Ch. 27 & 28 Flashcards
Cardiac Output and Tissue Perfusion
1
Q
automaticity (define in regards to specialized myocardial cells)
A
pacing function
2
Q
excitability (define in regards to specialized myocardial cells)
A
response of non-pacemaker cells
3
Q
conductivity (define in regards to specialized myocardial cells)
A
sends the stimuli from cell to cell
4
Q
contractility (define in regards to specialized myocardial cells)
A
muscles response to the stimuli
5
Q
cardiac conduction system: flow of electricity
A
SA node to AV junction to Bundle of HIS to Purkinje fibers
6
Q
Sinoatrial (SA) node
A
- electrical impulses 60-100 beats/min
- P wave on the ECG
7
Q
what is the P wave on the ECG?
A
P wave means that the electricity is coming from the SA node
- atrial depolarization
8
Q
Atrioventricular (AV) junction
A
- PR segment on ECG (electricity slows down)
- contraction known as “atrial kick”
9
Q
what is the PR segment on the ECG?
A
the AV junction
- 0.12 - 0.20
10
Q
what is the “atrial kick?”
A
the AV junction
11
Q
Bundle of His is comprised of
A
- right bundle branch system
- left bundle branch system
- Purkinje Fibers
12
Q
Bundle of His: right bundle branch system
A
carries electricity to the right side of the heart
13
Q
Bundle of His: left bundle branch system
A
carries electricity to the left side of the heart
14
Q
lead placement: continuous EKG monitoring v. 12 lead EKG monitoring
A
- the number of wires
- wires pick up electrical impulses going through the heart
- more info from the 12 lead vs the bedside monitor
- bedside monitor will not diagnose heart attack
- chest pain = 12 lead monitor
15
Q
hard-wired monitoring *
A
electrodes and lead wires are attached directly to the patient
- impulses are transmitted directly from the patient to the monitor
16
Q
telemetry monitoring
A
- 3 lead or 5 lead
- continuous monitoring, in real time
- to always keep eyes on the patient
17
Q
nursing responsibility with EKGs *
A
- ensure correct placement
- prepare patient
- set up machine
- monitoring the ECG
- interpret the strip/give to MD to interpret
18
Q
12 lead EKG
A
- starts at 4th ICS (sternal border)
- placement matters
- 12 different angles of the heart
- GOLD STANDARD for EKG rhythms/picking up heart problems (in rhythm)
- use for dx of something, then put it away
- snapshot of information
19
Q
duration is measured in __
A
fraction of second
on a graph: 1 small square is 1 mm/0.04 seconds; 1 large square is 5mm/0.2 seconds
20
Q
amplitude is measured in __
A
millivolts (mV)
on a graph: 1 small square is 0.1 mV; 1 large square is 0.5mV
21
Q
configuration (define in regards to reading an EKG)
A
the shape and appearance of a wave
22
Q
atrial depolarization occurs during the
A
P wave
- electricity is firing from atrium- SA node (action)
23
Q
ventricular depolarization occurs during the
A
QRS complex
- ventricle is deploying (action)
- 1-3 tiny squares
24
Q
early ventricular repolarization occurs during the
A
ST wave
- should almost be flat on graph (flat to isometric line)
- if bump, could mean heart attack
25
ventricular repolarization occurs during the
T wave
"the reset"
26
U wave
late ventricular repolarization
27
ventricular depolarization and repolarization occurs during the
QT interval
28
normal ECG
depol (P wave)
depol (QRS interval)
repol (T wave)
- is it regular or irregular, fast or slow? are all the parts there: pqrst?
29
ECG rhythm analysis includes (how do you read an ECG)
- determine heart rate
- determine heart rhythm: is the distance between complexes consistent
- analyze P waves
- measure PR interval
- measure QRS duration
- interpret rhythm
30
determining 6 second strip
- count R waves (the QRS complexes) in 6 seconds
- multiply by 10
31
determining rate can be measured by (methods)
- beat to beat measurement: R-R or P-P
- rule of 300
- 6 second strip
32
determining rate: rule of 300
- 300, 150, 100, 75, 60, 50
- find R wave that falls on bolded line, start counting down at next bolded line until next R wave (gives estimate if only have a little bit of strip, less than 6 sec)
don't really need to know:
- count number of large boxes between R to R (if small boxes, count them and each one is 0.2). ~ ie. 5 big boxes + 2 small boxes is 5.4.
- divide 300 by the number of boxes
- may be a range if irregular
- normal is 60-100
33
regular rhythm
- P wave before each QRS (atria drives the rate)
- PR interval is consistent**
- if no P wave before each QRS, determine the cause
34
what may cause no P wave before a QRS interval?
