Pathogenesis (development of disease)
The following forms of endocarditis can be distinguished:
- Abacterial endocarditis – caused by antibody reactions; e.g., endocarditis rheumatica.
- Infective endocarditis – endocarditis caused by bacteria, viruses, fungi:
- Acute endocarditis: mainly Staphylococcus aureus (about 45-65% of cases), streptococci (about 30% of cases) and enterococci (gram-negative bacteria from the HACEK group (H – Haemophilus aphrophilus and Haemophilus paraphrophilus, A – Aggregatibacter actinomycetemcomitans (prev. Actinobacillus actinomycetemcomitans), C – Cardiobacterium hominis, E – Eikenella corrodens, K – Kingella kingae), < 10% of cases; the pathogens are highly pathogenic and can also affect intact heart valves).
- Subacute endocarditis (most common pathogen: Streptococcus viridans; the pathogen is weakly pathogenic, therefore usually affects only pre-damaged heart valves or prosthetic heart valves = subacute endocarditis lenta)
- Mixed forms – in this case, an infective endocarditis grafted onto an abacterial infection.
In patients with infective endocarditis, infections with staphylococci (44% and enterococci (16% are most common; infections with orally transmitted streptococci (12%) are less common. Natural heart valves (57%) are more commonly affected than prosthetic heart valves (30%).
Bacterial endocarditis usually occurs in pre-damaged hearts. Bacteria circulating in the blood can lodge in the area of damaged endocardium and lead to infection.
Risk factors for bacterial endocarditis include:
- Congenital or acquired cardiac vitiation (valvular heart disease).
- Prosthetic heart valves (esp. after invasive dental procedures) → endocarditis prophylaxis (see below the topic of the same name).
- Cardiomyopathy – group of diseases of the heart muscle, which leads to the restriction of pumping function.
- Condition after infective endocarditis.
Etiology (causes)
Disease-related causes
Cardiovascular system (I00-I99)
- Endocarditis rheumatica
- Endocarditis Libman-Sacks – form of endocarditis (endocarditis) occurring in visceral lupus erythematosus.
- Endocarditis Löffler (endocarditis parietalis fibroplastica) – acute form of endocarditis (endocarditis), which affects mainly the right ventricle (heart chamber).
- Endocardial myocardial fibrosis
Infectious and parasitic diseases (A00-B99).
- Infections with bacteria (e.g., Staphylococcus aureus, streptococci, E. faecalis), viruses, fungi
Surgeries/invasive procedures
- Bronchoscopy (pulmonary endoscopy) and blood transfusion: 5-fold increased relative risk (RR) of developing endocarditis in the next 12 weeks (relative risk, RR: 5.00 and 5.50, respectively). In the case of a
- Bone marrow examination: increased 4-fold (RR: 4.33).
- Coronary angiography (radiologic procedure that uses contrast agents to visualize the lumen (interior) of the coronary arteries (arteries that surround the heart in a wreath shape and supply blood to the heart muscle)) (RR: 4.75)
- Dialysis (blood washing) (RR: 4.33)
- Hemodiafiltration (extracorporeal blood purification procedure a combination of hemodialysis and hemofiltration) (RR: 4.00)
Other causes
- I.v. drug addiction