Atrial ECG Flashcards
1
Q
key things about heart cells
A
rhythmicity
automaticity
refractory period
conductance
2
Q
heart - on the right side from where to where
A
3rd to 6th costal cartilages
approx 10-15 cm from sternum
3
Q
heart - on the left side from where to where
A
2nd to 5th intercostal space
4
Q
heart - apex is found where in relation to sternum
A
9cm to the left of sternum in 5th intercostal space
5
Q
where is the true heartbeat
A
in 5th intercostal space
6
Q
heart mvmnt is most noticeable when
A
during deep inspirations
7
Q
heart mvmnt with deep inspiration and why
A
descends down and to the right because central tendon from diaphragm inserts on pericardium and is pulling down
8
Q
heart mvmnt with expiration
A
opposite of inspiration - move back up
9
Q
atelectasis
A
collapsing of the lungs
10
Q
atelectasis does what to the heart
A
shifts the heart to the same side
Trying to fill the space
11
Q
with tension pneumothorax what happens to the heart
A
the positive pressure shifts the heart away from the side of the pathology
12
Q
heart valves - name
A
Tricuspid, Mitral, Aortic, Pulmonic
13
Q
Which valves are between the atria and ventricles
A
Tricuspid and Mitral
14
Q
Cusps of the valves
A
Mitral (2)
Tricuspid (3)
When ventricles fill, the cusps are forced up into the closed position
15
Q
Chordae tendinae prevent
A
the cusps from being forced into the atria
16
Q
Dysfunction of cords can lead to
A
regurgitation from ventricle into atria
17
Q
Cusps are relaxed when
A
in diastole to let blood flow freely into the ventricles from the atria
18
Q
Pulmonic and aortic valves have how many cusps and where do they attach
A
3 - attach to root of aorta and pulmonary artery
19
Q
Pulmonic and aortic valves - what happens at end of systole
A
blood in aorta and pulmonary artery force the cusps shut
20
Q
Pulmonary and aortic valves can be
A
inverted so they can support the column of blood flowing into ventricles during diastole and with contraction of systole they can open to allow blood to flow in
21
Q
artery supply - derived from
A
right and left coronary arteries - arise from aortic sinuses
22
Q
Left coronary artery divides into
A
anterior descending and left circumflex artery
23
Q
left coronary artery, ant descending, and left circumflex supply
A
most of left ventricle, left atrium, most of ventricular septum, and in 45% the SA node
24
Q
Right coronary artery supplies
A
most of the right ventricle, AV node, and in 55% of people the SA node
25
Veins - three groups of veins
Coronary sinus and supplying veins
Anterior cardiac veins
Thebesian veins
26
Veins - coronary sinus and supplying veins - location
Most of the veins drain into here
| Located on post aspect of coronary sulcus
27
Veins - coronary sinus and supplying veins - empties into
the right atrium between opening of IVC and tricuspid valve
28
Veins - anterior cardiac veins
Location -
Fed from -
Fed from anterior part of right ventricle
| Originates in subepicardial tissue and cross coronary sulcus into right atrium
29
Veins - thebesian veins
| Where most numerous
Tiny veins that enter into the cavities of the heart
| Most numerous in right atrium and ventricle
30
Vena cava empties into
right atrium
31
Blood flows from right ventricle into
pulmonary artery - to capillaries - across alveoli for gas exchange - to pulmonary veins - to left atrium
32
which artery has deoxygenated blood
pulmonary artery
33
Systemic circulation - purpose
carries nutrition and oxygen throughout the body while carrying away waste products
34
driving force of systemic circulation
heart
35
Systole does what
forwards oxygenated blood away from the heart
36
Diastole does what
elastic recoil of vessels maintain the forward propulsion of blood between ventricular systoles
37
Innervations
balance between intrinsic automaticity and extrinsic nerves
38
Intrinsic innervation centers around the
SA node - it is the pacemaker of the heart
39
Without vagal influence - SA node inherent pulse
100-110 beats per minute
40
Vagal influence (extrinsic influence) on SA node - pulse
60-80 bpm
41
Extrinsic is regulated by the
medulla with input from hypothalamus during stress and activity
42
AV pulse
40-60 bpm if AV was in charge
43
Bundle of His pulse
20-40 bpm
44
upper thoracic nerves cause
1 acceleration of discharge rate of SA node
2 increase in AV nodal conduction