- heart block (if the PR interval is very wide)
- junctional
- atrial arrhythmia
- ventricular arrhythmia (wide QRS)
35
irregular rhythm: regularly irregular
premature complexes
- bigeminy
- trigeminy
36
bigeminy *
when normal complexes and premature complexes occur alternately in a repetitive two-beat pattern, with a pause occurring after each premature complex, so complexes occur in pairs
37
trigeminy *
repeated three-beat pattern, usually occurring as two sequential normal complexes followed by a premature complex and a pause, with the same pattern repeating itself in triplets
38
irregular rhythm: irregularly irregular
- atrial fibrillation
- premature beats
- paced beats
39
atrial fibrillation
350-650 beats/min (slow to rapid V)
irregular rhythm
P wave fibrillatory (fine to course)
PR interval: N/A
QRS < 0.12 seconds
40
premature beats *
extra heartbeat that occurs when the heart contracts before it should
- for example, PVCs, PACs
41
paced beats *
an ECG finding that is shown during the cardiac rhythm, controlled by an electrical impulse from an artificial cardiac pacemaker
42
normal sinus rhythm: rate
atrial and ventricular rates of 60-100 beats/min
43
normal sinus rhythm: rhythm
atrial and ventricular rhythms regular
- the space between each R wave is consistent
44
normal sinus rhythm: P waves
- present
- consistent configuration
- one P wave before each QRS complex
45
normal sinus rhythm: PR interval
0.12 to 0.20 second and constant
46
normal sinus rhythm: QRS duration
0.06 to 0.10 second and constant (< 0.12 second)
47
types of dysrhythmias
- tachydysrhythmias
- bradydysrhythmias
- premature complexes
- repetitive rhythm complexes
48
tachydysrhythmias (sinus tachy)
rate > 100, < 150
regular rhythm
P wave identical, before each QRS
PR interval is 0.12 to 0.20 second
QRS < 0.12 second
49
bradydysrhythmias (sinus brady)
rate < 60
regular rhythm
P wave identical, before each QRS
PR interval is 0.12 to 0.20 second
QRS < 0.12 second
50
repetitive rhythm complexes
- bigeminy (in pairs)
- trigeminy (in triples)
- quadrigeminy (in quadruplets)
51
causes of sinus tachycardia
- blood loss
- dehydration
- exercise
- pain
- caffeine
52
symptoms of sinus tachycardia
- heart rate over 100 bpm; p wave present
53
treatment of sinus tachycardia
- treat the underlying problem before throwing cardiac meds at the patient
- ie dehydration: hydrate patient IV fluids; exercise a lot: relax; pain: give pain meds
54
causes of sinus bradycardia
- could be marathon runner (which in this case would most likely not be concern if this is their regular HR)
- hyperkalemia
- beta blocks, CCB, digoxin
- cardiac ischemia
55
treatment of sinus bradycardia
medicine vs Edison
medicine- atropine: pick up the pace
- given IV, does not get mixed with anything, push, works immediately/picks up in real time
Edison- pacemaker: transcutaneous: temporary, pacemaker pulse generator: permanent
55
symptoms of sinus bradycardia
- fatigue
- dizziness
- SOB
- foggy mentation
- low BP
56
types of pacemakers
- can be temporary or permanent
- temporary pacemakers can be invasive or noninvasive
- temporary: transcutaneous
- permanent: put into body surgically/cut into patient at bedside
- pacer spikes will be shown between the p wave and QRS- this means that the pacemaker is working
57
examples of atrial dysrhythmias
- premature atrial contractions
- supraventricular tachycardia
- atrial fibrillation
- atrial flutter
58
premature atrial contractions (PACs)
ectopic focus of atrial tissue fires an impulse before next sinus impulse is due
- p wave is funky looking, rhythm is irregular
- don't really do anything for this; reduce stress or decrease caffeine intake; not really a medical intervention
- not a rhythm; ie "in sinus rhythm with PACs"
59
premature atrial contractions (PACs) are caused by
- stress
- fatigue
- anxiety
- infection
- inflammation
- caffeine
- nicotine
- alcohol
- certain drugs
60
supraventricular tachycardia (SVT) definition/sx
- supra: electrical impulse is coming from above the ventricle not necessarily from the SA node though
- rapid stimulation of atrial tissue occurs at rate of 100-280 beats/min with mean of 170 beats/min (adult)
- sx: chest pain, SOB, dizzy mentation
61
supraventricular tachycardia (SVT) treatment
medicine vs Edison
medicine- give adenosine: slow it down; stops the heart for 6 sec (causes asystole, with idea that the heart will come back in regular sinus rhythm)
- push very fast, through large IV close to the heart, need second nurse
- can be repeated a couple times if necessary
