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Barenaked Cardiology: Episode 9; is it a STEMI?

Well Class after a lot of puzzling over this post, I decided my ST changes post would be split into 2. As it turns out, there is a shit ton of things that can cause ST changes and most of them are pretty fucking boring. So rather than wasting time going over ALL the different STEMI mimics and how to determine which of those it is, and can I call it an AMI anyway (IE Scarbossa Critera) We’re going to learn how to tell three things, Is it a STEMI? Is it one of the few easiest mimics? And if it is a STEMI where is it.

The first step in talking about ST changes is to figure out how we measure them. Observe below the J Point.

This is the point where the QRS meets the ST segment. Under normal circumstances this happens at the baseline, any deviation of the JPoint from the baseline is considered an ST change.

The ST change is considered clinically significant if it is more than 1mm in the precordial leads or 2mm in the limb leads. But how the hell do we tell a real STEMI from all the mimics? first thing you gotta do is make sure there is no BBB. its a little different in the hospital because a new BBB can be an indication of fuckery, but out in the streets we cant check old EKGs so we can’t assume much.

First Ventricular Hypertrophy: easy enough TALL complexes in the V leads.

were talking outside the constraints of the normal "boxes" tall here people, look at that shit.

Now on the the Bundle Branch Blocks: With the BBBs you will typically get an RSR’ pattern somewhere, because one of the BBs is transmitting faster than the other so you can see them separately. secondly the QRS will be wider than .12 or 3 little boxes. to determine LeftBBB from RightBBB I look at V1.

If there are 2 R waves in V1 this is a Right BBB. (more Rs is Right) you also have sluring of the S wave in V6 but i’ve yet to find a situation in which i’ve cared. maybe we will find one later.

If the QRS complex in V1 is wider than .12 and only negative (sometimes there is a slight uptick at the beginning if leads are placed improperly) this is a LBBB. (No Rs is not Right=Left) the QRS in V6 should be a sort of M Shape. Again, typically I don’t care unless I’m trying to rule out other things like Hyperkalemia.

Please note fellow nerds that a BBB does NOT mean A STEMI cannot be diagnosed, it just means that WE can't, YET. that shit will be reviewed when we get back to ST changes later.

If you don’t already know, and if you don’t, please start again from episode 1. a STEMI is caused by a loss of blood flow caused by an occluded vessel, first you get ischemia (depression), which progresses to infarct/tissue death, then much later, scar tissue (we won't talk about that here) Here's where the anatomy diagrams come into play.

In this first diagram every color represents a region of the heart. Ignore aVR for now because nobody likes it it just talks nonsense half the time.

This second diagram uses the major vessels to look at anatomy. You can kind of see the association. Everything starts at the aorta, and as we all know shit flows downstream. When something gets fetched up high in the LCA the septal, LAD and circumflex will suffer, if it gets fucked up a little lower only the LAD and Circ will feel it, and so on. How far the damage extends depends on where the vessel is occluded.

In order to declare a STEMI you must have ST segment elevation in 2 “anatomically contiguous” leads. That would be any 2 leads with the same color. With the V leads, it can also be any two sequential leads.

This here is the classic II, III, aVF inferior wall MI. drilled into the heads of everyone everywhere because these MIs can cause the patient to be preload dependent, and giving Nitroglycerine can take away your preload and bottom out your blood pressure really fucking quick. if you want a better idea on the status of the right ventricle, this is when you do a right sided 12 lead, you can reverse full 3-6 or just 4 in an exact mirror pattern to the left leads. Here is a similar case with V4R shown. (when acquiring you should notate V4R as such, however the isolated STE in lead V4 in the presence of an inferior STEMI should set off alarm bells.)

Paramedic says: “No nitrates for YOU!”

now what about this guy right here

We have ST Depression, maybe some ischemia, NSTEMI right? but what happens if we take a deeper look using V7-9 as shown below.

Look what happens

Surprise! its a STEMI after all. Even more shocking is that in the posterior leads we only need .5mm thats HALF a SMALL box of elevation for it to be clinically relevant. When you see that flat depression without T wave inversion in V2-V3 be suspicious for a posterior MI.

One more curveball folks.

