EKG Flashcards
1
Q
Automaticity
A
any cells in the heart can initiate an impulse
2
Q
Contractility
A
ability to respond mechanically
3
Q
Conductivity
A
ability to transmit an impulse
4
Q
Excitability
A
ability to be electrical stimulated
5
Q
Electricity in resting state
A
cardiac cells are negative on inside and positive on outside
6
Q
Depolarization
A
When cells are stimulated by pacemaker and Na moves rapidly to the inside of the cells and K moves to the outside leading to adjacent cells depolarizing
7
Q
Does electrical activity mean that the heart is mechanically pumping?
A
Hopefully, but not always. EKG looks at electrical conduction but that does not mean the heart is pumping
8
Q
Why is it important that depolarization is transmitted in a coordinated fashion?
A
Its important that there is contraction at the atrium then contraction and the ventricle to maintain CO and organization
9
Q
Where does depolarization start?
A
SA node AKA pacemaker
10
Q
What happens if the SA node fails?
A
The AV node is the backup pacemaker
11
Q
How fast can the AV node discharge firing?
A
40-60 beats per minute
12
Q
Where is the SA node located?
A
right atrium
13
Q
Electrical impulse pathway
A
SA node –> AV node –> bundle of his –> right and left branches –> purkinje fibers
14
Q
Repolarization
A
Muscles cells will recover and restore electrical charge
15
Q
Absolute refectory period
A
Period where cardiac muscles cannot be stimulated by any stimuli
Protective mechanism
16
Q
What is the absolute refractory period on the ECG?
A
beginning of QRS to peak of T wave
17
Q
Relative refractory period
A
Period where cardiac muscle will respond to a STRONG stimuli
Very vulnerable period
If you shock someone during this phase, you can send them into a lethal rhythm
18
Q
What is the absolute refractory phase as long as?
A
As long as the contraction phase
19
Q
Where is the relative refractory phase on an ECG?
A
Peak to the end of the T wave
20
Q
A change in a waveform is due to
A
change in electrical current or change in a lead
21
Q
What is an ECG used to evaluate?
A
Heart function, heart rate, ischemia, infarction, chest pain, pacemaker function and medications
22
Q
Left to right markings represent…
A
time
23
Q
Verticle marking represent…
A
voltage or energy
24
Q
Small boxes represent
A
0.04 seconds
25
Large boxes represent
0.20 seconds
26
Line/dashes at the top of the paper represent
3 seconds
27
An ECG waveform is
group of waves that record the electrical signal as it depolarizes that heart muscle cells
28
P wave represents and looks like
arterial depolarization
| Small, rounds and before QRS
29
PR interval is from the.. to the..
beginning of P wave to beginning of QRS
30
Normal PR interval time is
0.12 - 0.20
31
PR interval represents
time it takes for the original impulse to leave the SA node and travel through the AV node
Time required for partial depolarization
How well AV node is functioning
32
What is the atrial kick?
the brief delay at AV node that allows atria to empty and contract and it a contributor to the CO
33
What does the AV node do?
it acts as the gatekeeper to limit the ventricular rate
34
QRS interval is from the.. to the..
Beginning of the Q wave to the end of the S wave
35
Normal QRS time is
less that 0.12 seconds
36
What does the QRS represent?
ventricular contraction
37
ST segment is the
time between completion of ventricular contraction and beginning of repolarization
38
What is the ST segment measured by?
Normal = isometric
Elevation due to myocardial injury/infarction (irreversible)
Depressed due to myocardial ischemia (reversible)
39
T wave represents
ventricular repolarization
40
What does an inverted T wave mean?
any condition that interferes with normal repolarization such as ischemia or injury
41
QT interval is from the .. to the ..
beginning of QRS to end of T wave
42
QT interval represents
the total ventricular depolarization and repolarization
43
QT interval time is
0.34-0.43 seconds
44
What is the isoelectric line?
baseline, flat, straight line that connects all the curves
45
Regular rhythm
distance between two QRS complexes does not vary by more than 3 small boxes
46
Regular irregular rhythm
patten is recognized and predicted
47
Irregular irregular
no pattern and no periods of regularity
48
Steps to read ECG
1. determine if its regular
2. Calculate HR
3. Examine P waves
4. measure PR interval
5. Measure QRS interval
49
how to do you calculate the HR by looking at ECG?
count number of QRS intervals and multiple by 10
50
Examine P waves include..
