Medicine Which of the following can be used to calculate hea rate from an ECG? A Number of large squares in one R-R interval/300 B 300/ (Number of large squares in one Q-T interval) C 300/ (Number of large squares in one R-R interval) D (Number of large squares in one Q-T interval) / 300 💡 Explanation Which of the following can be used to calculate hea rate from an ECG? ✓ Correct Answer: C. 300/ (Number of large squares in one R-R interval)