Table 3.

Number of cardiomyocytes and interstitial cells in human ageing heart (atria) (mean ± SD)

Number/mm2	Newborns	Children	Adults
Cardiomyocytes	11,223 ± 2460	28,567 ± 5920*	24,817 ± 3260*,†
Endothelial cells	1930 ± 140	2340 ± 280*	2170 ± 210*
Vascular smooth muscle cells & pericytes	1014 ± 11	958 ± 10‡	896 ± 12†,‡
Schwann cells	261 ± 78	271 ± 89	280 ± 73*
Fibroblasts	241 ± 50	112 ± 11‡	438 ± 56*,§
Macrophages	125 ± 12	53 ± 7‡	350 ± 17*,§
Telocytes	22 ± 2	27 ± 4‡	19 ± 3†,‡
Putative stem cells	17 ± 3	7 ± 1‡	4 ± 1†,‡

^*The number of cells significantly increased in children and adults compared with newborns (P < 0.01).

^†The number of cells significantly decreased in adults compared with children (P < 0.02).

^‡The number of cells significantly decreased in children and adults compared with newborn group (P < 0.01).

^§The number of cells significantly increased in adults compared with children (P < 0.001).