ECG

Question 1

Describe the graph of an ECG?

Answer 1

five mini squares= one large square. each mini square= 1mm. 1mm= 0.1mv. 1mm= 0.04 seconds (1 second= 25mm)

Question 2

What are the intervals in an ECG and what do they represent?

What are the segments in an ECG and what do they represent?

Answer 2

Intervals
PR- start of P to start of QRS complex
QT- start of QRS to end of T wave
Segments
PR- end of P to start of QRS
ST- end of QRS to start of T

Question 3

limb leads

Answer 3

AVR - red
AVL - yellow
AVF - green
Neutral - blue

Question 4

chest leads

Answer 4

v1- red
v2- yellow
v3- green
v4- brown
v5- blue
v6- violet

Question 5

what does the p wave represent

Answer 5

atrial depolarization

Question 6

what does the PR segment represent?

Answer 6

AV node delay, isoelectric 0.0mV always on baseline

Question 7

what does the QRS complex represent

Answer 7

ventricular depolarization

Question 8

how do we name the individual waves of the QRS complex?

Answer 8

Q any negative wave preceeding R
R first positive deflection
S any negative wave following R wave
R’ any positive wave following R wave

Question 9

What does the QT interval represent?

Answer 9

Whole ventricular action potential

Question 10

What does the ST segment represent?

Answer 10

plateau phase of ventricular action potential