HOLY SHIT ITS EVERYWHERE! But wait, because luckily this fucker probably isn’t going to drop dead in front of you. notice how all of the ST elevation is concave, if someone was having this massive an MI we would probably have tombstones by now. Also note that the PR segments are depressed. This is Pericarditis. Probably the more unnecessarily pants shitting of the STEMI mimics.

And with that we conclude the lengthy explanation of most of our ST changes and most importantly, STEMI recognition. Give this time to sink in, go find some practice.

Barenaked Cardiology: Episode 8; Step 3=???

MORNING class, I fucked up my dentist apointment so now i have to wait untill my regularly scheduled naptime to go, so here I am in all my over worked and under slept glory, trying to entertain myself, So lets talk about step 3 on our 12 lead interperitation flow chart, QRS problems.

So, as you know it now, the width of the QRS is how we determine if a rhythm originates in, or above the ventricles. Unfortunately’ I’m about to take all of the simplicity out of that statement. you see in order to call a rhythm ventricular unless its slow and wide as shit (see below) we have to rule out a bunch of other shit.

(calling this ventricular is a pretty safe bet)

the first of these you talk about in 12 leads are the bundle branch blocks. these can either be a symptom of new damage, age changes, or completely benign in order to really tell you need to compare to an old EKG and since thats practically a miracle if you aren’t the patients cardiologist, we typically cant do that, but since its something on our elimination list, lets take a look. find your nearest EKG and flip to Lead V1, Lets talk about the bundle branch blocks.

Bundle branch blocks (BBB) can be Left or Right. There are a few criteria for BBBs the QRS must be greater than .12 if I catch you fuckers calling something a BBB with a QRS less than 3 little boxes so help me. DO NOT DO THIS. since we have now determined the QRS is widened. lets look at what it is doing. Is it a V shape pointing only downward?

CONGRATS its a Left BBB.

are there TWO R waves? (the second is known as R’)

This is a Right BBB. (NOTE 2 Rs in RRIGHT)

there are changes in V6 you can look at but I’ve found just looking at V1 to be sufficient since I’m not a fucking cardiologist and Ive got better shit to do and this probably isn’t going to kill someone.

if your QRS is wider than .19 however THIS IS BAD. you probably have hyperkalemia or some other conduction problem on top of the BBB. also, DO NOT forget to look at the T waves, use all the leads.

ER doc was quick to dismiss this as a LBBB, however the T waves are tall in V1-3 and there is an upward deflection at the beginning of the QRS in V1 which doesn’t necessarily mean anything, but personally triggers me to be suspicious. this patient was acutely ill and hyperkalemic.

The other bit of bad news is aberrancy. this is when the pathway of conduction through the ventricles is abnormal and the QRS is wider, and mostly comes into play when we’re trying to differentiate an SVT from a VT.

If its monomorphic but IRREGULAR its probably AFib with RVR with Aberrancy. if there is no progression of the QRS in the precordial leads (they are all positive or all negative) then its probably VT, same with a far right axis (two thumbs down) theres more, but but sometimes its just going to have to be trial and error to correct and if they’re sick enough just zap em.

Moving on to Pathologic q waves. a Pathologic q wave can be one of the following. Greater than 1mm/1 small box wide, greater than 2mm/boxes deep, more than 25% the depth of the QRS or any q wave apearing in V1-3 (notice how even in the EKG above the first deflection in V1-3 is positive) I’m not going to go into it too much more because either its an OLD MI or there’s probably something else cluing you in and if it wont kill you I probably don’t care that much. look here if you do though.

If the QRS alters in height (do not confuse with baseline wander) this is electrical alternans and can be a sign of pericardial effusion, especially ominous In trauma or with a rapid onset of symptoms.

if a widened QRS exits in the presence of abnormally (think outside the space normally allotted for a single lead) tall QRS, this can signify ventricular hypertrophy. again look at V1. mostly down? LVH, Mostly Up(or even equal)? RVH. tall QRS can be a normal variant in kids, and young, thin, athletic types. the QRS may also not be widened much, if any.

SPECIAL ABNORMALITIES: I’m still working on some of these personally. DO YOURSELF A FAVOR and come back to these after you have mastered the basics.

1. not new but important: the Delta wave in WPW. WPW is a common cause of sudden cardiac death in teens and young adults who have usually never had an EKG before, it is also a common cause of SVT in this same population. The Delta wave is a gentle sluring of the PR segment into the R wave. rather than a sharp point. this represents the alternative pathway in WPW that causes all the problems.

