From the Guidelines
Left ventricular (LV) mass is assessed in echocardiography using geometric formulas, with the most common method being the American Society of Echocardiography formula: LV mass = 0.8 × {1.04 × [(LVIDd + PWTd + SWTd)³ - (LVIDd)³]} + 0.6g, as recommended by the European Association of Cardiovascular Imaging 1.
Methods for Assessing LV Mass
There are several methods to calculate LV mass, including:
- M-mode echocardiography
- 2D echocardiography
- 3D echocardiography Each method has its advantages and limitations, with 3D echocardiography providing the most accurate assessment of LV mass, especially in abnormally shaped ventricles or in patients with asymmetric hypertrophy 1.
Importance of Accurate Assessment
Accurate assessment of LV mass is crucial for diagnosing left ventricular hypertrophy, which has significant prognostic implications in conditions like hypertension, aortic stenosis, and hypertrophic cardiomyopathy 1.
Normal Values
Normal values for LV mass are <95 g/m² for women and <115 g/m² for men, and values should be indexed to body surface area to account for patient size differences 1.
Clinical Implications
In patients with cardiomyopathies, 2D left and right ventricular dimensions should always be measured, and 3D echocardiography should be preferred for quantifying LV mass in abnormally shaped ventricles or in patients with asymmetric hypertrophy 1. In patients with systemic heart disease, quantitative information on LV diastolic function and LV global longitudinal strain (GLS) should be considered to evaluate early, subclinical changes of systolic function 1.
Recommendations
The most recent and highest quality study recommends using the American Society of Echocardiography formula for calculating LV mass, with 3D echocardiography being the preferred method for accurate assessment in abnormally shaped ventricles or in patients with asymmetric hypertrophy 1.
From the Research
LV Mass Assessment in Echocardiogram
- LV mass can be assessed using M-mode and two-dimensional (2D) echocardiographic algorithms, with the American Society of Echocardiography recommending diastolic area length and truncated ellipsoid methods for estimating LV mass by 2D echocardiography 2.
- The formula used for measurement of M-mode echo-derived LV mass is LV mass = 0.8 (ASE-cube LV mass) + 0.6 gm, while 2D echo-derived LV mass uses the ASE-recommended area length and truncated ellipsoid methods in systole and diastole, with and without incorporating the papillary muscles into the myocardial shell 2.
- Studies have shown that LV mass derived by M-mode echocardiography is comparable to that derived by 2D methods, and it is reasonable to use this technique for normally shaped ventricles 2, 3.
- The biplane Simpson and truncated ellipsoid methods are two established algorithms used to calculate LV mass from 2D echocardiographic measurements, with correlations between M-mode and 2D methods ranging from 0.75 to 0.81 3.
- However, the truncated ellipsoid formula averages approximately 20 gm less than that calculated from the 2D biplane Simpson or M-mode echocardiographic formulas, and these systematic differences must be taken into account when choosing an LV mass algorithm 3.
- The reliability of M-mode and 2D echocardiographic formulas for calculating LV mass has been questioned, with studies showing that these formulas assume a fixed geometric shape, which may be a source of error 4.
- Cardiovascular magnetic resonance images have been used to eliminate the confounding effects of acoustic access and image quality, and have shown that the cube-function and area-length formulas result in significant variation in LV mass estimates from direct measurement using a 3D technique 4.
- Two-dimensional echocardiography is an effective method for determination of LV mass in patients with normal or abnormal LV geometry, with two geometric approaches validated and recommended by the American Society of Echocardiography: an area-length approach and a truncated ellipsoid geometry 5.
- M-mode echocardiography has been widely used in hypertension, where LV geometry is usually normal, and the method of Devereux and Reichek (1977) has been found to correlate best with anatomical LVM 6.