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22 Cards in this Set
- Front
- Back
How would you position a dog and a cat for an ECG reading?
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Dog: Right lateral recumbancy
Cat: Sternal recumbancy |
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Why do you not want to sedate an animal for an ECG reading?
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Sedation, especially with alpha 2 agonists, may alter cardiac rhythm.
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What does the P wave correspond to?
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Atrial depolarization.
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What does the QRS complex correspond to?
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Ventricular depolarization
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What does the T wave correspond to?
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Ventricular repolarization
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How do you measure the average heart rate from an ECG reading with a paper speed of 25mm/sec.
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Count the number of R-R intervals in 15 cms and then multiply by 10.
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How do you measure the instantaneous heart rate from an ECG with a paper speed of 25 mm/sec?
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Count how many mm are between one R-R interval.
1500/ interval |
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What four questions should you ask when trying to determine if a rhythm is normal or abnormal?
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1. Is there a P for every QRS?
2. Is there a QRS for every P? 3. Are the Ps and QRSs consistently and reasonably related? 4. Are the Ps and QRSs all the same? |
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What does it mean if you dont have a P wave before a QRS complex?
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Means that the ventricles have depolarized without preceeding depolarization of the atria.
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What 5 things can cause the absence of a P wave before a QRS complex?
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1. Ventricular depolarization
2. Junctional depolarization (junction referring to the AV node or bundle of his) 3. Atrial standstill 4. A-fib 5. Sinus arrest with escape complexes. |
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What is A-fib and what would it look like on an ECG trace?
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When the atria have random and irregular depolarization. Usually caused by enlarged atria.
Wont see P waves, oscillating baseline, but normal ventricular depolarization. The interval between Rs will be random. |
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What do ventricular ectopic depolarizations look like on an ECG trace?
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The QRS complex will look wide and weird.
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What will atrial standstill look like and what would you think if you saw it?
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Will be no P waves at all because the atria are completely inactive.
Always think high potassium! May see in Addisons disease. |
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What does it mean if there is a P wave, but no QRS to follow?
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AV block
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Describe 1st, 2nd, and 3rd degree AV blocks.
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1st degree: Prolonged conductance through the AV node.
2nd degree: Occasional failure of AV conductance. 3rd degree: Complete failure of AV conductance. |
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What is it called when there is not a consistent relationship between P waves and QRS complexes?
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Atrioventricular dissociation
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What is it called if there is variation in P wave amplitude?
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Wandering pacemaker. This can be normal in dogs.
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What is the most common irregularly irregular heart rhythm?
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A-fib
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What is the mean electrical axis?
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It indicates the overall direction of depolarization of the ventricular myocardium. Its calculated from the magnitude of the deflection of the QRS complex in the six leads. It may be used to determine chamber enlargement, but it is not often useful.
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What is the normal heart rate in a dog?
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70-180 bpm. Depends on the breed.
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What is the normal heart rate for a cat?
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140-200 bpm
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What is the heart rate for a rabbit?
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198-330 bpm
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