成年人心脏中的心肌细胞是静止的，心脏损伤后丢失的心肌细胞不会被增殖的幸存者所取代。人们付出了大量努力来了解心肌细胞细胞周期退出和重新进入的机制，以期发现可以刺激心肌细胞增殖和心脏再生的治疗方法。大型化合物库和机器人液体处理平台的出现使得能够在一次实验中筛选数千种条件，但这些筛选的成功取决于所用模型的适当性和质量。高通量定量（人）心肌细胞增殖仍然存在问题，因为传统的基于抗体的染色成本高昂，技术上具有挑战性，并且不能区分心肌细胞分裂和核分裂或胞质分裂的失败。活细胞成像提供了促进高通量筛选的替代方案，但它们还有其他局限性。在这里，我们（i）回顾心肌细胞的细胞周期特征，（ii）讨论各种细胞周期荧光报告系统，以及（iii）推测什么可以提高它们在心肌细胞增殖背景下的预测价值。最后，我们考虑如何将这些新方法与最先进的三维人类心脏类器官平台结合使用，以确定可以刺激人类心脏再生的促增殖信号通路。

Cardiomyocytes in the adult human heart are quiescent and those lost following heart injury are not replaced by proliferating survivors. Considerable effort has been made to understand the mechanisms underlying cardiomyocyte cell cycle exit and re-entry, with view to discovering therapeutics that could stimulate cardiomyocyte proliferation and heart regeneration. The advent of large compound libraries and robotic liquid handling platforms has enabled the screening of thousands of conditions in a single experiment but success of these screens depends on the appropriateness and quality of the model used. Quantification of (human) cardiomyocyte proliferation in high throughput has remained problematic because conventional antibody-based staining is costly, technically challenging and does not discriminate between cardiomyocyte division and failure in karyokinesis or cytokinesis. Live cell imaging has provided alternatives that facilitate high-throughput screening but these have other limitations. Here, we (i) review the cell cycle features of cardiomyocytes, (ii) discuss various cell cycle fluorescent reporter systems, and (iii) speculate on what could improve their predictive value in the context of cardiomyocyte proliferation. Finally, we consider how these new methods can be used in combination with state-of-the-art three-dimensional human cardiac organoid platforms to identify pro-proliferative signalling pathways that could stimulate regeneration of the human heart.