CV monitoring - Exam 1 Flashcards
Impulses traveling toward the lead “eyeball” are ________.
positive
Impulses traveling away from the lead “eyeball” are ________.
negative
How many limb leads do we have?
4
* commonly only use 3
Augmented Limb Leads
aVR
pos:
neg:
- pos: right arm
- neg: b/w LA & RL
Augmented limb leads
aVL
pos:
neg:
- pos: LA
- neg: RA & LL
Augmented Limb leads
aVF
pos:
neg:
- pos: LL
- neg: RA & LA
Precordial Leads
V1 placement & view of heart:
- placement: 4th ICS, R sternum
- view: septal
should be negative
Precordial Leads
V2 placement and view of heart:
- placement: 4th ICS, L sternum
- view: septal
should be negative
Precordial Leads
V3 placement and view of heart:
- placement: b/w V4 and V2
- view: anterior
should be even/positive
Precordial Leads
V4 placement & view of the heart:
- placement: 5th ICS, L sternum @ mid clavicular line
- view: anterior
should be the most positive lead
Precordial Leads
V5 placement & view of the heart
- placement: 5th ICS, anterior axillary line
- view: lateral
should be positive
Precordial leads
V6 placement & view of the heart:
- placement: 5th ICS mid axillary line
- view: lateral
should be positive
12-lead EKG
What leads give an inferior view of the heart?
II, III, aVF
12-lead EKG
What views give a lateral view of the heart?
V5 & V6
I & avL = high lateral
12-lead EKG
What leads give an anterior view of the heart?
V3 & V4
12-lead EKG
What views give a septal view of the heart?
V1 & V2
12-lead EKG
what does a 12 lead help identify? (4 things)
- rhythm
- conduction delays
- infection
- damage
12-lead EKG
What EKG change is indicative of heart damage/problem?
> 2mm change in contiguous leads!
12-lead EKG
What is the turn signal rule?
helps identify BBB
1. find the J point in V1
2. look back into the complex (to the left)
3. positive deflection = RBBB
4. negative deflection = LBBB
5. QRS must be >0.12s
Axis Deviation
What leads do we look @ to determine axis deviations?
I, II, III
Axis Deviations
What is a normal axis deviation?
0-90 degrees
* I, II, III upright (positive)
Axis Deviation
What is a physiologic L axis deviation?
- 0 - (-40) degrees
- I: positive
- II: positive or =
- III: negative
Cause: hypertrophy (obese and athletic)
Axis Deviation
What is a pathological L Axis deviation?
- (-40) to (-90) degrees
- I: pos
- II: negative
- III: neg
- anterior hemiblock
Axis Deviation
What is a R axis deviation?
- 90-180 degrees
- always pathologic in adults
- I: neg
- II: pos/=/neg
- III: pos
- posterior hemiblock
Axis Deviations
What is an extreme R axis deviation?
- V-tach
- I: neg
- II: neg
- III: neg
- ventricular in origin
Axis Deviation Chart
12-lead EKG
Diagnosis for R atrial hypertrophy
- initial component of “P” larger in V1
- height > 2.5mm in any limb lead
12-lead EKG
Diagnosis for L atrial hypertrophy
- terminal portion of dipahsic P larger in V1
- occurs w/ mitral stenosis, systemic HTN
12-lead EKG
Diagnosis for R Ventricular hypertrophy
- more depolarization toward V1
- QRS in V1 positive, R waves get smaller
- concentric hypertrophy - more depolarization toward V1
12-lead EKG
Diagnosis/EKG for LV hypertrophy
- large S wave in V1
- larger R wave in V5
- depth of V1 and height of V5 = 35mm
12-lead EKG
Diagnosis/EKG in myocardial ischemia
- reduced supply of O2 from coronary arteries
- inverted, symmetrical T wave
12-lead EKG
myocardial injury
- acute MI
12-lead EKG
Myocardial Infarct (transmural)
- Q indicated necrosis, and makes diagnosis of old infarct
- > 1mm wide or 1/3 QRS tall & 2 related leads
Pacemakers
What are PM the treatment of choice for?
