EKG Review Flashcards
How much time equals a big block and small block?
Big block is .2 seconds and a small block is .04 seconds
What event does P wave represent, how long should it last for, and what 3 leads is it positive in?
Atrial depolarization. 0.06 - 0.12 seconds. 1,2 and F.
What does the PR interval represent, how long should it be, what does a short interval indicate, and what does a long interval indicate? Also, what is the one thing we want to focus in on with the PR?
It is the electrical impulse starting in the atria and going through the right and left bundle branches. 0.12 - 0.20 seconds. If its short, it means the impulse probably did not originate in the SA node. If it is longer, we have a delay or block.
We want to pay attention to duration here. Most important.
What does the QRS complex represent, how long should the duration be, what does a deep wide Q wave indicate, and which 4 leads is it positive in?
Intraventricular contraction. 0.06 - 0.10. MI. 1,2,F,L.
What does the ST segment represent, what are paying particular attention to with the ST segment, what does a depressed ST segment indicate, what does an elevated ST segment indicate?
End of ventricular depolarization and the beginning of ventricular recovery. Pay attention to direction of deflection. Depressed ST greater than .5mm could indicate ischemia. Elevated ST more than 1mm can indicate injury.
What does the T wave represent, what is its amplitude in leads 1,2,3, what is its amplitude in precordial leads, which lead is it inverted in, what does a tall T wave represent, what does an inverted t wave indicate in leads it should be upright?
Ventricular repolarization. 5mm. 10mm. R. Hyperkalemia or injury. Ischemia.
What does the QT interval represent, what are we paying special attention to when evaluating the QT, what should its duration be, what can a prolonged QT lead to, what drug class can cause prolonged QT that is very common, what 2 things can lead to short QT?
Ventricular depolarization/repolarization cycle. Paying attention to duration. 0.36-0.44. Torsades de pointes. Class 1a anti. Digoxin and too much calcium.
What does the U wave represent, what is its normal deflection, and what 3 things can cause a very prominent U wave?
Recovery period of ventricles and purkinje system. Positive. Hypercalcemia, hypokalemia, and digoxin.
