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Little Latin Generals (Cardiology and Politics)

I suppose most paramedic students experience some sort of frustration when they are going through Cardiology and trying to integrate what they are learning to recognize on the strip into the ACLS algorhythm and at the same time figure out how to implement their newly found knowledge into ever increasing treatments and interventions they have only read about thus far.

I struggled a little with the concept of recognizing when a dysrhythmia is a good thing that needs to be coddled and supported and when it needs to be escorted from the building in an expeditious fashion so to speak.

The concept became clear for me with a political metaphor of all things.

Before we get the political unrest – Let’s look at a much simplified explanation of how the “government” of the heart is supposed to work…

In normal conduction the electrical activity of the heart is “governed” by the intrinsic rate of the Sinoatrial node (SA) – due to differences in the slope of diastolic depolarization the specialized myocytes of the SA node reach their action potential stage faster then the other specialized conduction cells. Each of these specialized cells has an intrinsic rate that is governed by a leak of ions through the cell membrane leading them towards to their action potential, and they all want to be the “guy in charge” but the “influence” of the SA node is so powerful that they never get the chance to act out due to the SA nodes impulse reaching them before they can act out on their own.

When things start to go awry and the protestors march or occupy or whatever type of political unrest makes it easier for you to comprehend things can change a little.

Let’s start with default rhythms and how I think about them – If the SA node is “in charge” of this political process let’s call it the president – the president of the heart belongs to the sinus party and when he is running the show – we see a sinus rhythm on the strip.

What happens when the “president” for whatever reason can’t do its job – Much like the democratic process we have here in the USA the heart has a backup plan in place – a “Vice President” if you will – the AV node the AV node tends to look like he belongs to the sinus party as well, but subtle difference tell us he really belongs to the junctional party – which shows up as a junctional rhythm on the 12 lead. It runs a little slower then the president does, but can be quite effective at running things.

So what if the President and the Vice president are incapacitated – in our form of Government the Speaker of House would be next in line – in the heart it would be the ventricles – The ventricles belong to a totally different party then either the president or the vice president and they don’t try to hide it either – they appear as a ventricular rhythm on the 12 lead looking very different (in most cases) then either the sinus or junction. The ventricles are slower still and (for default purposes we’ll say they) run things marginally usually just enough to get by.

The heart and our Government are set up to allow lower level sites to take over or pick up the slack for a failed or ineffective “leader” when this happens it’s a default rhythm and we should do everything we can to nurture and support it – drastic interventions into this type of rhythm can lead to “anarchy” completely knocking out the system of government and leading to chaos.

On the other hand – we have usurping rhythms…

These rhythms are the “little Latin generals” staging a coup. For whatever reason an ectopic site (little Latin general) goes off the reservation and decides it can do better job running things and tries to take over. If the “little general” manages to fire faster then “el presidente” he can totally usurp the normal leader’s authority and due to those same conduction fibers make the higher ups bend to his will. Little Latin Generals usually work really fast as evidenced by their tachycardic rate.

Generally speaking the heart (and the Government) is in total chaos at this point and maybe minimal stuff gets done – but all of the Government is in total disarray and the “citizens” (tissues in need of perfusion”) suffer –

These are the instances when as a medic we need to call in “the Marines” and provide some sort of intervention to restore order and the normal balance – whether that means a surgical strike with a specific medication to try and interrupt the ectopic sites overactive ambition or a carpet bombing with the defibrillator where we force em to “ride the lightening” and hopefully reset the normal balance depends on both the rhythm strip and the patients general presentation.

The metaphor and concept seems to work for me and makes it easy to remember – Does it make sense to you? What kind of ways do you use to understand complex processes and how they relate to your treatment plan?

 

Posted by on February 17, 2012 in Cardiology, EMS 2.0, EMT, Paramedic School

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Rites of Passage

Ask any prospective paramedic student what they worry about trying to learn and you will likely get an answer that contains at least one of these words: Cardiology or Pharmacology. For some students – myself included the answer contained them both. Adding to my level of anxiety is the fact that the program I am attending is all but legendary locally for its program – and more legendary then the program is the exam – 200 questions – 100 multiple choice and 100 short answer questions relating to 14 different rhythm strips, with roughly a four hour time limit – Highest score ever on the test was a 98.

Interesting to me was the number of practicing medics sitting in the back of the room to “refresh” their knowledge base. The program allows it’s employees to sit in on Paramedic School lectures for CE’s – typical classes have one or two medics back there – Pharmacology had 5 or 6 – Cardiology had 15 – 20 easily EVERY NIGHT for the entire section.

