Physiology JIPMER 2018 f34f0009 When the HR is 72 beats per min, what would be the duration of cardiac cycle? A 445 ms B 1450 ms C 700 ms D 833 ms High-Yield Explanation Cardiac cycle: - 72 beats occur in - 60sec. 1 beat would occur in - 60/72 1 beat - 0.833 sec (~ 833 ms) (0.0139 minute per beat).