Influenza and H1N1 Bad for Your Heart
If you haven't gotten your flu shot yet, what are you waiting for? The hour or so it would take is nothing compared with the time you might spend fighting the flu or something worse - like recovering from the heart attack it could trigger.

As of early October 2009, much of the focus has been on swine flu (more formally called H1N1 flu). That's understandable. H1N1 is new, and no one knows how much damage it will cause. But the "regular" flu isn't something to sneeze at. Seasonal flu kills about 36,000 people each year in the United States, hospitalizes more than 200,000, and costs us more than $10 billion in direct medical expenses and lost productivity.

Seasonal flu and H1N1 flu are different in some ways and similar in others. One of the similarities is that both may be hard on the heart. Getting vaccinated against seasonal flu and swine flu is good insurance for your health and heart.


Infections of any kind can affect the heart and circulatory system. Influenza (the flu) is no different. It can make breathing difficult, boost blood pressure, make the heart beat faster, and rev up inflammation. All of these force the heart to work harder. A healthy heart usually weathers these changes without a problem; a damaged or weakened heart may not. Infection can also cause a vulnerable, cholesterol-filled plaque inside a coronary artery to break apart. The blood clot that forms to seal the break can block the artery, causing a heart attack or sudden death.

Over the years, a number of studies have linked flu with cardiovascular problems. An analysis of 39 studies showed consistent connections between influenza and heart attack or cardiovascular-related death (Lancet Infectious Diseases, October 2009).

There's no reason to believe that the H1N1 flu will be any less hazardous to the heart, and some experts worry it could be even more devastating. At the 2009 European Society of Cardiology meeting in Barcelona, top cardiologists warned that swine flu and heart disease could be a deadly mix. Although most people with heart disease are over age 60 -- a group that seems to be less susceptible to the H1N1 virus -- there could be major complications for those who do catch it.

One reason is that H1N1 flu tends to infect the lungs rather than the upper airway, as is more common with seasonal flu. The accumulation of fluid coupled with flu-related breathing problems could severely stress individuals with heart failure, many of whom already have fluid buildup in the lungs.


If you come down with flulike symptoms - a sore throat, fever or chills, headache or muscle aches, extreme tiredness, nausea, vomiting, or diarrhea -- there's no simple way to tell if you have seasonal flu or swine (H1N1) flu. A laboratory test for the H1N1 virus is the only sure way to tell the difference.

Most otherwise healthy folks recover fully from seasonal flu or H1N1 with rest, staying hydrated, and some ibuprofen or acetaminophen to help with pain or fever. Some people, though, will need antiviral medications or hospitalization. Seek medical care if you or the person you are caring for:

  • has chest pain or difficulty breathing
  • has purple or blue discoloration of the lips
  • suddenly becomes dizzy
  • has severe or persistent diarrhea or vomiting and is unable to keep liquids down
  • is confused or isn't responsive.