Infective endocarditis Flashcards
What is the definition of infective endocarditis?
Endovascular infection of the cardiac structures including cardiac vales, atrial and ventricular endocardium and intracardiac foreign bodies e.g. prosthetic valves, pacemaker leads etc.
How common is infective endocarditis?
Annual UK incidence is 6-7/100,000 but more common in developing countries. ↑↑ mortality and morbidity rate. Aortic and mitral valves most commonly involved
What is the pathophysiology of infective endocarditis?
- 2 main factors contribute to acquiring endocarditis: organisms in the bloodstream and abnormal cardiac endothelium
- Damaged endocardium = platelet and fibrin deposition to which organisms adhere and grow → infective vegetation
- α-haemolytic viridans streptococci – most common from mouth
- Staph aureus – IVDU
- Modified Duke criteria used to diagnose endocarditis
What is the aetiology/risk factors of infective endocarditis?
- Poor dental hygiene/dental treatment
- IV drug user – right sided lesion more common
- IV cannula
- Soft tissue infections
- Cardiac surgery
- Pacemaker
- Prior antibiotic therapy – culture negative endocarditis
What are the signs/symptoms of endocarditis?
- Fever
- Malaise
- Janeaway lesions
- Splinter haemorrhages
- Conjunctival haemorrhages
- Clubbing
- Oslers nodes – palmar side of hand
- Petechiae
- Roth spots (eyes)
- Cardiac murmur
- Cardiac failure – ventricular arrhythmias/conduction disturbances
- Splenomegaly
- Haematuria
What diseases present similarly to infective endocarditis?
- SLE
- Cardiac tumour
- Lyme disease
- Antiphospolipid syndrome
What investigations are carried out for suspected infective endocarditis?
- Blood culture, microscopy and specificity – 3 sets from different venepuncture sites
- Serological test for Q fever – IgG antibodies
- FBC - ↓ Hb, ↑ WCC
- U&Es - ↑ urea and creatinine
- LFTs - ↑ serum alkaline phosphatase
- ESR/CRP - ↑
- Urinalysis – protein and blood present
- CXR – pulmonary oedema in left side and pulmonary emboli/abscess in right side
- Echocardiography – shows mass on the valve, implanted material or abscess
What are the surgical treatments for infective endocarditis?
valve replacement surgery - if the valve is destroyed
What are the pharmacological treatments for infective endocarditis?
• Prolonged antibiotics (normally 4-6 weeks) – almost always involves penicillin so beware of allergy