EKG, dysrrhythmias Flashcards
1
Q
What are the four reasons someone would get an EKG?
A
- Chest pain
- Dyspnea
- Syncope
- Toxic ingestion
2
Q
What are some limits to EKGs?
A
Can be completely normal in patient with ACS, AMI, PE
3
Q
Do resting cells have a positive or negative charge?
A
negative
4
Q
What is depolarization?
A
Influx of POSITIVE charge resulting in contraction
5
Q
What are the lateral leads?
A
I and aVL
6
Q
What are the inferior leads?
A
II, III, and aVF
7
Q
Which chest leads (V1-V6) are positive?
A
all of them
8
Q
What are the right sided leads?
A
V1 and V2
9
Q
What are the septal leads?
A
V3 and V4
10
Q
What are the left sided leads?
A
V5 and V6
11
Q
J point
A
Junction of QRS and ST segment
12
Q
Interval between the end of ventricular activation and beginning of ventricular recovery
A
ST segment
13
Q
Ventricular repolarization
A
T wave
14
Q
What can cause an abnormality in the T wave?
A
MI, electrolytes, drugs, conduction delays
15
Q
Represents the complete cycle of ventricular systole
A
QT interval
16
Q
How do you find QTc?
A
QT/square root of RR interval
17
Q
What is QTc?
A
Estimated QT interval at HR of 60 bpm
18
Q
What can cause a prolonged QT?
A
electrolytes, drugs, hypothermia
19
Q
What is QTc > 500 associated with?
A
Torsades
20
Q
Small positive deflection after T wave seen best in V2 and V3
A
U wave
21
Q
What is a U wave caused by?
A
Caused by purkinje repolarization
22
Q
What will allow you to see a U wave better?
A
decreased rate, more prominent with hypokalemia
23
Q
What does it mean if you see an inverted U wave?
A
MI
24
Q
What takes over if the SA node should fail?
A
Atrial foci take over (60-80 bpm)
25
What takes over if the atrial foci should fail?
AV junction foci (40-60 bpm)
26
What takes over if the AV junction should fail?
Ventricular foci (20-40 bpm)
27
How much time does 300 big boxes represent?
1 minute
28
How can you find rate?
300/number of big boxes
29
How do you find the rate on an EKG if it's less than 50?
Use 3 second tick marks: Count cycles/beats in a 3 second run and multiply by 20
30
Where is the SA node?
Junction of RA and SVC
31
Where is the blood supply of the SA node from?
55% RCA, 45% LCA
32
What 3 things cause dysrrhythmias?
1. Enhanced automaticity
2. Triggered activity
3. Reentry
33
What is the cause of dysrrhymia that is from a calcium overload?
Triggered Activity
34
What is the cause of dysrrhythmia that is from a current taking an abnormal path for conduction?
Reentry
35
What is the cause of dysrrhythmia from spontaneous depolarization of a non-pacemeaker cell?
Enhanced automaticity
36
What is the cause of dysrrhythmia from ischemia?
Enhanced automaticity
37
What is the cause of dysrrhythmia from having a lower threshold of depolarization in a normal pacemaker cell?
Enhanced automaticity
38
What type of antiarrhythmic drug moderately slows conduction through atria, AV node, and bundle of His?
1A sodium channel blockers
39
What is procainamide best used for?
Ventricular and Supraventricular dysrrhythmias (Class 1A sodium channel blocker)
40
SE of procainamide?
Hypotension, QRS widening
41
What class blocks sodium channels?
1
42
What class blocks calcium channels?
4
43
What class blocks potassium channels?
3
44
What class is a beta adrenergic antagonist?
2
45
What class of antiarrhythmics minimally slows conduction and shortens repolarization?
1B sodium channel blockers
46
What is lidocaine best used for?
Ventricular tachycardia (Class 1B) Max dose is 3 mg/kg total
47
What class of antiarrhythmics MARKEDLY slows conduction to the point you can develop new dysrrhythmias?
IC sodium channel blockers
48
What is flecainide best used for?
SVTs
49
What class of antiarrhythmics suppresses SA node automaticity and slows AV conduction?
Class II beta blockers
50
What is Esmolol best used for?
AMI pt with A. Fib or A. Flutter. Controls ventricular rate in atrial dysrrhtymias
51
What are SE of esmolol?
Bronchospasm, hypotension, heart failure. C/I in asthma, COPD patients
52
Which antiarrhythmic is an alternative to class I agents for atrial and ventricular dysrrhythmias?
Class III potassium channel blockers
53
Which antiarrhythmic prolongs repolarization and refractory period?
Class III potassium channel blockers
54
What is amiodarone best used for?
Atrial and ventricular dysrrhythmias
55
What is Sotalol best used for?
BB with K+ channel inhibition
| SVT, ventricular tachycardia
56
What are side effects of Sotalol?
Risk of QT prolongation
57
Which antiarrhtymic is mostly used for SVTs and slows conduction within the AV node?
Class IV CCBs
58
Who should avoid using Class IV CCBs?
Patients with heart block
59
What is Diltiazem (Cardiazem) best used for?
A fib, A flutter (Class IV)
60
What are SE of Diltiazem (Cardiazem)?
Hypotension, peripheral vasodilation
61
What is Verapamil best used for?
