Normal Left Ventricular Internal Dimension at Diastole (LVIDD) on Echocardiography
The normal LVIDD on echocardiography ranges from 42.0-58.4 mm in men and 37.8-52.2 mm in women, with mean values of 50.2 mm for men and 45.0 mm for women. 1
Gender-Specific Normal Values
Left ventricular internal dimension at diastole (LVIDD) is a fundamental measurement in echocardiographic assessment of cardiac structure and function. According to the American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) guidelines, normal values differ significantly between genders:
Men:
- Mean: 50.2 ± 4.1 mm
- Normal range (mean ± 2SD): 42.0-58.4 mm
Women:
- Mean: 45.0 ± 3.6 mm
- Normal range (mean ± 2SD): 37.8-52.2 mm 1
Measurement Technique
The measurement of LVIDD should be performed using specific techniques to ensure accuracy:
- Ideally measured from 2D-guided images rather than M-mode alone
- Taken from the parasternal long-axis acoustic window
- Measured at the level of the LV minor axis, approximately at the mitral valve leaflet tips
- The cursor should be perpendicular to the long axis of the ventricle 1
Indexed Values
For more accurate assessment, LVIDD should be indexed to body surface area (BSA):
- Normal indexed LVIDD: approximately 2.7 ± 0.2 cm/m² 2
- Indexing to BSA helps account for variations in body size
Measurement Considerations and Pitfalls
Several factors can affect LVIDD measurement accuracy:
- Alignment issues: Improper alignment of the M-mode cursor can lead to inaccurate measurements
- Image quality: Suboptimal acoustic windows may compromise measurement accuracy
- Measurement convention: The current ASE/EACVI guidelines recommend measuring the actual visualized thickness defined by the tissue-blood interface 1
- Age-related changes: LVIDD tends to be lower with increasing age 3
Clinical Implications
LVIDD is a critical measurement used in various clinical assessments:
- Evaluation of LV remodeling and hypertrophy
- Calculation of LV mass using the formula: LVM = 0.8 × {1.04[(LVIDd + PW + IVSd)³ - (LVIDd)³]} + 0.6 g 1
- Assessment of relative wall thickness (RWT) using the formula: (2 × posterior wall thickness)/LVIDD 1
- Classification of LV geometry (normal, concentric remodeling, eccentric or concentric hypertrophy)
Advanced Imaging Considerations
While linear measurements like LVIDD remain standard practice, newer techniques offer additional advantages:
- 3D echocardiography provides more accurate volume measurements without geometric assumptions
- Volumetric measurements may better represent LV size than linear dimensions at the base
- When available, 3D measurements should be considered as complementary to standard linear measurements 1, 4
Remember that proper measurement technique is essential for accurate assessment, and measurements should be interpreted in the context of the patient's body size, age, and gender.