ABSTRACT

Growth of the heart can be induced by physiological stimuli (e.g. postnatal development, chronic exercise training) or pathological stimuli (e.g. pressure or volume overload). Physiological cardiac hypertrophy is characterized by a normal organization of cardiac structure, normal or enhanced cardiac function, and a relatively normal pattern of cardiac gene expression; whereas pathological hypertrophy is associated with an altered pattern of cardiac gene expression, fibrosis, cardiac dysfunction, and increased morbidity and mortality. An unresolved question in cardiac biology has been whether distinct signaling pathways are responsible for the development of pathological and physiological cardiac hypertrophy. Recent studies have suggested that some signaling pathways play unique roles in the regulation of pathological and physiological cardiac hypertrophy. Furthermore, inhibiting pathological cardiac growth while stimulating physiological growth could have therapeutic value in the setting of heart disease.