At a heart rate of 75 beats per minute, one complete cardiac cycle lasts about
- A. 0.1 second
- B. 0.4 second
- C. 1.2 seconds
- D. 0.8 second
Explanation
Sixty seconds divided by 75 beats gives 0.8 second per cycle, of which atrial contraction takes about 0.1, ventricular contraction 0.3 and the shared relaxation the rest. This arithmetic is a standard MDCAT calculation.