Cardiac Output

The Cardiac Output calculator computes the output of a heart based on the heart rate, end diastolic volume and the end systolic volume.

INSTRUCTIONS: Choose units and enter the following:

• (HR) Heart Rate
• (EDV) End Diastolic Volume
• (ESV) End Systolic Volume

Cardiac Output (CO): The calculator returns the output in liters per minute.  However this can be automatically converted to compatible units via the pull-down menu.

The Math / Science

Cardiac Output Is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute.

          CO = HR • (EDV - ESV)

 where:

• CO = Cardiac Output
• HR = Heart Rate in beats (strokes) per minute (BPM)
• EDV = End Diastolic Volume in volume unites, typically Liters (L)
• ESV = End Systolic Volume in volume unites, typically Liters (L)

Systolic and Diastolic Volume

End Diastolic Volume (EDV)  is the volume of the ventricle before the heart contracts.  End Systolic Volume (ESV) is the ventricle volume after blood has been ejected from the heart.  The typical end diastolic volume for a the average male is 120 milliliters of blood, and 50 milliliters of end-systolic blood.  

The systolic and diastolic pressures references in this equation refer to maximum (systolic) and minimum (diastolic) pressures generated by the pumping heart.  Movement of blood through the circulatory system is a result of the pumping action of the heart.  The volume of blood flow is dependent on both blood fluid pressure and the resistance to flow presented by the blood vessels of the entire circulatory system. Mean blood pressure decreases as the blood reaches smaller vessels further from the heart. Ultimately the blood pressure and resistance of the circulatory system translate as loss of energy. Mean blood pressure drops over the whole circulatory path. Note that end diastolic Volume can never be zero. End systolic volume in theory could be 0 or negative, but this never happens clinically as some blood is left in the heart even with an ejection fracture of 100%.

Heart and Cardiology Calculators

• Cardiac Stroke Volume: Computes the volume blood pumped in one stroke based on the end diastolic and systolic volumes.
• Cardiac Output: Computes the output of a heart based on the heart rate, end diastolic volume and the end systolic volume.
• Cardiac Output with Stroke Volume: Computes the volume rate of blood pumped by the heart in one minute based on the beats per minute and the stroke volume.
• Ejection Fraction: Computes the Ejection Fraction percentage based on the end-systolic and end-diastolic volumes.
• Heart Stroke Work: Computes the amount of work performed by the heart during a single heartbeat to pump blood based on the Mean Arterial Pressure (MAP) and Stroke Volume(SV).
• Mean Arterial Press: Compute the mean arterial pressure and pulse pressure based on the diastolic pressure and the systolic pressure.
• Cardiac Stroke Work: Computes work done by the ventricle to eject a volume of blood into the aorta based on the afterload pressure, stroke volume, blood stroke mass and blood flow velocity.
• Cardiac Flow (Q): Computes the flow factor of an artery based on the diameter and blood flow velocity.
• Body Surface Area (BSA): Wide range of calculators in one function to compute the body surface area base on one of many common methods (e.g., Mosteller, Takahira)