytes. Watch them like a hawk. Especially potassium when you combine drugs like an ACE or Barney with sparolactone. Check creatinine and electrolytes 7 to 14 15 days after starting or changing doses of ACIS, ARBs, ARIS, MRAS, or diuretics. And finally, the crucial sick day management rule. Tell patients to hold their AC inhibitors, ARBs, ARNIs, MRAS, and SGLT2 inhibitors if they get an acute illness that causes dehydration like bad diarrhea or vomiting. This helps prevent acute kidney injury when they're vulnerable.

Wow, that was quite the deep dive into heart failure management. We've covered a lot. The basics, non-drug approaches, the big pharmarmacologic strategies like quadruple therapy, for HFREF, the shifts in HFPEF, even those tricky special situations like pregnancy. Our real aim today for all you Canadian PBC candidates listening was to bring some clarity, accuracy, and those practical insights you need. Hopefully, you feel a bit more confident tackling this really complex but vital topic for your exams and your future practice.

Absolutely. Really understanding these details from the CTC reference, it builds such a strong foundation, not just for the exam, but for taking care of patients dayto-day.

So, As you think back on everything we've talked about today, considering how dynamic heart failure is, here's something to ponder. What do you think is the single most important thing for pharmacists to continuously monitor in their patients beyond just checking if they're taking their meds to ensure the best long-term outcomes? And just to test your recall from our discussion, here's a quick multiple choice question. Which of the following drug classes used for heart failure with reduced ejection fraction, HFREF, should not be initiated or have its dose increased when a patient is acutely decompensated. A loop diuretics, B ACC inhibitors, C beta blockers, D mineralcorticoid receptor antagonists.

Take a second to think about it. We've definitely covered this. The answer is C beta blockers.

Thank you so much for joining us on this deep dive. We really hope this session helps you on your learning journey.

تدابیر پس از سکته قلبی
Welcome to the deep dive. If you're gearing up for your PVE C exam, you know that feeling, right? It's just tons of information. Our job here is to cut through all that.

Exactly. We want to distill these big topics into uh really essential digestible insights, give you that critical knowledge so you feel confident, especially for high stakes exams like the PBC.

And today we are diving deep into post-ioardial infarction management. You know, MI is absolutely crucial stuff for any pharmacy. this and definitely for your PPC.

Yeah, we're talking therapeutic choices, medication algorithms, those key tables from the reference, um, essential tips you need to know.

We'll be covering the what, but also the why it matters.

And this deep dive is probably brought to you by the Pharma Board group. Everything we're discussing is based on the postmioardial infuction chapter from the CTC reference. We're aiming for clarity, accuracy, and, you know, practical insights.

So, expect a concise, easy to follow summary. We want you to feel that peace of mind knowing you haven't missed the crucial bits for M success. Okay, let's get started.

Sounds good.

So, let's unpack this first. Post-mocardial infuction. What exactly are we talking about here?

Right. So, this applies to patients who've had either a STEMI, you know, an ST elevation MI or an N STEMI, a non-ST elevation MI. Now, the early the acute management that differs initially.

Okay.

But the key thing is the long-term therapeutic goals, they become quite similar for both groups. We're shifting focus,

right? Moving from the immediate crisis to uh uh sustained recovery. So what are those long-term goals then?

Well, there are three main ones really critical. First, getting patients back to an ideal quality of life. That's huge.

Second, preventing the progression of their disease, their underlying coronary artery disease,

right? Stop it from getting worse.

Exactly. And third, maybe the most critical, preventing a repeat infuction. It's all about keeping them healthy long term.

Makes total sense. Get them back on their feet, keep them healthy. So, what specific complications should pharmacists be watching out for postMI? Good question. We evaluate for several things. Uh LV dysfunction is a big one. Left ventricular dysfunction that can lead to heart failure or arrhythmias.

Okay.

We also look for an LV clot, a blood clot inside the left ventricle that carries a real risk of stroke.

And then there are mechanical complications, things like ventricular septal defects, especially if the MI wasn't reperused quickly or effectively. And of course, ongoing monitoring for potential arhythmias.