3 increase in contractile force of atria and ventricles
45
vagus nerve causes
cardiac slowing and decreased AV node conduction
46
Concentric waves of excitation of the SA node travel through the AV node with what
.04 second delay
47
Why the delay in concentric waves of excitation of the SA node traveling the AV node
get blood out of atria and get it into the ventricles
48
What wave of depolarization gives rise to P-QRS-T
Wave of excitation passes through Bundle of His, down Bundle Branches, through Purkinje fibers, which then permeate the ventricles and cause them to contract
49
for the heart to work properly what has to occur first
electrical stimulation first followed by mechanical contraction
50
ECG is a graphic display of
the electrical event that is the stimulus for mechanical contraction
51
ECG records the
summation of action potentials of the mm cells in the atria and ventricles as P-QRS-T waveforms
52
AP is directly related to the difference between
```
the outside (pos) and inside (neg) charges
NA out and K in
```
53
Depolarization is the
rapid change of polarity on the inside and outside of the cell during phase 0
54
ECG records the
depolarization/muscle contraction
55
In the atria - the AP correlates with
depolarization of the P wave
56
PR interval represents
total time for depolarization and time required for the impulse to travel through the AV junction through bundle branches
57
Why do we not see repolarization of the atria
buried in QRS
58
In ventricles - depolarization correlates with
QRS complex of ECG
59
QRS interval represents
time required to depolarize both ventricles
60
ST segment represents
repolarization of ventricles
61
T wave represents
the end of repolarization of the ventricles
62
QT interval represents
total time required for both depolarization and repolarization of the ventricles
63
each 5 mm block represents how many seconds
0.20
64
1 second in time is represented by
5 larger blocks
65
P wave time
0.08 - 0.10 s
66
PR interval time
0.12 - 0.20 s
67
QRS interval time
0.06 - 0.10 s
68
QT interval time
less than or equal to 0.44 s
69
12 lead ECG
6 in frontal plane
| 6 in transverse plane
70
Frontal plane leads
3 standard limb leads
| 3 augmented limb leads (AVR, AVL, AVF)
71
Transverse plane leads
V1-V6
72
Standard limb leads - Lead 1
```
traveling away (negative to positive)
T might be inverted
```
73
Standard limb leads - Lead 2
how the blood and contraction go through the heart - all are upright
74
Augmented - AVR
All inverted, moving away from heart
75
Augmented - AVL
All inverted
76
Augmented - AVF
Should all be upright
77
Calculating HR - 3 ways
1500 method
R-R method
6 second method
78
1500 method
Most precise way
Count small squares btw QRS
Divide into 1500
79
R-R method
Rs on dark line
| 300-150-100-75-60-50
80
6 second method
least accurate
| count QRS complexes in 6 second intervals and multiply by 10
81
Info on EKG represents hearts ___ activity
electrical
82
Myocardial contraction is caused by ___ of the myocytes, which records on the EKG
Depolarization
83
The recovery phase that follows depolarization is known as ___
repolarization
84
Procedure for systematic evaluation of an ECG
```
Evaluate P wave
Evaluate PR interval
QRS complex
QRS interval
T wave
R-R interval
Observe patient
```
85
P wave -->
Atria, SA node
86
PR interval --->
Atria through AV node
87
QRS complex --->
Ventricles
88
QRS interval --->
ventricles
89
T wave --->
we aren't repolarizing - infarct
90
R-R interval --->
rate
91
Sinus rhythm includes (3)
P wave before each QRS
PR interval 0.12 - 0.20
QRS rate 60-100 bpm
92
Dysrhythmias originating in SA node
Wandering Atrial Pacemaker
Sinus Tachycardia
Sinus Bradycardia
Sinus Arrhythmia
93
Supraventricular Arrhythmias
What is it
May occur where
How categorized
Abnormality of the impulse above the level of the ventricles
May occur in atria or at level of AV junction
Categorized as sinus, atrial, junctional
94
Sinus Arrhythmia (3)
P wave before QRS
PR interval 0.12 - 0.20, varies
QRS rate 40-100 bpm (less than .12 s)
95
Respiratory Sinus Arrhythmia - common in
children and elderly
96
Respiratory Sinus Arrhythmia - respirations increase rate with ___ decrease rate with ____
increase - inspiration
| decrease - expiration
97
Non respiratory arrhythmia - may be observed in people with
