ECG Measurement 2
The horizontal axis measures time. The vertical axis measures voltage or amplitude.
1 millivolt m(V) is 2large boxes high. Figure 8 shows the major ECG intervals and their normal measurements and durations.
ECG Interval /Complex
PR interval Measures from the beginning of the P wave to the beginning of the Q wave
Normal: 0.12 ot 0.20 sec
QRS complex Measures from the beginning of the Q wave to the end of the S wave
Normal: <0.12 sec
QT interval Measures from the beginning of the Q wave of the end of the T wave
Normal: Needs to be corrected for heart rate-usually 0.44 to 03.2 sec (heart rate of 60 to 10 bpm for both men
and women)