2. Brugada Syndrome: Brugada syndrome has 3 different pattern types, is especially common in asian males, and is a potential cause of sudden cardiac death.

of the three “types” of Brugada patern, only type 1 is potentially diagnostic IF correlated to clinical criteria. and you MUST have >2mm STE in >1 lead (v1-3) followed by a negative T wave. (V1 and V2 in the image above) type 2 and 3 are currently nondiagnostic. Clinical criteria include HX VF/VT, known brugada patern in a family member, history of sudden cardiac death in the family, syncope or noctournal agonal respirations. Diagnosis warrants ICD placement. REMEMBER this is NOT an EKG exclusive diagnosis, it can “suggest” Brugada, clinical correlation can confirm, but you can not call this ekg alone “Brugada Syndrome”

3. QRS widening with overdose of a calcium channel blocking medication, typically a tricyclic antidepressant, or an antiarrythmic. calcium channel blocking ALSO affects the central nervous system. Seizures and Ventricular dysrhythmia are the most serious presentations.

EKG changes come in the form of widening QRS, sinus tachycardia, and Right Axis deviation and possibly a RBBB.

like so.

Thats all I have for you in this episode but we’re finally starting to make sense of some shit, how does that feel.

Get on with it.

Barenaked Cardiology: Episode 7; Chewing Gum and Paperclips

Greetings nerds. Today is the day you’ve been waiting for while I drone on for weeks. Jokes on you though because if you weren’t paying attention none of this shit is going to make sense. Review your notes because here we fucking go.

I looked at this picture good and hard before posting it and have figured out that this, is a 12 lead.

If we want to know more we have to go about it systematically. Now, the facility this 12 lead comes from sucks because their cardiologist wants V1 as the rhythm lead and not lead II, so fuck that guy. regardless lets start with step #1.

What fucking rhythm is this? To figure that out we need to go through this systematically, my system is Rhythm (is there one?) Rate (greater/less than 100 to be revisited in extremes) is there a P wave? is the QRS wide or narrow? is the rhythm regular (looking at R-R interval)? and lastly is the P-R normal and/or P-P regular?

LOOKING AT LEAD II we can see, there is in fact a rhythm. score 1 for us. the rate is about 60, there are P waves, the QRS is narrow, the R-R is regular, and the PR interval is within normal limits this is a normal sinus rhythm just on the cusp of sinus bradycardia.

Now lets talk about determining axis. this fucks a lot of people up, including me in the beginning but i developed what I call the thumbs up method. we’re going to look at lead I, and lead aVF. lead I is your right hand, and lead aVF is your left. if the QRS is mostly positive in the matching lead, put the appropriate thumb up. 2 thumbs up is a normal axis. right thumb down is right axis deviation, left thumb down is left axis deviation. two thumbs down is extreme right axis deviation- no mans land. the majority of the QRS is above the baseline in both lead I and lead aVF meaning both your right and left thumbs should be up. this is a normal axis.

The QRS is not widened as we determined early on when we declared this NSR. there are no other abnormalities with the QRS (we haven’t learned any yet, but we will)

The ST segment is equal to the baseline in all leads, if there are any subtle changes they aren’t enough to be significant (2 small boxes for precordial leads and 1 small box for limb leads) again, we will go over STEMIs and other causes of STE in more depth in the future so unknot your trousers and BE PATIENT.

Next lets look at the T wave. If you have no idea what you are doing you might want to call these peaked since, no fucking way, they have a “peak” don’t fucking do this. if they didn’t have a point to them, they would be “flattened” and that is also bad.

This is a peaked T wave its less of a mountain and more of an inverted icicle.

After all of that we look at the other little things we have yet to talk about, U waves, Delta waves. and after all that you are able to spit out an answer like.

“This is a completely normal 12 lead”

and while most of the 12 leads you look at in practice (if that is where you are looking) will be normal, boring shit like this. In our next episode we’ll start using our pathway to look at some EKS where things are NOT “normal” including non pathological variables and darker dirtier shit like hyperkalemia, or my friend STEMI and its many posers.

Heres a rundown of what we just did.

Carry on wayward sons.

