Musings on intrinsic cardiomyocyte cell cycle activity and myocardial regeneration

Although the myocardial renewal rate in the adult mammalian heart is quite low, recent studies have identified genetic variants which can impact the degree of cardiomyocyte cell cycle reentry. Here we use the compound interest law to model the level of regenerative growth over time in mice exhibiting different rates of cardiomyocyte cell cycle reentry following myocardial injury. The modeling suggests that the limited ability of S-phase adult cardiomyocytes to progress through cytokinesis, rather than the ability to reenter the cell cycle per se, is a major contributor to the low levels of intrinsic regenerative growth in the adult myocardium. •The intrinsic rate of cardiomyocyte renewal in the adult mammalian heart is low.•Recent studies identified genetic variants which impact cardiomyocyte cell cycle entry in mice post-injury.•Modeling suggests meaningful regeneration in some variants if the cardiomyocytes enerting the cell cycle would divide.