A 70-year-old woman had an ECG at her annual checkup. Using her lead II recording below calculate her hea rate
70
92
84
104
The hea rate can be calculated by 60 divided by the R-R interval, which is 0.86 second. This results in a hea rate of 70 beats/min. (1500/No of small squares between R-R interval - but R-R interval should be regular)
ECG