Week One Flashcards
(77 cards)
1
Q
automaticity
A
electrical signals generated by pacemaker cells
pacemaker cells can generate stimulus without outside stimulation
2
Q
Cardiac Cycle
A
Electrical (caused by automaticity)
mechanical (muscular) (contraction)
3
Q
Electrical Activity
A
depolarization
repolarization
4
Q
mechanical responses
A
systole
diastole
5
Q
depolarization = ______ = contraction
A
systole
6
Q
repolarization= ______ = resting or filing phase
A
diastole
7
Q
Depolarization begins with?
A
SA node firing
atrial contraction and atrial kick
8
Q
SA node beats?
A
60-100 bpm
9
Q
AV node beats
A
40-60 bpm
10
Q
Ventricles (purkinje fibers) beats?
A
15-40 bpm
11
Q
What can the ECG tell us?
A
orientation of the heart in the chest
conduction disturbances
electrical effects of medication and electrolytes
mass of cardiac muscles
presence of ischemic damage
ELECTRICAL (not mechanical -contraction)
12
Q
lead 1
A
records flow from right to left arm
13
Q
lead 2
A
Records flow from right arm to left leg
14
Q
lead 3
A
records flow from left arm to left leg
15
Q
augmented limb leads
A
unipolar center of heart to lead
16
Q
aVR
A
from heart to right arm
17
Q
aVL
A
heart to left arm
18
Q
aVF
A
heart to left foot
19
Q
lead 2,3, aVF see what part of the heart?
A
inferior heart
20
Q
V1 and V2 see?
A
septal (mid heart)
21
Q
V3 and V4 see?
A
anterior heart
22
Q
1, aVL, V5 and V6 see?
A
lateral heart
23
Q
one small ecg square is how many seconds?
A
0.04 s
24
Q
how many small squares make up a large square?
A
5
25
how many seconds is a large square?
0.20 s
26
P wave
atrial depolarization (SA node is firing)
27
normal P wave
round, upright, before every QRS complex, all look the same
28
QRS complex
ventricular depolarization
29
Q wave
less than 0.04 s
less than 1/3 the height of the R wave
30
PR interval
beginning of P wave to beginning of QRS complex
0.12- 0.20 sec (3-5 small blocks)
31
longer PRI
first degree AV block
32
shorter PRI
impulse from AV junction
33
QRS interval
0.06-0.12 s
34
wide QRS interval means
slowed conduction
35
ST segment
end of QRS to beginning of T wave
is it elevated or depressed
should be at baseline
36
T wave
ventricular repolarization
follows QRS complex
bigger than T wave
upright, round, smooth
37
when is the most vulnerable period of the ECG?
the peak of the T wave
38
QT interval
beginning of QRS to end of T wave
0.39-0.43s
39
atrial rate
peak of P to peak of the next P wave
40
ventricular rate
R-R wave
41
Normal Sinus Rhythm
regular
6-100 bpm
normal P wave in lead 2
P wave before QRS complex
normal PRI, QRS, and QT intervals
42
Sinus Tachy
rate: 101- 150 bpm
43
causes of tachy?
