Infective endocarditis is an infective disease of the endocardium or the inner layer of the heart, causing damage and destruction of the cardiac valves and mural tissue. Although it is a disease of the cardiac tissue, it has many systemic implications resulting in significant morbidity and mortality.
Aetiology and epidemiology of infective endocarditis:
- The reported incidence of infective endocarditis is 3-10 cases per 100 000 per year (European Society of Cardiology, ESC). According to the American Heart Association, ≈ 29,000 patients are diagnosed with endocarditis each year.
- Female to male ratio of 1:2.
- The median age: 47–69 years (increased from 30–40 to years).
The most common underlying pathologies are:
- Presence of exogenous intracardiac material
- Artificial valves
- CIEDs
- Degenerative heart disease
- Rheumatic heart disease: leading cause of IE in developing world.
Better healthcare and improved life expectancy have increased the patient population with vulnerability to develop IE and shifted the disease epidemiology in developed countries. Rheumatic fever is no longer the most prevalent cause of IE, and the median patient age shifted to 47-69 years (instead of earlier reported 30-40 years). However, rheumatic heart disease continues to be the most common culprit in developing countries.
Microbiology:
Gram-positive bacteria
- Staphylococcus aureus (31–54%)
- The most frequent causative agent in acute IE and lately in chronic cases too.
- IE tends to involve the mitral valve more often than the aortic and is the most common cause of IE among injection drug users.
- Infects natïve valves, the primary pathogen in community-acquired infection.
- Methicillin-resistant staph aureus (MRSA): primary pathogen in nosocomial infection, wound infection, permanent i.v. Catheters or surgical intervention in the previous six months. MRSA accounts for 23–31% of prosthetic valve infections.
To continue reading the rest of the chapter, download the Infective endocarditis module by targetedaic. The chapter covers IE pathophysiology, aetiology, microbiology, clinical presentation, management, recent updates on antibiotic prophylaxis and anaesthetic implications of the disease.
Targetedaic course modules are an excellent resource for EDAIC and FRCA exam preparation. Our modules are based on the syllabus and frequently asked questions in MCQ and viva examinations. The study material is designed to be a one-point reference for all your study needs for a topic and are available as separate chapters or combined system-based modules for your convenience and to suit your need. Feel free to contact us for any queries.
In addition, you can join our Facebook group to stay updated with targetedaic content and MCQ discussion.