Term
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Definition
includes:
- automaticity
- excitability
- conductivity
- contractility
- refractoriness
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Term
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Definition
this is the ability of pacing cells to spontaneouly initiated an action potential
SA node 60-100 bpm
AV node 40-60 bpm
Ventricles 15-40 bpm |
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Term
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Definition
| this nod eis the most efficient and effective pacemaker thus it is the sinus rhythm |
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Term
Automaticity
(ectopic pacemaker) |
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Definition
- heart cells other than SA node initiate impulse due to excitability focus outside the normally funciton SA node
- the SA node has not initiated the beat, the atrium will
- occurs outside the normal conduction system
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Term
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Definition
| can cells in the atrium make an impulse? |
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Term
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Definition
| this is the ability of heart to respnd in response to an electrical stimulus and generate an action potential |
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Term
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Definition
| this is the ability to conduct impulses down through the heart muscle |
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Term
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Definition
| this is the ability of muscle to respnd to electrical stimulation with a mechanical contraction |
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Term
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Definition
this is the extent to which the cardiac cells can respnd to an incoming stimulus and be depolarized
when completely refractory, the cells cannon be re exited |
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Term
refractory period
(1. relateive refractory period) |
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Definition
this occurs near the end of repolarization
during this time the membrane can be depolarized again, but only by a greater than normal stimulus |
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Term
refractory period
(2. absolute refractory period) |
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Definition
| no stimulus can cause it to contract or generate an action potential |
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Term
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Definition
normal: SA node and atril depoarization
atria contract and pump blood into ventricles |
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Term
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Definition
| Normal: ventriclar depolarization |
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Term
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Definition
| normal: ventriclar repolarization or rest period |
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Term
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Definition
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Term
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Definition
this comes from SA node
p wave is present |
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Term
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Definition
p-p interval regular
r-r interval regular |
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Term
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Definition
| what is the normal sinus rhythm? |
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Term
common dysrhythmias
(sinus bradycardia)
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Definition
HR<60
why does it occur:
excess vagal stimulation
sleep
trained athletes
drugs (beta blockers, digoxin)
hypothermia
increased intracranial pressure |
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Term
| what will you look for with patient with Sinus NOde bradycardia? |
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Definition
treat if symptomatic
may have decreased bp
angina
weakness
dizziness
synocope |
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Term
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Definition
HR >100
normally between 100-160
arises from SA node
P waves present
regular p-p and r-r intervals |
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Term
| what is causing the trachycardia? |
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Definition
elvevated temp
exercise
emotion
pain
stimulants
anemia
hypoxia
hypotension
hypovolemia |
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Term
what is causing tachycardia
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Definition
response to:
meds- atropine, epinephrine, aminophylline, ephiderine, eye drops
pathological state- pericarditis, shock pulmonary embolus, MI, CHF |
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Term
| what do you look for with tachycardia? |
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Definition
may compromise CO- becuase of poor filling time due to fast HR
s/s- decreased bp, angina, weakness, dizziness, synocope |
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