Cardiovascular Therapeutic Management Flashcards
what is the equation for cardiac output
heart rate X stroke volume
what is the defintion for heart rate
number of beats per minute
what are the factors for stroke volume
preload
contractility
afterload
preload defintion
how much fluid is in the ventricles
stretching in diastole
what are some things that can influence preload
hypovolemia or hypervolemia
regurgitation of cardiac valves
heart failure
contractility defintion
contraction of the heart
afterload defintion
force the heart has to push against to exit the heart
what are some things that can effect afterload
arterial contraction
hypertension
average heart rate
70bpm
average stroke volume
70mL
average cardiac output
4-8L
what are some things that can impact heart rate
stress
meds
caffeine
what happens if we increase after load
increase cardiac workload
what does frank starling law mean
increased preload leads to increase stroke volume which leads to increased cardiac output
intrinsic rate
the patients own heart beat
extrinsic rate
a rate that is set by an artificial source
capture
heart responds to the pace maker stimulation
sense
the ability of the pacer to see the intrinsic activity of the heart
trigger
an intrinsic event causes a stimuli to be delivered
inhibited
an intrinsic event causes the pacer to turn off because some activity is seen
Asynchronous pacing (fixed)
set at a fixed rate, a non sensing mode
pacer paces regardless of the intrinsic activity
synchronous pacing
pacer delivers a stimuli in response to what it senses
what do we need for atrial pacing
intact AV node condition system
why might we do ventricular pacing
loss of atrial kick
ventricular pacing will sustain
cardiac output
atrial and ventriclar pacing is more like
intrinsic pacing
what is the most physiologic pacing mode
DDD
what dose DDD do
pace both the atria and the ventricle
both of the chambers are sensed
dual response to sensing
why might we do temporary pacemakers
ischemia
electrolyte imbalance
myocardial infarction
cardiac surgery
heart surgery
low HR
3rd degree block
three types of pacing routes
transcutaneous
epicardial
transvenous
transcutaneous pacing route
outside of the body
large skin electrodes
non invasive
epicardial pacing route
routine after many cardiac surgeries
right into the heart
what side of the body do the atrial wires come out
right side of the sternum
what side of the body do the ventricular wires come out of
left side of sternum
transvenous pacing route
into the endocardial tissue through a vein or artery
what do pacing artifacts mean
this is good
it means that the pacemaker is working
how might atrial pacing look
spike and then P wave
how might ventricular pacing look
spike and then QRS
how might both atrial and ventricular pacing look
spike, P wave, spike, QRS
what does rate control control
how quickly we want the heart to beat
what is the output dial
how much electrical impulse is giving
what is output dial measured in
miliamps
sensitivity control
how much the pace maker is sensing intrinsic
what is the sensitivity control measured in
millivolts
if the pace maker is not sensing what will we do
turn down millivolt
if we are pacing the patient externally what should we do
give pain meds and sedation
what happens if we don’t have our millivolts low enough
it is not going to see what the patients heart rate is doing
what happens if we do not have our milliamps high enough
then it is not giving enough of an electrical impulse for the heart to respond
how do the QRS look in ventricular pacing
wide and bizarre QRS
what is the solution for failure to sense
increase pacemaker sensitivity
DECREASE MILIVOLTS
what is happening in under sensing
pacemaker is not seeing the intrinsic activity and sending out impulses when it is not needed
what is happening during over sensing
the pacemaker is sensing there is a QRS when there isn’t
why is over sensing dangerous
potential for decreased cardiac output
why might failure to sense be dangerous
if a spike lands on the T wave and then R on T phenomenon can occur leading to V tach or V fib
how might failure to capture look
throwing a pacemaker spike but there is no wave that follows
why might failure to capture occur
low pacemaker battery
electrolyte abnormality
how do we fix failure to capture
increase pacer output
INCREASE MA OR VOLTS
under sensing how to fix
increase pacemaker sensitivity or MILIVOLT
how to fix over sensing
decrease pacemaker sensivitiy
what are some education for pacemakers
avoid large generator or large magnetic fields
the use of what can inhibit pacemaker function
electrocautery
what is ICD
these can shock patients who go into a dangerous rhythm
such as vfib and vtach
why might someone get an ICD
sudden cardiac arrest
spontaneous and sustained VT
inherited conditions
postoperative nursing management for cardiac surgery
normalize cardiac output
rewarming but not too quickly
control bleeding
promote early extubation
what happens to body temp during bypass
lowered to 28-32
what is a complication of bypass
altered coagulation
what could happen with a valve replacement
rejection
infection
clot formation
what should we watch for with carotid endaretrectomy
cranial nerve intact
difficulty swallowing or breathing
what CN do we want to assess for with carotid endarterectomy
VII (7), X, XI, XII
how does an intraaortic balloon pump work
in diastole the balloon inflates to promote blood flow to the coronary arteries
in systole the balloon deflates and decreases afterload
how do we treat 3rd degree heart block
pacemaker
what meds decrease preload
nitro
morphine
diuretics