Okay, so before we jump into the treatments, the how what are the key investigations the tests that help us figure out risk and guide those treatment choices

right we need to assess risk and guide therapy uh coronary angography is key evidence supports using it early for most STEMI and NTEMI patients it lets us see the blockages

then for lower risk patients

for lower risk and STEMI patients sometimes stress testing is used first but if that shows high risk then angography is still needed

and what about checking the actual damage the heart function itself

oh absolutely vital. We need to assess the infark size or left ventricular function, usually shortened to LV function. A significantly diminished ejection fraction or EF, that means the heart isn't pumping well, puts patients at higher risk

higher risk for

for things like LV thrombus, heart failure, and arrhythmias. Yeah.

An echo cardiogram is really the go-to for assessing LV function and looking for clots.

And do you repeat that assessment?

Yes, definitely. We typically repeat the LV function evaluation at uh 1 month if they weren't revascularized or 3 months if they were that's if the LVEF was initially low say less than 30 35% it helps decide if they might need an implantable defibrillator an ICD

okay and of course alongside all this we're looking at those modifiable risk factors smoking blood pressure BMI cholesterol glucose all that standard stuff

absolutely tackling those is fundamental

so moving on to therapeutic choices before we get into the medications what about non-drug therapies these are often just as important aren't they

they absolutely absolutely are foundational really

no

beyond the coronary angography we mentioned key non-farmacologic strategies include weight management the target BMI is 18.5 to 25

and waist circumference

less than 100 cm for men less than 90 cm for women often aiming for a 5 to 10% weight decrease initially

okay

nutritional counseling is vital and regular exercise like 30 45 minutes of moderate aerobic activity maybe 3 four times a week the goal is burning around 1,000 kiloal per week through activity.

What about the mental health side? MI can be pretty traumatic.

Very true. Individual or group counseling for psychosocial issues like anxiety or depression is important and for some select patients, the ones with significant persistent LV dysfunction, an implantable cardioverter defibrillator, ICD, might be needed down the line.

Right now, here's where it gets really interesting for secondary prevention and definitely something for PBC candidates to note. The source highlights this concept called the power of four.

Yes, this is a critical Takeaway. After an MI, patients are at substantial risk for Macy major adverse cardiovascular events. What's really powerful is that using four key drug classes independently reduces MCE by about 25% each.

25% each

each. And if you use all four drug classes together, the cumulative relative risk reduction is approximately 75%. You can see this laid out clearly in table one in the CTC reference.

Wow, 75%. That is a massive potential benefit. So it's Not just additive, it's synergistic.

Exactly. It highlights the importance of comprehensive medical therapy.

You lay out those power four drug classes for us.

Sure. First, ASA aspirin gives you about a 25% relative risk reduction.

Okay.

Second, beta blockers. Another 25% RR,

right?

Third, lipid lowering agents, primarily statins. These provide around a 30% RR, especially when they lower LDLC by about 1.5 millol.

Got it. And the fourth

fourth is an ACE inhibitor contributing another 25% RR.

So, So add those up roughly 75%. And the source also mentions smoking sessation can cut recurrent MI risk of by half after 2 years.

That's right.

So theoretically, you combine all of that, the four drug classes plus quitting smoking, and you could be looking at something like an 80% relative risk reduction. That's well that's an aha moment right there.

It truly underscores the impact we can have with evidence-based secondary prevention.

Absolutely. Okay, let's dive deeper into these pharmacologic agents. Starting with the antiplatlets. MI involves plaque rupture active ated platelets. So platelet inhibition is key, right?

No. Especially after procedures like PCI. That's why dual antiplatlet therapy or DAPT using ASA plus a P2Y12 inhibitor is so crucial initially.

Let's break them down. ASA what are the key points for pharmacists?

Okay, ASA it's indefinite therapy for basically all postinfar patients

and importantly low dose like 7500 milligrams is just as effective as higher doses but usually better tolerated less bleeding risk.

Makes sense. What about clapidogil?

Clapidogil is very common especially after PCI. Uh sometimes a higher dose 150 milligrams daily is used for the first six days post PCI and stem and STEMI then down to the standard 75 milligrams daily. It's also the main alternative if someone has an ASA allergy.

Okay. Then there's prugil sounds more potent.

It is more potent faster onset. Often considered firstline post in STEMI or STEMI but and this is a big butt for exams you absolutely avoid it in patient with a prior stroke or TIA.

Crucial point. Any other cautions?

Yeah, caution in patients over 75 or who weigh less than 60 kg.

Sometimes a reduced dose is considered there if available.

Got it. And tuggler.

