Cardiac Rhythms Flashcards
what is automaticity
ability of cardiac cells to initiate electrical impulses- av node
what is excitability
ability of non-pacemaker cells to respond to pacemaker cell
what is conductivity
transmission of impulses from one cell to the next
electrical conduction
SA
between 1 and 2….. intranodal pathway
AV
bundle of his
bundle branches
purkinje fibers
inherent rate of SA node
60-100 x per min
what is inherent rate of AV node
40-60 bpm
inherent rate of purkinje fibers
20-40 bpm
chronotropic properites
affect hr itself
slow/increase hr
dromotropic properties
speed of conduction through heart
inotropic properites
affects contractility
how much the heart is able to squeeze
what are arrhythmias
D i s o r d e r s o f f o r m a t i o n o r
c o n d u c t i o n ( o r b o t h ) o f
e l e c t r i c a l i m p u l s e s w i t h i n
h e a r t
* C a n c a u s e d i s t u r b a n c e s o f
* R a t e
* R h y t h m
* B o t h r a t e a n d r h y t h m
* P o t e n t i a l l y c a n a l t e r b l o o d
f l o w a n d c a u s e
h e m o d y n a m i c c h a n g e s
* D i a g n o s e d b y a n a l y s i s o f
e l e c t r o g r a p h i c ( E C G )
w a v e f o r m
causes of arrhythmias
Coronary artery disease (CAD)
* Cardiomyopathy
* Hypertension
* MI
* Valve disorders
* Electrolyte imbalances
* Cardiac medications
how to arrhythmias affect perfusion
sv
co
preload
contractility
afterload
what is afterload
resitance heart is pumping against
diagnostics for arrhythmias
12-lead EKG
* CXR
* Labs
* CBC
* Electrolytes
* Thyroid (tachycardias)
what causes action potential
electrolytes moving in and out of cell
what is p wave
atrial depolarization
hat is qrs
ventricular depolarization
t wave
ventricular repolarization
repolarization is
diastole
depolarization is
systole
systemactic approach to rhythm interpretation
Measure Heart Rate (slow,
normal, fast?)
* Evaluate Rhythm (regular or
irregular?)
* Is there a P wave before every
QRS?
* Is the QRS narrow or wide?
* Evaluate the ST segment- flat,
depressed, elevated?
* Interpret Rhythm
sinus bradycardia
the same as sinus rhythm but lower than 60 bpm
causes of sinus bradycardia
l o w m e t a b o l i c n e e d s , v a g a l s t i m u l a t i o n ,
m e d i c a t i o n s , S A n o d e d y s f u n c t i o n , i n c r e a s e d
I C P , C A D , M I
how to treat sinus bradycardia
atropine
transcutaneous pacemaker
sinus tachycardia
regular rhythm
higher than 100 bpm
causes of sinus tachy
ph y s i c a l / p s y c h o l o g i c a l s t r e s s ,
m e d i c a t i o n s , i l l i c i t d r u g s , a u t o n o m i c
d y s f u n c t i o n ( P O T S )
TREAT UNDERLYING CAUSE
treatment for sinus tachy
iv fluids
blood transfusion
antipyretics
analgesics
vagal maneuvers
iv beta blockers
calcium channel blockers (verapamil)
premature ventricular contraction (PVC)
could be sinus/tachy/brady
p waves sometimes absent
not conducted normally
Rate: 60-100 bpm (could vary depending on underlying)
* Rhythm/ Regularity: Irregular due to early beat
* P Waves: upright, round, 1:1- PVC’s P wave often absent
* QRS Complexes: normal beats narrow, PVCs wide
* ST Segment: without elevations
causes pvc
stimulants
etoh
mi
heart failure
digitalis toxiicty
hypoxia
acidosis
electrolyte imbalances
amiodarne side effects
sun sensitivity
dizziness/syncope
wt gain edema
blurry vision
thyroid toxicity and other toxicities
determine is\f pvcs are….
