Clinical estimation of left ventricular size: Precordial electrocardiographic voltage corrected by the measurement of thorax.

The left ventricular muscle volume (LVMV) was determined echocardiographically and the radius of the circle with equal circumference to the thorax (R1) was calculated from thorax-circumference in 688 children as a part of the Shimane Heart Study. correlation of the summed precordial voltage (SV1 + RV5) with LVMV was not close (r = 0.377 in boys and -0.095 in girls). The precordial voltage (SV1 + RV5) was corrected by the square of R1 to compensate for the diminution of electrical potential by distance. Correlation between (R1) 2 x (SV1 + RV5) and LVMV was good in boys (r = 0.681) and relatively good in girls (r= 0.554). This fact indicates that LVMV can be predicted from ECG and anthropometric measurements of thorax without using echocardiography. Therefore, (R1) 2 x (SV1 + RV5) seems to have clinical applicability as the index of LV size, if the differences in (R1) 2 x (SV1 + RV5) and in the correlation coefficient between both sexes are clarified further.