ECG Basics Flashcards
What is a normal PR interval (time)?
0.12-0.20 seconds
Where do you measure the PR interval?
from the beginning of the P wave to the beginning of the QRS complex (base of the peak)
What is a normal P-wave (time)?
less than 0.11 sec
What is a normal QT interval?
0.36-0.44 sec
Where do you measure the QT interval?
beginning of QRS to the end of the T-wave
Calculation by division method:
count large boxes between R-R and divide it by 300, each small box is 0.2
*ONLY used if regular
What is a normal QRS (time)?
0.06-0.12 sec
How do you know if a rhythm is regular?
If R-r intervals are the same
- less than 4 boxes different= “essentially regular”
- more than 4 boxes different= “irregularly irregular”
Calculation by division method:
count large boxes between R-R and divide it by 300, each small box is 0.2
Where do you measure the ST segment?
Remember that the ST segment runs from the end of the S wave to the beginning of the T wave. Does the ST segment look normal (i.e., in lead II does it look flat?)
What’s the difference between a segment and an interval?
segment is a line, interval has a wave form
