Can you explain cardiac output monitoring?

Most common method: Cardiac output is basically the amount of blood the heart pumps over a unit of time, usually measured in liters per minute. When divided by the heart rate, one gets a stroke volume calculation, or milliliters per beat. All these may be corrected for your body size for comparison with "normals". The most common technique is with thermodilution catheters, but non-invasive techniques are validated.

CO SV & HR: Cardiac output is the product of stroke volume and heart rate. Heart rate is, of course, easy to measure. Stroke volume is a little more complicated. This is the volume of blood pumped with each beat. It can be measure invasively with a swan-ganz catheter or non-invasively with echo. There are other means of measuring stroke volume as well that are less often used.