1. What is Stroke Volume Index (SVI)?

Stroke Volume Index (SVI) is a hemodynamic parameter that represents the volume of blood pumped by the left ventricle per beat (stroke volume) normalized to body surface area. It provides a more accurate assessment of cardiac function by accounting for patient size.

2. How Does the Calculator Work?

The calculator uses the SVI formula:

Where:

• \( SV \) — Stroke volume in milliliters (mL)
• \( BSA \) — Body surface area in square meters (m²)

Explanation: The index normalizes stroke volume to body size, allowing for better comparison between patients of different sizes.

3. Importance of SVI Calculation

Details: SVI is important in assessing cardiac performance, especially in critical care settings. It helps evaluate ventricular function and guide fluid management in conditions like heart failure, shock, and after cardiac surgery.

4. Using the Calculator

Tips: Enter stroke volume in mL (typically measured by echocardiography or other cardiac output monitoring) and body surface area in m² (calculated from height and weight). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal SVI range?
A: Normal SVI is typically 33-47 mL/m². Values below 25 mL/m² may indicate significant cardiac dysfunction.

Q2: How is SVI different from stroke volume?
A: While stroke volume is the absolute amount of blood pumped per beat, SVI adjusts this value for body size, making it more comparable across patients.

Q3: When is SVI particularly useful?
A: SVI is especially valuable in pediatric patients, critically ill adults, and when comparing patients of vastly different body sizes.

Q4: How is stroke volume typically measured?
A: Common methods include echocardiography, thermodilution (via pulmonary artery catheter), or pulse contour analysis.

Q5: What factors can affect SVI?
A: Preload, afterload, contractility, heart rate, and valvular function can all influence SVI measurements.