How to Use This Calculator
- Enter the Ventricular Volume Time Integral (VTI) measurement from your echocardiogram. This represents the area under the ventricular volume curve during one cardiac cycle.
- Input your patient's Heart Rate (measured in beats per minute).
- Select the appropriate Ventricular Type (Left or Right) if the measurement was taken from that specific ventricle.
- Click the Calculate button to compute the estimated cardiac output.
- The calculator will display the estimated cardiac output in liters per minute (L/min).
Understanding VTI
The Volume Time Integral (VTI) is a measure of stroke volume obtained from echocardiography by integrating the area under the ventricular volume curve during one cardiac cycle. It provides an alternative to direct stroke volume measurements when needed.
Clinical Applications
This method is particularly useful in situations where:
- Direct stroke volume measurement is difficult or unavailable
- Cardiac output needs to be estimated quickly
- Serial measurements are needed for trend analysis
- Echocardiographic assessment is the primary imaging modality available
Limitations
While useful, this method has some limitations:
- Accuracy depends on the quality of the echocardiographic images
- May not be accurate in patients with severe valve disease
- Doesn't account for variations in ventricular compliance
- Provides an estimate rather than a direct measurement