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35 Cards in this Set
- Front
- Back
what does the pacing circuit consist of
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power source
one or more conducting leads myocardium |
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what can be paced with the pacemaker
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atria and or vents
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how does the electrical signal travel wth the pacemaker
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pacemaker ---through the leads---- to wall of myocardium
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how does the pacemaker cause the heart to contract
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the myocardium is captured and stimulated
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what is needed for the impulse to be accepted
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healthy tissue
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reasons for pacemaker
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bradydysrhythmias
antitachycardia |
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delivery of a stimulus to the vent to terminate tachdysrhythmias
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antitachy pacing
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pacing the atrium at raes of 200-500 impulses/min to terminate atrial tachycardias
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overdrive pacing
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how long does pacemaker last
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8-10 yrs
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needed for current to flow
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lead
muscle conductive solution |
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pacing stimulus results in depolarization of chamber being fired
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capture
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AKA firing
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capture
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what is needed for capture to occur
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distal tip of pacing lead in contact with healthy myocardium
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what is capture measured in
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milliamperes
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pacemaker able to detect presence of intrinsic cardiac activity
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sensing
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sensing measured in what
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millivolts
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power outside the body
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temporary pacemaker
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types of temporary pacemaker
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transvenous
epicardial transcutaneous |
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placed onto heart during surgery
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epicardial
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patches that pace
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transcutaneous
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threaded into superior vena cava w/ external piece
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transvenous
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can be painful and req's sedation and analgesia
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transcutaneous
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where are electrodes placed for epicardial pacemaker
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on atria or vent
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epicardial pacemaker process
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ends pulled through chest wall
sutured to chest wall attached to external pulse generator |
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implanted within the body
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permanent
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pacing technique that resynchronizes the cardiac cycle by pacing both vents
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CRT-- cardiac resynchronization therapy
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what is CRT often combined with
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ICD
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failure of pacer to sense pt's spontaneous atrial or vent activity and continues to fire inappropriately
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undersensing
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causes of undersensing
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lead damage
battery failure sensitivity too high--turn down mv disogdement of electrode |
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pacer fires and no contraction follows
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failure to capture
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reasons for malfunction
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voltage too low
battery failure fibrosis at electrode tip |
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what to do it undersensing
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turn up milliamps
turn to left side check connections check electrolytes |
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pacer fires at a pace lower than the set rate... no paced beats
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oversensing
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causes of oversensing
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sensitivity too low
electrical interference battery depletion |
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what to do if oversensing
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decrease sensitivity to rhythm
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