Frequency and Cardiac Cycle Timing f = 1 / T Heart rhythm can be described by frequency. If one cardiac cycle takes T seconds, then the heart beats at frequency f. Cardiac cycle duration T: 1.0 seconds Frequency: 1.00 Hz Heart Rate: 60 beats/min ♥ Frequency and Cardiac Cycle Timing f = 1 / T Heart rhythm can be described by frequency. If one cardiac cycle takes T seconds, then the heart beats at frequency f. Cardiac cycle duration T: 1.0 seconds Frequency: 1.00 Hz Heart Rate: 60 beats/min ♥ Moving Point on Circle and Sine Wave Start Pause