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57 Cards in this Set
- Front
- Back
Rheobase |
lowest point on a strength duration curve at an infinitely long pulse duration |
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Two components of Minute Ventilation |
Respiratory Rate, Tidal Volume |
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4 sensors currently used in pacemakers |
Accelerometer, QT, MV, CLS |
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What are the basic parameters for programming rate response? |
LRL, MTR, MSR, Threshold, Slope, Reaction/Recovery |
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If pacing in the A at a rapid rate above LRL first assumption should be? |
Rate Response, could also be preference pacing |
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Most common for of SVT? |
AVNRT |
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Characteristics of AVNRT |
HR 150-250, Neck Pounding, Palpitations, Narrow QRS, P wave is either buried within the QRS or just after QRS. Most common in women, Abrupt onset, most frequent after 20 years of age. |
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What is Chronaxie? |
Pulse width at twice the rheobase value. This is the most efficient pulse duration. |
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What is Function Refractory Period? |
Couping interval which first results in a measurable degree of delay in impulse conduction |
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What is Effective Refractory period? |
The longest couping interval to be associated with block |
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What is Resting (transmembrane) potential? |
Voltage difference between the inside and outside of the cell fiber |
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Action potential- Phase 0 |
Depolarization phase. Rapid sodium channels are stimulated to open causing the resting membrane potential to spike from -90 to 0 mv. |
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Action Potential- Phase 1 |
Early Repolarization |
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Action Potential- Phase 2 |
Plateau Phase. This phase mediated by the slow sodium channels, essentially disrupts and delays the repolarization started in phase 1 and prolongs the refractory period. |
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Action Potential- Phase 3 |
The end of repolarization. |
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Action Potential - Phase 4 |
Resting phase. During this phase in some cardiac cells, ions leak back and forth between membranes and cause a gradual incrase in the resting potential. |
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What could incrased Atrial Naturetic Peptide (ANP) also known as Brain Naturetic Peptide (BNP) be associated with? |
Could be associated with dysnchrony, VVIR pacing, or loss of atrial capture. |
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Calculate Slew Rate |
Slew Rate is dV/dt (voltage (mv) over time (ms)). This is the peak slope of an electrogram signal. Values of .3 v/s in the atria and .5 v/s in the ventricle are considered normal. |
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What is the steroid used in steroid eluting electrodes? |
The corticosteroid dexamethason sodium phosphate |
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What kind of polyurethane is considered reliable? |
55D |
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What is a poor insulating polyurathane? |
80A |
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What causes pacemaker syndrome? |
Loss of AV synchrony, Sustained Retrograde conduction, a single ventriculare rate when rate modulation is requred for exercise. |
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Explain what Fallback is? |
Decouples the atrial and ventricular events at the upper rate limit, Ventricular inhibited pacing then gradually decrements to a programmed lower or fallback rate over a programmed duration. When the fallback rate is reached atrial synchrony is resumed |
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Rate Smoothing is what? |
Eliminates large cycle to cycle variations by preventing the paced rate from changing more than a certain percentage from one V-V to the next. Eliminates large fluctuations in rate during fixed ration or psuedo Wenkebach |
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How does K channel blocking effect of a drug demonstrate on the surface ECG? |
Lengthens QT interval |
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Name some AA agents which have negative inotropy. |
disopyramide, propafenone, flecainide |
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Name a class of drug which may have impotence depression and nightmares as a side effect |
betablockers |
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A patient is in the CCU with recurrent and near incessant VT requring repeated cardioversion. Lidco and Amio have not been completely successful. What other drug might you suggest? |
Esmolol infusion |
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Which drug has properties from all 4 Vauhan-Williams drug classifications? |
Amiodarone |
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What type of monitoring should be done routinely on patients taking amio? |
Liver and thyroid studies. Amiodarone levels, annual eye exams and chest xray |
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What is the most common serious side effect of Dofetilide (Tikosyn)? |
Long QT |
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Bidirectional or alternating VT is a symptom of tox levels of what drug? |
Digoxin |
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In what Class are the following drugs; Amiodarone, sotalol, Dofetilide? |
Class III |
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What class drugs are verapamil and dilitiazem? |
Class IV |
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A patient suddenly starts speaking in a very garbled voice after you admistered a drug intravenously. What did you just give? |
Lidocaine |
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Name 2 contraindications for starting someone on sotalol |
Ashthma Prolonged QT |
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What is an absolute contraindication for administering flecanide? |
Structural Heart Disease |
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Does amio rais or lower pacing and defib thresholds? |
Raises |
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Magnesium sulfate is primarily given to prevent recrrent torsades de pointes in patients with coronary artery disease. True or False. |
False it is given to prevent Torsades with patients with long QT not CAD |
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The first anti-arrhythmic drug recomended to be given in a "code" pulseless VT situation is ___ and how is it administered? |
Amio 300 mg given IV push |
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Drugs that can be administered via an ET tube are; |
NAVEL N (naloxone) A (atropine) V (vasopressin) E (epinephrine) L (lidocaine) |
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Name AA drugs that increase pacing thresholds |
Quinidine, Procainamide, Disopyramide, Flecanide, Propafenone |
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Name AA drugs that Increase Defibrillation Thresholds |
Quinidine, Lidocaine, Phenytoin, Flecanide, Amiodarone |
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Name two drugs that lower DFTs |
Sotalol and Bretylium |
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The premise of a proposed theory of defibrillation is that a shock need only eliminate the fibrillatory wavelets in a percentage of myocardium to extinguish the arrhythmia |
Critical Mass |
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Factors that can affect whether a shock will succeed include: |
Fibrillation duration, potassium accumulation, and circulating pharmacologic agents |
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Biphasic waveforms have been shown to result in higher implantation success rates due to... |
lower DFTs |
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Prefered position for an external Defib pad placement in a patient with an implanted ICD is: |
Anterior-Posterior |
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This feature is designed to avoid delayed when an arrhythmia straddles the VT and VF zones of an ICD |
Combined Count detection |
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Guidant ICDs use which method to maintain appropriate sensing of QRS complexes and VF while avoiding oversensing T-waves? |
Automatic Gain Control |
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This detection enhancement uses an abrupt change in rate to distinguish sinus tach from true VT |
Onset |
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The Guidant Atrial View Detection enhancements adds which features to stability and onset? |
A Rate>V rate and A fib rate threshold |
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ELAs PARAD Detection enhancement utilizes what discriminators? |
Chamber of onset, AV association and interval stability |
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What are the elements of PR logic? |
Rate Pattern Regularity AV Dissociation Far field R waves and AF Evidence |
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What are the prevention/termination therapy options delivered by Medtronic's atrial defibrillators? |
Atrial rate stabilization, High-Rate Overdrive pacing, Atrial ATP, 50 Hz burst, Atrial Cardioversion |
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What are the benefts of storing far-field egms for ICD analysis? |
More closely resembles surface ECG, can sometimes distinguish P waves, and easier to distinguish between sinus and VT morphologies. |
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Percentage of VT episodes that are asymptomatic? |
60% of episodes |