stimulants, exercise, fever, and alteration in fluid status
44
Symptoms of low CO
change LOC
chest pain
HoTN
SOB (RR distress)
dizziness, syncope
fatigue
restless
45
Management of STach
find and treat the cause
(pain give pain meds, fever give anti-pyretic)
46
Sinus Bradycardia
<60 bpm
regular
normal PRI and QRS
47
Management of SBrady
atropine
pacemaker
48
Sinus Arrhythmia
irregular RR
rate: 60-100
no real treatment (can live with them)
49
atrial dysrhythmias
increased automaticity in the atrium (SA node firing)
generally see changes in P wave
PRI normal
QRS normal
50
Causes of Atrial Dysrhythmias
stress
electrolyte imbalances
hypoxia
atrial injury
digitalis toxicity
hypothermia
hyperthyroidism
alcohol
pericarditis
caffeine
51
Premature Atrial Contractions
early beats initiated by atrium (SA node firing too early)
P waves and PR interval may vary
P wave may be found on T wave
52
Atrial Flutter
sawtooth (leads 2, 3, aVF)
RATE: 250-350 bpm
seeing many p waves before QRS (2:1, 4:1, etc)
no true p wave
QRS normal
53
Management of A Flutter
anticoagulant (blood is just laying in the body so blood thinners are 1st thing to do)
rate control with meds
elective cardio-version
interventional radiology - ablation of irritable site
54
Atrial Fibrillation
erratic impulse formation in atria
no PRI
P waves do not look the same
irregular ventricular rate
55
Causes of AFIb
heart disease
ischemia
mitral or tricuspid valve disease
CHF (overstretched chambers)
56
management of AFib
anticoagulation 4-6 weeks before cardioversion (so clots do not go everywhere in the body after being shocked)
ventricular rate control
emergent synchronized cardioversion if instability and not responsive to meds
CCB, Beta-blockers, digoxin, amiodarone
MAZE procedure
57
Ventricular Dysrhythmias
in the lower portion of the heart
depolarization occurs (wide QRS complex >0.12s)
the polarity of T wave
no p waves
58
Causes of Ventricular Dysrhythmias
myocardial ischemia, injury, and infarction
low K+ or Mag
hypoxia
acid-base imbalance (pH is acidic)
59
Premature Ventricular Contractions (PVCs)
no p wave
compensatory pause
early beat that interrupts the underlying rhythm
QRS > 0.12s
irregular
no PRI
60
When are PVCs dangerous?
frequently happen
multifocal - look different
two in row
three of more in row
R on T
61
R on T PVCs can cause what
VTach or VFIb
62
management of PVCs
find the cause and treat it
anti-dysrhythmic meds
63
causes of PVCs
drug induces (caffeine, alc, cocaine, sympathomimetic drugs)
hypoxia
cardiac disease, ACS, cardiomyopathy, vent aneurysm
hypokalemia
irritation of ventricle
64
Supra ventricular Tachycardia (SVT)
above the ventricle
abrupt onset and termination
RATE: 150-250 bpm
regular
*note Stachy rate was 101-150, this rate is above 150*
normally not tolerated well
65
ventricular tachycardia
rapid, life-threatening dysrhythmia
three of more PVCs in a row
fast RATE >100 bpm
THERE IS NO CO
wide QRS (>0.12 s)
regular
may or may not have a pulse
HoTN
66
management of V Tach
pulseless
- defibrillate
-CPR
- epinephrine
pulse
- amiodarone
- sotalol
- lidocaine
- cardioversion
67
Torsade de Pointes
type of Vtach
smaller to larger looking
68
Ventricular Fibrillation
chaotic
no P Q, R S, or T waves
no CO
emergent defibrillation
always assess pt for pulse and consciousness
69
management of VFib
check for pulse
no pulse = shock and CPR for 5 cycles (2 min)
check for pulse again
med: epinephrine
70
Idioventricular Rhythm (Ventricular Escape Rhythm)
Purkinje Fibers has an escape
RATE: 15-40 bpm
regular
wide QRS (> 0.12s)
no p waves
DO NOT GIVE LIDOCAINE
71
Asystole
a line
no nothing
no cardiac activity
first check leads
if forreal start CPR
epinephrine every 3-5 min
72
Pulseless Electrical Activity (PEA)
electrical system of heart works but the muscles do not contract
management: CPR, epine, must treat cause
this is a late sign
73
First Degree Block
delayed conduction from SA node to AV node
prolonged PRI (>0.20s)
same PRI for each beat
assess cause and treat it
74
Second Degree Block: Mobitz Type I Wenckebach
progressive lengthening PRI
some P waves without QRS
PP interval regular
RR interval regular
QRS normal
irregular rhythm
75
Second Degree Type II
more severe block
PR interval is fixed
PP interval is regular
P waves not followed by QRS
Management: transcutaneous (skin) or transvenous (vein) pacing
76
Third Degree
Complete
atria and ventricles beat independently
P's not related to QRS
P wave not associated with QRS complex
PP interval regular
RR interval regular
BP is extremely low
77
Artifact
loose electrodes
broken ECG cables or broken wires
muscle tremor
patient movement
external chest compressions
60 cycle interference