Is there any P waves absent or present
Are P waves all the same shape
Is there one P wave for every QRS?
51
Normal sinus rhythm interpretation
```
Atrial/Ventricular rate: 60-100 bpm
Rhythm: regular
P wave: 1:1
PR interval: normal, .12-.20 seconds
QRS complex: normal, less than 0.12 seconds
```
52
Sinus bradycardia
```
Atrial/Ventricular rate: less than 50-60 bpm
Rhythm: regular
P wave: 1:1
PR interval: normal
QRS complex: normal
```
53
Cause of sinus bradycardia
Normal variation in athletes, sleep. Might be associated with a disease like MI, medication, vagal maneuver
54
Treatment for sinus bradycardia
ONLY TREAT IF SYMPTOMATIC due to decrease CO which looks like SOB, chest pain, hypotension
1. Treat underlying cause
2. maintain airway, assist breathing, give O2
3. cardiac monitoring and IV access
4. if adequate perfusion and stable, monitor patinet
5. If s/s of poor perfusion: All Trained Dogs Eat
55
What does All Trained Dogs Eat in terms of treatment for sinus bradycardia mean?
All: atropine
Trained: transcutaneous pacing
Dogs: dopamine
Eat: NE
56
How often and how much atropine should you give?
0.5-1.0mg every 3-5 minutes with a max of 3.0mg
57
Sinus tachycardia
```
Atrial/Ventricular rate: between 100-150 bpm
Rhythm: regular
P wave: 1:1
PR interval: normal
QRS complex: normal
```
58
Causes of sinus tachycardia
CAUSED BY EXTERNAL INFLUENCE
| blood loss, fever, anxiety, medications, hypovolemia, ect
59
Treatment for sinus tachycardia
TREAT ONLY IF SYMPTOMATIC
1. maintain airway, assist breathing, give oxygen
2. IV access
3. if stable with adequate perfusion, observe
4. Stable patient may try: diltiazam (CCB) inderal (B blocker), vagal maneuvers
60
What does symptomatic look like due to decrease CO
Angina, hypotension, SOB, altered mental status
61
Arterial dysrhythmias
Atrial ectopic pace making sites replace that SA node as the pacemaker
Rate of 250-400
62
What keeps all the electrical impulses that the atria are conducting from getting to the ventricles?
The AV node
| It acts as a gatekeeper and controls how many impulses reach the ventricles
63
major concerns with a flutter and a fib are?
1. thrombi formation due to incomplete emptying of ventricles
2. Low CO due to loss or partial kick and ventricular rate is too fast or too slow
64
What medication should someone with atrial fib or atrial flutter be on?
they should be on anticoagulants because a major risk is clot formation
65
Atrial Flutter rate and discharge
Rapid discharge at a single ectopic foci
Rate of 250-400 bpm
Since the AV protection, only some get through
66
Atrial flutter
```
Atrial/Ventricular rate: Artial rate: 250-250 ventricular rate: 75-150
Rhythm: Regular but can be irregular
P wave: Saw-tooth patter called F waves
PR interval: Not mesurable
QRS complex: normal
```
67
During atrial flutter what is the ventricular rate if it is controlled?
less than 100
68
During atrial flutter what is the ventricular rate if it is uncontrolled?
over 100
69
Causes of atrial flutter
Rarely normal, usually associated with a disease like cardiomyopathy, coronary artery disease, valvular disease and hypertension
70
Treatment of atrial flutter
Unstable: synchronized cardioversion
Stable: looks for a cause because might not need treatment other than treating the cause. Treatment depends on how pt. tolerate the rhythm. May try chemical or electrical cardioversion.
