Clinical Methods TEST ONE Flashcards
(117 cards)
1
Q
Polarity
A
is maintaned by membrane pumps necessary to keep the inside of the cells electronegatave
2
Q
which pump maintains membrane electrical polarity
A
sodium/potassium
3
Q
Ratio of Na to K
A
3 Na outside for every 2 K inside
4
Q
What is needed to keep cell polarized
A
ATP
5
Q
pacemaker cells
A
electrical power source of the heart
6
Q
electrical conducting
A
the hard wiring of the heart
7
Q
myocardial cells
A
the contractile machinery of the heart
8
Q
what determines rate of depolarization
A
innate electrical characteristcs of the cell and the external neurohormonal input
9
Q
action potential
A
a record of one elecrical cycle of depolarization & repolarization from a single cell
10
Q
sinus node
A
dominant pacemaker of the heart, located in the RA, rate 60-100 BP, altered by Autonomic NS
11
Q
Automaticity
A
all hearts cells posses ability to behave as a pacemaker.
12
Q
intrinsic pacing SA node
A
60-100
13
Q
intrinsic pacing atrial foci
A
60-75
14
Q
junctional foci AV
A
40-60
15
Q
Ventricular foci (his bundle, etc.)
A
30-40
16
Q
horizontal small square distance in time
A
.04 sec
17
Q
horizontal large square distance in time
A
.2 secc
18
Q
vertical small square voltage
A
.1mV
19
Q
vertical large square voltage
A
.5mV
20
Q
P Wave
A
depolarization
21
Q
3 parts of ventricular conduction
A
1-bundle of Hi, 2-Bundle Branches, 3-Terminal Purkinje fibers
22
Q
Q wave
A
1st downard deflection
23
Q
R wave
A
1st upward deflection
24
Q
R prime
A
a second upward upward deflection
25
S wave
1st downard deflection following an R wave
26
QS wave
entire configuration consits solely of one downward deflection
27
Repolarization
restoration of electronegative state
28
T wave
represents the wave ventricular repolarization
29
PR Interval
from p wave to the start of QRS
30
ST Segment
from the end of the QRS complex to the beginning of the T wave
31
QT interval
includes the QRS complex, ST segment, and the T wave
32
positive deflection
a wave of depolarization towards a positive electrode
33
negative deflection
a wave of depolarization away from a positive electrode
34
biphasic wave
a depolarizing wave moving perpendicular to a postive electrode
35
lead I
right arm (-) left arm (+)
36
lead II
right arm (-) legs (+)
37
Lead III
right arm (-) legs (+)
38
AVL
left arm (+) other limbs (-)
39
AVR
right arm (+) other limbs (-)
40
AVF
legs (+) arms (-)
41
Anterior view of the heart
V2, V3, V4
42
Left Lateral view of the heart
I, aVL, V5, V6
43
Inferior view of the heart
II, III, aVF
44
right ventricular
aVR, V1
45
arrhythmia
disturbance of rate, regularity, site or origin, or conduction.
46
NSR
60-100 bpm
47
clinical manifestations
palpitations, syncope, angina, CHF, death
48
awarenes of own heartbeat
syncope
49
angina
rapid arrhythmia pain, ^ O2 demands
50
HIS DEBS
hypoxia, ischemia, symp stim, drugs, electrolytes, bradycardia, stretch
51
most info from which lead
Lead II
52
first action when you see an arrythmia?
print a strip
53
Holter monitor
ambulatory, portable EKG, 1-2 days, 1 limb lead, 1 precordial
54
Event monitor
rhythm disturbances, infrequent, patient records
55
KNOW! Rhythm analysis (5 steps)
rate, regularity, P waves, PR interval, QRS duration
56
inefficient depolarization of ventricles
ectopy
57
how do you calculate rate?
divide 300 by the # large boxes seperating two R waves
58
5 large sqares
1 sec
59
If R-R distances have a pattern the rhythm is?
regular
60
What if there is no P wave?
originate below the atria
61
Inverted P waves?
current flowing backwards
62
Normal PR interval?
atrial depol to beginning of vent. depola. 0.12-0.20 sec
63
Prolonged PR interval>
AV block
64
QRS duration?
0.04-0.12s 1-3 small boxes
65
electrical activity normal but too fast, slow, or irregular
arrythmia of sinus origin
66
origin of electrical activity elsewhere
ectopic rhythm
67
electrical activity trapped in electrical racetrack
reentrant arrythmias
68
usual pathway with blocks or delays
conduction blocks
69
accessory conduction pathway (short cut)
pre-excitation syndromes
70
When can you see sinus tachycardia?
exercise, CHF, lung dx, hyperthyroidism
71
Sinus bradycardia?
