PET CT can find hidden infection of heart valves and heart devices when echo is unclear. Learn when it is used and how special preparation reduces false results.
Infective endocarditis is infection of the heart valves or the lining of the heart, and device infection involves a pacemaker, defibrillator or other implant. When echo and blood cultures are unclear, FDG PET CT can show active infection around valves and devices and also find where infection has spread. It requires a special diet before the scan, to switch off normal heart muscle uptake.
Why Endocarditis Is Dangerous
Infection on the heart valves can destroy the valve, shower clots to the brain and body and cause heart failure. Symptoms include prolonged fever, tiredness, weight loss, breathlessness and new murmurs. Early diagnosis improves survival. The core tests are blood cultures and echocardiography. See PET CT for fever and infection.
SituationRole of PET CTProsthetic (artificial) valve with suspected infectionHelps when echo is unclearPacemaker or ICD pocket and lead infectionShows pocket and lead activityNative valve endocarditisMainly echo; PET CT for spreadSpread to spleen, spine, jointsWhole-body scan finds sitesFever after heart surgeryEvaluates sourcesWhere PET CT Helps
- Prosthetic valve infection, where echo can be hard to read
- Device and lead infection, especially deep infection
- Finding spread (septic emboli) to other organs
- Looking for the source of infection in unexplained bacteraemia
Why Special Preparation Is Needed
Normal heart muscle takes up FDG, which can hide infection. To suppress it, a high-fat, very-low-carbohydrate diet is advised for 24 hours, followed by fasting for 12 or more hours, sometimes with heparin before the injection. Failing to follow this can make the scan useless. See PET CT for sarcoidosis and PET CT preparation.
Limits
Recent surgery (less than 3 months) causes inflammation that looks like infection. Small vegetations on native valves may be missed. Antibiotics before the scan can reduce uptake. The result is read together with echo, cultures and clinical findings. Other tests include cardiac CT and white blood cell scans.
Safety and Practical Points
Tell the team about diabetes, since fasting and a low-carb diet need adjustment. Carry blood culture reports, echo reports and surgery notes. Avoid unsupervised changes to insulin. See PET CT for diabetic patients.
A Practical Example
Mohan, 60, had an artificial heart valve five years ago and now has fever for three weeks. Echo is unclear, but cultures grow bacteria. A PET CT after the special diet shows active uptake around the valve and a spot in the spleen. His doctors diagnose prosthetic valve endocarditis, start long antibiotics and plan surgery.
After the Scan and Next Steps
Take the report to a cardiologist and infectious disease specialist. Treatment needs prolonged intravenous antibiotics and, in some people, surgery to replace the valve or remove the device. Maintain excellent dental hygiene, report fever early after any heart procedure and tell every doctor and dentist about your valve or device.
Questions to Ask Your Doctor
- Is my valve or device infected?
- Do I need surgery or removal of the device?
- How long will antibiotics last?
- Which dental precautions do I need?
Common Mistakes to Avoid
- Ignoring the special diet before the scan.
- Stopping antibiotics early.
- Skipping dental care with a heart valve.
Booking, Timing and Report
Ask your doctor for the best timing of the scan. Book a morning slot so that fasting is easier, arrange someone to accompany you, and allow 2 to 3 hours at the centre. Carry biopsy, scan and blood reports and a medicine list. Reports are usually ready within 24 to 48 hours, and images can be given on a CD or digital link for your doctor.
Key Facts at a Glance
- PET CT helps in prosthetic valve and device infection
- A special high-fat, low-carb diet is essential
- Cultures and echo remain the main tests
- Treatment needs long antibiotics
Frequently Asked Questions
What is endocarditis?
Infection of the heart valves or lining.
When is PET CT used?
For prosthetic valves and devices when echo is unclear.
Why is a special diet needed?
To reduce normal heart muscle uptake.
Do I need to fast?
Yes, usually 12 hours or more.
Can PET CT replace echo?
No.
Can recent surgery affect it?
Yes, it can cause false positives.
Is the scan safe?
Yes when advised.
How long does it take?
About 2 to 3 hours.
When is the report ready?
Usually 24 to 48 hours.
Book Your Test at Ganesh Diagnostic
Ganesh Diagnostic & Imaging Centre in Rohini, Delhi offers this test with trained radiology staff and clear reports. You can book an appointment online, check our branches across Delhi NCR, contact us for current rates, or explore all our services. Reports can be downloaded online through our patient portal, so you do not need to make a second trip just to collect them.
This article is for general information only. It does not replace advice from your doctor. Always follow your doctor's instructions for your test.
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