Jun 20, 2021 12:00:00

Why are non-human animals less prone to heart attacks?

Heart attacks, which result from the loss of blood flow to the heart and the inability to deliver enough oxygen to cardiomyocytes, kill many people each year. However, it is known that non-human animals are less likely to have a heart attack, and the scientific media Live Science has summarized the question 'Why are non-human animals less likely to have a heart attack?' I will.

Do other animals get heart attacks? | Live Science
https://www.livescience.com/do-animals-get-heart-attacks.html

In the United States, one person suffers a heart attack every 40 seconds, and it is estimated that as many as 805,000 Americans have a heart attack each year. According to Professor Flavio Fenton, who studies the human and animal hearts at the Shojia Institute of Technology, a heart attack is caused by the blockage of blood vessels that supply oxygenated blood and the death of part of the heart tissue. When one part of the heart dies, it cannot contract well, and the electrical signals that cause the heart to contract are not transmitted well to other parts, which can result in the heart stopping and dying. “The hearts of all mammals are very similar, so many mammals can, in principle, have a heart attack,” Fenton said.

However, although theoretically speaking, many mammals can have a heart attack, it is extremely rare for non-human animals to actually have a heart attack. 'In general, animals don't die naturally from a typical human-like heart attack caused by a blockage in the coronary arteries ,' Philip Gordts, an assistant professor of heart disease at the University of California, San Diego, told Live Science. I told you.

For example, dog heart attacks are rare, and they are one of the closest animals to humans, and even captive chimpanzees with heart attack conditions such as lack of exercise and high cholesterol are less likely to have a heart attack. Was reported in a 2009 paper. In addition, rabbits and rodents, which have genes that easily accumulate fat and cholesterol in blood vessels and are prone to develop atherosclerosis , which is the main cause of heart attack in humans, are also less likely to have a heart attack. Is pointed out in the same paper.

'It may make more sense to ask why humans are more likely to have a heart attack than to ask why other animals do not have a heart attack,' Live Science said.

Risk factors for a heart attack include lack of exercise and an unhealthy diet, but studies have shown that 15% of people who have a heart attack for the first time do not have a risk factor for a heart attack. ..

In a study published in 2019 by Gordts and colleagues, a human-specific gene mutation that inactivates the 'CMAH gene ' involved in the production of N-glycolylneuraminic acid (Neu5Gc) is a major factor in heart attacks. It has been pointed out that it may be involved. When the research team inactivated the CMAH gene in mice genetically edited to develop atherosclerosis, they developed atherosclerosis twice as much as mice that did not inactivate the CMAH gene. It is said that it has become easier to develop. The results suggest that inactivation of the CMAH gene may be the cause of atherosclerosis and heart attack in humans.

However, there is little research on whether animals other than humans have a heart attack in the first place. 'We sometimes see animals die suddenly, but we rarely do visual inspections to look for blockages in the coronary arteries,' said Tomasz Owerkowicz, a comparative vertebrate physiologist at California State University. He states that it is difficult to know if non-human animals actually have a heart attack.

Still, researchers can predict 'which animals are likely to have a heart attack' based on the structure of the heart. For example, the heart of mammals and birds has only the coronary arteries as the source of oxygen, and oxygen is sent from the coronary arteries to the heart tissue through blood vessels and capillaries. Therefore, if the coronary arteries are blocked by mammals or birds, oxygen may be lost and a heart attack may occur.

On the other hand, some vertebrates, including crocodile, have spongy heart tissue in addition to blood vessels and capillaries, which can supply oxygenated blood deep into the heart by routes other than blood vessels. That's right. The system could act as a buffer when the coronary arteries are blocked, and vertebrates such as crocodiles will be less likely to have a heart attack than mammals and birds, Owerkowicz said.

In addition, research results have been reported that humans who have a habit of taking a nap or who take a bath every day have a reduced risk of heart attack, and having a dog may reduce the risk of death from heart attack. Sex is also pointed out.

Research results that 'keeping a dog reduces the risk of death from heart attack and stroke' --GIGAZINE