EKGs: Overview & the Atria & Tachyarrythmias Flashcards
what leads show you…..
- posterior heart
- lateral heart
- inferior heart
- anterior heart
Posterior Heart: avR
Lateral Heart: I, avL, V5 & V6
Inferior Heart: II, III, avF
Anterior Heart: V1, V2, V3, V4
what is the Rate of the heart? where are areas in the heart which are able to set the rate
4 places
on the EKG: how do you calculate rate? easy and hard way
Rate: Speed at which the heart can beat
SA node: the main pacemaker of the heart: maintains the rate of 60-100 BPM
brady: < 60
tachy: > 100
automaticity foci: areas of the heart which if something happens to the rate pacemakers above will kick in a beat at their own speed
atrium: 60-80
junctional: 40-60
ventricular: 20-40
Rate Calculations
— 300/ (number of peaks of the R waves starting with the first R that starts on the bold lines and then the next R tha t falls on a bold line )
– or read the rate on th ecomputer print out
3 questions to ask when deciding the rhythm of an EKG?
is it sinus or not?
1. is there a P wave before every QRS
2. is there a QRS after every P
3. is the P wave in Lead II going UP?
if yes x3 = sinus rhythm from the SA node
what is sinus arrythmia?
why does it occur
- a SINUS rhythm – from the SA node
- but irregular intervals between each section
occurs - NORMALLY (exaggerated in kids)
- a sympathetic stimulation during inhale
- a parasympathetic stimulation during exhale
- can happen post-MI
if the rhythm is not coming from the SA node (not sinus) –> what are the 4 broad categories it will be called
- irregular rhythms
- escape beats
- premature beats
- tachy-arrythmias
what is normal Axis deviation (degrees?)
- how to determine axis (math way & easy way)
normal deviation of axis: -30 –> 110 degrees
axis determination
Math Way: find the lead where the QRS is equal up and down –isoelectric) should be the avL & then find the axis perpendicular
Easy Way: the thumb method
- left thumb: point the direction of the QRS complex in lead I
- right thumb: point the direction of the QRS complex in lead avF
Length of Time for Intervals
- PR interval
- QRS complex
- QTc interval
conditions of which ther will be abnormal intervals
PR interval: 5 little boxes = .2 seconds
QRS complex: 3 little boxes = .12 seconds
QTc interval: should be 1/2 of the proceeding R-R interval (longer in women slightly)
conditions of abnormal intervals
- 1, 2 &3 heart blocks
- BBB
- long QT
3 types of irregular arrythmias (types of arrythmias)
Irregular Arrythmias = rhytms being made from sites other than the SA node
- wandering pacemaker
- mutlifocal atrial tachycardia
- atrial fibrillation
what is Wandering Pacemaker
what will be seen on EKG & due to what
what do you do for treatment
wandering pacemaker: a type of irregular arrythmia
- result of a battle between the SA node and anotehr atrial etopic foci of automaticity attempting to set the rhythm for the heart
- resulting in 3 various p wave formations on the EKG
- normal
- inverted (from AV travels back)
- P prime (double Pwave) from the etopic trying to set the rhythm
what do you do
- nothing: this is benign
- can monitor pts. with this but no intervention needed
what is Multifocal Atrial Tachycardia?
- what condition is associated with it
- what will you see on EKG that is specific to the WAT
- what is treatment
- think of COPD– most commonly pt. will present with this & have concurring COPD
- multiple foci of automaticity in the atria attempt to make the pace, SA node still attempting too
- see 4+ different P waves
- specifically: see a SPIKEY triangular P wave in lead II
treatment: treat the underlying condition
What is atrial fibrillation
- how with the atrial contractions appear on EKG
- how will ventricular
- a fib = quivering atria because there are SO many etopic foci attempting to pace the heart – no clear winner
- results: a quivering “baseline” with NO clear P wave
Ventricles: QRS will appear normal – the AV node is still properly only allowing some signals to pass down
- ** the intervals between the QRS complexes will have no rhyme or reason – irregular in nature**
what are Esacpe Rhythms? Beats?
- when do they occur
- where can they originate from
Escape rhythms & beats: are triggered when the SA node does not fire – someone needs to step in!
- the beat: a one type trigger from a foci that triggers the beat & then SA node comes back
- the rhythm: the SA node is not coming back, the foci takes over as the pacer
these escape beats are life-saving!!! and necessary!
the beats arise from atrial, junctional or ventricular foci
there is sinuse pause (brief) or sinus arrest (>3 seconds)…. how to differentiate which foci started the following esacpe rhythm?
- atrial
- junctional
- ventricular (prone to what & why)
Atrial: (60-80) might look the same as a normal EKG — only if you had a previous strip to compare to would you notice smaller P waves
Junctional: (40-60) would look much slower & absent P waves
might see the p-wave SLIGHTLY before QRS or slightly after depending on where to foci is in the junction – but because its traveling UP towards atria its gonna be inverted
Ventricular: (20-40) would look very slow with absent P waves & a WIDE QRS
wide QRS: because the foci is in the ventricles –> spreasd from one to the otehr taking time & so they depolarize at slightly different times
ventricular Esacpe rhythm prone to Stokes-Adams Syndrone because it s so slow its not compatable with life
what are irritable beats?
three types?
- premature beats: firing of the etopic foci before the caridac cycle is complete!!!
atrial, junctional and ventricualr beats can do this
premature contractions
reasons for atrial or junctional irritable beats?
- what will they look like?
what is bigeminy and trigeminy?
atrial and junctional beats: will be a result of sympathetic stimulation think caffeine, stress, etc.
look like…
-atrial: look like normal P wave, just early (on top of the T wave of previous)
-junctional: can be missing or inverted (just coming way early)
bigeminy: the regular pattern of 1 normal beat, 1 premature
trigeminy: the regular pattern of 1 nomral, 2 premature
bi & trigeminy can be atrial or junctional beats