Stable w/ high ventriculuar rate or mildly/moderately symptomatic: slow ventricular rate with medication then use chemical or electrical cardioversion
71
Electrical synchronized cardioversion
1. load amiodarone 150mg slow IVP (over 10 min) before cardioversion
2. electrical impulse or current delivered to the heart during the R wave which is ventricular depolarization to allow SA node to take over again
PLACED IN SYNC MODE with pts. R wave
Done with sedation and analgesics
72
What should you have ready at the bedside before cardioversion?
suction, intubation tray, crash cart
73
If patient is stable with atrial dysrhythmias without clots
synchronized cardioversion and/or chemical cardioversion
74
If patient is stable with atrial dysrhythmias with clots
Anticoagulate with heparin, warfarin, or lovenox before cardioversion and send home. Check TEE again in 4-6 weeks then cardioversion
75
If patient is unstable with atrial dysrhythmias with or without clots
immediate cardioversion, no amiodarone prior to
76
Patient with chronic a.fib or a.fluter with be on..
anticoagulant therapy indefinitely
77
What is another lifelong therapy option for a patient with atrial flutter?
radioactive ablation
78
Atrial fibrillation electrical site
Rapid discharge of multiple atrial ectopic foci with a rate of more than 400 per minute
Atria is twitching/fibrilating because they can't contract effectively
79
Atrial fibrillation
```
Atrial/Ventricular rate: Atrial rate: 350-600 Ventricular rate: 100-150
Rhythm: irregularly irregular
P wave: fibrillary f-waves
PR interval: Not measurable
QRS complex: normal
```
80
Causes of a.fib
Same as a flutter
| Can be d/t high alcohol intake, COPD, cardiac valve disease or CHF
81
Treatment for a.fib
same as a flutter
82
First degree AV block can be a...
precursor to other blocks
83
Frist degree AV block
Atrial/Ventricular rate: normal, regular
Rhythm: regular
P wave: normal 1:1
PR interval: constant more than .20 seconds
QRS complex: normal
84
Causes of a first degree block
lesion along the conduction pathway like calcification or necrosis, MI, myocarditis, medications like digoxin, CCB, B-blockers and frequently seen in athletes and children
85
Treatment for first degree block
1. monitor patient for tolerance
2. monitor for progression to 2nd degree
3. no treatment if patient is tolerating rhythm or has been present for a long time and rarely causes anything negative
86
Second degree AV block type 1
Atrial/Ventricular rate: Normal/slower due to dropped QRS
Rhythm: regularly irregular
P wave:
PR interval: progressively lengthens until QRS not conducted
QRS complex: normal or wide, dropped with nonconductor P wave
87
Second degree AV block type 1 PR interval
cyclic progressive lengthen or PR interval until atrial impulse is not conducted and QRS complex is dropped
88
Second degree AV block type 1 causes
ischemia
89
Second degree AV block type 1 treatment
1. monitor patient for tolerance
2. monitor for progression to 3rd degree
3. no treatment if pt. is tolerating it
4. if symptomatic atropine or temporary pacemaker
90
Second degree AV block type 2
Atrial/Ventricular rate: normal/normla but slower due to dropped beat
Rhythm: irregular
P wave:
PR interval: constant, normal or prolonged
QRS complex: normal or wide with dropped QRS
91
Second degree AV block type 2 causes
ischemia or heart disease
92
Second degree AV block type 2 treatment:
1. atropine but sometimes can increase demand on heart
| 2. pacemaker may be required
93
Third degree block also known as
complete heart block where the atria and ventricles beat independently and are not communicating with each other. No impulses get through AV node
94
Third degree block
Atrial/Ventricular rate: may or may not be normal/may or may not be normal. Vent and atria are synchronous and uncoordinated
Rhythm: Generally regular
P wave: normal
PR interval: not measured, changes randomly
QRS complex: normal or wide
95
Third degree block causes
ischemia and heart disease
96
Third degree block treatment
1. symptomatic SB algorithm
| 2. early pacemaker
97
First degree block shortened
constant prolonged PR, always P for each QRS
98
Second degree block type 1 shortened
Progressively prolonged PR until a dropped QRS
99
Second degree block type 2 shortened
Constant prolonged PR and dropped QRS
100
Premature ventricular contraction in general
ectopic foci in ventricle cases an impulse to start a contraction before the next sinus impulse
QRS wave takes longer to conduct and is wide, bizarre and typically does not have a P wave
101
Premature ventricular contraction
Atrial/Ventricular rate: may occur at any rate and with any basic rhythm
Rhythm: irregular due to early beats
P wave: typically none
PR interval: not present before PVC
QRS complex: wide and bizarre, more than 0.12 seconds
102
Do you treat PVC?