Barenaked Cardiology: Episode 6: Grey’s Anatomy

Hopefully this lesson will be less painful than that time I tried to watch Grey’s a few weeks ago. but finally we have reached that unavoidable part where in order to talk about interpretation of 12 leads we gotta know a bit of anatomy. so lets get it over with.

Einthoven’s Triangle.

The first thing you need to know about EKG is that the RL lead is a ground and doesn’t actually do jack shit. the other three leads are what we are dealing with. the leads move counterclockwise around the heart starting and ending at the LA.

We use lead II for interpretation most often because it starts at the RA and ends at the LL. which most closely resembles the path of electricity in the heart, which starts at the top of the atria and heads towards the apex before fanning out.

like this.

lead I, II, and III are bipolar leads, because they travel between two points.

the Augmented leads aVR, aVL and aVF are made using fucking math, and travel between the midpoint on one of the first 3 leads, and are labeled based on what they go towards (the a stands for augmented, no shit). possibly they also start at a midpoint and head out but this may be manufacturer dependent/not that important.

so the first 6 leads are known as the limb leads, and are BIPOLAR they travel between 2 points. the next 6 leads are the precordial leads and they are UNIPOLAR. they start right where they sit on the skin and look straight in, nothing more, nothing less.

So. Heres our 12 lead sheet the way its usually printed out.

when we start talking about EKG changes knowing where in the heart we are talking about is important. most people use something like this to help them out.

note aVR is probably the most useless of the leads. it starts at the middle of the heart and looks up and right, which if you know anything, means its pretty much going away from the heart and doesn’t look at shit. Heres a diagram about the vessels because thats the shit that still fucks me up.

there are some varyations but for the most part when dealing with disease effecting a certain vessel, these are the leads that will be affected.

so where does this all fit? While a long strip of lead II will be the most useful for determining rhythm its important not to forget the big picture. just as in radiology “one view is no view.” only looking at one lead can miss a lot of pathology, looking at the 12 lead can help clear up ambiguity in rhythms and clue you in to a number of disease processes. remember to refer back to this when we move forward.

have at it!

Barenaked Cardiology: Master Post

NOTE: This is a down and dirty look at interpretation of EKGs aimed at identifying life threats. If you want a deeper look a cardiac pathophysiology buy/rent/borrow/steal “Pathophysiology of Heart Disease” by Leonard S. Lilly.

DISCLAIMER: I’ve collected a lot of the images in this series from the internet for the purpose of demonstration. I DO NOT claim ownership of these images. any images that ARE mine are free for use so long as you do the same. This information is based on my personal knowledge, there may be some inaccuracies and simplifications, this series is intended to demystify ekgs not to be used as a guideline for treatment of patients.

Part 1: the EKG waveform

Part 2: Atrial Rhythms

Part 3: Junctional Rhythms

Part 4: Ventricular Rhythms

Part 5: Ectopy

Part 6: 12 lead anatomy

Part 7: A systematic look at the 12 lead.

Part 8: QRS changes

Part 9: ST Changes Part 1

Sugested Practice: Figure1 or Medshr apps, Will post my own practice EKGs in a future post.

Barenaked Cardiology: Episode 5; Still not 12 leads.

We have covered the basic underlying rhythms, but we have one more thing to talk about before we can move on. The not-so-basic heart blocks and Ectopy.

Ectopy will be short, so lets start there.

So we’re marching along at whatever the fuck our heart is doing and suddenly we end up with this.

Premature Atrial contractions one of which is actually missed in the arrows above. (bonus points, DM me with where it is.) Are when the atria gets ahead of itself and fires too early, and the rest of the heart just rolls with it. This is a little confusing for the heart and it takes a second to get back on its feet, kind of like when i trip over my boots at work. this slightly longer than normal space between the PAC and the normal complex after it is called a Compensatory Pause.

You can also have Junctional and Ventricular premature complexes, figuring out which one it is is pretty much the same as figuring out what kind of rhythm it is. look at P waves first, then the width of the QRS.

If you have two premature complexes in a row, that is called a couplet, 3 is a triplet, and 4 or 5 is a salvo, anything longer than that is considered a “run” of whatever the new rhythm is (AIVR, VT, SVT etc.) KEEP IN MIND that “premature” refers to the pacing rate for that part of the heart. so if the SA node fucks up and the ventricle starts its firing where it normally would but looks all wide and confused this is still a PVC.