Turguler is also considered first line. Studies show it's more effective than clapadril in ACS. But you need to be aware of potential adverse effects. Bleeding obviously, but also transient dispna, shortness of breath, which happens in about 14% of patients.

Okay. Now, the duration of DPT How long do patients typically stay on both?

That's a really important clinical question. The standard recommendation is at least 1 year after MI, especially if the bleeding risk is low.

At least 1 year. Can it be longer?

Yes. In some patients, there might be a benefit to extending it, maybe up to 3 years. There are tools like the DPT risk calculator that can help weigh the benefit against the bleeding risk, but it's always balance, always individualized.

And what about that combination you mentioned earlier, Riveroxin with aspirin?

Right. That's an option further down the line. Usually, at the one-year mark for stable coronary disease. It's river oxen 2.5 milligrams twice daily with lowd dose aspirin. It's particularly considered in patients who also have peripheral vascular disease or maybe a high stroke risk. Adds another layer of anti-thrombotic protection.

Okay, moving on. Beta blockers. You mentioned they're one of the power of four. What's their specific role postmi?

Beta blockers are fascinating. They reduce reinfarction, yes, but they also play a key role in preventing dangerous ventricular arithm. as especially in that early postMI phase.

So who should get them?

They should really be considered in all patients post STEMI or N STEMI unless there's a clear contraindication. The goal is usually to titrate the dose to get the resting heart rate below 70 beats per minute.

Any cautions with beta blockers?

Definitely you need to be cautious with IV beta blockers right at the start in the acute phase because of potential hemodynamic instability and you'd avoid them altogether in patients with significant hypotension, bradic cardia or active heart failure

and long-term use.

Patients with reduced LV function, that low ejection fraction we talked about, they get significant long-term benefit. For them, beta blockers should generally be continued indefinitely.

Okay, next group. RAA is inhibition. That's AC inhibitors, ARBs, and MRAs. This raises a key question. Who really gets the most benefit from these after an MI?

Good question. ACE inhibitors should be considered for all postMI patients, but they're especially beneficial for those with V dysfunction meaning LVF less than 40% or those who also have hypertension or diabetes.

Why are they so beneficial?

They help prevent negative LV remodeling changes in the heart's shape and function after damage and they've been shown to reduce cardiovascular death and recurrent MI.

What should pharmacists watch for?

The main things are that dry cough which is quite common and potential issues like worsening renal function or hypercalemia hypotassium. So monitoring is key and it's important to titrate them up to the evidence-based dosages like those listed in table two of the reference,

right? Table two for target doses. And if someone can't tolerate an ACE inhibitor because of the cough,

then an ARB, an angotensin receptor blocker, is the standard alternative. They work similarly, but don't typically cause cough.

Can you use both together? AC inhibitor and ARB?

No, absolutely not. That combination therapy doesn't add benefit and actually increases the risk of adverse events like hypercalemia and renal dysfunction. So, it's one or the other.

Okay. And the MRA's mineral corticoid receptor antagonists,

right? Agents like epinon or spironolactone. These should be considered specifically in patients who already have significant LV dysfunction. So, EF less than or equal to 40% often alongside an AC or ARB and a beta blocker. Eperon in particular has shown reduced mortality and hospitalizations in this group.

Main caution with MRAAS.

Again, hypercalemia, you really need to monitor electrolytes closely when these are added.

Makes sense. Now, statins, you said they're part of the power for contributing about 30% risk reduction seems like a cornerstone.

Absolutely a definite cornerstone. Statins should be started early postMI and importantly we generally aim for intensive treatment with higher dose statins

like which ones?

Like avoatin 80 milligrams daily or rosatin 40 milligs daily. The benefit goes beyond just lowering LDL cholesterol. They also help stabilize plaques making them less likely to rupture.

And the goal for LDL

for postMI patients the target is an LDLC of less than 1 and 8 millol therapy is indefinite. It's a long-term commitment.

What if someone is statin intolerant?

If they genuinely can't tolerate statins despite trying different ones, then other agents like aetime or even PCSK9 inhibitors might be considered to reach that LDL target.

Okay, that covers the core medications for most patients. But things can get trickier. What about patients who need oral anti-coagulants, maybe for AIB or an LV thrombus? How does that interact with DIPT?

Yeah, this is where it definitely gets complex, especially managing the bleeding risk. Oral anti-coagulants are recommended postMI if the patient also has atrial fibrillation AIB or if they have a demonstrable LV thrombus.

