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Flashcards in ECG Cardio Stuff Deck (13)
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2nd degree AV block: whats going on and what does it look like?

Something is slowing down the path between the SA node and the AV node. This is usually due to high vagal tone (opioids or GI disease)
- variable PR intervals
- missing QRS waves


3rd degree AV block: whats happening and what does it look like?

There is no correlation between the atria and the ventricles. The atria are beating at 120bpms and the ventricles are beating at 60 bpm. It is an escape rhythm.
- extra P waves
- Missing QRS waves


What is a supraventricular rhythm

The signal starts from "above the ventricles" ie the SA node. This is normal:
- normal P waves
- QRS is skinny indicating depolarization happened fast
- HR is generally faster


Junctional rhythm

When the signal starts from the AV node:
- absent P waves
- slower HR


Ventricular rhythm

The signal is starting from below the AV node (ie the ventricles)
- no P waves
- wide and bizarre QRS
- HR is slow


LBBB: whats going on and what does it look like?

The impulse starts in the AV node and the ventricles take longer to depolarize because there is a block.
- wide QRS
- QRS is mostly positive


RBBB: whats happening and what does it look like?

The impulse starts at the AV node and it takes longer for the ventricles to depolarize because something is blocking it.
- wide QRS
- QRS will be mostly negative


Ventricular tachycardia: whats going on and what does it look like?

The SA node and AV node are not working. So the ventricles take over but they arent doing well, so the Perkinje cells start to take over.
- > 3 consecutive VPCs.
- it's a REGULAR rhythm! (This is how you differentiate it from a-fib or supraventricular tachycardia)
- increasing R-R intervals

Watch out for the R-on-T phenomenon - can set off ventricular fibrillation!


Paper speed: 50mm/s
Describe x axis for one tiny box and one big box

- most common
X axis:
small - 20ms
large - 100ms


Paper speed: 25mm/s
What is 1 tiny box and one large box on the x axis

Slower - best for rhythm analysis
Tiny box = 40ms
Larger box = 200ms


Irregular rhythms:
What is regularly irregular vs irregularly irregular?

Regularly irregular: if the irregular rhythm has a rhythm of its own

Irregularly irregular: no discernable rhythm


5mm/mV = half sensitivity
WHat is the length (y-axis) of one large box?

1mV = 5mm (this is used when complexes are so large that they start running into each other on the ECG)


Atrial fibrillation: whats going on and what does it look like?

The SA node is firing way faster than the AV node.
- irregularly irregular rhythm
- more P waves than QRS complexes