That is ventricular bigeminy I captured back in school.

If every other complex is one of the premature ones, this is called bigeminy, every third is called trigeminy, fourth is quadrigeminy and if you refer to anything longer than that you have too much time on your hands.

Moving on, the MOST common abnormal rhythm you are going to have to deal with unless you are in fucking pediatrics or some weird shit like that, is Atrial fibrilation. like its much more lethal cousin V-Fib, A-Fib is the atria freaking the fuck out and every once in a while it freaks out in the right spot (or the AV node kicks in) and the ventricles fire. the hallmarks of this are narrow, irregularly spaced complexes without P waves.

NO (this is sinus arrythmia, everything is normal and yet the interval is still irregular)

Yes. NOTE while hear you can see the chaotic baseline, oftentimes artifact will make this and a junctional complex indistinguishable, again, make sure there are no P waves, and make sure its irregular.

Atrial Flutter is typically regular, with jagged sawtooth “flutter waves” instead of P waves.

Wandering Atrial Pacemaker/Multifocal Atrial Tachycardia are rare and are either regular rate, or accelerated rhythms identified by varying P wave morphology and PR intervals.

I haven’t sworn in a while, so I’ll just come out and say that these are pretty shitty. different parts of the atria are all trying to be the boss, and while sometimes this is just a matter of being, this can also lead to things like lethal arrhythmias preexcitation etc.

Now for the bit that too this day fucks me up sometimes. The AV blocks.

A PR interval consistently longer than .20 (one big box) is a first degree AV block. Easy enough right?

Now, someone somewhere fucked up explaining this to me and I’ve suffered ever since, but i’m going to try and avoid doing the same to you.

if the PR interval is longer than .20, stays the same but not every P wave has a QRS this is a 2nd degree type 2 AV block. If the PR interval changes and not every P wave has a QRS its probably a 2nd degree type 1 AV block, BUT you have to check on this one. If every P-P interval is the same and every R-R interval is the same this is not a 2nd degree at all, but a third degree AV block.

not the best example but try to see what I’m talking about and google it for further examples.

Now go forth and hit up doctor google, and next time we might just talk about 12 leads.

Barenaked Cardiology: Episode 4; Coarse Asystole?

Well class, I have to avoid the responsibilities of adult life, so here we are. Ventricular Rhythms.

The ventricles get pretty fucking lost without someone up above telling them what to do, kind of like the people I work with. Anyway under normal “oh shit” conditions the ventricles will pace themselves at 20-40 beats a minute. We call this an Idoventricular rhythm or IVR. sometimes this is also called ventricular escape because in the absence of upper management the ventricles are trying to escape immanent death.

(If you listen closely you can hear the panic)

If the rhythm is ventricular in origin and faster than 40 beats a minute but slower than 100 you have Accelerated Idioventricular Rhythms or AIVR. Remember, a patient who is ventricularly paced may appear to be in AIVR, especially with newer pacers, history is important in telling the difference.

Both of these rhythms are considered PEA in arrest and follow the PEA/Asystole algorithm (no shocks)

If the rhythm is faster than 100 usually it will be significantly so, and this is the big bad Ventricular Tachycardia. this rhythm can be pulseless or with pulse, stable or unstable. but is never “good”

Good old Monomorphic V tach looks like this

but as long as the patient is stable, and has a pulse you have to be able to differentiate between this ^ and this v

Polymorphic V Tach has a slightly different treatment algorithm, theres a pretty good chance that the polymorphism is caused by an area of the heart thats pissed off, but a subset of polymorphic Vtach is called Toursades-de-pointes (literally twisting of points) and it looks exactly like the above.

BUT if you make the mistake of calling every polymorphic VT Toursades I will personally come to your house and slap you across the face. you can SUSPECT Toursades, but true identification of TDP requires knowing how the rhythm starts. Toursades happens with “R on T” phenomenon which is when the heart misfires and an ectopic beat happens when the heart is trying to repolarize, which really pisses it the fuck off. Toursades is typically self limiting (not always in a good way) but can recur frequently and the longer the QT interval the more likely it is to happen.

it looks like this.

These rhythms are shockable if they are pulseless, or unstable. The main thing with ventricular rhythms is to keep them from turning in to this motherfucker right here.

this is (course) Vfib. different parts of the ventricle are trying to pace the whole heart and nobody can agree on how to do it. the end result is the last agonal shitshow before death.

