Read My Rhythm

Rhythm recognition made easyBlake Cleveland

Before We Get StartedWHAT THIS POWER POINT IS NOT MEANT TO DO……•This power point is not going to make you “the MAN” or “the WOMAN” at reading 3-lead rhythms•It will not give you the knowledge to diagnose whether someone has a 1st degree block from a 3rd degree block•You will not be able to determine if the patient is having a true cardiac emergency or a “fake” one (we have all seen the fake ones)•You will not come close to seeing all the different cardiac rhythms •It is not meant to and should NOT give you the confidence to request or cancel medics by what you have “read” on the monitor•And I can guarantee it will not make you rich (unless your Rock)

Before We Get Started Still……

WHAT THIS POWER POINT IS MEANT TO DO……

•I hope that you will be able to add a little more knowledge to your already overflowing toolbox•You might be able to see a rhythm on the monitor and determine if the rhythm is regular or irregular and why•To become familiar with some of the more common rhythms•To understand the cardiac cycle and its components•To understand the way the monitor paper works with time

But most important I want you to be able to take these small nuggets of information and have them available to you while on scene as use them as a tool that they are. Always keeping in mind that we still treat the patient and not the machine.

Hold Your Horses, Almost Started

OUTLINEFor those of you who must know ahead of time•Understanding the monitor paper

•Time markings•Calculating rate•Little Boxes•Big boxes

•Cardiac cycle and it’s components•Resting phase•P wave•PR interval•PR segment•QRS complex•T and U wave

•Common basic rhythms we might see•Normal Sinus Rhythm•Premature Ventricular Contraction•Suparventricular Tachycardia•Atral Fibrillation•Ventricular Tachycardia

First things

Understanding what the D-Fib paper is trying to tell you….before the actual rhythm is even printed.

1st

Time Markings and what they mean

Time Marks

Time MarksTime Marks

Little Boxes and what they mean•Every little tiny box on the monitor paper represents time•Each little box = 40 milliseconds otherwise know as .04 seconds•Two little boxes = 80 milliseconds otherwise know as .08 seconds•Three little boxes = 120 milliseconds otherwise know as .12 seconds•Four little boxes = 160 milliseconds otherwise know as .16 seconds•Five little boxes = 200 milliseconds otherwise know as .20 seconds•And so on and so on…..

•BUT….important note here•Five little boxes equals one big box

Big boxes and what they mean•……so we know that five small boxes equals one big box•……so if we put 2 and 2 together we also know that one big box equals 200 milliseconds or .20 seconds•Five big boxes = 1,000 milliseconds otherwise known as 1 second•Ten big boxes = 2,000 milliseconds otherwise known as 2 seconds•Fifteen big boxes = 3,000 milliseconds otherwise known as 3 seconds

CONCEPT!!!!

•We know that 3 seconds is the distance between the “time markings” we talked about earlier…..so…..there are 15 big boxes between two time marks.

What I Want You to Know so FarIf nothing else know these few important facts before you move on….

• All the boxes, little or big, represent time• It is important to understand and think of each box as time in seconds• One small box = .04 seconds• Two small boxes = .08 seconds• Three small boxes = .12 seconds • And so on and so on…..

Why know this some might question?

When it comes to measuring intervals between events, you will really be measuring the time, mostly in seconds. So if I said that the normal “PR” interval is between .12 seconds (120milliseconds) and .20 seconds (200milliseconds), you will know that the normal “PR” interval is between 3 and 5 small boxes.

Cardiac Cycle and its Components

Breaking it all down and up from the beginning

Resting Phase

The period of time where electrical activity is absent, the heart and the hearts electrical activity is at rest.

•The second part of the electrical cycle is the depolarization (firing) of the Sinus Node (SA Node)•SA Node is commonly referred to as the “Pacemaker” of the heart

All “P” waves should look alike. If not, chances are that the electrical cycle is not starting with the SA Node but somewhere else in the Atrium……

“P” Wave

PR Interval

“Now that my friends, is the PR Interval and all its glory. Until next time, Flash ya later….”

PR

This interval represents the time between the onset of the Atrial depolarization and the onset of the Ventricular depolarization. This interval normally ranges from .12 to .20 seconds (3-5 little boxes long).

If the time it takes for the PR interval to start and to finish is longer than .20 seconds (1 big box), there is a possibility of a heart block in the first degree.

PR Segment

PRPR

Segment

Is a slight delay in the Atrial/ Ventricular Node to permit the atrium to pump and fill the ventricles with blood before they contract.

Also known as the “backup pacemaker” because it will take over the job of the SA Node if it does not produce generally between 50 and 60 impulses a minute.

Atrial/ Ventricular

Node (AV Node)

QRS Complex

Q

R

S

First downward deflection is the Q waveFirst upward deflection is the R waveFirst downward defelction following the R wave is the S wave

•The QRS complex represents the depolarization of the ventricles. •The complete QRS complex should not exceed .12 seconds.•If the QRS complex is greater than .12 seconds, then this mean the SA Node (pacemaker) and the AV Node (back-up pacemaker) are not initiating the ventricle contractions….Houston, we might have a problem….

T Wave and U Wave

This is the T wave….

Well really it is just I who calls it the Mr. T wave….

….that some call the “Mr. T” wave

The T wave represents the repolarization phase of the ventricles

The U wave……seldom ever seen so we just wont worry about it today

Coming Full Circle Now

SA NodeDepolarizationStarting the P wave

AV Node allowing time for the ventricles to fill with blood causing the PR segment

Depolarization of the ventricles creating the QRS complex

Repolarization of the ventricles as seen by the T wave

5th is the PR Interval…..Is it less than .20 seconds (one big box)

6th is the QRS width…..Is the QRS complex less than or equal to .12 secondsIf greater than .12 seconds the cardiac cycle was initiated by the ventricles themselves

3rd is there a P for every QRS…..Each P wave should resemble each other, if not chances are they are not beginning with the SA Node but somewhere else in the Atrium.If the P wave is missing altogether there is a chance that the AV Node is initiating the cardiac cycle.