Let's take LV thrombus first. Which anti-coagulant

for LV thrombus? Warin is still generally the anti-coagulant of choice. There's just not enough solid evidence for using the DOAC's the direct acting oral anti-coagulants in this specific situation yet.

How long do they stay on warin for the thrombus?

Typically treatment is for about 3 months. Then you'd repeat the echo cardiogram if the thrombus is gone you can consider stopping the warin assuming there's no other indication like aphib

okay and for patients with atrial fibrillation postmi

for aphib the docs like river ox bandan daba pixaban adoxaban are generally preferred especially when they need to be combined with a p2y12 inhibitor

because of the bleeding risk with triple therapy

exactly triple therapy meaning ASA a P2Y12 inhibitor and warerin carries a significantly increased bleeding risk several big trials like pioneer AFPCI dual PCI. Augustus and Trust looked at this

and what did they find?

They explored safer strategies often involving stopping the ASA early, sometimes as early as day one after PCI or maybe up to 6 months and just continuing with the DOAC plus a P2Y12 inhibitor usually cla

so if triple therapy is needed even for a short time which P2Y12 inhibitor is preferred with Warin.

If warrin has to be used with dual antiplatelets cloped is often the preferred P2i12 inhibitor. studies suggest it might have a lower bleeding risk compared to prashagril or dicagriller in that specific triple combination but these are complex decisions always need individualization and cardiologist input

definitely sounds complex okay let's shift gears slightly to special populations what's unique about managing MI during pregnancy or breastfeeding

right MI in pregnancy is rare thankfully but when it happens the most common cause isn't typical plaque rupture it's often spontaneous coronary artery dissection or scad

how is scad managed differently.

SCAD is usually managed more conservatively, often with medications rather than immediate stenting unless there's ongoing eskeeia. DAPT, beta blockers, and ACE inhibitors if there's LV dysfunction might be considered. But a key point, statins are generally not indicated for SCAD unless the patient also has underlying atheroscllerotic CAD.

Okay. And during breastfeeding, what are the concerns?

There are definite concerns for the infant. ASA and lowd dose beta blockers can sometimes be used cautiously. However, if the mother needs P2Y12 inhibitors, ACCE inhibitors or statins, breastfeeding is generally not recommended. The risks are usually considered too high.

Got it. So, bringing this all together for our PBC candidates listening.

What are the absolute essential therapeutic tips, the practical insights they need to nail down for exam success and good practice?

Okay, this is really about maximizing adherence and outcomes. Think of it maybe three parts. First, maximize drug effectiveness. That means ensuring close adherence to these evidence-based therapies. Starting them early in hospital helps. Also, ongoing dosage titration. Keep pushing those beta blockers and ACE inhibitors towards the target doses found in table 2 as tolerated. And for statins, use the highest tolerated dose. Yeah.

Don't settle for less if more is possible.

Okay. Effectiveness first. What's second?

Second, empower the patient through lifestyle. Offer smoking sessation support. Bropion or verenocline are considered safe early postmi. And strongly encourage cardiac rehabilitation. makes a huge difference.

And third,

third, be vigilant about coorbidities and pitfalls. Manage blood pressure to target. Treat diabetes aiming for an HBA1C generally under 7%.

Any specific drug cautions we should highlight again?

Yes, definitely avoid thosol and those diabetes drugs like pyoglazone because of the heart failure risk. Make sure patients have sublingual nitrates and know exactly how and when to use them for chest discomfort.

Good point on the nitrates. Anything else?

Encourage annual flu vaccination. Be aware of depression. It's common postMI and SSRIs might help. And definitely know what not to use.

Like what?

Routine antioxidant vitamins or hormone therapy for secondary prevention. Not recommended, potentially harmful. And the big one, avoid anesides if possible.

Why avoid NSAIDs?

They can increase athermotic risk or interfere with ASA's effect. Especially avoid celoxip and ibuprofen if you can. If an NSA is absolutely necessary, naproxen is generally considered to have the least cardiovascular risk among them.

Okay, that's Great summary of tips. And finally, those algorithms and tables in the reference figures 1 2 3 and table two. How should listeners best use those for studying?

They are incredibly valuable study tools. Figures 1, 2, and three really map out the decision-m especially for those complex antiplate lantic coagulant choices like an AIB postci. They show how different factors influence the drug choice and duration.