- disturbances in cardiac impulse conduction (brady or tachy)
- causes: excessive BB (elderly), SSS
- also used after cardiac surgery s/a valve replacement/CABG
What are the 3 types of PM?
- transthoracic (permanent)
- transcutaneous (pads)
- transvenous (similar to PA cath)
Pacemakers
Ex: pt has high degree block not responding to meds (atropine)
What do we do??
- transcutaneous pacer
- set HR 60-80
- slowly increase voltage until electrical capture seen
- monitor for mechanical capture (heart responding to impulse)
Pacemakers
What are the 2 main parts of the pacemaker?
- pulse generator: provides electricity through the leads (zoll, external device, implantable device)
- electrode leads
Pacemaker definitions
Generator:
- energy source & electrical circuits
- provides current to go through leads
Pacemaker definitions
Lead:
- insulated wire from generator to electrode
- insulated: wire comes into contact w/ other things before it gets to place it is supposed to be
Pacemaker definitions
Electrode:
- exposed metal end in contact w/ endocardium or epicardium (epicardial leads)
- where energy is exposed to the heart
Pacemaker definitions
Unipolar electrodes
- neg. electrode in chamber
- pos. electrode (grounding)
- more sensitive to electromagnetic interference (EMI)
- requires more energy
Pacemaker definitions
Bipolar electrodes:
- both electrodes in chamber being paced (going from point A to point B)
- more common & uses less energy
Pacemaker definitions
Multipolar leads
- multiple electrodes within 1 lead but multiple chambers
- ex: biatrial/biventricular electrodes
- electrode transverses the septum
Pacemaker Codes
What is I?
0:
A:
V:
D:
chamber that is paced
* 0: none
* A: atrial
* V: ventricular
* D: dual (A+V)
0 = no pacer, not programmed/active
Pacemaker Codes
What is II?
0:
A:
V:
D:
chamber that is sensed: on-demand device (watches what HR is doing and that determines the response)
0: none
A: atrial
V: ventricular
D: dual (A+V)
Pacemaker Codes
What is III?
0:
T:
I:
D:
response to sensing
* 0: does nothing different when it senses
* T: triggered - if pt falls outside of set parameters (bradycardic) the PM responds to the low HR
* I: inhibit - if PM senses traditional/spontaneous depolarization it will not activate
* D: dual - does both most common response to sensing
Pacemaker Codes
What is IV?
0:
R:
rate modulation – artifact setting
* may mean it is able to adapt
* not common - response to overdrive pacing usually
* 0: none
* R: rate modulation
Pacemaker Codes
What is V?
O:
A:
V:
D:
multisite pacing
* biatrial/biventricular or both atrial and ventricular
* O: none
* A: atrium
* V: ventricle
* D: dual (A+V)
Pacemaker Codes
What is inhibition?
- intrinsic activity perceived - chamber is NOT PACED
Pacemaker Codes
What is Triggered?
What is it used for?
- Pacemaker discharges if intrinsic activity is sensed
- used for testing devices - make pt bradycardic/tachycardic to prove good capture
Pacemaker Codes
What is Rate Modulation?
- artifact setting
- tailored for pt
- vibration
- motion
- Vm
- R Ventricular pressure
Pacemaker Codes
What pt population do we see the use of biventricular pacers in?
- horrible cardiomyopathies
PM- EKG examples
Traditional QRS
- both atria/ventricles working
PM Codes - EKG examples
Normal atrial impulse & Ventricles not working
- pacer spike then QRS complex
PM - EKG examples
AV pacer
- atrial spike followed by impulse
- ventricular spike followed by depolarization
Peri-op Care of PM:
What 2 main things do we need to consider w/ PMs?
- how can we safely manage the pt?
- do we need to change anything?