Hypertrophic cardiomyopathy (HCM) is characterized by ventricular wall hypertrophy with diastolic dysfunction. Pediatric HCM is distinguished from the adult in many aspects. Most children with HCM do not present clinically until the adolescent period, even when they are born with genetic mutations. Some infants with early-onset HCM present with massive progressive myocardial hypertrophy in the first few months of life, which is often fatal. The mortality of pediatric HCM peaks during the infantile and adolescent periods. These periods roughly correlate with children's growth spurt. Non-sarcomeric causes of HCM are more frequent in pediatric HCM, while sarcomeric causes are more common in adults. From the perspective of cardiac development, the fetal heart has immature cardiomyocytes, which are characterized by proliferation and exit their cell cycles with a decreased regenerative property after birth. In the perinatal period, there is a dynamic change in maturation of cardiomyocytes from immature to mature cells. Infants who are treated with steroids or born to mothers with diabetes or hyperthyroidism often show phenotypes of HCM, which gradually resolve. With remarkable advancement of molecular biology, understanding on maturation of cardiomyocytes has increased. Neonates undergo abrupt environmental changes during the transitional circulation, which is affected by oxygen, metabolic and hormonal fluctuations. Derangement in physiological transition to the normal postnatal environment may influence maturation of proliferative immature cardiomyocytes during early infancy. This article reviews updates of infantile HCM and recent molecular studies related to maturation of cardiomyocytes from the clinical point of view of identifying distinct characteristics of infantile HCM.

中文翻译：

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从心肌细胞成熟的角度看婴儿肥厚性心肌病。

肥厚型心肌病 (HCM) 的特征是心室壁肥厚伴舒张功能障碍。小儿 HCM 在许多方面与成人不同。大多数患有 HCM 的儿童直到青春期才出现临床表现，即使他们出生时就有基因突变。一些早发性 HCM 婴儿在出生后的最初几个月出现大量进行性心肌肥厚，这通常是致命的。儿科 HCM 的死亡率在婴儿期和青少年期达到高峰。这些时期大致与儿童的生长突增有关。HCM 的非肌节原因在儿科 HCM 中更常见，而肌节原因在成人中更常见。从心脏发育的角度来看，胎心有未成熟的心肌细胞，它们的特点是增殖并在出生后以降低的再生特性退出细胞周期。在围产期，心肌细胞的成熟过程是由未成熟细胞向成熟细胞动态变化的。接受类固醇治疗的婴儿或患有糖尿病或甲状腺功能亢进症的母亲所生的婴儿通常会出现 HCM 表型，这些表型会逐渐消退。随着分子生物学的显着进步，对心肌细胞成熟的认识不断增加。新生儿在过渡循环过程中会经历突然的环境变化，这受到氧气、代谢和荷尔蒙波动的影响。向正常出生后环境的生理转变的紊乱可能会影响婴儿早期增殖性未成熟心肌细胞的成熟。