HR in this ECG is about 100/min.
For the ECG taken at paper speed 25mm/sec
Method 1
- Count the number of R waves in a 6 second rhythm strip (i.e. 30 large box), then multiply by 10.
- Useful in irregular rhythm cases
(In this ECG, number of R in 6 sec strip is 10, so HR is about 100/min)
Method 2
- Heart rate = 300 divided by number of large boxes between 2 adjacent R waves
- Used only in regular rhythm