Week 10: Cardiac Rhythm Disorders Flashcards
1
Q
What are the 2 major phases of the cardiac cycle
A
- Contraciton (Depolarization)
2. Relaxation (repolarization)
2
Q
Chronotrophy
A
Heart Rate
3
Q
Ionotrophy
A
Contraction Force
4
Q
Dromotrophy
A
Conduction Speed
5
Q
Path of Cardiac Conduction
A
SA Node –> AV Node –> Bundle of His –> Right and Left Bundle Branch –> Purkinje Fibers
6
Q
Depolarization
A
when Na moves into a cell and K moves out
activity causes electrical activity which causes cardiac muscle movement
as one cell depolarizes it makes the next do so as well and causes a chain reaction
7
Q
Repolarization
A
occurs when the cell returns to its resting or baseline state
8
Q
SA Node
A
Sinus Node / Sinoatrial Node
Main pacemaker of the heart
Stimulates 60-100 BPM through depolarization
Located high in the right atrium
9
Q
What part of the heart conduction pathway can a right sided MI destroy
A
the SA node –> this leads to bradycardia and hypotension
10
Q
Tx when a Right Sided MI occurs
A
IV fluids!!!
Nitroglycerin
Patient to cath lab
11
Q
AV Node
A
atrioventricular Node
Gatekeeper of the heart
fires if the SA node rate is too low at an intrinsic rate of 40-60 BPM
12
Q
What does the AV node allow for
A
it allows the atria to contaract and empty by slowing impulses from the SA node
13
Q
Where is the AV node located
A
small group of cells in the lower right atrium
14
Q
Bundle of HIS
A
short bundle of fibers at the bottom of teh AV node
they are specialized electrical cells that travel in the septum and spread to both sides of the heart in both ventricles
leads into the bundle branches
15
Q
The Bundle Branches
A
Left and Right
Rapidly conduct impulses to the left and right ventricles after the Bundle of HIS
16
Q
The Purkinje Fibers
A
Terminal point in the conduction system in the ventricles
they are hair like fibers spreading out from the bundle branches along the endocardial surface of the ventricles
rapidly conduct the impulse to the ventricular cells
17
Q
The Purkinje Fibers are capable of causing impulses at ___-___ BPM
A
20-40
18
Q
P Wave
A
a normally small smooth and rounded bump at the start of the impulse
indicated atrial contraction / atrial depolarization
19
Q
PR Interval
A
Conduction from the atrium to Purkinje fibers depolarizing
Measured from start of P wave to the tip of the R
20
Q
How long is the PRI usually
A
normally less than 1 large (or 5 small) blocks so less than 0.2 seconds
So usually 0.12-.20 seconds
21
Q
Each small box on the EKG is ___ s
A
0.04 seconds
22
Q
Each large box on the EKG is ___ s
A
0.2 seconds
23
Q
5 of the large boxes (25 small boxes) on the EKG is ___ s
A
1 second
24
Q
QRS Complex
A
Occurs with ventricular contraction/depolarization
Q is the first down, R is the first up, and S is the negative deflection after r
Usually less than 2.5 small boxes (0.1 s) –> 0.06-0.1 s
25
T Wave
Follows the QRS
Indicated ventricular repolarization
heart resting period
26
What wave indicates a vulnerable period of the heart where if there is an issue something lethal can occur
T Wave
27
Different deflections from baseline of the PQRS complex indicates..
different views or LEADS of hearts conduction patterns (lead 2-3 may look different)
28
When Assessing EKGs it is important to look at what 2 things
1. Rhythm - regular/irregular - the origin of beat
| 2. Rate - number of ventricular contractions per minute
29
We should check the EKG first to see if there is a...