On Scene Reference Guide

Before we get started looking at some rhythms, lets look at a reference guide that will help reading rhythms on scene.This is a basic guide of questions to ask ourselves when trying to determine, not necessarily to diagnose the rhythm, but to determine if the rhythm is regular or not.

1st is the RATE…..Is it Normal (60 -100 BPM) Is it Fast (greater than 100) Is it Slow (less than 60)?

1st is the RATE…..

2nd is it REGULAR…..Yes or No

2nd is it REGULAR…..3rd is there a P for every QRS…..

4th is there a QRS for every P…..Does the start of the electrical cycle trigger a ventricle response every time

4th is there a QRS for every P…..5th is the PR Interval…..6th is the QRS width…..

Normal Sinus Rhythm•Recognition

•Rate: 60-100 BPM•Rhythm: Regular•Initiation of the electrical activity: Originates in the SA Node

On scene questions to ask ourselves….Rate- normalRegularity- regularP for every QRS- yesQRS for every P- yes

PR interval- .16 secondsS go to baseline prior to T wave- yesQRS width is less than .12 seconds- yes

Premature Ventricular Contraction

•Recognition•Rate: 60-100BPM•Rhythm: Normal Sinus Rhythm with two irregular sections•Initiation of the electrical cycle: Originates in the SA Node (except for the two PVC’s which originates somewhere below the AV Node in the Ventricles)

What makes a Premature Ventricular Contraction (PVC) a Premature Ventricular Contraction????

Lets look at the Rhythm below….It looks like a normal sinus rhythm with two irregular sections, right?

Irregular Irregular

What makes a PVC premature is the fact that there has been an electrical impulse started outside of the normal cycle. In the case of a PVC, the ventricles initiate the cycle before the SA Node gets the chance. As you can see the irregular QRS’s do not have a P wave. How do we know it’s the ventricles are initiating the QRS? Two reasons; its called a “Premature VENTRICULAR Contraction” which is the most obvious one and the QRS is “wide”, larger than the normal .12 seconds, which we know means it was started in the ventricles.

On scene questions to ask ourselves….Rate- normalRegularity- regular with two irregular sectionsP for every QRS- noQRS for every P- yes

PR interval- .16 secondsQRS width is less than .12 seconds- yes except for the two PVC’s

Supraventricular Tachycardia•Recognition

•Rate: 140-220BPM•Rhythm: Regular•Initiation of the electrical activity: Originates somewhere above the ventricles

On scene questions to ask ourselves….Rate- FastRegularity- RegularP for every QRS-Yes, but often buried inthe preceding T waveQRS for every P- Yes

PR interval- Depends on the site of initiation of the electrical activityQRS width is less than .12 seconds- Yes

“SVT” is a general term used to describe a number of different types of arrhythmias of the heart that are initiated above the ventricles in the……

SA NodeAtriumAV Node

Atrial Fibrillation

•Recognition•Rate:100-160 BPM•Rhythm: Irregularly irregular•Initiation of the electrical activity: Originates in the atria

On scene questions to ask ourselves….Rate- 90 BPMRegularity- Irregularly irregularP for every QRS- No

QRS for every P- NoPR interval- Not measurableQRS width is less than .12 seconds- Yes

•Recognition•Rate:100-160 BPM•Rhythm: Irregularly irregular•Initiation of the electrical activity: Originates in the atria

Imagine the Atrial tissue firing electrical impulses from 300-600 different area all at one. If you can imagine that then you have just imagined A-Fib. It is pretty self explanatory, the atria are fibrillating.

If you look at the isoelectric line, it looks like P waves everywhere. That is due to the atria fibrillating at an extremely high rate. If you notice the ventricle response is about 90 due to the AV Node slowing or “blocking” most of the impulses, but in no consistent order or fashion. That is why the ventricle response is irregular.

Just to be Clear

A-Fib Vs. SVT’sA-Fib is a rapid rhythm and the electrical cycle begins above the ventricles, right? So why is it not considered a SVT rhythm then?

•The atrium is sending electricle impulses from hundred of different points in no order at all•The ventricles do not receive every electrical impulse that is started. The impulses that are received too are rapid but are irregular

•Either the SA Node, AV Node or somewhere in the atrium is sending one electrical impulse rapidly…but only one at a time •The ventricles receive every impulse that was initiated. One atrium contraction to one ventricle contraction making the rhythm regular, but fast.

So the moral of the story is A-Fib and SVT rhythms are different!

On scene questions to ask ourselves….Rate- Fast, very fastRegularity- regularP for every QRS- Not one P waveQRS for every P- N/A

PR interval- N/AQRS width is less than .12 seconds- no, not at all

Ventricular Tachycardia

•Recognition•Rate: 180-190BPM•Rhythm: Regular•Initiation of the electrical activity: Somewhere in the ventricles

IF A PATIENT IS IN VENTRICULAR TACHYCARDIA AND……..•UNCONSCIOUS•UNRESPONSIVE•NO PULSE •NOT BREATHING

THEN…..

…….They have probably already met “Evil Homer” because they are DEAD!And D-Fib protocol's should be initiated ASAP.

That all I wrote

For the conclusion, please review slides 2-25

I hope this presentation added to your toolbox in one way or another.

And made your day…or made you smile.

….or laugh