Cardiac Output Vti Calculator American Heart Association

Cardiac Output Formula:

\[ CO = \frac{VTI \times Area \times Heart\ Rate}{1000} \]

Cardiac Output (CO):

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1. What is Cardiac Output?

Cardiac output (CO) is the volume of blood the heart pumps per minute. It is a crucial hemodynamic parameter that indicates how well the heart is functioning and delivering oxygen to tissues throughout the body.

2. How Does the Calculator Work?

The calculator uses the American Heart Association recommended formula:

\[ CO = \frac{VTI \times Area \times Heart\ Rate}{1000} \]

Where:

\( VTI \) — Velocity Time Integral (cm)
\( Area \) — Cross-sectional area of the outflow tract (cm²)
\( Heart\ Rate \) — Heart rate in beats per minute (bpm)

Explanation: This formula calculates cardiac output by multiplying stroke volume (VTI × Area) by heart rate, then dividing by 1000 to convert from mL/min to L/min.

3. Importance of Cardiac Output Measurement

Details: Cardiac output measurement is essential for assessing cardiac function, guiding treatment in heart failure, shock, and critical care settings, and evaluating response to cardiovascular medications and interventions.

4. Using the Calculator

Tips: Enter VTI in centimeters, cross-sectional area in square centimeters, and heart rate in beats per minute. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal cardiac output value?
A: Normal cardiac output ranges from 4-8 L/min in adults at rest, but varies based on body size, age, and metabolic demands.

Q2: How is VTI measured?
A: VTI is typically measured using Doppler echocardiography by tracing the spectral Doppler envelope of blood flow across a heart valve.

Q3: What are common sites for measuring cross-sectional area?
A: The left ventricular outflow tract (LVOT) is most commonly used, but measurements can also be taken at other valves depending on the clinical scenario.

Q4: Are there limitations to this calculation method?
A: Accuracy depends on precise measurement technique, assumes circular geometry, and may be affected by arrhythmias or valvular abnormalities.

Q5: When is cardiac output measurement most important?
A: It's crucial in critical care settings, during heart failure management, perioperatively, and when assessing response to inotropic or vasoactive medications.