Figure 2.

A, B) Cardiomyocyte length was best described by bisegmental regression, with increased growth occurring in the neonatal segment (n = 79 fetuses and neonates were studied, of which n = 75 LV and n = 74 RV had binucleated myocytes, and n = 15 had quadrinucleated myocytes in sufficient quantities to measure; at least 100 myocytes were measured per ventricle of each animal). C, D) Cardiomyocyte width was best described by bisegmental regression only in the LV; linear regression best describes myocyte width in the RV. Shown are the best-fit linear regression lines (solid) of each data set and 95% CI (dashed); bars show 95% CI of the breakpoints. Fetal data from Jonker et al. (3). Regression data are included in Tables 1 and 2. bi, binucleate; mono, mononucleate.