< 60 bpm. athletes, enhances vagal tone, early MI
72
Is a sinus arrythmia normal?
yes, slightly irregular but normal. inspiration=^HR, expiration=vHR
73
This occurs when sinus node stops firing
sinus arrest
74
myocardial cells take over pacing
escape beats
75
what occurs if escape beats do not occur after sinus arrest?
asystole
76
Which myocardial cells can behave as pacemakers?
virtually all of them
77
Prolonged electrical activity/
asystole, no CO or blood flow.
78
Treatment for asystole
CPR and epinephrine
79
Can you defibrillate arrythmias?
nope
80
what is the rate of nonsinus pacemakers?
atrial foci (60-75 bpm), junctional foci (40-60bpm). ventricular foci (30-40 bpm)
81
what are atrial foci?
some point IN the atrium that acts as a pacemaker
82
what are ventricular foci?
HIS bundle, bundle branches, purkinje system
83
Most common escape mechanism
junctional escape. depol near AV node,
84
a P wave is ________ in aVR
inverted
85
What is a sustained rhythm of escape beats?
ectopic rhythm
86
what can cause ectopic rhythms?
enhanced automaticity, digitalis toxicity, reentrant loop
87
Four questions to be answered?
normal P wave? QRS wide or narrow? relationship between P wave and QRS? rhythm regular of irregular?
88
single ectopic supraventricular beat that originated in atria?
PAC, premature atrial cx
89
single ectopic supraventricular beat that originated near the AV node?
junctional premature beats
90
Sudden, narrow QRS tachycardia initiated by a premature supraventricular beat/
PSVT. paroxysmal supraventricular tachycardia. 150-250 bpm
91
How do you slow or terminate?
carotid massage. 15 seconds.
92
Common triggers of PSVT?
alcohol, coffee, stress (so all of us)
93
Mechanism of carotid massage?
increases pressure that is sensed by baroreceptors, vagus nerve cause HR to slow
94
Order of steps:
listen for carotid bruits, 1 carotid at a time, watch for rhythm changes on strip
95
Regular saw toothed, 250-350 bpm
atrial flutter. variety of different ratios of atrial:ventricular rates.
96
Does carotid massage help with atrial flutter/
NO! increases block
97
What is treatment?
cardioversion/drugs
98
Most common AV block?
2:1. for q 2 flutter waves= 1 QRS complex
99
Atrial flutter is common in?
HTN, obese, DM, electrolye imbalances, alcohol intox, drug abuse (cocaine/amphetamines), COPD, CAD, CHF....
100
AV node bombard with > 500 impulses/min
A-Fib, irregularly irregular. tx: cardioversion and drugs
101
At least 3 different P wave shapes, rate 100-200 bpm
multifocal atrial tachycardia MAT. common in severe lung disease.
102
Multifocal atrial tachycardia is AKA
wandering atrial pacemaker
103
Results from enhanced automaticity of ectopic atrial focus or reentrant circle w/in atria?
paroxysmal atrial tachycardia PAT. most common cause? digitalis toxicity
104
summary: ectopic rhythms
PSVT, A-flutter, A-fib. MAT, PAT
105
Carotid massage?
PSVT, A-fib
106
Most common ventricular arrythmia?
PVC. wide bizarre QRS. no tx. common. REPLACE Mg2+
107
1 normal beat:1 PVC
bigeminy
108
2 normal beats:1 PVC
trigeminy
109
When are PVC's a concern?
frequent, three consecutive, vary in size, fall on T wave of previous beat (R on T phenomenon)
110
Three of more consecutive PVC's?
V-tach. emergency. preceded cardiac arrest
111
Polymorphic V-tachycardia?
Torsades De Pointes. (changes appearance beat to beat). "twisting of the points". patient with prolonged QT intervals
112
What electrolyte disturbances can cause prolonged QT/
decreased Ca, Mg, K
113
Drugs that can cause it?
antiarrythmic, tricyclics, phenthiazines, erythromycin
114
Pre-terminal event seen in dying hearts?
V-fib. tx: CPR/defibrillation
115
Most frequently encountered arrhythmia with sudden death?
V-fib
116
Benign rhythm seen with acute MI?
accelerated idioventricular rhythm
117
Treatment of arrythmias?
programmed electrical stimulation, defibrillators
