What are the normal values for heart valve measurements on echocardiogram (echo)?

Normal Values for Heart Valve Measurements on Echocardiography

Normal heart valve measurements on echocardiography are essential for accurate assessment of valve function, with specific reference ranges established for different valve types, sizes, and patient characteristics. 1, 2

General Considerations for Valve Assessment

• Echo reports should include normal reference values to differentiate normal from pathological conditions 1
• Measurements should be indexed to body surface area (BSA) for accurate interpretation, especially for valve areas 1, 2
• Quality of imaging, machine type/vendor, and patient's blood pressure and heart rhythm should be documented as these factors affect measurements 1, 2

Aortic Valve Normal Values

Aortic Valve Area (AVA)

• Normal AVA: >1.5 cm² 1
• Normal indexed AVA: >0.85 cm²/m² 1
• Normal velocity ratio: >0.50 1

Aortic Valve Hemodynamics

• Normal peak velocity: ≤2.5 m/s 1
• Normal mean gradient: <20 mmHg 1
• Normal pressure half-time: >500 ms 1

Prosthetic Aortic Valve

• Normal peak velocity: <3 m/s 1
• Normal mean gradient: <20 mmHg 1
• Normal acceleration time: <80 ms 1
• Normal acceleration time/LV ejection time ratio: <0.32 1
• Normal effective orifice area (EOA): >1.1 cm² 1
• Normal Doppler velocity index: ≥0.35 1

Mitral Valve Normal Values

Mitral Valve Hemodynamics

• Normal pressure half-time: <130 ms 1
• Normal peak velocity: <1.9 m/s 1
• Normal mean gradient: ≤5 mmHg 1

Prosthetic Mitral Valve

• Normal effective orifice area: ≥2 cm² 1
• Normal Doppler velocity index: <2.2 1
• Normal indexed EOA: >1.2 cm²/m² for BMI <30 kg/m² and >1.0 cm²/m² for BMI ≥30 kg/m² 1

Pulmonary Valve Normal Values

• Normal pulmonary valve area index: 1.70 cm²/m² 3
• Pulmonary valve assessment is more challenging due to limited acoustic access 1

Advanced Echocardiographic Parameters

• Left ventricular global longitudinal strain (GLS): >20% (absolute value) 1, 2
• Right ventricular free wall GLS: >23% (absolute value) 1, 2
• 3D EDV index: <80 mL/m² (males), <72 mL/m² (females) 1
• 3D ESV index: <33 mL/m² (males), <29 mL/m² (females) 1
• 3D LVEF: >54% (males), >57% (females) 1, 2

Important Considerations and Pitfalls

• Sex-specific differences exist in normal valve measurements, with women generally having smaller valve areas even after indexing to BSA 4
• Age-related changes in valve measurements should be considered, as older subjects tend to have smaller LVOT diameters and AVAs 4
• Racial differences exist in normal valve measurements, with Asians having lower LVOT diameter and AVA compared to whites and blacks 4
• Significant discrepancies (up to 30%) can exist between catheter-based and echocardiographic measurements of valve areas 5
• Serial assessments should be performed using the same vendor's equipment due to intervendor variability 2
• Flow-dependent parameters (like peak velocity and mean gradient) can be misleading in low-flow states 1

Prosthetic Valve Considerations

• Normal reference values for prosthetic valves vary by valve type, size, and position 1
• Prosthetic valve assessment should include both structural evaluation and hemodynamic parameters 1
• Patient-prosthesis mismatch should be considered when evaluating prosthetic valve function 1

By understanding these normal values and their variations based on patient characteristics, clinicians can more accurately identify valve pathology and guide appropriate management decisions.