Term
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Definition
| An electronic device used to initiate heart beat when the intrinsic electrical system cannot efectively generate a rate adequete to support cardiac output. May be used temporarily, supportively, or permenantly. |
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Term
| When are pacemakers indicated? |
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Definition
| Bradydysrhythmias, Tachydysrhythmias, To support CO after cardiovascular surgery, and for diagnostic studies. |
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Term
| What are the 3 different pacing routes? |
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Definition
1. Transcutaneous (through the skin) noninvasive, but has pt discomfort due to higher energy levels.
2. Epicardial(in the heart muscle) used after CV surgery and can be ventricular and/or atrial
3. Trasvenous-through the subclavian or internal jugular to rt atrium or rt ventricle. |
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Term
| What is a Fixed Rate (Asynchronous)? |
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Definition
| Fires at the set rate no matter what the pt heart is doing. |
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Term
| What is demand (Synchronous)? |
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Definition
| Fires a beat only when the pt heart fails to function at a predetermined rate. The stimulus is triggered either by the sensing of intrinsic activity. |
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Term
| What does Atrioventricular (AV) mean r/t a pacemaker? |
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Definition
| sequential (dual chamber)-delivers a pacing stimulus to both the atrium and ventricle in physiologic sequence with sufficient AV delay to permit adequete ventricular filling. |
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Term
| What does the pacemaker setting rate control mean? |
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Definition
| Regulates the number of impulses that can be delivered to the heart per minute. |
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Term
| What does the pacemaker setting output dial mean? |
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Definition
| regulates the amount of electrical current in milliamps that is delivered to the heart to initiate depolarization. |
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Term
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Definition
| The point at which depolarization occurs is termed threshold and is indicated by a myocardial response to the pacing stimulus (capture). Can be determined gradually decreasing the output setting until 1:1 capture is lost. Output is set 2-3 times threshold. |
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Term
| What is Sensitivity Control? |
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Definition
| Regulates the ability of the pacemaker to detect the heart's intrinsic electrical activity measured in millivolts and determines the size of the intracardiac signal that the generator will recognize. Sense indicator light signal intrinsic activity. |
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Term
| What is AV Interval Control? |
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Definition
| Only on dual chamber generator; regulates the time interval between the atrial and ventricular pacing stimuli, is analogous to PR interval (150-250 milliseconds) |
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Term
| What is a pacing artifact? |
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Definition
| A spike seen on ECG tracing as the pacing stimulus is delivered to the heart. A p wave is visible after the pacing artifact in the atria is being paced and a qrs complex follows a ventricular pacing artifact. |
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Term
| What are pacing abnormalities? |
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Definition
failure of the pacemaker to deliver the pacing stimulus resulting in disappearance of pacing artifact even though the patient rate is less than the set rate.
Check batteries, wires, connections, and EMI |
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Term
| What are sensing abnormalities? |
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Definition
| Undersensing is the inability of the pacemaker to sense spontaneous myocardial depolarization which results in competition between paced complexes and the heart's intrinsic rhythm. Pacing artifacts occur after patient complex. |
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Term
| What does oversensing result from? |
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Definition
| The inappropriate sensing of electrical signals leading to unnecessary triggering or inhibiting of stimulus output. Paces other things. |
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Term
| What is the nursing management for a pacemaker? (4 things) |
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Definition
1. Prevent pacemaker malfunction (keep from dropping on the floor; put in pouch and then on pt)
2. Microshock protection (wear gloves)
3. Infection control (clean the site; change dressing)
4. Patient Education |
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Term
| What is an Implantable Cardioverter Defibrillator (AICD)? |
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Definition
| Electrical device capable of identifying and terminating life threatening ventricular dysrhythmias; contains sensing electrodes and defibrillation electrodes. |
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