LV Mass and LVH Experimental

PHN 2D LV mass and wall Z scores (Lopez 2017, Table 2)

LVEDV    = 5/6 × LVEDA × LVEDL               (ml; cm² × cm)
LVEDVEPI = 5/6 × LVEDAEPI × LVEDLEPI
LVM      = 1.05 × (LVEDVEPI − LVEDV)          (g)
Z = (value / BSA^α − mean) / SD,  BSA = Haycock

            α     mean     SD
LVM        1.25   53.02    9.06
LVEDV      1.30   62.02   11.94
LVEDVEPI   1.30  113.14   17.85
LVMTV      0      0.88     0.16   (LVM / LVEDV, g/ml; not BSA-indexed)
LVST       0.40   0.58     0.09   (cm)
LVPWT      0.40   0.57     0.09   (cm)
LVEDD      0.45   3.89     0.33   (cm)
LVTTD      0      0.15     0.03   (LVPWT / LVEDD)

Coefficients verbatim from Lopez 2017 Table 2 (PMC5812349). The test suite matches ParameterZ's PHN calculator for LV mass, volumes, walls and ratios to 10⁻⁶. PHN measured walls and diameters on 2D short-axis images, not M-mode. Population: healthy, non-obese, term children aged 18 years or younger. PHN chose BSA over height for LV mass and excluded obese children, so in obesity a BSA-based Z score can understate hypertrophy.

M-mode LV mass and index

LVM (g)  = 0.8 × 1.04 × [(IVSd + LVIDd + LVPWd)³ − LVIDd³] + 0.6     (cm)
LVMI     = LVM / height[m]^2.7                                  (g/m^2.7)

The factor 0.8 and the +0.6 g are quoted from the Devereux 1986 abstract (“LV mass = 0.80 (ASE-cube LV mass) + 0.6 g”). The ASE-cube term 1.04 × [(IVSd + LVIDd + LVPWd)³ − LVIDd³] was not read in the Devereux full text. It is printed in open-access Schoenmaker 2013 and reproduces ParameterZ’s “ASE convention” result: 113.6 g and 38.0 g/m^2.7 for 0.8 / 4.5 / 0.8 cm at 150 cm, a value that is in the tests.

Khoury 2009 cutoffs

From the abstract (M-mode, 2273 non-obese healthy children aged 0 to 18 years, Cincinnati): “For patients aged > 9 years, quantiles of LVM/height^2.7 vary little, and values > 40 g/m^2.7 in girls and > 45 g/m^2.7 in boys can be considered abnormal (ie, > 95th percentile).” Under 9 years the index varies with age, and the 95th percentile ranges from 80 g/m^2.7 in newborns to 40 g/m^2.7 at 11 years. This page applies only the over-9 cutoffs: above 9 years, the cutoff for the entered sex; not above 18.

Omitted: the age-specific percentile curves are in the paper’s figure and table, which are not openly available, so no percentile is shown at 9 years or younger. Those age-specific values can be lower than the simplified cutoffs. ParameterZ’s Khoury upper limit for a 12-year-old is 39.8 g/m^2.7 for a boy and 37.0 for a girl [unverified against the paper], so a value under 45 or 40 does not exclude LVH. See ParameterZ LV mass (legacy, unmaintained) for age-specific values. The AAP 2017 hypertension guideline’s LVH definitions were not retrieved and are not shown.

References

• Lopez L, Colan S, Stylianou M, et al. Circ Cardiovasc Imaging 2017;10(11):e006979. doi:10.1161/CIRCIMAGING.117.006979
• Khoury PR, Mitsnefes M, Daniels SR, Kimball TR. Age-specific reference intervals for indexed left ventricular mass in children. J Am Soc Echocardiogr 2009;22(6):709-714. doi:10.1016/j.echo.2009.03.003
• Devereux RB, Alonso DR, Lutas EM, et al. Echocardiographic assessment of left ventricular hypertrophy: comparison to necropsy findings. Am J Cardiol 1986;57(6):450-458. doi:10.1016/0002-9149(86)90771-x
• Schoenmaker NJ, van der Lee JH, Groothoff JW, et al. Low agreement between cardiologists diagnosing left ventricular hypertrophy in children with end-stage renal disease. BMC Nephrol 2013;14:170. doi:10.1186/1471-2369-14-170
• Haycock GB, Schwartz GJ, Wisotsky DH. J Pediatr 1978;93(1):62-66. doi:10.1016/S0022-3476(78)80601-5