Overview

Subacute bacterial endocarditis (SBE) is a slowly developing type of infective endocarditis — an infection of the lining of your heart (endocardium). Infective endocarditis can affect your heart’s valves, too.

SBE differs from acute bacterial endocarditis, which develops suddenly and can become a life-threatening condition within a few days.

SBE can cause serious damage to your heart tissue and can have symptoms and complications that affect your entire body. It’s usually a preventable condition. If it develops, it must be treated promptly to minimize harm to your heart.

What are the symptoms?

Many of the main signs of SBE, such as aches and fever, are common to other conditions. However, if you start to experience these symptoms, don’t hesitate to see your doctor soon.

The more noticeable signs of SBE include:

  • unexplained fever or chills
  • joint and muscle aches
  • night sweats
  • mildly elevated heart rate
  • weight loss
  • decreased appetite
  • lack of energy
  • pain in your chest or back
  • skin rashes

What causes it and who’s at risk?

SBE can develop when bacteria enter your bloodstream. If your gums bleed while brushing your teeth, bacteria can get into your blood. That’s why people with periodontal disease are at a higher risk of developing SBE.

The use of injectable drugs or prolonged use of intravenous (IV) medications can make you more vulnerable to infections. If you develop symptoms, you need to share with your doctor any information about previous or current drug use.

Children born with congenital heart problems, such as abnormally formed valves or a hole in their heart, are also more likely to develop conditions like SBE.

Adults with a history of endocarditis or who have congenital heart defects are at higher risk. The risk of SBE is somewhat elevated if you have calcium deposits in your mitral or aortic valves, or you have had valve surgery or other heart operations. Having an implantable cardiac device, such as a pacemaker, also raises your risk slightly.

Men are twice as likely as women to develop infective endocarditis, and about one-quarter of all cases occur in people age 60 and older. Part of the reason older adults are at higher risk is because over time, your heart’s valves can degenerate and calcium can build up around the valves.

How it’s diagnosed

Diagnosing SBE can be a challenge because the symptoms aren’t specific. This is why it’s especially important that you provide a detailed medical history to your doctor.

Your doctor will usually order a blood test and a blood culture. A blood culture can sometimes identify the specific type of bacteria causing your infection. A standard blood test can reveal a low red blood cell count, which is a common symptom of SBE.

Other tests include echocardiography. This painless and noninvasive screening tool uses high-frequency sound waves to create images of your heart while it’s beating. These images provide a detailed view of your heart’s valves, chambers, and attached blood vessels.

How it’s treated

It’s essential that SBE be treated once it’s diagnosed. If it’s not, the condition is fatal.

In many cases, treatment is primarily a course of high-dose IV antibiotics. The course could last two to six weeks. Treatment often starts in the hospital after you’re admitted.

Once your health appears to be stable and the antibiotics are working without side effects, you may be discharged. You will continue your treatment on an outpatient basis, either visiting the hospital for IV treatment or at home with the help of a visiting nurse.

In some cases, you may need surgery. This may involve draining an infected abscess that has formed on your heart or replacing a valve that has become infected. If a congenital heart problem is the cause of SBE, you may need surgery to repair the condition.

What are the complications?

SBE can trigger some life-threatening complications in addition to the infection. Bacteria can build up in your arteries and cause growths to form on your valves. These masses that develop are called vegetations and can cause blood clots to form around them.

If a blood clot breaks loose in one of your coronary arteries and blocks blood flow to your heart, you can have a heart attack. If a clot restricts blood flow in an artery supplying blood flow to your brain, you may have a stroke.

In addition, an infection that develops in your heart can also travel through your bloodstream to other organs. Your kidneys, lungs, spleen, and brain are among the organs most at risk.

What’s the outlook?

If you’ve never had any form of endocarditis, you can take preventive measures to reduce your odds of developing it. Maintain proper dental hygiene and gum health. Have regular cleanings and follow your dentist’s advice about gum health. If you experience gingivitis, talk with your dentist or a periodontist about steps you can take for better gum health.

SBE is a life-threatening condition that is treatable in many cases. Your ability to survive this serious heart infection depends on several factors, including your age and overall health, as well as the severity of the infection and the portion of your heart that’s affected.

If you’re diagnosed with SBE, a strict regimen of high-dose antibiotics should lead to a successful outcome and minimal harm to your heart. Be aware that you may be at a higher risk for another attack of SBE. Be sure to discuss with your doctor how to lower those odds and what type of heart health monitoring is best for you.