P wave
30
We can check rhythm by
measuring distance between P-P2 R-R2 waves and comparing peaks
31
What are the 3 methods of calculating rate off an EKG
1. # Small boxes Between QRS Complexes / 1500
2. # Large boxes between QRS complexes / 300
3. 6 Second Method - number of peaks x 10
32
What are the things to ask when evaluating the P wave and PR Interval
Does the rhythm originate in the atrium
Are P waves regular
Are P waves followed by QRS
Is the Pr normal .12-.2 in length or is it longer than .2
33
What are the things to ask when evaluating QRS complex
Is it normal duration of .06-.1 or is it higher
Do the QRS complexes look the same - wide ones can indicate ventricular arrhythmias
34
What are the thigns to ask when evaluating ST Segments
Is T Wave height less than 1/2 the QRS height
Is ST elevation above or depression below isometric line - indicates ischemic changes or MI
35
Raised ST increases threshold which can...
cause a heart attack
36
What are some other unusual findings on EKGs to see
ST Depression
Q Waves - scar from MI
Ectopic Beats - originate from abnormal pathways
Abnormal Herat Rhythms
37
Sinus rhythm
normal rhythm
38
Premature Rhythm
complex earlier than expected
39
Compensatory rhythm
pause in the beat occurring after a premature beat
40
Junctional rhythm
at or below AV node, above ventricle
41
Normal Sinus Rhythm
Rate 60-100 BPM
Regular R to R Interval
Normal PR Interval
42
Sinus Bradycardia
Rate < 60 BPM
Regular R to R interval
Normal PR Interval
P Wave
Beats are initiated in SA node
43
Sinus Tachycardia
Rate >100 BPM
Regular R to R Interval
P Wave Present
Normal PR Interval
Beat Initiated in SA Node
44
Sinus Arrhythmia on EKG
Rate 60-100 BPM
IRREGULAR R-R INTEVAL
P wave present and Normal PRI
Beat initiated in SA Node
BPM increases with inhalation and decreases with exhalation!!!
45
Dysrhythmias
disorders of formation or conduction (or both) of electrical impulses within heart
potentially alters blood flow, causes hemodynamic changes
46
Dysrhythmias can cause disturbances of...
rate
rhythm
both rate and rhythm
47
Dysrhythmias are diagnosed by ...
analysis of electrographic waveform
48
Dysrhythmias can be ___ or ___ in origin
supraventricular (above - SA/AV node)
Ventricular (bundle branches/perkinje)
49
What are the 3 most common Supraventricular Rhythms
Junctional Rhythms
A Fib
A Flutter
50
What are the 3 most common Ventricular Rhythms
PVC
VT
VF
51
What is more deadly supraventricular or ventricular rhythms?
Ventricular Rhythms
52
Premature Atrial Contraction (PAC)
Abnormal P Wave that comes early and fuses with T wave
There is then a pause after it occurs
Lots of people have this occur
53
What can cause PAC
caffeine
Nicotine
stress
ischemia (big problem)(
54
Atrial Fibrillation
Rate: 400-600 BPM atrial; Ventricular rate varies but can be high as 110-160
R to R is irregular
No P WAVES!!!
QRS appears normal usually
55
What is the most common rhythm seen next to normal sinus rhythm (NSR)
A fib
56
If A Fib has a rapid ventricular rate as well...
this may cause reduced cardiac output
57
A Fib may lead to ...
Mural Thrombi
58
In A Fib what is lost and can lead to heart failure
atrial kick
59
Tx for A Fib
Watch for CO (BP, UO, LOC, Color)
Meds - variety used to control rate or restore normal rhythm (digozin, verapamil, beta blockers)
ASA - anticoagulants
Watchman
Cardioversion or pacemaker may be necessary if unstable
60
Watchman
Device that is like a coffee filter surgically implanted into the inferior vena cava/major vessel/vessel that catches the clots if you were prone to clots
61
Atrial Flutter
Regular R-R Rhythm!!!
Similar to A Fib but has no P Waves - rate is still high (fast though)
Saw Tooth Pattern P Waves
Atrial rate usually 200-300 and ventricular rate usually normal
62
In A Flutter the patient shows s/s of
Decreased CO
63
What may form in A Flutter
Mural Thrombi
64
Persistent atrial flutter converts...
to sinus rhythm or atrial fib by itself or in response to meds
65
What is A Flutter treatment like
A Fib Treatment
66
Junctional Rhythms
Rate 40-60
R-R Regular
No P Wave or Inverted P Wave
Occurs above ventricle and at the AV node or Bundle of HIS
67
What is Junctional Rhythm like
treat underlying causes: pacemaker, drug toxicity
tx s/s!
68
Where is the junctional rhythm issue occurring?
