Basic study for computer analysis of the pediatric electrocardiogram: relation of the distance-corrected precordial electrocardiographic voltage with the echocardiographically determined left ventricular muscle volume.

The left ventricular muscle volume (LVMV) and the distance from the anterior chest wall to the middle of the left ventricle (D) were determined echocardiographically in 476 children as a part of the Shimane Heart Study. Correlation of the summed precordial voltage (SV1 + RV5) with LVMV was not good (r = 0.377 in males and -0.095 in females). The precordial voltage (SV1 + RV5), therefore, was corrected by the square of D to compensate the diminution of electrical potential by distance. Correlation between D2 (SV1 + RV5) and LVMV was good in males (r = 0.712) and relatively good in females (r = 0.469). Moreover, the values of D2 (SV1 + RV5) were different between both sexes at the age of 12--16 years. The thickness of subcutaneous fat may be one of the most important factors for these differences in D2 (SV1 + RV5) and correlation coefficient.