Left Ventricular Myocardial Mass and LVH: Calculation of LVMI, Normal Thresholds, and Relative Wall Thickness
Calculation of Left Ventricular Myocardial Mass
The left ventricular myocardial mass should be calculated strictly using the linear method, not in 2D mode. According to the Penn convention, the Devereux formula is applied:
LV mass = 1.04 × [(STd + PWTd + LVIDd)³ − LVIDd³] − 13.6,
where STd is the interventricular septal thickness in diastole, PWTd is the posterior wall thickness of the LV in diastole, and LVIDd is the left ventricular internal diameter in diastole. Approximate myocardial mass values are about 99 g for women and about 135 g for men.
Linear dimensions are measured perpendicular to the heart structures just beyond the ends of the mitral valve leaflets, placing calipers at the interfaces of "wall–cavity" and "wall–pericardium" (ASE Guidelines, J Am Soc Echocardiogr 2015;28:1-39). The ASE/EACVI 2015 update emphasizes measuring linear dimensions in 2D mode without relying on M-mode due to oblique angles in one-dimensional images.
Left Ventricular Mass Index (LVMI) and LVH Thresholds
The main parameter used is the left ventricular mass index (myocardial mass / body surface area). All three communities (American guidelines 2015, joint American-European 2015, ESC 2018) provide the same upper limit of normal:
| Gender | Upper Limit of LVMI (g/m²) |
|---|---|
| Women | ≤ 95 |
| Men | ≤ 115 |
Exceeding these values allows for the diagnosis of left ventricular hypertrophy.
Indexation to Height²·⁷
The joint ASE and European Society 2015 recommendations for examining patients with hypertension include an additional parameter of indexation to height raised to the power of 2.7, as well as indexation simply to height without the power. Indexation to height²·⁷ is also included in the European Society of Cardiology 2018 guidelines with the following thresholds:
| Gender | Upper Limit (g/height²·⁷) |
|---|---|
| Women | ≤ 47 |
| Men | ≤ 50 |
This parameter (indexation to height²·⁷) is not recommended by the North American and European associations for chamber quantification — it is only present in the ESC 2018 edition.
Relative Wall Thickness
Normally, the interventricular septum (IVS) and the inferolateral wall (LVPW) are equal in thickness (ratio 1:1), thicker than the right ventricular walls, and concentrically contract in systole. Approximate diastolic thickness values of the IVS are 6–9 mm for women and 6–10 mm for men. Specific threshold values for relative wall thickness to differentiate concentric and eccentric remodeling [to be specified].
A sigmoid interventricular septum with thickening of the basal segment is a normal finding in older patients.
Correction in Obese Patients
In individuals with obesity, elevated blood pressure is accompanied by remodeling, but standard assessment may "miss" hypertrophy. It is recommended to calculate an individual correction factor — the ratio of actual body surface area to ideal. Example: actual BSA 1.63 / ideal 1.37 = factor 1.19. This factor is used to multiply linear dimensions and wall thickness. Thus, IVS thickness 11 mm × 1.19 = 13 mm — the corrected value is already considered as myocardial thickening of the LV. Similarly, myocardial mass, EDV, and LA volume are corrected. Indexation to ideal rather than actual BSA significantly changes ranges and more accurately reflects the risk of adverse outcomes.
Frequently asked questions
What method should be used to calculate LV myocardial mass?
Strictly the linear method (Devereux formula, Penn convention) based on IVSd, PWTd, and LVIDd, not in 2D mode.
What are the LVMI thresholds for diagnosing LVH?
The upper limit of normal is the same in all three guidelines: ≤95 g/m² for women and ≤115 g/m² for men; exceeding these values indicates LVH.
How does indexation to height²·⁷ differ according to ESC 2018?
According to ESC 2018, the upper limit is ≤47 g/height²·⁷ for women and ≤50 g/height²·⁷ for men. This parameter is not recommended by North American and European associations.
How to assess myocardial mass in an obese patient?
Use an individual correction factor — the ratio of actual BSA to ideal, multiplying dimensions, wall thickness, and myocardial mass by it to apply standard ranges.
What is the normal ratio of IVS to posterior wall thickness?
Normally, the interventricular septum and the inferolateral wall are equal in thickness (ratio 1:1) and concentrically contract in systole.