A. Fib, A flutter (Class IV)
62
What are SE of Verapamil?
Hypotension, less peripheral vasodilation than Cardiazem
63
Na/K+ ATPase inhibitor that is not first line but used for A.fib and A. flutter because it leads to stronger, more forceful contractions (calcium influx)
Digoxin
| toxicity = green halos
64
Terminates narrow complex tachydysrrhythmias and SVTs
Adenosine
65
Dose, Route, and Frequency of Adenosine
Dose/Route: 6 mg IV bolus
| Frequency: '6, 12, 12'
66
Palpitations, lightheadedness, dyspnea on exertion and anxiety
Stable
67
Hypotension, chest pain
unstable
68
altered LOC, syncope, respiratory distress
unstable
69
Causes of sinus bradycardia
healthy young adults and athletes, increased parasympathetic stimulation, hypoxia and hypothermia
70
How do you treat symptomatic bradycardia?
Atropine up to cumulative dose of 3 mg
71
Normal P waves with varied RR interval. Ventricular rate is <60 bpm
sinus arrhythmia
72
What do you do about sinus arrhythmia?
Nothing.. normal variant
73
Failure of the SA node to generate an impulse
Sinus arrest
74
Failure of the conduction out of the SA node
Sinoatrial Exit Block
75
Absent P waves with an escape rhythm or dropped beats
Sinus arrest and sinus block
76
Group of dysrrhythmias from a diseased sinus node. What are the 3 characteristics?
Sick sinus syndrome
| Bradycardia, sinus arrest, sinoatrial exit block
77
Who is sick sinus syndrome seen in?
Adults from fibrosis of the conduction system
78
Impaired conductions through the atria, AV node, or the proximal His/Purkinje system
AV block
79
Slowed conduction without the loss of any beats. PR interval >0.2 seconds
First degree AV block
80
Some sinus impulses failing to reach the ventricles. Will have one or more dropped beats. P wave without a QRS wave.
Second degree AV block
81
"Longer and longer until you drop" Disturbance within the AV node itself.
Type 1 Second degree AV block
| Wenkebach or Mobitz 1 Block
82
What makes Wenkebach better and worse?
Better with Atropine
| Worse with Vagal
83
Block just below the AV node. Seen in AMI setting. Consistent PR intervals
Mobitz II Block
| Second degree AV block
84
What makes Second degree AV block better? Worse?
Better with Vagal
Worse with Atropine
(opposite of type 1)
85
What's the difference between type 1 and type 2 AV block?
```
Type 1: Normal variant
Type 2: Never a normal variant
Type 1: Inconsistent PR intervals
Type 2: consistent PR intervals
Type 1: Worse with vagal, better with atropine
Type 2: Reversed
```
86
Complete AV block or complete heart block. No conduction gets through the ventricles. PP and RR intervals are consistent, just not paired.
Third Degree AV Block
87
QRS 100 BPM
Narrow Complex Tachycardias
| Supraventricular tachycardia
88
Normal P waves before each QRS. Rates rarely above 170 BPM
Sinus tachycardia
89
Abnormal P waves (P prime). Atrial rhythm over 100 BPM. Pacer originates from a site other than the SA node
Atrial tachycardia
90
What's seen in kids and young adults with structural heart disease?
Atrial tachycardia
91
Atrial tachycardia with 3 or more different P waves
Multifocal atrial tachycardia.
| Usually seen in COPD patients
92
"Everything is happening"
"Irregularly irregular"
No identifiable P waves
Atrial fibrillation
A. Fib with RVR (rapid ventricular response)
V. rates can be 150-170 bpm
93
Atrial depolarization at a rate of 250-350 BPM. Due to re-entry mechanism.
Atrial Flutter
94
Saw tooth pattern at Lead II
Atrial flutter
95
Regular narrow complex tachycardia with a ventricular rate >160 BPM. Results from reentry circuit within the AV node. Travels through HIS with retrograde back to the atria
AVNRT
| AV nodal reentry tachycardia
96
Acute onset and acute termination of rhythm. Triggered by emotional stress or exercise. Usually without underlying disease. No risk of CV collapse.
AVNRT
97
What's best for treating A.fib and a. flutter?
Beta blockers and CCBs
98
What's good prophylactic treatment of AVNRT?
Beta blockers and CCBs
99
What's acute treatment given to AVNRT?
Adenosine
100
On EKG: Short PR 0.10 seconds, slurred QRS (delta wave)
Wolf Parkinson White
101
Any tachycardia with a QRS >0.12 seconds. Source is pacer from within the ventricle or above the AV node
Wide Complex Tachycardia
102
Ventricular tachycardia that lasts <30 seconds
Nonsustained
103
Ventricular tachycardia that has consistent QRS appearances
Monomorphic
104
Ventricular tachycardia with varied QRS appearance
Polymorphic
105
How do you treat stable ventricular tachycardia?
Amiodarone
| Lidocaine
106
How do you treat unstable ventricular tachycardia?
Synchronized Cardioversion (Defibrillator)
107
Ventricular tachycardia with rate >200 BPM, undulating QRS, and paroxysms less than 90 seconds. Seen in QT prolongation.
Torsades de Points
108
What are causes of torsades de points?
Hypokalemia, hypomagnesium, drug induced, starvation, hypothyroidism, MI