What should they pay close attention to in the figures?

Definitely read the footnotes. They contain critical details, nuances, etcept. And two is your go-to for specific drug details, dosages, key adverse effects, major interactions, perfect for exam.

Fantastic. So listeners, you've just had a really comprehensive deep dive into postMI management. We've covered the goals, the core therapies, those tricky anti-coagulant situations, special populations, and essential tips, all geared towards your PBC success.

Yeah, our aim was clarity, accuracy, and hopefully some peace of mind. Summarizing this, critical info so you feel confident you've got the essentials covered. And remember, it's not just knowing what to do, but really understanding why it matters. That's key.

So, what stands out most to you from our chat today? Maybe think about that power of four and how those therapies work together for that impressive cumulative risk reduction.

Or perhaps consider that constant challenge balancing the need to prevent clots, prevent eskeemia against the risk of bleeding, especially in those complex patients needing multiple agents. It really makes you think, how would you counsel a patient? Maybe someone with a history of MI who now has new AIB. How do you explain that complex regimen, the risks, benefits, that careful balance?

Great point. Food for thought. Okay, before we wrap up, let's test your knowledge with a quick multiple choice question based on our deep dive.

All right.

A patient experiences an acute STEMI and underos primary PCI. They are deemed low bleeding risk. According to current guidelines, what is the minimum recommended duration of dual antiplatlet therapy, DAPT, postMI? Is it A 3 months, B 6 months, C 1 year, D 3 years.

Okay, take a moment to think. The answer is C 1 year. That's the minimum recommended duration for low bleeding risk patients postMMI after PCI. Longer duration might be considered, but one year is the baseline minimum.

Perfect. We really hope this deep dive has helped clarify postMI management and boosted your confidence for the PBC exams. Remember, this deep dive was brought to you by the Pharma Board Group and it's bas on the essential CTC reference.

Thank you so much for joining us on the deep dive. Keep learning, keep asking those critical questions, and we'll catch you on the next one.

اریتمی فوق بطنی
Welcome to the deep dive. You know, navigating all the medical information out there, especially when you're prepping for big exams like the PBC. Well, it can feel overwhelming, right? Like drinking from a fire hose. Our goal here is really to be your guide, cut through that noise, and get you the core insights you absolutely have to know so you don't miss those crucial details. Basically, we want you to feel confident, clear, and ready. So, today we're taking a really close look, a deep dive into super ventricular attack. cardia SVT. This is a huge topic for you as a Canadian pharmacist candidate. It comes up a lot on exams. You'll definitely see it in practice. We're going to focus on um giving you concise, easy to follow, accurate insights. Think therapeutic choices, medication algorithms, those key tables, and yeah, those vital tips for exam success and for real world practice. Just so you know, this deep dive is brought to you by Pharma Board Group and it's based on the therapeutic choices or CTC reference.

Absolutely. And uh maybe the best place to start is just Defining SVT what is it

fundamentally it's well it's any fast heart rhythm attack that starts above the ventricles usually you'll see a narrow QRS width on the ECG so 120 milliseconds or less

but here's the first absolutely critical step if you see a tacic cardia with a broad QRS complex

your immediate thought your priority has to be ruling out ventricular tacic cardia

oh okay because that's much more dangerous

exactly much more serious you need to exclude that possibility before you start digging into SVT causes.

Got it. So, fast rhythm starts above the ventricles, usually narrow QRS. Okay, unpack this a bit. What are the different types of SVT under this, you know, umbrella and why does knowing the type matter so much for our listeners?

That's a really important question because the type tells us a lot about the risks and uh how we should treat it. So, if we look at the common forms atrial fibrillation, AS and atrial flutter, these two are really significant. Why? Well, it boils down to thrombboic risk.

Well, stroke risk precisely. the danger of blood clots forming and potentially causing a stroke. That risk really drives a lot of the management decisions for AF and flutter. Then you have other types like atrio vventricular nodal re-entry tacocardia that's AVNRT and atrioventricular re-entry tacicardia or AVRT and also focal atrial teacardia at these are generally thought of as more benign uh less likely to cause really serious complications

generally benign

but there's always a butt isn't there with AVRT there is a rare, but um serious risk of sudden death. That can happen if it degenerates into what's called a pre-exited SVT. That's usually linked to accessory pathways.

