What is the Origin of Cardiomyocyte Growth?

The term is a combination of "cardio," from the Greek kardia (heart), and "myocyte," from mys (muscle) and kytos (cell), specifically naming the heart muscle cell. "Growth" denotes the biological process of increasing in size. This terminology is foundational in cardiac physiology and pathology, emphasizing the cell-level dynamics of heart remodeling.

What is the Mechanism of Cardiomyocyte Growth?

Cardiomyocyte growth is regulated by a complex network of intracellular signaling pathways, notably the phosphoinositide 3-kinase (PI3K)/Akt and the mitogen-activated protein kinase (MAPK) cascades. Hormones, binding to specific receptors, activate these pathways, which then influence the expression of genes responsible for protein synthesis and sarcomere assembly, leading to increased cell size. The balance between pro-growth and anti-growth signals, often hormonally mediated, determines whether the cardiac remodeling is adaptive or maladaptive.

Cardiomyocyte Growth ∞ Area

Cardiomyocyte Growth

Meaning

Cardiomyocyte growth refers to the processes of hypertrophy or hyperplasia that lead to an increase in the size or number of the individual muscle cells that constitute the heart tissue, the myocardium. While controlled, physiological growth is necessary for adaptation to exercise, excessive or pathological cardiomyocyte growth contributes to conditions like ventricular hypertrophy, a significant predictor of cardiovascular morbidity. Hormonal signaling, including thyroid and growth factors, plays a pivotal regulatory role in this cellular expansion.