Below SA Node but above the ventricle
69
PVC (Premature Ventricular Complexes)
Normal QRS, Flipped T Wave - looks like wide bizarre QRS complexes that come in early and have a pause after
70
What may cause PVCs to happen
Premature Depolarization in Ventricular Myocardium:
```
Hypoxia
Myocardial Ischemia
Hypokalemia
Acidosis
Exercise
Increased Digoxin Level
Increase with Aging
More common with CHD
```
Not dangerou w/ normal hearts; higher mortality with heart disease
71
PVCs may indicate what serious problems occurring
MI
Digoxin Toxicity
Hypoxia
Electrolyte Imbalance (Potassium)
Associated with Acute MI
72
PVC are dangerous when...
1. more than 6 per minute
2. its near a T wave
3. In couplets or triplets or more in a row
4. Multifocal
5. when associated with acute MI
73
Treatments for PVC
Acute - IV Lidocaine
Treat Cause: Hypokalemia
Other agents for long term control ex: Cortisol - amiodarone (push slow)
If ischemic problem - nitrates (vasodilates) and O2
74
Bigeminy
normal sinus beat interspersed with PVC
75
Trigeminy
2 sinus beats interpersed with PVC
76
Causes of Bigeminy/Trigeminy
MI, CHF, Digoxin Toxicity
77
Treatments for Bigeminy and Trigeminy PVC
Long term problems: Antiarrhythmics, Procan SR, Pronestyl
78
V-Tach
Ventricular Tachycardia
No P Waves
Wide Bizarre QRS Complex - VTach Mountains
Ventricular Rate of 150-200+ BPM
rhythm - Regular
79
How lethal is V Tach
can be very lethal - pulseless V Tach even needs defibrillation or CPR as it means no perfusion (its just electrical activity)
80
What is the first thing to do when a patient enters V Tach
check patient and talk to them and feel for a pulse
81
Causes for V Tach
similar to PVCs but this is considered more dangerous because of decreased cardiac output and its ability to degenrate further
82
What is V Tach called based on if its 30 seconds or longer
If less than 30 seconds = Nonsustained VT
If more than 30 sec = Sustained VT
83
V Tach is a precursor to...
ventricular fibrillation
84
What can occur with V Tach for the patient
inadequate perfusion leading to loss of consciousness
85
V Tach Treatment
IV lidocaine or amiodarone
Cardioversion (Sync Shock)
Treat Underlying Cause: MI, K Imbalance, Chornic - may need implantable defibrillator
86
What can be assumed is low if K is low
Magnesium
87
Ventricular Fibrillation
No P Waves, No QRS Complex, Rhythm is Irregular and Chaotic, rate is rapid and uncoordinated and ineffecteive
No CO = No pulse
Fatal if not treated
88
During V Fib what will be absent
A pulse is definitely absent
89
V Fib is ___ if not treated
Fatal
90
V Fib is a cause of...
sudden cardiac death
91
Treatment of V Fib
Defibrillation (Immediate!) and or CPR!!!!!!!!
Use ACLS protocols for defibrillation
Antiarrhythmic drugs may be used as well
92
Cardioversion and Defibrillation
treat tachydysrhythmias by delivering electrical current that depolarizes critical mass of myocardial cells - when cells repolarize, sinus node usually able to recapture role as heart pacemaker
93
What happens in Cardioversion
current delivery synchronized with the patients ECG
94
What happens in defibrillation
current delivery is not synchornized with the patient EKG
you often have to do this first when you cannot sync and then do cardioversion after
95
Safety Measures for Cardioversion and Defibrillation
Assure good contact between skin, pads, or paddles
PLace paddles so they do not touch bedding or clothing and are not near mediation patches or o2 flow
If cardioverting turn sync on
if defibrillating turn sync off
no wet or metal surface
dont touch patient when attached
96
A user of Defibrillation must be ___ ____
ACLS trained
97
What has to be used when a user is not ACLS certified
AED - Automatic Defibrillation
98
Asystole
No rate
