Term
| Purpose of pacemaker; modes of pacemaker |
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Definition
Provide and maintain a heart rate adequate to meet patient's metabolic demands.
Atrial, ventricular, dual chamber pacing |
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Term
| How is the patient paced? |
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Definition
Epicardial wires left in after surgery
Pulmonary artery catheter (transvenous)
Transthoracic pacing in emergency |
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Term
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Definition
Symptomatic Bradycardia: sinus brady, junctional rhythm, 2nd degree type II heart block, complete heart block
suppression or pace termination fo tachydysrhythmias (rapid pacign for SVT, burst pacing for VT)
Dx of certain dysrhythmias by atrial electrograms
Improvement of hymodynamic function in congestive heart failure |
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Definition
| Pacemaker box that contains the energy source and programmable parameters |
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Term
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Definition
| Pacemaker stimulus (spike) produces depolarization or the myocardium resulting in a complex on the cardiac monitor |
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Definition
| ability of pacemaker to recognize when the patient has an inherent or native beat; the pacemaker perform in cetain ways if the beat is sensed depending on the programming |
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Definition
| Minimum voltage in milliamps (mA) required by the pacemaker to produce depolarization of the myocardium with every stimulus |
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Definition
| Pacing impulse is not followed by a complex; myocardium does not respond to stimulus |
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Term
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Definition
| Pacemaker loses ability to sense native beats and emits impulses at the programmed rate; this can result in competition between the pacemaker and the patient's native beats; if a ventricular pacemaker stimulus falls at a critical time in the T wave, VFib can occur |
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Term
| FIxed Pacing/Asynchronous Pacing |
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Definition
| Pacemaker discharges impulses regardless of heart's native activity; rarely used |
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Term
| Demand pacing/Synchronous pacing |
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Definition
| Pacemaker discharges impulses as needed based on heart's native actity; commonly used |
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Definition
| INterval measured in milliseconds (120 milliseconds = 0.12 seconds) between atrial and ventricular impulse discharge; can be thought of as the pacemakers PR interval |
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Definition
| amount of pacemakers impulse energy |
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Definition
| size of QRS to which pacemaker will recognize or respond; WRS height is measured in mV (millivolts) |
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Definition
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Definition
| Signals when pacemaker is firing |
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Definition
| durationg of pacemaker impulses; may be a short burst, or can be increasingly sustained |
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Definition
| rate set at which pacemaker will initiate pacing |
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Definition
| signals when pacemaker is detecting or sensing native atrial/P wave or ventricular/QRS complex activity |
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| Pacemaker 3 letter coding |
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Definition
Chamber paced
V: ventricle
A: atrium
D: double; dual
Chamber Sensed
V: ventricle
A: atrial
D: dual
O: none
Mode of REsponse
I: inhibited
T: triggered
D: atrial triggered and ventricle inhibited
O: none |
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Term
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Definition
Three types
AAI: Atrial demand
VVI: ventricular demand
DVI & DDD: dual chamber |
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Term
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Definition
used when sinus node does not generate impulses at rte fast enough to maintain CO:
Used for: symptomatic bradycardia, Sinus arrest, frequent sinus pauses, SIck Sinus syndrome, sinus exit block
Setup: turn ventricular output to zero. senses presence of p waves; if p waves exceed set rate, pacemaker continues in a sense mode. If p waves fall below set rate, the pacemaker will fire impulse to pace the atrium.
NOT used with AV block, A flutter, or AFib.
MD sets rate |
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Term
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Definition
Used: when ventriuclar rate is too slow to maintain CO.
Uses: AV block of any type; used when AV node is not dependable to transmit impulses to the ventricles
Setup: set by turning atrial output to zero. Senses QRS complex. If QRS rate exceeds set rate, the pacemaker stays in sense mode. If QRS falls below set rate, the pacemaker fires an impulse to pace the atrium
Caution: pure ventricular pacing loses atrial kick
Disadvantage: no coordiantion with atrial activity, lose atrial kick. SV and thus CO is lowered |
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Term
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Definition
Used when pt needs AV synchrony for adequate CO. Atrial wires to atrial channels and Ventr wires to ventricle channels. Rate set for AV interval and output for atria and ventricles.
DVI:
Use: AV node undependavle and need to preserve atrial kick (rarely used)
Used in any AV block
Setup: does not sense atrial activity, but does sense ventricular activity. Atria are paced in a fixed mode. If native QRS fire prior to set A-V interval duration, the ventricular pacing is inhibited. If native QRS complex does not fire during set A-V interval, the ventricular pacing impulse fires
Caution: due to fixed atrial pacing, there can be competition between pacer and native beats. Pacer cross talk is possible; pacemaker is sense as a native impulse by the ventricular sesing
Helps to coordinateatrial kick with ventricular activity thus preserving CO. This mode is more like normal physiologic response as compared to VVI.
DDD
Uses: same as DVI
Pacer function: Senses both atrial adn ventricular activity; paces only if native atrial or native ventricular function do not exceed set rate on pacemaker
Caution: Crosstalk possible
Help to coordinate atrial and ventricular activity, thus preserving CO. DDD eliminates atrial competition encountered with DVI pacing. |
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Term
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Definition
Placed in surgery. Atrial to the right, ventricular to the left.
When pacing is required, the wires are connected to pacemaker usign pacing cables with alligator clamps at one end (attached to epicardial wires) and prngs on the other (inserted into the pacemaker cable, then attached to pacemaker bed) |
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Term
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Definition
Patient is exposed to inadvertant delivery of microshock into heart, resulting in VFib.
Pretect with dressing, always wear gloves when handling, house wires in blue sleeve |
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Term
| Pacemaker generation units |
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Definition
Medtronic 5388, can be single or dual chamber.
Default mode is DDD
Rate: 80
A: 10 mA
V: 10 mA
Upper rate: 110
A-V interval: 0170 sec
A sensitivity: 0.5 mV
V sensitivity: 2.0 mV |
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Term
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Definition
Pushing emergency key emits high output dual chamber fixed rate pacing at these values
Rate: 80
A output: 20 mA
V output: 25 mA
A-V interval: 0.170
A sensitivity: ASYNC
V sensitivity: ASYNC
TO initiate:
Press Emergency Key/ASYNC
Press ON KEY to resume normal pacing |
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Term
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Definition
Top of pacer device
Pace LEDS: green lights
1. next to A or V; flashes green with each impulse delivered
Sense LEDS: orange, next to A and V; flashes when events are sensed, and no impulse is delivered from the pacer |
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Term
| Viewing Patient's intrinsic Rhythm |
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Definition
Viewed by reducing the pacing rate or useing teh pause key
Pacing and sensing are suspended for 10 seconds, unless you release the pause button sooner |
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