HSPB6 and heart failure: Accumulating evidence suggests that slight elevation of cardiomyocyte apoptosis can cause depressed cardiac contractility and heart failure upon pregnancy.9, 10, 24 To investigate the effects of the S10F‐Hsp20 human mutation on apoptosis, cardiomyocyte survival in female mutant hearts was assessed under non‐pregnant and post‐partum conditions, using TUNEL staining, with NTGs as controls.