Cardiac Stroke Work

The Cardiac Stroke Work calculator 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.

INSTRUCTIONS: Choose units and enter the following:

• (P_AL) Afterload Pressure
• (SV) Stoke Volume
• (m) Blood Mass
• (v) Blood Flow Velocity

Cardiac Stroke Work (SW):  The calculator returns the value as mmHg·L. 

The Math / Science

Stroke Volume he volume of blood pumped from one ventricle of the heart with each beat.  The formula for stroke work is:

SW = P_AL ⋅ SV + 0.5 ⋅ m ⋅ v²

where:

• SW = stroke work
• PAL = Afterload Pressure
• SV = Stroke Volume
• m = mass
• v = velocity

Stroke work (SW) refers to the work done by the ventricle to eject a volume of blood (i.e., stroke volume) into the aorta.  The force that is applied to the volume of blood is the intraventricular pressure. Therefore, ventricular stroke work can be estimated as the product of stroke volume and mean aortic pressure during ejection. The use of aortic pressure instead of intraventricular pressure assumes that kinetic energy is negligible, which is generally true at resting cardiac outputs. Sometimes this is simplified to stroke volume (SV) times mean aortic pressure (MAP), although this will further underestimate the stroke work.

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.  

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)