Stroke Work Calculator
Estimates the work done by the ventricle to eject a volume of blood based on stroke volume and mean arterial pressure.
Refer to the text below the calculator for more information about stroke work and its methods of estimation.
Stroke work (SW) refers to the work done by the ventricle to eject a volume of blood (stroke volume) and this is linked to the intraventricular pressure, which is the force that is applied to the volume of blood.
Ventricular stroke work can be estimated as the product of stroke volume and mean systolic pressure during ejection (MAP can be used because these values are similar in a normal heart).
Stroke Work ≈ Stroke Volume (SV) in mL/beat x Mean Arterial Pressure (MAP) in mmHg/mL
Where:
SV = Cardiac output in mL/min / Heart rate in beats/min
MAP = DBP + 1/3 (SBP – DBP)
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Steps on how to print your input & results:
1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.
2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.
Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.
About Stroke Work
Stroke work (SW) refers to the work done by the ventricle to eject a volume of blood (stroke volume) and this is linked to the intraventricular pressure, which is the force that is applied to the volume of blood.
Ventricular stroke work can be estimated as the product of stroke volume and mean systolic pressure during ejection (MAP can be used because these values are similar in a normal heart).
Stroke Work ≈ Stroke Volume (SV) in mL/beat x Mean Arterial Pressure (MAP) in mmHg/mL
Where:
SV = Cardiac output in mL/min / Heart rate in beats/minMAP = DBP in mmHg + 1/3 (SBP in mmHg – DBP in mmHg)
Stroke work is sometimes used to assess ventricular function but must not be confused with cardiac work (or cardiac minute work or ventricular minute work) which is the product of stroke work and heart rate, which is the equivalent of the triple product of stroke volume, aortic pressure and heart rate.
Left and Right Ventricular Stroke Work
The relation between left ventricular mean systolic pressure (LVSP) determined by planimetric integration and systolic and diastolic pressure measured in a peripheral artery (SAP and DAP) can be employed to determine the LVSW.
LVSW = SV x (MAP – PAWP) x 0.0136
Where PAWP is Pulmonary Artery Wedge Pressure.
Respectively, right ventricular stroke work (RVSW) can be extracted from the following formula:
RVSW = SV x (MPAP – RAP) x 0.0136
Where MPAP is mean pulmonary artery pressure and RAP is right atrial pressure.
LVSW normal range is 58 – 104 gm-m/beat whilst RVSW = 8 – 16 gm-m/beat.
By replacing stroke volume with stroke volume index (SVI) in the above formulas, the LVSW index and the RVSW index can be determined:
Left Ventricular Stroke Work Index (LVSWI) = SVI x (MAP – PAWP) x 0.0136with normal range: 50 – 62 gm-m/m2/beat;Right Ventricular Stroke Work Index (RVSWI) = SVI x (MPAP – RAP) x 0.0136with normal range: 5 – 10 gm-m/m2/beat.
References
Schramm W. The Units of Measurement of the Ventricular Stroke Work: A Review Study. J Clin Monit Comput. 2010 Jun;24(3):213-7.
De Tombe PP, Jones S, Burkhoff D, Hunter WC, Kass DA. Ventricular Stroke Work and Efficiency Both Remain Nearly Optimal Despite Altered Vascular Loading. Am J Physiol. 1993; 264(6 Pt 2):H1817-24.
Settergren G. The calculation of left ventricular stroke work index. Acta Anaesthesiol Scand. 1986 Aug;30(6):450-2.
Specialty: Cardiology
System: Cardiovascular
Article By: Denise Nedea
Published On: June 13, 2020 · 12:00 AM
Last Checked: June 13, 2020
Next Review: June 13, 2025