Mammals are known for their diverse characteristics and their ability to survive in various environments.

Research has shown that while many mammals share similarities in heart structure and function, humans stand out due to their distinctive heart features when compared to great apes.

Humans and great apes, including chimpanzees, bonobos, orangutans, and gorillas, shared a common ancestor approximately five to six million years ago. As humans evolved to walk upright and developed larger brains, their bodies required increased metabolic energy.

This led to the adaptation of the human heart to support the higher demands of physical activity and brain function.

Research Findings

A study spanning a decade involved examining the cardiovascular systems of great apes worldwide. Through cardiac ultrasound, researchers discovered that the left ventricle of the chimpanzee heart contains trabeculations - muscle bundles arranged in a mesh-like pattern. In contrast, the human heart has a smooth wall in the left ventricle, indicating a significant structural difference.

Further investigation using speckle-tracking echocardiography revealed that humans, with their less trabeculated hearts, exhibit greater twisting and rotation during contraction compared to non-human great apes. This enhanced motion allows the human heart to pump a larger volume of blood per beat, meeting the demands of physical exertion and larger brain size.

Implications for Cardiac Disease

In addition to understanding human heart evolution, research on endangered great apes is crucial due to cardiac disease being a leading cause of death in captive individuals. Great apes do not show signs of coronary artery disease like humans but experience heart muscle thickening, leading to poor contraction and arrhythmia susceptibility.

The cause of this disease remains unknown, prompting the International Primate Heart Project to conduct assessments of great ape cardiovascular physiology globally.

By collaborating with veterinary professionals, valuable data has been generated to enhance the understanding, diagnosis, and management of heart disease in great apes, shedding light on the evolution of the human heart.