Question

Define a cardiac cycle and the cardiac output?

Answer 1

The cardiac cycle is all the activities of the heart through one complete heartbeat, it is through one contraction and relaxation of both atria and ventricles. The contraction event is called systole and the relaxation event is diastole.The cardiac cycle includes a description of the systolic and diastolic activities of the atria and ventricles, the blood volume and pressure changes within the heart, and the action of the heart valves.

Cardiac output is the amount of blood pumped by the heart in one minute. It is the product of the heart rate, which is the number of beats per minute, and the stroke volume, which is the amount pumped per beat.

Cardiac Output = heart rate X stroke volume.

For example: If the heart rate is 70 bpm and stroke volume is 70 ml.

Using the formula: HR X SV

= 70 X 70

= 4900 ml/min or 4.9 liters per minute.