Cardiac Output Chart
Keep this handy cardiac output chart PDF on hand for quick calculations using stroke volume and heart rate, and ensure you have all your working correctly shown.
Fact Checked by Ericka Pingol.
What is a Cardiac Output Chart?
Before we dive into the formula chart for cardiac output and the factors that can impact it, let’s have a quick reminder of what cardiac output is.
Cardiac output, sometimes abbreviated as CO, is the volume of blood pumped by the left ventricle into the aorta every minute (Martini et al., 2017, 680-681), typically given in units of liters of blood per minute, and it is a fundamental measurement of heart function. It can also be thought of as the volume of blood flowing into the systemic circuit every minute.
While cardiac output can be measured analytically using Fick’s principle, a more straightforward way to estimate cardiac output is by using the two main determinants of cardiac output: stroke volume and heart rate.
As a quick refresher, stroke volume is the volume of blood pumped per heartbeat, and heart rate is beats per minute. From dimensional analysis, we can see that multiplying these two parameters will give us the units of blood volume per minute or the cardiac output.
We can then deduce that cardiac output can be expressed as the product of heart rate and stroke volume, as shown below:
Cardiac Output = Heart Rate x Stroke Volume.
You might also see this formula shortened to:
CO = HR x SV.
Sounds simple? Well, there’s a little more to it, but luckily, our cardiac output formula template can help you make sense of all the factors that can impact heart rate, stroke volume, and cardiac output.
Printable Cardiac Output Formula
Download this Cardiac Output Formula to measure the amount of blood pumped through the heart in a minute.
How Does it Work?
This printable cardiac output chart can be edited digitally using the fillable areas or printed out and filled out by hand. Just follow these simple steps to ensure you calculate cardiac output correctly every time.
Step 1. Enter the end-diastolic volume (EDV)
If you already have a value for stroke volume, skip straight to step three. Otherwise, the first step is to input the end-diastolic volume, in milliliters, into the EDV box.
Step 2. Enter end-systolic volume
Next, enter the end-systolic volume in milliliters into the ESV box.
Step 3. Calculate Stroke Volume
If you have a direct value for stroke volume, enter this into the SV box; otherwise, subtract ESV from EDV, and the result will be your value for stroke volume; then enter this value into the SV box in equation two in liters per beat.
Step 4. Enter heart rate
Enter the heart rate value into the HR box in beats per minute (bpm).
Step 5. Calculate cardiac output
The last step is multiplying the stroke volume and heart rate, or the values in the SV and HR box, to get the cardiac output in liters per minute.
Cardiac Output Formula Example (Sample)
An example problem involving cardiac output calculation from end-systolic volume (ESV), end-diastolic volume (EDV), and heart rate is given below:
Calculate the cardiac output for Marie whose end-systolic volume is 45mL, end-diastolic volume is 120mL, and heart rate is 90 bpm.
We have created a cardiac output chart PDF sample, which you can download to work through this example problem and check your understanding of this cardiac output formula.
Download this Cardiac Output Formula Example:
When Would You Use This Cardiac Output Chart?
There are several ways cardiac output can be estimated, including echocardiography, thermodilution techniques, Fick techniques, or angiography.
This cardiac output formula can be used with any imaging technique that allows for quantitative measurement of the left ventricular volume at different phases of the cardiac cycle, such as cardiac MRI, echocardiography, or angiography. While Fick techniques are more precise and considered the best option, imaging-based techniques can provide an efficient estimate, particularly useful for tracking changes in relative cardiac output over time (Maleki et al., 2017).
What do the Results Mean?
It’s important to remember that a single number can not encapsulate all the factors impacting a patient’s cardiac health. Additionally, cardiac output is highly variable and can be influenced by many factors, such as exercise, hormones, or body temperature. As such, every patient will differ in their normal baseline heart function, and there can be a wide range of normal values for cardiac output.
Commonly cited values for stroke volume are 70mL for a healthy adult person, which, alongside a typical value of resting heart rate of 60-80 bpm, gives a range of cardiac output values from 4.2-5.6 L/min.
A cardiac output lower than the value expected for a healthy patient may be due to a heart condition such as congestive heart failure, cardiomyopathy, or another underlying condition leading to heart failure.
A cardiac output higher than the value expected can occur as a result of hyperthyroidism, stress, or simply exercising, so it is clear that a single cardiac output value needs to be interpreted in context to determine if it is indicative of an underlying pathology.
Why Use Carepatron as Your Cardiac Output Formula App?
Heart diseases are highly prevalent in the population and, as such, represent a large workload for practitioners in terms of ordering tests, interpreting images, sharing lab results, and determining the best course of treatment. Luckily, with automation and electronic health records, many more menial tasks can be minimized. If you’re looking for a way to streamline your medical billing system, scheduling, and dictating- then look no further than Carepatron.
Carepatron is a comprehensive software suite designed to save you time through smart practice management solutions. Offer your patients access to their patient portal software to book appointments with you, see their results, or conduct telehealth appointments. Utilize our AI-powered smart dictation software or library of helpful templates, such as this cardiac output formula, to keep you working efficiently.
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References
Maleki, M., Alizadehasl, A., & Haghjoo, M. (Eds.). (2017). Practical Cardiology. Elsevier.
Martini, F., Ober, W., Nath, J., Bartholomew, E., & Petti, K. (2017). Visual Anatomy and Physiology. Pearson.
Young, D. B. (2010). Control of Cardiac Output. Morgan & Claypool Life Sciences.
Commonly asked questions
The EDV, or the end-diastolic volume, is the amount of blood in the ventricle at the end of ventricular diastole or filling. The ESV, or the end-systolic volume, is the amount of blood remaining in the ventricle after ventricular systole or ejection. These volumes are important as the difference between the EDV and ESV is the stroke volume, which is used for cardiac output calculation. (Martini et al., 2017, 686)
There are many different cardiac output formulae, some more complicated than others. This simple formula can be used whenever stroke volume, or EDV and ESV, are known. Other cardiac output formulae are more appropriate for different techniques, such as thermodilution or Fick cardiac output calculation- but will require knowledge of more parameters.
This cardiac output formula is one of the simplest and quickest you can use to estimate cardiac output. If you have the stroke volume, all you will need to do is measure the patient’s heart rate, input the numbers into the formula, do one or two simple calculations, and you will have the cardiac output.
