Endocarditis — Heart Valve Infection
Infective endocarditis (IE) is a serious infection of the inner lining of the heart — most commonly affecting the heart valves. Bacteria (or rarely fungi) enter the bloodstream, adhere to valve tissue, and form infected vegetations that damage the valve, cause emboli, and can seed infection to other organs. It is a life-threatening condition requiring prolonged antibiotic treatment and, in many cases, urgent cardiac surgery.
Who is at risk?
- Patients with congenital heart disease — bicuspid aortic valve, ventricular septal defects, and other structural abnormalities.
- Patients with prosthetic (artificial) heart valves — including both surgical valve replacements and TAVR valves.
- Patients with prior endocarditis — the highest-risk group for recurrence of infection.
- Intravenous drug users — injection of contaminated drugs can directly introduce bacteria into the bloodstream.
- Patients with rheumatic valve disease — still common in India.
- Patients with intracardiac devices — such as pacemakers and defibrillators.
Diagnosis
- Blood cultures — the most important diagnostic test. Three sets are taken from different sites before starting antibiotics. Helps identify the causative organism and guide targeted antibiotic therapy.
- Echocardiogram (TTE and TOE) — visualises vegetations on heart valves, assesses valve damage, and detects complications such as perivalvular abscess. Transoesophageal echocardiography (TOE) is more sensitive for detecting small vegetations and prosthetic valve endocarditis.
- CT and PET scan — used to detect embolic complications (such as splenic, cerebral, or renal infarcts) and to support diagnosis, especially in prosthetic valve endocarditis.
Symptoms
- Fever — persistent, often low-grade, and the most consistent symptom.
- New or worsening heart murmur — due to valve destruction by the infection.
- Fatigue, night sweats, and weight loss — constitutional symptoms of chronic infection.
- Embolic events — include stroke (cerebral embolism from vegetation fragments), splenic infarction, renal infarction, and peripheral embolism.
- Osler nodes — painful nodules on the fingertips.
- Janeway lesions — painless haemorrhagic macules on the palms and soles.
- Splinter haemorrhages — dark linear streaks under the fingernails.
- Roth spots — oval retinal haemorrhages seen on fundoscopic examination.
Treatment
- Prolonged intravenous antibiotic therapy — typically 4 to 6 weeks. Antibiotic selection is guided by blood culture results and organism sensitivity. Hospitalisation is usually required for close monitoring.
- Cardiac surgery — indicated in cases of severe valve destruction causing heart failure, large vegetations with high embolic risk, perivalvular abscess, fungal endocarditis, or failure of infection clearance with antibiotics. The timing of surgery is complex and involves balancing operative risk with ongoing infection.
- Antibiotic prophylaxis — recommended for high-risk patients (prosthetic valves, prior endocarditis, certain congenital heart disease) before dental procedures involving manipulation of gingival tissue or the periapical region of teeth.