Okay. And speaking of AF and flutter, I know the way we classify them has changed. The term chronic AF isn't really used anymore, right? Can you walk us through the current terms?

Yeah, that's right. We've moved towards more precise definitions. So, peroxismal AF or flutter, that means the episodes come and go. They stop on their own usually within seven days.

Self-limiting.

Exactly. Then there's persistent That's when the arhythmia is continuous. It lasts more than 7 days but less than say 12 months. After that we have longstanding persistent. This means it's been continuous for over a year but crucially restoring a normal sinus rhythm is still seen as you know a possible goal. And finally permanent AF or flutter. This isn't just about duration. It's a clinical decision. It's when the patient and the clinician together decide to stop trying to get back to or maintain sinus rhythm.

So it's accepting that rate control is the strategy

pretty much. Yes. It acknowledges that for that particular patient, rhythm control isn't feasible or maybe even desirable anymore. Now, while the overall management approach for AF and flutter is quite similar, especially that stroke risk assessment, there are a couple of important differences.

First, getting the heart rate under control, it can often be well a bit trickier in atrial flutter compared to AF.

Harder to slow down

often. Yes. And second, and this impacts treatment, the threshold for considering catheter ablation is generally lower for atrial flutter. It tends to respond really well to ablation, often providing a long-term fix.

Makes sense.

And just quickly on those other usually benign SVTs, the mechanisms, AVRT is caused by an extra electrical pathway, a congenital thing, like a shortcut between the atria and ventricles that bypasses the normal AV node,

an accessory pathway,

right? And if electricity travels forward down that pathway during normal rhythm, you get that classic delta wave on the ECG, that sort of slurred upstroke on the QRS. That combo is wolf parkinson white syndrome or WPW. AVNRT on the other hand, that's a short circuit inside the AV node itself and focal AT. That just means there's one specific spot in the atrium that's firing off way too fast.

That clarifies the different players nicely. But let's bring it back to the patient sitting in front of you.

What are we actually trying to achieve when we treat SVT? What are the main goals?

Good question. We really think about goals in sort of two stages plus one absolutely vital overall aim.

So, In the acute stage, when someone presents with SVT, the immediate goal is usually to get them back into a normal sinus rhythm, especially for those re-entrant ones like AVRT and AVNRT rhythm control is almost always possible there, right?

But for AF, flutter or atrial tacicardia, if getting back to sinus rhythm isn't happening right away or maybe it's not the best long-term plan for that patient, then the acute bill shifts. It becomes controlling the rate of the SVT,

slowing it down.

Exactly. Slowing that fast ventricular rate down to something safer and frankly more comfortable for the patient. Then thinking longer term, the objective is to stop the arhythmia from coming back or at the very least to significantly reduce how often it happens and how much it impacts the patient's life. Reduce the arhythmia burden we call it. And overarching all of this particularly for AF and atrial flutter is that crucial goal reducing the risk of thrombolic events specifically stroke. That's absolutely paramount.

Okay. So before we jump into treatments, it sounds like getting the diagnosis right is key. What investigations are essential? What clues do we need to gather?

Absolutely. Diagnosis first. It's like putting pieces of a puzzle together. We always start with a really detailed patient history.

What kind of things are you asking?

We want to know about the episodes. When did they start? How often? How long do they last? Any specific triggers, things like alcohol, caffeine, exercise, maybe symptoms of an overactive thyroid. Understanding the pattern helps point us towards the likely type of SVT. Though It's worth noting lots of patients don't actually have consistent triggers. It just happens, right?

Then the absolutely critical piece, we need to document the arrhythmia itself. The gold standard is catching it on a 12 lead ECG while it's happening.

But what if it comes and goes?

Exactly. For those intermittent cases, a halter monitor worn for 24, maybe 48 hours or even a longerterm loop recorder can be invaluable for actually capturing the rhythm disturbance. And finally, echo cardiography, an ultrasound of the heart. This is essential. It lets us look at the heart structure and function, things like left ventricular function, the size of the left atrium, how the valves are working.

Why is the echo so important?

Because those findings heavily influence our treatment choices, especially around things like anti-coagulation and certain anti-arithmic drugs. Some drugs are unsafe if there's underlying structural heart disease.

Okay, that makes perfect sense. Diagnosis sorted.

Now, let's get into treatment. And maybe surprisingly, let's start before medications. What are the key non-drug strategies?

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.