The European Heart Journal has published a review of what happens to the human heart as it ages, noting the cellular effects of mitochondrial dysfunction and cellular senescence along with more visible changes such as hypertrophy and fibrosis.

A constantly working organ

The reviewers begin this paper by noting the constant work of the heart, as it must unceasingly pump blood for us to be able to live. Unfortunately, this organ is well-known to fail with age; while only roughly 1% of people under 55 suffer heart failure, it occurs in over 10% of people over 70 [1].