EKG interpretations Flashcards
Test 1
Where are the pacemaker cells located?
SA node
AV node
Bundle of His
Right and left bundle branches
Perkinje fibers
What are the two types of cardiac cells? Which is the bulk?
Pacemaker and contractile
Contractile cells make up 99% of myocardium
What is your SA node rate?
60 - 100
Which system has the biggest influence on your SA node?
PNS
What 2 medications can block the PNS response? what type of drugs are they? what do they do?
Atropine
glycopyrrolate
Anticholinergics
increase HR
How does electrical signal get from the SA node to the AV node? What are they called?
Internodal pathways:
Anterior/middle/posterior
How does electrical signal get from the right atria to the left atria
Bachmann’s bundle
What is the rate of the AV node and bundle of His?
40 - 60
The AV node has a conduction delay time of ______. Why?
0.1 seconds
To give time for the atria to contract before the ventricle contracts
What is the rate of the bundle branches and Purkinje fibers?
20 - 40
What rhythm has a rate less than 20? Where is this originating from?
Agonal
Purkinje fibers
How long is a whole ECG strip?
6 seconds
How much is a a small box on an EKG?
0.2 secs (x-axis)
0.5 mV (y-axis)
How long is your P wave? What leads is it upright in?
< 0.12 seconds
Positive in leads: I, II, aVF, V4-V6
What is the flat part in the PR represent on the EKG?
The delay in AV node conduction that allows the atria to contract
How long is your PR interval on the EKG?
0.10 - 0.20 secs
How long is QRS on EKG?
< 0.12 secs
What causes a long QRS?
Not following normal conduction pathway –> BBB
What does an elevated T wave represent?
Hyperkalemia
ST elevation/depression is greater than _______ mm than it is significant.
1 mm
What leads are the T wave positive in?
I, II, V3-V6
What is the HR for ST?
100 - 150
Describe junctional rhythms
Inverted/flat/post QRS p wave
conduction not originating in the SA node
junctional: HR 40-60
junctional Brady: HR <40
Junctional tachy: HR >60
Regular R-R
P for every QRS
If you have wide SVT its originating in the ________ and its narrow its originating in the ________
Ventricle
Atria
Describe a PAC
results in a reduced amplitude of the QRS and a compensatory pause afterwards
Which medications can help Tx A fib?
Amio
Digoxin
Cardizem
Metoprolol
Last 2 rate control only
T/F: caffeine can cause A-flutter & can resolve on its own
T
What does it mean/called when your PVCs look the same? When they look different?
Same: Unifocal
-originating from the same cells in the vent
Different: Multifocal
-originating from different cells in the vent
Why should we use caution when treating PVC?
These PVCs could be the heart only ventricular perfusion. If you treat them and take that away, the HR could be profoundly reduced. This would profoundly reduce CO.
Your PR interval is _______ in 2nd degree, type 2 HB
fixed
T/F: You can Tx 2nd degree, type 2 and 3rd degree HB w/ atropine
F
Rhythm not due to vagal influence
The QRS complexes in 3rd degree HB are ______.
Wide
Halothane/enflurane cause _________. What does this do?
myocardium sensitivity
Causes dysthymias to be more pronounced
Cocaine, Ketamine, & other NE reuptake inhibitors cause _________
tachycardia
Sevoflurane causes ________ in infants
bradycardia
Desflurane causes ________ during induction
prolong QT
Zofran & droperidol causes __________
prolong QT interval
Local anesthesia injection can cause ______ but large amounts, such as in spinals, can cause ________.
tachycardia
severe bradycardia
What happens if you inject large amounts of local anesthesia IV?
Asystole
Large amounts of blood transfusion does what to electrolytes?
Increases K+
Decreases Ca++
Hypoventilation can cause ____kalemia.
Hyper
Intubation can trigger their _____ nerve or cause _______ from pain.
Vagal
tachycardia
What are ways that the vagal nerve is stimulated?
carotid
peritoneum
cervix
Think of Sx that manipulate these organs/areas
Children have _____ vagal tone
high
How does CVP cannulation affect the heart?
It causes ectopy
Which means you’re in the right place; pull back out a little.
Sx manipulation of the heart can _________ CO
decrease
How can we prevent the oculo-cardiac reflex in eye Sx?
Local block
Ketamine _____ CO, HR, and contractility
Increases
Whats the difference between agonal and idoventricular rhythms?
Agonal: HR <20 & irregular
Idiovent: HR 20-40 & regular