Edison- synchronized cardioversion: monitor controls when electrical shock happens; put pads on patient and put synchronized on monitor- shock is delivered at specific time in cardiac cycle, less electricity delivered so patient will not go into asystole
62
atrial tachycardia
140-250 bpm
regular rhythm
P wave is abnormal, before each QRS but difficult to see
PR interval < 0.20 second
QRS interval < 0.12 second
63
pathophysiology of atrial fibrillation
chaotic rhythm (always irregular)
no clear P wave (looks like a bunch of waves, a bunch of foki firing)
irregular ventricular response
64
causes of atrial fibrillation
- incidence increases with age
- associated with atrial fibrosis and loss of muscle mass
- common in heart disease (HTN, HF, CAD)
65
most common dysrhythmia
atrial fibrillation
- increases with age
66
cardiac output can decrease by ___ % with atrial fibrillation
20-30%
67
a fib puts a person at high risk for ___
stroke (BIG stroke risk)
- blood is sitting in the atrium, forms clot, clot is shot out of heart
68
atrial fibrillation treatment
- monitoring bleeding (pt probably on blood thinners)
- looking at coag studies
- give lovenox (low molecular weight heparin)
- beta blocker could be used
medicine vs Edison
medicine- CCB is 1st line med: diltiazem (slows rhythm down); give as IV bolus first, push through IV, then hang a bag for small drip dose (*watch blood pressure, it will tank) *give this slowly, little bit then check BP, little more check BP again
Edison- cardioversion: if patient is talking, has rhythm and pulse
69
a fib: assessment
- signs of poor perfusion: SOB, hypotension, poor mentation
- anxiety
- 12 lead ECG
- present with SOB
- patients can live in chronic a-fib
- probably on blood thinner: bleeding risk
- worry about bleeding risk
70
a fib: potential patient problems
- potential for embolus formation
- potential for heart failure
71
a fib: patient problems
- preventing embolus formation
- preventing heart failure
72
a fib: patient-centered collaborative care
- risk for stroke
- antidysrhythmic drugs
- cardioversion
- percutaneous radiofrequency catheter ablation
- bi-ventricular pacing
- maze procedure
73
digoxin: watch out for
- narrow therapeutic range; need to take blood levels
- watch for hypokalemia, visual disturbances (halo around lights), fatigue, anorexia, arrhythmias
74
digoxin
old med
anti-irrhythmic drug
older patient with chronic a-fib
take apical HR for 1 min; hold if HR < 60 bpm
dig toxicity: patient sees halos around light
75
atrial flutter
- rapid atrial depolarization occurring at a rate of 250-350 times per minute
- looks like saw tooth on strip
220-430 bpm, <300 bpm (V)
regular or variable rhythm
P wave sawtoothed appearance
PR interval: N/A
QRS < 0.12 second
76
ventricular dysrhythmias vs atrial dysrhythmias
ventricular are more life-threatening
- they will kill you
- not good cardiac output, cant live long if big part of heart is not perfusing well
77
What is happening during ventricular dysrhythmias?
left ventricle is not pumping oxygenated blood through the body to perfuse vital organs and other tissues
78
premature ventricular complexes
a result of increased irritability of ventricular cells- early ventricular complexes followed by a pause
- wide QRS interval, not obvious P wave
79
ventricular tachycardia
- repetitive firing of an irritable ventricular ectopic focus
- usually at a rate of 140-180 bpm
- big wide complexes, no P waves
**always check a pulse FIRST- this determines treatment
80
managing cardiac arrest
- cardiopulmonary resuscitation (CPR)
- defibrillation
- cooling
- catheterization
81
managing cardiac arrest: cardiopulmonary resuscitation
- advanced cardiac life support
- C-A-B
82
managing cardiac arrest: defibrillation
asynchronous countershock depolarizes a critical mass of myocardium simultaneously to stop the re-entry circuit and allow the sinus node to regain control of the heart
83
managing cardiac arrest: cooling *
therapeutic hypothermia is a treatment for unconscious cardiac arrest survivors that involves lowering their body temperature to reduce brain damage and increase chances of recovery
84
managing cardiac arrest: catheterization *
cardiac catheterization lab- used for patients who have experienced out of hospital cardiac arrest (OHCA)
- provides a setting for resuscitation and stabilization, and can be especially useful for treating OHCA caused by coronary artery disease
85
cardioversion (define)
synchronized countershock that may be performed in emergencies for unstable ventricular or supraventricular tachydysrhythmias or electively for stable tachydysrhythmias that are resistant to medical therapies
