What is ventricular fibrillation?
- Some coarse, random electrical activity is present, but no clear QRS complex
What is asystole?
- Flat line
- No residual electricity
What is the normal duration of a P wave?
< 0.12 sec
What duration of the QRS interval is considered abnormal?
0.12 secs or greater
What does a long PR duration suggest?
1° AV block
What does a short PR duration suggest?
Pre-excitation syndrome bypassing the AV node (such as WPWS)
Direction of ventricular depolarization in the frontal/coronal plane
What is a normal axis?
Down and leftward (0-90º)
What is the sequence of ventricular depolarization?
- Septum depolarizes right & downward
- Bundle branches simultaneously depolarize the R and L ventricles (mass wins --> left & downard axis)
What is a bipolar lead?
Impulse that goes one way (up/down) first, then goes the other way
What is the simplest way to determine axis?
Look to see if QRS is positive for leads 1 and aVF