cardiac disease and myocardial infarction - especially in association with sinus bradycardia, digoxin therapy, or enhanced vagal tone
98
Clinical signs and symptoms with sinus arrhythmia
irregular pulse
| usually asymptomatic
99
tx for sinus arrhythmia
treat underlying cause
100
Sinud Bradycardia (3)
P wave before each QRS
PR interval .12-0.20
QRS less than 60 bpm, regular
Not often below 40
101
Common etiology - sinus bradycardia
Damage to SA node
Inc parasympathetic tone
Hypoxemia
Normal in conditioned athletes
102
Clinical signs and sx - sinus bradycardia
seldom symptomatic
| may lead to blocks or escape rhythms
103
Tx for sinus bradycardia
drug therapy
| pacemakers
104
Sinus tachycardia (3)
P wave before each QRS
PR interval 0.12 - 0.20
QRS rate - greater than 100 (usually 100-140)
105
Sinus tachycardia common etiology
```
Pain
fever
hypoxemia
CHF/pulmonary edema
Shock
Agitation
Illicit drugs
Caffeine
Nicotine
```
106
Clinical signs and sx - sinus tachycardia
```
Very with rate
Rapid, regular pulse
Palpitations
Dyspnea
Asymptomatic
with MI - might have ischemia and/or CHF
```
107
Tx for sinus tachycardia
Beta blockers and Ca channel blockers to slow heart
| Elimination of underlying cause
108
Wandering atrial pacemaker (3)
P wave present but vary in configuration
PR interval - vary but within normal limits
QRS rate - identical and within 0.04-0.10 s
109
Common etiology with wandering atrial pacemaker
irritable foci
| Injury to SA node, CHF, increased vagal firing
110
Signs and sx with wandering atrial pacemaker
rhythm that is irregular and without consistant pattern
| usually doesnt cause sx
111
Tx for wandering atrial pacemaker
no tx necessary unless rhythm develops into atrial fibrillation
112
Dysrhythmias originating in the atria
Atrial Fibrillation
Atrial Flutter
Atrial Tachycardia
Atrial Premature Beat
113
Atrial premature beat (3)
P wave - premature P may have diff configuration
PR interval - might be less than .12 or more than .2
QRS rate - if APC is conducted a premature QRS is present
114
Common etioloty of atrial premature beat
Atrial stretch (valve disease, liver disease, lung hypertension, drugs)
Hypoxemia
Atrial stimulation (pacemaker, catheter)
Frequent PACs may precede atrial flutter, a fib, or SVT
115
Clinical signs and sx - atrial premature beat
irregular pulse
116
atrial premature beat - tx
not usually indicated unless signs and sx present
| if drug therapy is indicated, quinidine, procainamide, disopyramide
117
Atrial tachycardia (3)
P wave before each QRS, might be hidden
PR interval - might be less than .12 or more than .2
QRS rate - more than 100 - 200
118
atrial tachycardia - common etiology
```
Atrial stretch
Inc sympathetic tone
Hypoxemia
Digitalis toxemia
Atrial stimulation
```
119
Atrial tachycardia - clinical signs and symptoms
Rapid, regular pulse
May exhibit signs and sx of dec CO or CHF
Extremely dangerous in MI (inc O2 consumption, inc workload)
120
Treatment for atrial tachycardia
Withhold digoxin
Treat underlying heart disease
B blockers or verapamil
121
Atrial flutter (3)
P wave - saw toothe baseline, 250-350 bpm
PR interval - constant or variable
QRS rate - 75 to 250 bpm, regular or irregular
122
Common etiology for atrial flutter
```
Inc sympathetic tone
Atrial stimulation
Hypoxemia
Valvular disease
Hyperthyroidism
```
123
Clinical signs and symptoms - atrial flutter
Depend on ventricular rate
maybe palpitations, angina, dyspnea
may cause ischemia and/or CHF
124
Tx for atrial flutter
Slow ventricular rate by blocking conduction through AV node with digoxin, beta blockers, Ca channel blockers
Class 1 or 3 anti-dysrhythmic agents to convert atrial futter to sinus rhythm
Cardioversion 10 - 50 watts
125
Atrial fibrillation (3)
P wave - irregular, undulant baseline, 300 or more
PR interval - variable
QRS - 50 to 250, irregular
126
Atrial fibrillation etiology
```
Inc sympathetic tone
ASHD
Hypoxemia
Hyperthyroidism
Valvular disease
```
127
Atrial fibrillation signs and sx
```
Irregular pulse
diff btw apical and atrial pulse
palpitations, angine, dyspnea
dec CO
Ischemia/CHF
May develop emboli from atrial wall thrombus formation
```
128
Tx for atrial fibrillation
same as for atrial flutter
| newly dx tx with anticoagulants
129
Atrial foci have the inherent rate of ___ bpm
60-80
130
Ventricular focu have the inherent rate of ___ bpm
20-40