86
cardioversion (broken down/simple)
- elective procedure
- client awake and frequently sedated
- synchronized with QRS
- 50-200 joules
- EKG monitor
- consent form
87
defibrillation (broken down/simple)
- emergency
- v-fib/ v-tach without a pulse
- no cardiac output
- begin with 200 joules, up to 360 joules
- client unconscious
- EKG monitor
if its v fib we defib
88
ventricular fibrillation aka v fib is a result of
result of electrical chaos in the ventricles- cardiac arrest
- looks like a bunch of squiggles on EKG strip
89
ventricular asystole aka ventricular standstill is
the complete absence of any ventricular rhythm- cardiac arrest; "dying heart"
- flat line accompanied by a ventricular blip (big wide QRS)
90
ventricular asystole treatment
medicine vs Edison
medicine- epinephrine (adrenaline to start the heart)
NO Edison- do not defibrillate/shock them; not shockable rhythm
Do CPR; determine if there is an underlying cause to attempt to reverse it (ie electrolyte imbalance)
91
managing dysrhythmias is determined by
- depends on the rhythm
- first step is to identify rhythm
- too slow --> speed up
- too fast --> slow down, may need to interrupt cardiac cycle for this to occur
92
non-surgical management of dysthymias is
- antidysrhythmic agents
- other drugs
- drugs used during cardiac arrest
- vagal maneuvers - carotid sinus massage, vagal reflex
93
automated external defibrillation
- allows for earlier defibrillation
- when used, there is a greater chance of successful rhythm conversion and patient survival
94
implantable cardioverter/defibrillator
- indicated for patients who have experienced one or more episodes of spontaneous sustained VT or VF not caused by MI
- transvenous and subcutaneous types
- wearable cardioverter/defibrillator (WCD)
95
what is a wearable cardioverter/defibrillator (WCD)?
an external vest-like device worn 24 hours/day except when showering/bathing
96
sinus tachycardia
heart rate: >100 bpm
rhythm: regular
P wave: present before each QRS
PR interval: 0.12-0.2 sec
QRS: < 0.12 sec
97
sinus bradycardia
heart rate: < 60 bpm
rhythm: regular
P wave: present before each QRS
PR interval: 0.12-0.2 sec
QRS: < 0.12 sec
98
which is worse: PAC or PVC?
PVC will kill you faster than PAC
- if multiple PVCs happen in a row we are concerned: electrolyte imbalance
- a few in a minute not really concerning: caffeine, anxiety
99
paroxysmal supraventricular tachycardia rhythm is
- is intermittent, terminated suddenly with or without intervention (means that it comes and goes)
100
ventricular beats are narrow or wide
wide
101
vagal manuever
non-invasive way to stimulate the vagus nerve; does not always work
- carotid massage
- bear down like trying to have BM
- blow in straw and block end of it
102
atrial flutter interventions/precautions
same as a-fib! *watch bleeding risk/bld thinners, watch BP w/ diltiazem
medicine- CCB is 1st line med: diltiazem (slows rhythm down); give as IV bolus first, push through IV, then hang a bag for small drip dose (*watch blood pressure, it will tank) *give this slowly, little bit then check BP, little more check BP again
Edison- cardioversion: if patient is talking, has rhythm and pulse
103
unifocal PVCs vs multifocal PVCs
identical shapes (one funky spot shooting) vs a single PVC is labeled isolated
multifocal is more worrisome; two different funky spots shooting
104
PVC treatments
TREAT THE CAUSE
- if patient has low oxygen: give O2
- electrolyte imbalance: fix imbalance (ie give potassium)
- heart attack: do 12 lead EKG
105
v-tach sx
EMERGENCY
- not talking
- SOB
- chest pain
- syncope/fainting
- palpitations/fluttering
106
v-tach with a pulse treatment
cardioversion
107
v-tach without a pulse treatment
no pulse = cardiac arrest
- defibrillate and CPR
- give epinephrine, IV push, don't mix with anything
- in a perfect world, defibrillate the patient first
- defibrillation can fix the problem, CPR buys time
108
v tach without a pulse is the same treatment as
v-fib (v-fib will never have a pulse)
- both get defibrillated and CPR, epinephrine
109
a fib treatment ("A" drug)
anti-irrhythmic drug: amioderone
110
managing dysrhythmia (treatments)
too slow: atropine, pacing
too fast: adenosine, cardioversion
111
non-surgical management of dysrhythmias
- antidysrhythmic meds: amioderone (can go home on pill), cholesterol meds, blood thinners
- vagal manuevers: carotid massage, vagal stimulation
112
implantable defibrillator is for patients with
for patients with chronic V tach or V fib
