How to Read
an ECG Strip
ECG paper is a grid where
time is measured along the horizontal axis.
- Each small square is
1 mm in length and represents 0.04 seconds.
- Each larger square is
5 mm in length and represents 0.2 seconds.
Voltage is measured along
the vertical axis.
- 10 mm is equal to 1mV
in voltage.
- The diagram below illustrates
the configuration of ECG graph paper and where to measure the components of
the ECG wave form
Heart rate can be easily
calculated from the ECG strip:
- When the rhythm is regular,
the heart rate is 300 divided by the number of large squares between the QRS
complexes.
- For example, if there
are 4 large squares between regular QRS complexes, the heart rate is 75
(300/4=75).
- The second method can
be used with an irregular rhythm to estimate the rate. Count the number of
R waves in a 6 second strip and multiply by 10.
- For example, if there
are 7 R waves in a 6 second strip, the heart rate is 70 (7x10=70).
Instant
Feedback:
On
a typical ECG grid, 5 small squares, or 1 large square, represent 0.20 seconds
of time
©RnCeus.com