EKGs: Blocks, Axis & Hypertrophy Flashcards
what is a block
- how is rhytm restarted
a stop or slow in the depolarization of the heart through the electrical condition pathway
- happening at the sinus (SA node)
- happening at the AV node
- happening at hte bundle branches
rhythm restored through an escape node from another foci
what is sick sinus syndrome
- what is happening in the heart
- what are some EKG findings
- what does the pt. need
sick sinus syndrome: the SA node is sick –> fibrosis, etc. and not able to fire and set the ryhthm
- there is no backup escape beat from the foci!!!
- so its a free for all -w hoever can create any type of beat will
EKG: see sigs of brady-tachycardia
- see afib/flutter mixed in
- extremely slow, no P waves
treatment:
implantable pacemaker
what is an AV block
- 3 types
AV block: a block in the signal to get down to the ventricles
- first degree block
- second degree block: (2 kinds)
- third degree block
look at PR intervals to determine
what is a first degree AV block
- what does it look like
- how do you treat
a prolongation of depolarization between the atria and the ventricles
PR segment will be longer than .2 seconds
treatment
- observe them, compare to old EKG
Second Degree Heart Block
- 2 types
- what is what and how to differentiate
- treament
Type 1 second degree: Weinchebach
- the PR segments get long, longer longest & then ** the QRS is eleminated**
Type 2: Mobitz – much lower in the ventricles — at the perkinje
- the PR segments are the same length, then sudden drop of QRS
- may see a widened QRS because the signal is coming from so low
- type 2: more serious because its further from teh SA node— progress to complete herat block much more common – immediate pacemaker
Third Degree Heart Block
- what is it
- identify on EKG
- treatment
- different types of 3rd degree blocks
- a complete divorce of the atria and ventricles – NO communications
SA node will do its own thing, the ventricles will do its own from a foci so on EKG there will be no relation between the P wave and QRS
- will be bradycardic
- need to be paced — pacemaker immediately
identify on EKG because there will be no relation between P wave and QRS
Types of 3rd Degree– where they are originating
- upper node: the junctional foci will pace the ventricles (narrow QRS)
- complete AV node block: the ventricaulr foci will pace
- below node: ventricular pace (wide QRS)
these slow pacers is why the heart is brady
Bundle Branch Blocks
types
Left BBB
Right BBB
incomplete BBB
Intermittenet Mobitz
blocking the bundle branch means that the ventricles will depolarize at different times – wider QRS or bunny ear apperance
in a RBBB which peak of the QRS is the right? the left? what about LBBB?
what leads will you see right v left
significane of LBBB v RBBB?
in RBBB….
the First peak will be the left ventrcile (since there is no block – it will depolarize just fine)
right looks like bunny ears
right: V1, V2
- significane: not much
in LBBB….
the first peak is the right ventricle (since hte left has the problem)
left looks like bunny ears with a wave connecting them
left: V5,V6
- significane: ISCHEMIA!!! not getting enough blood flow
in a RBBB which peak of the QRS is the right? the left? what about LBBB?
what leads will you see right v left
significane of LBBB v RBBB?
in RBBB….
the First peak will be the left ventrcile (since there is no block – it will depolarize just fine)
right looks like bunny ears
right: V1, V2
- significane: not much
in LBBB….
the first peak is the right ventricle (since hte left has the problem)
left looks like bunny ears with a wave connecting them
left: V5,V6
- significane: ISCHEMIA!!! not getting enough blood flow
in the presence of a R and L BBB, what cannot be accuratel determiend
axis
hypertrophy of the heart
what is a hemiblock?
what will you see in a left anterior hemiblock on EKG? left posterior?
left BB: spilts into the left posterior and left anterior fascicles
LAFB: deep s waves in II,III, AvF doing DOWN
LPFB: see Q3S1 so the Q in lead III will be deep, the S in lead I will be deep*
what types of body habitus might cause right and left axis deviation?
- tall skinny person: heart might be rightly deviated
- overweight: herat might be left deviated
how will the axis be shifted in ischemia? in hypertrophy?
In Hypertrophy: the axis will be towards the hypertrophy
in Ischemia: the axis will be away from the ischemia
how are the precordial leads (v1-v6) able to tell you about axis
noraml axi: look at lead 1 (up) and AvR: down
V1-V6 should go from V1 benig completely inverted to V6 being completely positive
v3/v4 will be isoelectric: equal up as down
how will hypertrophy of the atria (atrial enlargement of right and left) appear on EKG
looking at V1: the p wave will be isoelectric
if up is bigger than down: right atrial
if down is greated than up: left atrial