We were told to purchase calipers – as there was no way we could pass the exam without them… Granted most medics don’t even carry them let alone use them in the field – but they wanted to be sure we knew how to break a strip – even the most complicated strip down.

The exam lived up to its reputation – it was EASILY the most difficult test I have ever taken – memorization wouldn’t have helped – the exam required a genuine understanding – after we took the test they told us that as far as they were concerned anyone who got a 70 on that exam was an expert in the field of pre-hospital ECG interpretation – I got a 92 – but I certainly don’t FEEL like an expert…

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If only it was this easy

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Cardiology started with the warning that the instructors goal for us was if someone ever asked us where we learned cardiology we didn’t embarrass them when we gave their names. Both of the instructors are captains at the division I want to work at and one of them is instrumental in the hiring process – cause you know the standard student anxiety over cardiology wasn’t enough for me – I had to ramp it up a little.

I have heard many times so far during school we don’t use a certain book for this because a good one doesn’t exist to teach you what we want you to learn (More experienced providers that write – take notice) Cardiology was an exception – they did have a book for that – but it’s interesting the one they choose.

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Practical Guide to ECG Interpretation By: Ken Grauer MD FAAFP

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Available from Amazon here if you are interested.

What makes Dr. Grauer’s book so interesting is that it is out of print – The program actually contacted Dr Grauer (he includes his contact information in the book in case you want to contact him about the book or cardiology in general – wow) to ask his permission to copy the book for their students – all 500 pages of it.

The process they taught us for breaking down a strip was methodical but lengthy – in fact it takes me 10 to 15 minutes to go through each step and wrote the findings out –

  • Rate
  • Rhythm
    • P- Are p waves present in lead II
    • Q – is the QRS wide or narrow – (if wide examine for BBB)
    • R- Regular or irregular
    • S – Single or married – are the wave complexes married to each other or separate
  • Intervals
    • PRI
    • QRS
    • QT
  • Axis (fasicular blocks?)
  • Hypertrophy
    • Right or Left atrial abnormality
    • Left Ventricular Hypertrophy
    • Pulmonary Disease pattern
  • Infarction – any signs of infarction, strain or ischemia?
    • Q – are Q waves present in any lead? are they pathological? are they expected in that lead?
    • R – Is the R wave progression normal? where is the zone of transition?
    • S – ST segment changes – Elevation, depression, strain pattern?  Are the changes related to a vessel or global? What area of the heart is affected?
    • T – Are there T wave changes? what do they indicate?

The answers to all of these questions only give you HALF of the information you need to interpret the strip – This just gives you the descriptive analysis of the strip – you have to take the patients presentation and past medical history into account or the “clinical impression” as the book calls it.

Dr. Grauer also says that to get the most accurate information possible from a strip you should try to have a prior strip available for comparison – and our instructors took that one step further – if you can actually get a prior strip (unlikely in our setting – but stranger things have happened) was it the patients strip on admission or on discharge ?

My head has been spinning with all the information contained in this module – Brugada’s Syndrome, Ashman’s Phenomenon, WPW (Type A & B),  Default Vs. Usurping rhythms, differentiating between V-Tach and SVT with aberrant conduction, Fib-Flutter, the potential causes of a tall R wave in V1, the causes of QT prolongation…To the point where I have to run through the steps I listed above mentally or I end up staring at the strip with a blank look on my face.

The most reassuring message came after the exam – you don’t have to be an expert at this stuff now – nor do you have to be an expert during your rides… or even during your Field Internship when you get a job as a Medic… You DO have to be an expert when you are cleared to independent duty and are making the interpretation “solo” – That’s a relief I have probably another year of practice then.

Our instructors recommended several books and a few blogs to take our studies further – I’ll share them here in case some of you may be interested

Practical Electrocardiogr aphy by Henry J. L. Marriott (Hardcover) - Called the bible of ECG by our instructors

Pathophysiology of Heart Disease 4th (Fourth) Edition by Lilly (Paperback)

Pure Practice For 12-Lead ECGs: A Practice Workbook by Robin Purdie RN MS (Paperback)

 

The blogs they recommend – Dr. Grauer’s Blog , www.ecgpedia.org , www.ems12lead.com , Dr. Smith’s ECG Blog

Be good – get good – or give up

 

Posted by on February 15, 2012 in Cardiology, EMS, Paramedic School

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