The heart, like me, gets tired of this shit pretty quickly and will settle to a fine V-Fib. And then finally

Boom. Nothing. this is Asystole, or the absence of contraction. You may get a low amplitude blip here or there and then you can call it agonal but either way, the heart has given up and its typically pretty unlikely anything good is going to come out of it. Don’t be the guy that shocks this rhythm. I will find you.

Next class we will talk about ecto-cooler ectopy. Be ready.

One last time repeat after me WE DO NOT SHOCK ASYSTOLE I do not care what McDreamy told you.

outsidehospital

If there is one thing nobody in this buisness is a stranger too, its that people die, they die old, they die young, when you expect it, and out of the blue.

so why is it that it still manages to catch us off guard when its one of our own.

I was driving back from picking up a few groceries on the north end of town. I decided to take the long way back. I saw the per-diem pickup parked at Walgreens and a cop and a grouping of people standing outside. I decided to turn around and see if they needed help, I knew it was M working as well as one of the Lts, (most the officers are great to work with) soi swung around and stopped by to see if they needed any help.

the pt was a middle aged woman who had a few seizure like episodes in the past few days. we got her loaded up and about 5 of us crowded into the ambulance where it was warm (because boy was it cold outside) the Lt stayed outside.

“Not gonna let Ricky in?” one of the paramedics said.

“Nah, Hes just a Lt he can stay outside” someone else replied, and we all laughed.

as the ambulance left the rest of us stood outside joking around a bit him and M tossing rhymes back and forth as they loaded back into the pickup and we all disbursed.

When I got back tot he station I saw that Ricky was the only one who managed to beat me in song pop for the week and I thought about how wether I wanted to comment on his Facebook or wait till I saw him to joke with him about it. It was one of the days at the station with him and everyone else playing that had gotten me into it in the first place. I decided I would just wait till training on wednesday to say something.

I’ll never get that chance now.

I opened facebook on my phone this morning and saw the deputies wife had posted about loosing another firefighter, someone else commented saying it was one of windham’s. I wondered if it was someone I didn’t know, nobody I knew was sick. someone else commented on how sudden it was, and i got nervous. maybe it wasn’t someone i knew well though. I saw “RIP Ricky” and thought, no. Surely not that Ricky, I just saw him.

But it was.

He collapsed in the shower this morning, his wife called 911 and his towns rescue responded. they worked the code and after 20 minutes they told our chief who by this time had arrived on scene that they weren’t going to be able to transport.

He was 48 years old, leaves behind two daughters, and a one month old grandson.

Its the second time in a year Facebook has told me someone I know has died, and each time it gets closer.

Barenaked Cardiology: Episode 3; Whats your function.

Morning class, I’m currently waiting for either the Advil I shouldn’t be taking or the caffeine I wont admit I’m dependent on to take my headache away. so lets move on to episode 3.

Today were going to be talking about the Conjuction AV junction.

The AV (atrioventricular) junction it whats normally responsible for the P-R interval the little pause that lets the atria empty thereby filling the ventricles before they themselves give it a go otherwise our cardiac function would suck and we’d all be fucking dead. So when the SA node responsible for all our sinus rhythms is malfunctioning the AV node/junction gets fucking bored and decides to pick up the slack producing what we call “Junctional Rythms” the AV node isn’t used to filling in for the SA node though, so its confused little self usually only fires at 40-60 beats a minute, but if its really on its game you can get a faster rhythm, known as “accelerated junctional” which is typically more the rate you would expect a sinus rhythm to be. If we get faster than that we are getting into the pre-excitation syndromes, but for now just know to ignore anything faster than 100/min

But Outside, how do I know the difference?

GREAT fucking question.

The answer lies in the P wave. because the electrical impulse is starting AFTER the atria, the P waves get all fucked up. most classically, you wont have any, but because the impulse is still coming through the AV node, the QRS complex is still narrow, because the ventricle is even slower so it cant really tell the difference.

But sometimes some weird ass shit happens and because the atria still WANT to depolarize, they will, only starting at the AV node and moving backwards. If you remember I said the PR interval should be .12-.20 if its LESS than that its a good indicator that the AV junction is where the impulse is starting its just trying to send the signal back through the atria to pretend like nothing is wrong. but we’re smarter than that. sometimes the P wave can even be fucking UPSIDE DOWN or come AFTER the QRS in the ST segment. Fucking crazy right?