Everyone has PVC but you only treat for certain scenarios or if the patient has symptoms
103
What scenarios do you treat a PVC?
1. occurs frequently (more than 6 times/minute)
2. Occur on every other beat (bigeminy)
3. Strike on a T wave of preceding beat
4. Originate from more than 1 focus (multifocal)
5. Occur in consecutive fashion (couplet, triplet)
6. occur after an MI (treat for 24 hours)
104
PVC causes
with or without cardiac disease. Most common cause is hypoxia, can be due to caffeine intake or ventricular irritability
105
Treatment for PVC
1. look for a cause, might be benign
2. monitor for tolerance
3. consider amiodarone slow IVP
106
Ventricular tachycardia in general is
A run of 3 or more PVCs with a rate greater than 100 bmp
| Orriginates from a very irritable ectopic foci in vent at 150-250 bmp
107
Ventricular tachycardia
```
Atrial/Ventricular rate: not measurable/vent 150-250bmp
Rhythm: regular
P wave: no present
PR interval: no measurable
QRS complex: wide and bizarre
```
108
VT monomorphic
all QRS are the same
109
VT polymorphic
QRS complexes change shape/twisting
110
VT causes
with or without cardiac disease
| Associated with cardiomyopathy, electrolyte imbalance like low K, proarrythmic medication or congenital long QT syndrome
111
VT treatment with pulse
Medically manage with IV< O2, labs, 12 lead ECG, echo, cardiology consult, load with amiodarone and prepare for immediate cardioversion
112
VT without pulse
treated same as V-fib, defibrillate
113
Treatment of pulseless VT/V-fib
1. BLS/CRP, O2, attach monitor/defibrillator
2. Give CPR for 2 mins
3. Give 1 shock when defibrillator is available
4. Resume CPR, 5 cycles
5. Give 1 shock
6. Resume CPR, 5 cycles
7. When IV/IO is available give vasopressor (EPI) during CPR
8. Give 1 shock
9. Resume CPR, 5 cycles
10. consider anti arrhythmic like amiodarone or lidocaine, consider Mg
11. repeat above sequence
114
Ventricular fibrillation in general
Ventricles are fibrillating, no effective CO or contractions
Always fatal unless treated
most common cause of cardiac arrest
V-fib tends to convert to asystole
115
Ventricular fibrillation rate, rhythm and waveforms
unable to identify due to rapid disorganized activity
116
Causes of V-fib
heart disease, ischemia or infarction
117
V-fib treatment
CPR, defibrillation with sync off
118
Concept of defibrillation
shock tries to depolarize and have the natural pacemaker take back over
119
Defibrillation nursing responsibilities
1. Patient safety: no water or metal surfaces
2. Apply pads: cardiac sandwich
3. Make sure personnel are not directly or indirectly touching patient
4. Ensure synch switch is off!
120
Implantable cardioverter defibrillator
Surgically implanted generator that can sense intrinsic electrical activity and deliver an electrical impulse
121
What patient can have a ICD
survived a VT or VF or sudden cardiac death
Experienced syncope with VT/VF
At high risk for VT/VF after cardiac surgery and cannot tolerate medications or ablation
122
Pulseless electrical activity
absence of detectable pulse despite evidence of electrical activity
Usually caused vey clinical states that can by reversed if caught early
Any organized rhythm w/o pulse is PEA
Condition more than rhythm
123
Causes of PEA
1. Hypovolemia
2. Hypoxia
3. Acidosis
4. hypo/hyper K
5. Hypoglycemia
6. Hypothermia
7. Tablets/Toxins
8. Tamponade
9. Tension pneumothorax
10. Thrombosis
124
Treatment PEA
P-E begin BLS
P - search for Probable cause, Push fluids
E - Epi 1 mg IVP every 3-5 minutes, or vasopressin 40 units IVP
Cannot shock these patients
125
Asystole
Total absence of electrical activity or CO
126
Asystole treatment
1. look for cause - Hs and Ts, CPR, early intubation
2. Epi
DO NOT SHOCK THESE PATIENTS: interferes with natural pacemaker recovery
127
Asystole on ECG
just a flat line
128
CO is
HR x SV
| Volume of blood that the head pumps per minute
129
What is the s/s of decreased CO
SOB, hypotension, angina, altered mental status
