pacemakers Flashcards
codings system 5th letter
indicates multi site pacing
rarely used
what does an ICD do when it senses V-fib
defibrillate
good for people whose body cannot appropriately increase the HR during activity
rate responsive
___ requires shielding to prevent EMI
therapeutic radiation
___ system produces short pacemaker spikes
bipolar
temporary pacemaker are
transcutaneous
a series of small rapid electrical pacing pulses to interrupt V tach (by capturing the ventricle and breaking the re-entry circuit) and returning heart to the normal rhythm
anti-tachydysrhythmia pacing
sensors identify changes in the pt’s acitivity and adjust pacing to meet metabolic needs
rate responsive pacing
fast HR with a pacemaker spike preceding each QRS complex
pacemaker mediated tachycardia
sxs of bradycardia
syncope/ pre-syncope
dizzy
CHF
AMS
palpitations
SOB
exercise intolerance
relentless fatigue
50-60 Hz radio-frequency waves that interfere with pacemakers
electromagnetic interference
VVIR
ventricular inhibitory pacing with rate modulation
vent pacing
vent sensing
inhibits if vent activity sensed
rate mod active
types of pacing modes
which is most common
fixed rate
rate responsive
demand (most common)
lower/ upper rate limits
where do you look for atrial enlargement
V1 and lead 2
coding system 3rd letter
how the pacemaker responds to sensing
O = none
T= triggers pacing
I = inhibits pacing
D = dual (both triggers and inhibits)
coding system 2nd letter
the chamber being sensed by the pacemaker
0 = none
A = atrium
V = ventricle
D = dual
when is cardiac resynchronization therapy used
to resynchronize biventricular contraction
common in pts w/ HF
pacemaker spikes that fall where they should have been inhibited
failure to sense
the pacemaker doesn’t sense the intrinsic impulse and fires unnecessarily
which is more common, single chamber or dual chamber pacemakers
dual aka AV sequential chamber
3 indications for pacemakers
non-reversible
symptomatic
bradycardia
where should you first look for ischemia
precordial leads (V1-V6)- anterolateral heart
fires only when the pt’s intrinsic rate falls below a give threshold
demand pacing mode
can you do RF ablation
defer to EP
permanent pacemakers used to tx
symptomatic bradycardia
sick sinus syndrome
a-fib w/ bradycardia
3rd degree AV block
symptomatic 2nd degree type 2 AV block
AV block or BBB in pt w/ acute MI
resynchronization in heart failure
AAI
atrial inhibitory pacing, no rate modulation
atrial pacing
atrial sensing
inhibits atrial pacing if atrial activity sensed
where do you look for BBB
V6 and lead 1
pacemaker spikes that are not followed by a P wave or broad QRS complex
failure to capture
logic circuits
part of permanent pacemaker that detects cardiac electrical activity and determines the appropriate response
only ICD permanent pacemakers are used in
V-fib
V-tach
(recurrent tachycardias)
DDI
dual chamber pacing without atrial synchronous vent pacing
dual paced
dual sensed
inhibits vent pacing if vent activity sensed
what does an ICD do when it senses asystole
pace only
type of shocking that most pacemakers do
antibradycardia pacing
low or high energy shock (up to 35 joules) which is timed to the R waves to terminate VT and return heart to normal rhythm
cardioversion
coding system 1st letter
represents the heart chamber being paced
0 = none
A = atrium
V = ventricle
D = dual
w/ a TENS units,
___ system is OK
___ system should be avoided
bipolar system is OK
unipolar system should be avoided
___ system produces talll pacemakers spikes
unipolar
ODO
pacemaker is off
no pacing
dual sensing
no response to sensing (b/c not pacing)
what 3 things do ICDs do?
deliver paced beats
cardiovert
defibrillate
Cardiac Resynchronization Therapy leads (3)
- right atrium
- right ventricle
- coronary sinus (to pace the free wall of the L ventricle)
pacemakers do what 4 things
- stimulate cardiac depolarization
- sense intrinsic cardiac fxn
- respond to increased metabolic demand by providing a rate responsive pacing
- store diagnostic info to diagnose atrial/ vent arrhythmias
extracorporeal shock wave lithotripsy can cause EMI if
an abdominal device
VOO
asynchronous ventricular pacing
ventricular pacing
no sensing
no response to sensing
what does an ICD do when it senses V tach
anti tachcardia pacing
defibrillate
electraocautery can cause EMI if
within 6 inches of heart
high energy shock (up to 35 joules) to terminate ventricular fibrillation and return heart to normal rhythm
defibrillation
coding system letters 1-4
(screw 5)
- chamber being paced
- chamber being sensed
- how pacemaker responds to sensing
- rate responsive?
failure to pace is also called
oversensing
do not withold ___ for fear of EMI
transthoracic defibrillation
absence of pacemaker spikes when the HR that is slower than the rate set for the pacemaker
failure to pace
aka oversensing
DDDr
dual chamber pacing
dual paced
dual sensed
dual response (inhibitory and triggered)
rate mod active
can you do an MRI w/ a pacemaker
there are many compatible systems
permanent pacemakers are
implanted
where do you look for axis deviation
AVF and lead 1
coding system 4th letter
whether rate responsive feature is activated
O = none
R = rate responsive