The heart is electrically and mechanically controlled as a syncytium by the autonomic nervous system. The cardiac nervous system comprises the sympathetic, parasympathetic, and sensory nervous systems ...

The human heart is composed of 5 major cell types: cardiomyocytes, fibroblasts, endothelial cells, macrophages, and smooth muscle cells. 14, 15, 16 Cardiomyocytes contribute roughly 30% to 40% by ...