Bacterial infections are a less common cause of heart disease, but they’re no less serious than the others. Dr. DeLisa Fairweather, Ph.D., is an expert on the subject and serves as the Director of Translational Research for the Department of Cardiovascular Medicine at Mayo Clinic’s campus in Florida. She, alongside the Myocarditis Foundation, offers some insights into how bacterial infections in the heart begin, how the body responds, and their most common signs and symptoms.

How Infections Begin

For a bacterial infection to occur, bacteria have to find their way into the bloodstream. “There are a number of places bacteria can enter,” says Fairweather, “but the skin is a very good defense. It has to enter where the skin has been broken.” The most common way this happens is through a cut.

Another possible route of entry is through the intestines, which are loaded with bacteria. Though healthy and essential for digestion, it can be destructive if bacteria roam elsewhere in the body. For example, certain illnesses, like bowel diseases, can break down the mucus membranes in the intestines. This breakdown creates openings through which intestinal bacteria can enter the bloodstream and even reach the heart.

The Body’s Immune Response

Once the body notices the bacteria, the immune system begins to respond. Bacteria grow much more slowly than viruses, so they’re sometimes easier for the immune system to fight. “However, foreign bodies have developed ways to hide from our immune system,” says Fairweather. An immune response doesn’t guarantee that all the bacteria will be destroyed.

The immune response is also where most of the symptoms of bacterial infections originate. A localized infection, like from a cut, results in a red, puffy region of skin that feels warm to the touch. This is caused by the body’s attempt to overheat and kill the bacteria. A systemic infection has similar symptoms, but they occur throughout the whole body, resulting in a fever.

Bacterial Infections in the Heart

Though bacterial infections don’t commonly affect the heart, it does happen. The resulting cardiac inflammation is called myocarditis, which can be difficult to detect but presents symptoms such as:

  • Chest pain or pressure
  • Shortness of breath
  • Irregular heartbeat
  • Lightheadedness and fainting
  • Swollen legs or abdomen
  • Aching muscles and joints
  • Fatigue

“The inflammation is what causes symptoms,” Dr. Fairweather explains, “possibly more than the bacteria itself.” She also notes that the body’s immune response can be so intense that it can cause more damage than it prevents. Because of this, the best way to treat a heart infection is to calm that response down. Doctors use anti-inflammation medicines to reduce the swelling and heat and keep the inflammation from causing too much damage.

Treating the inflammation isn’t enough, however. If doctors don’t take care of the problem at its source, the infection will continue to return again and again. Therefore, effective treatment also requires the use of antibacterial medicine to wipe out the bacteria and prevent inflammation from recurring.

Learn More about Heart Bacterial Infections

Bacterial infections in the heart might be rare, but understanding them is still important. By knowing the signs, doctors can more quickly and effectively diagnose bacterial infections in the heart and plan a treatment that will work. To learn more, contact the Myocarditis Foundation today.

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