PERFUSING
check pulse while auscultating heart or watch monitor and correlate findings
afib
Characteristics:
* Rate: Atrial rate 300-600 bpm;
Ventricular rate varies
* Regularity: Irregular
* P Waves: fibrillatory waves
* QRS Complexes: narrow
* C o m m o n a r r h y t h m i a a s s o c i a t e d w i t h i n c r e a s e d
a g e a n d r i s k f a c t o r s d i s c u s s e d i n e a r l i e r s l i d e
treatment for a fib
- A n t i t h r o m b o t i c s - l o n g t e r m - w a r f a r i n , F a c t o r X a i n h i b i t o r s
( a p i x a b a n , e t c . ) ; s h o r t t e r m - h e p a r i n , e n o x a p a r i n - H e a r t r a t e c o n t r o l - ( m a i n t a i n H R < 8 0 ) - b e t a b l o c k e r , c a l c i u m
c h a n n e l b l o c k e r - M e d i c a t i o n s t o C o n v e r t - s o d i u m c h a n n e l b l o c k e r ( f l e c a i n i d e ) ,
p o t a s s i u m c h a n n e l b l o c k e r ( a m i o d a r o n e , d o f e t i l i d e ) - C a t h e t e r a b l a t i o n - d e s t r o y s s p e c i f i c c e l l s t h a t a r e t h e c a u s e o f a
t a c h y a r r h y t h m i a - E l e c t r i c a l c a r d i o v e r s i o n - i f h e m o d y n a m i c a l l y u n s t a b l e
- T i m e d e l e c t r i c a l c u r r e n t
- S y n c h r o n i z e d w i t h E C G o n c a r d i a c m o n i t o r t h a t p r e v e n t s s h o c k f r o m
o c c u r r i n g d u r i n g r e p o l a r i z a t i o n - M e d i c a t e c l i e n t w i t h s e d a t i v e & a n a l g e s i c , o r d o n e u n d e r a n e s t h e s i a
what is r on t phenomenon
Can cause ventricular tachycardia
or ventricular fibrillation
v tach
Rate: 120-200 bpm
* Regularity: May be regular or irregular
* P Waves: Will not see
* QRS Complexes: Wide, abnormal shape
increased risk in vtach
p r o l o n g e d Q T , M I , h e a r t f a i l u r e
treatment for vtach
S t a b l e - A s s e s s m e n t a n d m o n i t o r 1 2 - l e a d E K G
* U n s t a b l e w i t h p u l s e - s o d i u m o r p o t a s s i u m
c h a n n e l b l o c k e r s ( a m i o d a r o n e , l i d o c a i n e ,
p r o c a i n a m i d e ) ; c a r d i o v e r s i o n
no pulse- CPR and defib (unsynchronized shock)
vfib
Rate: Unable to determine, no pulse
* Regularity: Irregular
* P Waves: Will not see
* QRS Complexes: Unable to determine, irregular waves, changing amplitudes
CALL A CODE
causes of vfib
M I c a u s e d b y C A D , u n t r e a t e d V T ,
v a l v u l a r h e a r t d i s e a s e , c a r d i o m y o p a t h y ,
m e d i c a t i o n s , a c i d - b a s e / e l e c t r o l y t e a b n o r m a l i t i e s ,
e l e c t r i c a l s h o c k
treatment for vfib
defibrilation
cpr
amiodarone
epi
asystole
Rate: Unable to determine, no pulse
* Regularity: Unable to determine
* P Waves: Unable to determine
* QRS Complexes: Unable to determine
CALL A CODE
management asystole
cpr
epi
identify and treat possible underlying cause
nsg interventions
- Assess vital signs on an ongoing basis
- Assess for lightheadedness, dizziness, fainting
- If hospitalized
- Obtain 12-lead ECG
- Continuous monitoring
- Monitor rhythm strips periodically
- Antiarrhythmic medications
- Minimize anxiety of client
indications for pacemakers
lower than normal impulse formation, symptomatic AV or
ventricular conduction disturbance
types of pacemakers
permanent
temp: ex is transcutaneous
* On-demand vs. Fixed/asynchronous
* Implantable Cardioverter Defibrillator (ICD)
* Provides additional ability to cardiovert or defibrillate VT or VFib
pacemaker complications
Infection
Bleeding or
hematoma
formation
Dislocation of
lead
Skeletal muscle
or phrenic nerve
stimulation
Cardiac
tamponade
Pacemaker
malfunction
restrict what with pacemaker insertion
arm movement
do not raise above head for 2 weeks
pacemaker discharge education
carry id
avoid electromagnetic interference
mri precautions
pulse diary
icd discharge ed
log of icd discharges
know rate cut off
avoid activities that raise hr near cut off
notify ems
no airport want security screenings, request hand search
no driving