No Rhythm
P waves can be present if SA or AV is fxning
QRS Complex gone
No CO, Pulse, very poor prognosis
NEEDS IMMEDIANT TREATMENT
Check pt first then monitor
No pulse here
99
When do you shock in asystole
never - thats only done in movies
theres nothign to shock
100
Tx for Aystole
Must be Immediate:
EP
Atropine
Pacemaker (External, Temp internal, CPR (do this first))
101
Pacemaker
electronic device that provides electrical stimuli to heart muscle
102
Types of Pacemakers
Permanent
Temporary
103
What situations indicate Pacemakers
sick sinus syndrome
heart blocks
post op cardiac surgery
post MI with heart block
104
Heart Block
dissociation between SA node to AV to bundle branches
communication between top or bottom of the heart
105
What shows a pacemaker is in use on the EKG
a pacemaker spike before the QRS (and a slightly wider QRS)
106
ICD Implantable Defibrillators
Senses and converts V Tach and V Fib
Similar to a pacemaker with similar teaching
Medic alert bracelet
Battery check every 6 months
typically sits on left side
107
Complications of Pacemaker/Defibrillator Use
infection
bleeding or hematoma formation
dislocation of lead
skeletal muscle or phrenic nerve stimulation
cardiac tamponade
malfunction of pacemaker/defibrillator
108
Cardiac Tamponade
Bleeding into the pericardial sac leading to tamponade which restricts the heart and can lead to cardiogenic shock
109
Nursing Interventions for pts with Pacemakers
Monitor cardiac rhythm - sensing and capturing
Note pacemaker rate, MA (milliamps), and Mode
Patient response to pacing
110
Care of the patient with an ICD - assessment
device function : ECG
cardiac output
hemodynamic stability
incision site
coping
patient and family knowledge
PAIN
111
Patient teaching on Pacers and Defibrillators should involve
regular pacemaker monitoring
taking heart rate
avoiding magnets like in an MRI
wearing medi bracelet or having the card
112
Invasive Methods to Diagnose and Treat Recurrent Dysrhythmias
Electrophysiologic Studies (EPS)
Cariac Conduction Surgery: Maze Procedure or Catheter Ablation Therapy
113
Ablation
An a fib treatment
burning off or ablating the area causing the A Fib
114
Potential s/s of Cardiovascular Problems
Fatigue
Fluid Retention
Irregular Heartbeat
Dyspnea
Pain
Syncope or Near Syncope
Leg Pain
115
What is included in a cardiac health assessment
```
medication
nutrition
elmiination
activity and exercise
sleep adn rest
self perception and self concept
roles and relationships
sexuality and reproduction
coping and stress tolerance
prevention strategies
```
116
Important Risk Factors for CV Disease
elevated serum lipid
HTN
tobacco use (Smoking and chewing)
sedentary lifestyle
obesity DM II
stressful lifestyle
117
Why do we keep an arm at the level of the heart during BP
if elevated it lowers pressure
if dependent it raises pressure
118
Pulse Pressure
Systolic - Diastolic
Not significant alone but in the wider picture it is
usually 30-40 mmHg
Drop can indicate heart failure, shock, hypovolemia
Increase seen with increased stroke volume likeatherosclerosis anemia hyperthyroid or pregnancy
119
Normal Response to Postural BP
transient increase of 5-20 BPM
drop in systolic of <10 mmHg
AND
increase in diastolic of 5 mmHg
120
Orthostatic or Postural hypotension can be accompanied by
dizziness
lightheadedness
syncope
121
3 most common causes of postural hypotension
intravascular volume depletion
inadequate vasoconstrictor mechanisms
autonomic insufficiency
122
When does Orthostatic BP (orthostasis) occur
when there is a drop in systolic of 20 mmHg or more, a drop in diastolic of at least 10 mmHg and a pulse rise greater than or equal to 20 bpm
123
Is posutral BP change from lying to sitting food enough for orthostasis diagnosis?
