Cardiac Index Calculator
Determines cardiac index based on cardiac output and body surface area, as a measure of the heart’s pumping function.
Refer to the text below the calculator for the variables and formulas used.
The Cardiac Index (CI) is a hemodynamic parameter that can tell how well the heart is fulfilling its function as a pump, by directly correlating the cardiac output (or the product of stroke volume and heart rate) from the left ventricle of the heart in one minute with the body surface area.
The measurement unit for this heart performance parameter is L/min/m2.
There are two ways to calculate CI: the first based on cardiac output and body surface area and the second based on stroke volume, heart rate and body surface area:
CI (L/min/m2) = CO/BSA
CI (L/min/m2) = SV x HR / BSA
The normal range of cardiac index (at rest) is 2.6 – 4.2 L/min/m2.
Where BSA (body surface area) is calculated from patient height and weight, based on Haycock formula:
BSA = 0.024265 x (Height in cm)0.3964 x (Weight in kg)0.5378
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About the Cardiac Index
The CI is a hemodynamic parameter frequently measured in intensive and cardiac care units. Is correlates the cardiac output (volume of blood leaving the left ventricle per minute) with the body surface area, to provide guidance on heart performance, i.e. how well the heart’s pumping works.
The measurement unit for this heart performance parameter is L/min/m2 and its values range from 2.6 to 4.2 L/min/m2 and if the CI falls below 2.2 L/min/m2, the patient may be in cardiogenic shock.
Cardiac output is indexed to the patient’s body size by dividing it to the BSA:
CI (L/min/m2) = CO/BSA = SV x HR / BSA
Where BSA (body surface area) is calculated from patient height and weight, based on Haycock formula:
BSA = 0.024265 x (Height in cm)0.3964 x (Weight in kg)0.5378
Normal ranges for the parameters used:
- CO = 4.0 - 8.0 L/min
- SV = 60 - 100 mL/beat
- HR = 60 - 100 beats/min
References
Ragosta M. Textbook of Clinical Hemodynamics. Elsevier; 2017.
Fagard R, Conway J. Measurement of cardiac output: Fick principle using catheterization. Eur Heart J. 1990; 11 Suppl I:1-5.
Carlsson et al. Cardiac output and cardiac index measured with cardiovascular magnetic resonance in healthy subjects, elite athletes and patients with congestive heart failure. J Cardiovasc Magn Reson. 2012; 14(1): 51.
Specialty: Cardiology
System: Circulatory
Abbreviation: CI
Article By: Denise Nedea
Published On: April 28, 2020 · 12:00 AM
Last Checked: April 28, 2020
Next Review: April 28, 2025