Heart effects of COVID-19: What we know so far:

Heart problems are complex. Therefore, it is not surprising how complex the relationship between the heart and the coronavirus is.

One in four people hospitalized for COVID-19 is said to have heart damage. New research published in Journal of American Universities of Cardiovascular..

so A series of review papers, Researchers have outlined what is known about the effects of COVID-19 on the heart, and why people with heart disease are at increased risk of severe COVID-19.

Here are five important points.

Cardiovascular disease makes you more vulnerable

Studies have shown that cardiovascular disease increases the risk of severe COVID-19 and death in men, over 60 years of age, or in addition to chronic health.

In Australia, cardiovascular disease (a collective term for all diseases that affect the heart and blood vessels) affects 4.2 million people.

If you are infected with COVID-19, cardiovascular disease or its risk factors (high cholesterol, high blood pressure, obesity, diabetes, etc.) are more likely to make you less fate than someone with a “good baseline”. .. Intervention cardiologist Sarah Zaman.

“COVID-19 causes myocardial or heart damage in the majority of patients,” said Dr. Zaman of Monash University.

The body’s ACE2 receptors, to which the SARS-COV-2 virus binds, play an important role in regulating processes such as blood pressure and inflammation, making them especially important for people with heart disease and other cardiovascular risk factors.

“By binding to these receptors [the virus] It can cause many downstream effects that can affect inflammation and arterial contraction, and can cause high blood pressure, “says Dr. Zaman.

“Therefore, those people need to be a little more careful and limit the risk of infection.”

COVID Cardiac Metabolic Syndrome Identified

Recognizing the importance of these individual risk factors, US researchers have identified new COVID-related cardiac metabolic syndrome in patients with high body fat, unstable blood glucose (or diabetes), high cholesterol, and hypertension. ..

Jason Kovacic, a cardiologist and secretary general of the Victor Chan Heart Institute, said he has put together overlapping risk factors into a unified theory of cardiac metabolic health and poor COVID-19 outcomes.

“Cardiac metabolic syndrome has been well explained over the last few decades,” said editor Kovacic. Journal of American Universities of Cardiovascular However, he was not involved in the study.

“These four factors actually seem to intersect and interact throughout COVID-19 … causing worse results.”

According to Professor Kovacic, people with COVID-19 and metabolic and cardiovascular dysfunction are more likely to experience blood clotting and decreased immune function. Obesity can also make breathing difficult when equipped with a ventilator.

“They tend to have poor lung function, and when they enter the ICU, their blood sugar levels are very high. All of this together causes more problems,” he said.

According to researchers, the coronavirus pandemic has revealed unexpected cardiovascular fragility and the need to improve cardiovascular health on a global scale.

For high-risk individuals, especially those with diabetes, they emphasized the importance of maintaining a healthy diet and regular exercise routines.

“The role of healthy lifestyles and drug therapies for metabolic drivers to reduce cardiovascular risk is well established,” the researchers write. “But lessons from the COVID-19 pandemic support the short-term benefits of these interventions.”

Dr. Zaman said he did not know how useful it would be to classify risk factors for cardiac metabolism into the new COVID-19 syndrome, but agreed that the focus should be on improving them in the context of a pandemic.

“If half of the population is obese, diabetic, or hypertensive, infection will make half of the population worse,” she said.

Heart gets caught in COVID crossfire

Although COVID-19 primarily targets the lungs and other parts of the respiratory system, the virus also affects the heart and can worsen the condition of the existing heart.

This is done by causing acute heart damage, heart inflammation, or myocardial damage so that the heart does not function as well.

“The ACE-2 receptor is expressed primarily in the lungs, but also in the heart,” said Dr. Zaman. “COVID-19 can cause direct damage to the heart by the virus actually invading the heart, which is probably a less common mechanism.”

More common is inflammation-related damage to the heart muscle caused by a huge immune response caused by the virus. Professor Kovacic said there is a strong link between inflammation and blood clotting.

“Inflammation can block the blood vessels of the heart, the arteries, and cause a heart attack,” he said.

A heart attack can also occur as a result of damage to the lungs caused by COVID-19. This requires the human heart to work hard to pump blood to the rest of the body.

“COVID-19 reduces the ability of the lungs to oxygenate blood, which increases the demand for the heart because it has to do a lot of work,” Kovacic said.

“The heart is under a lot of stress, but because of the weakened lung capacity, this oxygen is out of balance and can cause a heart attack.”

According to researchers, COVID-19 can also cause microvascular dysfunction (complications of small blood vessels and capillaries of the heart) and stress cardiomyopathy.

“This can occur in the heart under severe stress conditions, including emotional and physical stress, such as being in the ICU bed,” Kovacic said. “It can itself cause myocardial damage or damage.”

All of these factors can cause heart damage in hospitalized COVID-19 patients, according to Professor Kovacic. In other words, it can be difficult to know exactly which mechanism is causing which damage.

“A lot of things are happening.”

The long-term impact is still unknown

In the last few months, the following has become clear: COVID-19 can have protracted effectsMany patients report continuous malaise, shortness of breath, and “brain fog” for weeks or months after infection.

However, data on its effects, especially on the cardiovascular system, are still limited.

“We know that in some patients, heart damage can occur, which can lead to lung scarring … heart damage, and in fact just as it appears. “Other features,” said Professor Kovacic.

“But the long-term complications of COVID-19 … it just takes time to see what happens.”

Although the majority of patients with COVID-19 recover completely, researchers say the long-term risk of survivors of severe COVID-19 remains uncertain and early observations are a concern. Said.

Several studies have found evidence of ongoing cardiac dysfunction in patients with recovered COVID-19.

But Dr. Zaman said it’s hard to tell if “we’re looking for more” because of the unprecedented research efforts directed at the disease.

“I think there’s a bit of prejudice there,” she said.

The effects of COVID-19 on the heart look unique

Even with special care, Dr. Zaman said that the heart damage observed in patients with COVID-19 was higher than that normally seen with other viral infections.

“Influenza has an increase in myocardial infarction (heart attack), but not the degree of injury seen with COVID-19,” she said.

“Several reports from New York and other centers show that myocardial damage is somewhere in 30 to 50 percent of hospitalized patients.

Professor Kovacic said there are several things that made COVID-19 unique in terms of its effects on the heart.

Inflammation was a common feature of almost all infections, but the “severe inflammation” that occurred with COVID-19 was particularly prominent.

“The dramatic activation of blood clotting is also very impressive with COVID-19,” said Professor Kovacic.

“These two factors-blood clotting and severe inflammation together … really make the disease stand out.”