Cardiac Index Calculator
Calculate cardiac index to assess heart function normalized for body size
Calculate Cardiac Index
⚠️ Medical Disclaimer: This calculator is for educational purposes only and should not replace professional medical assessment. Always consult with a cardiologist or qualified healthcare provider for proper interpretation of cardiac function and hemodynamic parameters.
Normal range: 4.0-8.0 L/min for adults
Patient's height for BSA calculation
Patient's weight for BSA calculation
Example Calculation
Example Patient
Stroke Volume: 70 mL
Heart Rate: 64 bpm
Height: 169 cm
Weight: 71 kg
Cardiac Output: 70 × 64 = 4,480 mL/min = 4.48 L/min
BSA: 0.024265 × 169^0.3964 × 71^0.5378 = 1.835 m²
Cardiac Index: 4.48 / 1.835 = 2.44 L/min/m²
Result: Normal cardiac function
CI Reference Ranges
Units: L/min/m² (liters per minute per square meter)
Clinical Applications
ICU Monitoring
Critical care hemodynamic assessment
Cardiac Care
Heart failure and shock evaluation
Therapy Guidance
Inotrope and fluid management
Research
Cardiovascular studies and trials
Factors Affecting CI
Heart failure, cardiogenic shock, severe valve disease
Hyperdynamic states, sepsis, hyperthyroidism
Medications: inotropes, vasodilators, beta-blockers
Age, fitness level, pregnancy, anxiety
Understanding Cardiac Index
What is Cardiac Index?
Cardiac Index (CI) is a hemodynamic parameter that measures the heart's pumping efficiency normalized for body size. It's calculated by dividing cardiac output by body surface area, providing a more accurate assessment than cardiac output alone, especially when comparing patients of different sizes.
Clinical Significance
- •Assesses adequacy of tissue perfusion
- •Guides therapeutic interventions in critical care
- •Monitors response to treatment
- •Prognostic indicator in heart failure
Calculation Methods
CI = CO / BSA
Cardiac Output (CO)
CO = Stroke Volume × Heart Rate
Body Surface Area (BSA)
Haycock formula: 0.024265 × height^0.3964 × weight^0.5378
Measurement Methods
- •Thermodilution (Swan-Ganz catheter)
- •Echocardiography (Doppler method)
- •Impedance cardiography
- •Pulse contour analysis
Normal Cardiac Index Values
| Population | Normal Range (L/min/m²) | Notes |
|---|---|---|
| Adults (18-65 years) | 2.5 - 4.0 | Standard reference range |
| Elderly (>65 years) | 2.2 - 3.5 | Age-related decline |
| Athletes | 3.0 - 5.0 | Enhanced cardiac function |
| Pregnancy | 3.5 - 6.0 | Physiological increase |