Here are some fucking examples.

The P wave is that little hiccup on the R wave. this is accelerated

Look ma, no P waves! this is accelerated.

inverted P waves this is plain old junctional

Retrograde P wave this is also accelerated

Please note that all of these rhythms are regular. we will be talking about blocks, preexitation and Atrial fuckery in later post(s).

Go forth and find junctional rhythms kids.

Barenaked Cardiology: Episode 2; Having a good day.

alright class. I need something to do while I sit here and sip tea like the lady i’m fucking not. so lets move on to the next lesson, in which i give you strips to actually look at.

Like I said before, the first step in determining what’s going on when things are all fucked up, is to know what things look like when everything is working as it should be. so today, were going to be looking at the SA node.

If you think of cardiac depolarization like doing the wave at a sports game. the SA node is the motherfucker that starts that shit. the electricity moves between the SA (sinoatrial) node and the AV (atrioventricular) node. depolarizing the atria and causing them to contract. this is represented on the tracing by that P wave we were talking about before.

STEP ONE of EKG interp is to find that p wave.

STEP TWO is to measure the PR interval each small box on the EKG is 0.04 milliseconds the big box is .20 ms (5 little boxes) by default. If you’re an asshole like me, you can change this sometimes, but for now we’re going to live dangerously and assume.

the beginning of the P wave to the beginning of the R wave is the PR interval, which you should know if you were paying attention. anyway, the PR interval should be .12-.20 ms thats 3-5 little boxes. if it isn’t that sucks because its something we’re not quite ready for. if it is GREAT we have a sinus rhythm.

STEP 3: is it regular? some people use calipers for this but thats a waste of fucking money and im not going to carry those in my pocket, so lets cheat. the easiest way to do this is to fold the paper over and hold it up to a light and see if everything matches up. but since you look like a fucking idiot doing this in front of people. grab some scrap paper. make a mark at the beginning of the top of the R wave on one QRS complex and the top of the next one. then slide the paper down so that the first mark is where your second mark had been. there should be a QRS right where your second mark is now. if there is, congrats its regular! if not it could be a number of things we will get in to another time, put that rhythm over in the pile with the not sinus ones.

Now we have to look at the rate of the heart itself. there are two methods of doing this. the 6 second method and the box method.

For the 6 second method 30 big boxes = 6 seconds count the number of QRS complexes in that 6 seconds and multiply it by 10 this is probably the most reliable method as it deals away with rhythm irregularities but sometimes its a pain in the ass to count out 30 fucking boxes, so we have the box method.

find a point on a QRS that lines up with the edge of a big box. I like to use the point at the top, but that wont always line up. If there are only 1 large box between your point and its matching point on the next QRS thats 300, 2 is 150, 3 is 100, 4, is 60, 5 is 50, 6 is 43 and 7 is 37. more than that is just straight bad.

So, whats important about that rate? it determines what kind of sinus rhythm we have. the SA node should fire at 60-100 beats/minute so a rate from 60-100 is a NORMAL SINUS RHYTHM the ideal heart rhythm often shortened to NSR anything faster than this is Sinus tachycardia, anything slower is Sinus bradycardia. and thats it. we now know 3 rhythms here is some practice.

Find the PR interval, the Rate, and then identify the Rhythm. Answers at the bottom. GO.

1: PRI: .16, rate 70 Normal Sinus Rhythm.

2: PR .16, Rate 140 Sinus Tachycardia.

3: PRI: .16 Rate 80 NSR

4: PRI: .14 Rate 110 Sinus Tachycardia.

5: PRI: .20 Rate 50 Sinus Bradycardia.

Now go forth with 3 pretty new rhythms to look at.

Barenaked Cardiology: Episode 1; the Fuck is this shit?

Alright sports fans sit tight, were about to learn some shit. specifically shit having to with EKGs. starting from square 2. because im going to assume we’ve at least had 1 biology course in our life and know that the human heart doesnt look like this <3.