no but it can be a screening test
124
Allen Test
occlusion of radial and ulnar pulse test
125
Amplitude Scale
Absent = 0 = Need doppler
Diminished = +1
Normal = +2
Mod Increased = +3
Markedly Increased = +4
126
Other than pulses what other pulse should we check
the abdomen aorta for aneurysms
127
Pulsus Alterans
regular alteration of weak and strong beats w.o changes in cycle length
from heart failure or pericardial effusion
128
Bruits
a blowing sound that occurs with turbulent blood flow - suggests partial obstruction to blood flow
a palpable thrill
arteries are normally silent is why this is bad
129
Jugular Venous Pulse
can give information about right hear hemodynamics
while in semi fowlers you observe pulsations of right internal jugular vein and the measure of cm above sternal angle - if above 3 cm thats abnormal
may indicate heart failure or fluid overload
130
Where are the Aortic, Pulmonic, Tricuspid, and Mitral areas
Aortic - 2nd ICS on RSB
Pulmonic - 2nd ICS on LSB
Tricuspid - 4th ICS on LSB
Mitral - 5th ICS on LSB
131
Stethoscope diaphragm for ___ pitch sounds like ___ and ____
high; S1 and S2
132
Stethoscope bell for ___ pitched sounds like ___ and ___ and ____
low; S3 S4 murmurs
133
S1
first heart sound
closure of mitral and tricuspid valves
onset of systole
loudest at apex
134
S2
second heart sound
closure of aortic and pulmonic valves
beginning of diastole
loudest over pulmonic area
135
S3
third heart sound
physiologically normal in children, fit athletes and well exercised
pathologic in new onset or found after age 40
sounds like Lub Dup Ta
Gallop Rhythm / Sloshing In
136
S4
least common fourth heart sound
HTN and stiff walls from cardiovascular damage causes this
Ta Lub Dup - precedes S1
Best heart with bell like S3
Can mean aortic stenosis scarring or HTN
137
Murmurs
Are sound produced by abnormal turbulance:
bruit within a vessel
murmur across a valve
location of murmur tells what valve is troubles
can sound like whoosh, click, mechanical
138
Murmurs are classified by...
timing in cardiac cycle
pitch (low medium high)
location - apex, sternum
quality - soft blowing harsh mechanical
duration - throughout cycle or at the beginning
intensity - scale of I to VI
139
If a murmur is heard at apex between S1 and S2 then it is a ___ murmur and PROBABLY is ____
systolic; mitral valve
140
Cardiac Markers
CPK - creatine kinase
CRP
Troponin T and I
Homocysteine
141
What level should HDL be
>35
142
What does LDL <160, 130, and 100 mean
<160 - primary prevention, 1 or no risk factors
<130 primary prevention, 2 or more risk factors
<100 secondary prevention, person with known CAD
143
Medications for cholesterol are only used for...
high levels of LDL cholesterol
144
A client with angina asks the nurse “What information does the EKG
provide?” The nurse would respond that the EKG primarily gives information
about the:
1. Electrical conduction of the myocardium.
2. Oxygenation and perfusion of the heart
3. Contractile status of the ventricles
4. Physical integrity of the heart muscle.
1. electrical conduction of the myocardium
145
```
Which of the following are tests used to specifically evaluate the
function of the heart? (Select all that apply)
1. EEG
2. TEE
3. BUN
4. CK-MM fractions
5. Holter monitor
6. Cardiac catheterization
```
2. TEE
5. Holter Monitor
6. Cardiac Catheterization
146
```
When discussing the patient's
elevated LDL and lowered HDL
levels, the patient shows an
understanding of the significance
of these levels by the statement:
```
```
A. “Increased LDL and decreased HDL
increase my risk of coronary artery
disease.”
B. “Increased LDL and decreased HDL
decrease my risk of coronary artery
disease.”
C. “The decreased HDL level will increase
the amount of cholesterol moved away
from the artery walls.”
D. “The increased LDL will decrease the
amount of cholesterol deposited on the
artery walls.”
```
A. Increased LDL adn decreased HDL increase my risk of CAD
147
In preparation for a transesophageal
echocardiography, the nurse must:
A. Have the patient drink 1 liter of water
before the test.
B. Heavily sedate the patient.
C. Inform patient that blood pressure (BP)
and electrocardiogram (ECG) will be
monitored throughout the test.
D. Inform the patient that an access line
will be initiated in the femoral artery.
C. Inform patient that blood pressure (BP)
and electrocardiogram (ECG) will be
monitored throughout the test.
148
```
Which of the following indicates a
positive result of an exercise stress
test?
A. Chest pain
B. Drop in BP and pulse
C. Target heart rate reached
D. ST segment depression
```
A. Chest Pain
149
In teaching the client to avoid orthostatic
hypotension, the nurse should emphasize
which of the following instructions? (select all
that apply).
1. Plan regular times for taking medications
2. Arise slowly from bed
3. Avoid standing still for long periods
4. Avoid excessive alcohol intake
5. Avoid Hot baths
2. Arise slowly from bed
| 3. Avoid standing still for long periods
