Your doctor may suspect endocarditis based on your medical history, signs and symptoms you're experiencing, and your test results. A diagnosis of endocarditis is usually based on several factors instead of a single positive test result or symptom.
Your doctor may order several tests to help make a positive diagnosis, including:
- Blood tests. A blood culture test is used to identify any bacteria or fungi in your bloodstream, and it's the most important test your doctor will perform. Blood tests can also help your doctor identify certain conditions that can be a sign of endocarditis, such as anemia — a shortage of healthy red blood cells.
Echocardiogram. An echocardiogram uses sound waves to produce images of your heart while it's beating. This test is often used to check for signs of infection. Your doctor may use two different types of echocardiograms to help diagnose endocarditis.
In a transthoracic echocardiogram, sound waves directed at your heart from a wandlike device (transducer) held on your chest produce video images of your heart in motion. This test can help your doctor look at your heart's structure and check it for any signs of infection or damage.
Doctors may conduct another type of echocardiogram called a transesophogeal echocardiogram to get a closer look at your heart valves. During this test, a small transducer attached to the end of a tube is inserted down the tube leading from your mouth to your stomach (esophagus). This test can allow your doctor to get much more detailed pictures of your heart than is possible with a transthoracic echocardiogram.
- Electrocardiogram (ECG). While an ECG isn't specifically used to diagnose endocarditis, it can show your doctor if something is affecting your heart's electrical activity. During an ECG, sensors that can detect your heart's electrical activity are attached to your chest, arms and legs. This test is used to measure the timing and duration of each electrical phase in your heartbeat.
- Chest X-ray. X-ray images help your doctor see the condition of your lungs and heart. Your doctor can use X-ray images to see if endocarditis has caused your heart to enlarge or if any infection has spread to your lungs.
- Computerized tomography (CT) scan or magnetic resonance imaging (MRI). You may need a CT scan or an MRI scan of your brain, chest or other parts of your body if your doctor thinks that infection has spread to these areas.