Gorlin Formula Calculator
Calculate aortic and mitral valve areas using the Gorlin formula for cardiac valve assessment
Hemodynamic Parameters
Normal range: 4-8 L/min at rest
Normal range: 60-100 bpm at rest
Aortic Valve Assessment
Mitral Valve Assessment
Example Calculation
Aortic Valve Assessment Example
Cardiac Output: 5.5 L/min
Heart Rate: 75 bpm
Mean Pressure Gradient: 15 mmHg
Systolic Ejection Period: 0.25 sec/beat
Calculation Steps
1. Convert CO: 5.5 L/min = 5500 ml/min
2. Apply Gorlin formula: AVA = 5500 / (44.3 × 75 × 0.25 × √15)
3. Calculate: AVA = 5500 / (44.3 × 75 × 0.25 × 3.87) = 1.7 cm²
Result: Mild Aortic Stenosis
Aortic Stenosis Grading
Normal
AVA: 3-4 cm²
Normal function
Mild
AVA: 1.5-3 cm²
Gradient: 10-19 mmHg
Moderate
AVA: 1-1.5 cm²
Gradient: 20-39 mmHg
Severe
AVA: < 1 cm²
Gradient: ≥ 40 mmHg
Mitral Stenosis Grading
Normal
MVA: 4-6 cm²
Normal function
Mild
MVA: 1.5-4 cm²
Gradient: < 5 mmHg
Moderate
MVA: 1-1.5 cm²
Gradient: 5-10 mmHg
Severe
MVA: < 1 cm²
Gradient: > 10 mmHg
Clinical Tips
Gorlin formula may underestimate AVA in low-flow states (CO < 2.5 L/min)
Consider continuity equation for aortic valve in low-flow conditions
Measure SEP and DFP accurately for reliable results
Correlate with clinical symptoms and other imaging findings
Understanding the Gorlin Formula
What is the Gorlin Formula?
The Gorlin formula is a mathematical equation used to calculate cardiac valve areas indirectly from hemodynamic measurements. It's particularly useful for assessing the severity of valve stenosis when direct measurement is not possible.
Clinical Applications
- •Assessment of aortic stenosis severity
- •Evaluation of mitral stenosis
- •Planning for valve intervention
- •Monitoring disease progression
Formula Details
AVA = CO / (44.3 × HR × SEP × √ΔP)
MVA = CO / (37.7 × HR × DFP × √ΔP)
- AVA/MVA: Aortic/Mitral valve area (cm²)
- CO: Cardiac output (ml/min)
- HR: Heart rate (bpm)
- SEP: Systolic ejection period (sec/beat)
- DFP: Diastolic filling period (sec/beat)
- ΔP: Mean pressure gradient (mmHg)
Note: The constants 44.3 and 37.7 are empirically derived correction factors specific to aortic and mitral valves respectively.
Clinical Considerations
Limitations
May underestimate valve area in low-flow states or irregular rhythms. Requires accurate hemodynamic measurements.
Advantages
Non-invasive assessment possible with echocardiography. Well-validated for stenosis grading.
Best Practice
Always correlate with clinical symptoms, physical examination, and other imaging modalities.
Related Cardiovascular Calculators
Important Medical Disclaimer
This Gorlin Formula calculator is designed for educational purposes and clinical reference only. It should never replace professional medical judgment or comprehensive cardiac assessment.
Healthcare professionals should:
- Correlate results with complete echocardiographic evaluation
- Consider clinical symptoms and physical examination findings
- Follow current guidelines for valve disease management (AHA/ACC, ESC)
- Verify hemodynamic measurements and calculation accuracy
- Consider alternative assessment methods in low-flow conditions
Patients should always consult with qualified cardiologists or cardiac surgeons for diagnosis, treatment recommendations, and medical decisions regarding valve disease.