How the flu can cause a heart attack or stroke. Doctor: “It can directly infect heart cells”

While most people know that the flu virus can lead to other health complications such as pneumonia, bronchitis and bacterial lung infection, recent research shows that the flu – a common and contagious respiratory illness – can increase the risk of heart attack and stroke.

Flu virus can cause heart attack PHOTO Shutterstock

According to a 7-year research series published in The Journal of Infectious Diseases, it was shown that adults aged 50 and over who had even a mild case of the flu had double the risk of have a heart attack or ischemic stroke (CVA) 2 weeks after contracting the virus, Yahoo Life reports.

That likelihood quadrupled for adults with pre-existing conditions who dealt with a severe case of the flu, with their risk lasting up to 2 months after infection.

One in 8 patients had an acute cardiac event

However, this is not the first time that researchers have discovered this connection. A 2020 study by the Centers for Disease Control and Prevention (CDC) of more than 80,000 adults hospitalized with the flu reported that 1 in 8 patients (nearly 12%) had an acute cardiac event, such as acute heart failure or acute ischemic heart disease.

Also, research published in 2018 in The New England Journal of Medicine found a significant association between the flu and acute myocardial infarction – also known as a heart attack – where adults were 6 times more likely to have an attack of heart disease within a week of contracting the flu.

It can cause inflammation of the heart muscle

What's the link between the flu and serious cardiac events — and how can adults prevent becoming a statistic? Three cardiologists explain.

Infections that seem to affect only one part of the body actually tend to affect multiple parts of the body, Dr. Gregory Katz, assistant professor of medicine in the Leon H. Charney Division of Cardiology at NYU Langone, tells Yahoo Life Health.

Flu can have direct and indirect effects on the heart,” he says. “In terms of direct effects, there is a possibility that the flu virus – or indeed any type of virus – can cause an inflammation of the heart muscle, which is called myocarditis. It can also cause inflammation around the sac (or lining) of the heart, called pericarditis.”

“This stress can lead to a rupture of cholesterol deposits”

Dr. Majid Basit, a cardiologist at Memorial Hermann in Houston, tells Yahoo Life: “In some cases, the flu virus can also directly infect heart cells, leading to weakened heart function and heart failure.”

As for the indirect effects, Katz explains that the immune system is working hard to fight a viral infection, and this response can interfere with the buildup of cholesterol in the arteries. Basit agrees and adds that a flu infection puts the body under enormous stress.

This stress can lead to a breakdown of cholesterol deposits, leading to a heart attack.”continued Basit. “Additionally, there is an increase in inflammation during a disease, which can make cholesterol plaques more prone to rupture. A stroke is like a heart attack with plaque rupture, but occurs in the blood vessels that supply the brain.”

Stress, another risk factor

Blood pressure levels can also be affected — another cardiovascular risk factor that can trigger heart attacks and strokes, says Dr. Jim Liu, a cardiologist at The Ohio State University Wexner Medical Center. “In more severe respiratory infections, oxygen levels can become low and blood pressure can become either too high or too low,” he says.And these fluctuations can also contribute to increased stress on the heart.”

Both age and health also play a vital role in this connection. “People with a weak heart or known heart disease are more likely to have a heart attack during a flu infection.”says Basit.Older people are at even greater risk.”

How you can protect yourself

The statistics are overwhelming: According to the CDC, there were an estimated 25 million to 46 million cases of the flu between October 2023 and February 2024, while heart disease continues to be the leading cause of death for men and women in most racial groups and US ethnicities.

However, the good news is that preventative measures can be taken to help avoid the flu while boosting cardiovascular health. For starters, practicing healthy lifestyle behaviors year-round can be a very effective strategy, says Katz.

“As for what you can do to protect yourself, the answer is to eat well, exercise regularly, not smoke, maintain a healthy weight, reduce stress levels and get good sleep“, he advises. “These strategies are always good because, as a general rule, healthier people who get the flu tend to have a milder course of the disease.

Basit points out that flu is spread through droplets when people cough or sneeze. “Wearing a mask and making sure you wash your hands frequently – especially after touching common areas such as doorknobs – can also help prevent a flu infection.”he says.

At the same time, all three cardiologists encourage vaccination. “One of the most important tips would be to get the annual flu shotl,” says Liu. “In people with cardiovascular disease or at increased risk of cardiovascular disease, the flu vaccine has been shown to help reduce the risk of serious cardiovascular complications from the flu.