EKGs What the fuck is that?

an EKG (ElectroKardioGram) or ECG if your a grammar nazi and/or hate germans uses the eletrical impulses of the heart to get an idea of how the heart is working. knowing how this looks when everything is going great and knowing some typical “oh shit” paterns we can get somewhat of an idea whats going on inside without doing roadside thoracostomies. (life is boring sometimes i know)

But before we can start looking at the ugly stuff we have to know the first part. what are things SUPPOSED to look like. so lets get to studying anatomy.

not this. fuck that.

Im talking anatomy of the EKG waveform.

ignore the shit to the right for now. you need to know the P QRS and T bit. U waves are more rare and we will talk about that maybe eventually. the fundamentals are going to rely on these waves or the lack thereof and how they look. while not important now, know that most assessment of rhythm is done in lead II, which stretches from the right arm to left leg, most closely mimicking the direction of electricity in the heart this is important because the description of waves positivity or negativity might not be accurate if you are looking elsewhere, so when practicing remember to stay in lead 2

Lets start with my friend the P wave.

the p wave should be a little bump before the QRS. it represents depolarization of the atria. if this looks funky it can mean the impulse isn’t coming from where it should be, and if its absent it means it definitely isn’t coming from where it should be.

The PR interval stretches from the beginning of the upslope of the P wave to the beginning of the downslope of the S wave. or wherever the QRS begins if somethings fucked up and were starting with an upslope.

the Q wave is the first negative deflection. sometimes it isn’t there. the R wave is the first positive deflection. if there are 2 positive deflections this second one gets called R’ the S wave is the positive deflection after the R wave. trying to bring us back to baseline. the space from the beginning of the R wave, to the end of the S wave is the QRS complex. this is where the ventricles depolarize (hopefully) and the big bad pumping action happens.

The point where the S wave ends and the ST segment begins is called the J point. this will usually be right at the baseline and fairly sharp, but may become slurred with some EKG changes. if you look at most curves there will be a point that you can say “that there is the middle of this curve” that is the j point.

only mind the J point up there.

the next wave is the T wave. This represents repolarization of the ventricles. damaged or otherwise angry tissue doesn’t repolarize the same, and that is why funky T waves are generally bad news.

the space from the J point to the beginning of the T wave is the ST segment. this is what everyone blabs on about. really theres a lot to go in to figuring out if the ST segment is pathological or not. for now just know that it exists, often looks funky and only sometimes means anything.

the U wave is a little blip after the T wave. but is not a common sight save for certain pathologies, so don’t go looking for it just yet.

Those are the basic parts of the EKG waveform. newbies, practice identifying them! we will talk about intervals and rates next. i think.

teddiiphotography

Lifesavers.

Also from 2008, some photos I took for a motion assignment at my summer camp.

whatshouldwecallemts

When I’m driving to the hospital and I hear my distressed partner in the back of the rig.

medic-stories

I swear since ive started in EMS, the most uncomfortable looking sitting positions have become the most comfortable.

Happy EMS week

RN: Driving an ambulance seems like such an easy job! I wish I could make money sitting down!

Me: Yeah it's not bad. The pay isn't that great though. Especially when you consider I can do infinitely more on standing orders than anyone with a BSN in this building. In fact, I have the same cardiac knowledge as the MD in this emergency room. But yeah, the driving part is pretty easy.

medic-stories

Apparently fisdap is a bad word.

outsidehospital

YOU WASH YOUR MOUTH OUT WITH SOAP RIGHT NOW

flightmediclife-deactivated2013

Doing an ALS intercept for a person not breathing, BLS crew and fire ahead of me. I walk in to find them doing CPR. Family is crying their eyes out, begging them to stop. They have a valid DNR in their hands. They presented it to first EMS on scene who verified it, but decided to disregard it. Did they believe it wasn’t valid? No. Did they think it had been rescinded? No. Did the family ask to revoke it? No. Their reason for starting CPR? “The new guy has never worked a code before. This will be good practice for him”. Not only no, but FUCK NO!!!! You do NOT have the right to completely disregard the patient’s and family’s express wishes which are legally and appropriately documented and conveyed properly to you just so you can give the new guy some practice. Patient care is NOT about you, it is about the patient. These people are a damned disgrace to this profession. Enjoy the shitstorm I unleashed on you this morning boys. You deserve every bit of it. - NS

This was posted on Facebook earlier and it made me cringe… (via flightmediclife)

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