Endocardial diseases

The internist Sir William Osler first described infective endocarditis in 1885 (Al-Nawass 2021). The mucosal nodules on the tips of the fingers and toes, the so-called "Osler nodules", which can occur in the course of endocarditis lenta, also bear his name (Schuchart 2021).

In 1909, the oral cavity was first postulated as a portal of entry for germs, and in 1923, the association between invasive dental treatments and endocarditis was recognized (Al- Nawass 2021).

Libman- Sacks endocarditis was first described by Libman and Sacks in 1924 (Ball 2014).

The term "endocardial fibroelastosis" (EFE) was coined in 1943 by Weinberg et al. Previously, the condition had been referred to as "fetal endocarditis" (Sana 2022).

The endocardium is the so-called inner lining of the heart, which lines the entire lumen of the heart and forms all four heart valves. Diseases of the endocardium therefore primarily occur in the area of the heart valves (endocarditis valvularis [Herold 2022]) (Fischbach 2014), but can also affect the atrial and ventricular walls (E. parietalis), tendon filaments, and papillary muscles (Herold 2022).

Infective endocarditis is the most common form of endocardial disease (Hellmich 2017). The incidence of the community-acquired form is approximately 2 - 5 cases per 100,000 population annually in industrialized countries (Renz- Polster 2008). Kasper (2015) gives an incidence of 4 - 7 cases per 100,000 population.

The incidence is significantly higher in the elderly, as well as in the first 6 - 12 months after valve replacement (Kasper 2015).

Risk factors are:

- immunodeficiency

- previous endocarditis

- post heart valve surgery (Renz- Polster 2008)

- congenital heart defects (Knirsch 2014)

- chronic rheumatic heart disease (the most common predisposition [Kasper 2015])

- pre-damaged valve apparatus

- dialysis patients

- drug addicts (Renz- Polster 2008)

Endocardial fibroelastosis (EFE), which is very rare, is primarily a disease of infancy or childhood. However, it can also occur in rare cases as late as adulthood (Sana 2022).

The causes of endocarditis may be:

- Infectious as bacterial endocarditis by e.g.:

- Staphylococci in approx. 45 - 65 %.

- Streptococci in approx. 30 %

- Enterococci < 10 % ( Herold 2022 / Kasper 2015)

- pneumococci

- Rare pathogens are e.g. Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Coxiella burnetii, Chlamydia, Eikenella corrodens, Kingella Kingae, Mycoplasma, Legionella, pathogens of the HACEK-group

- Fungi (approx. 1 %) (Herold 2022)

The main entry sites are the oral cavity, skin and upper respiratory tract (Kasper 2015).

- Abacterial form:

This form is also known as non-infectious endocarditis.

It can occur as:

- E. rheumatica (verrucosa), a disease caused by beta-hemolytic streptococci, which can occur as a complication of rheumatic fever (Herold 2022).

- E. Libman- sacks, which is caused by systemic lupus erythematosus (SLE) (Herold 2022).

- Endomyocarditis eosinophilica, also known as "Löffler- syndrome", which can occur in the context of various diseases and is always associated with an increase in eosinophilic granulocytes (Herold 2022).

- Mixed form:

In this case, additional bacterial inflammation occurs on the floor of abacterial endocarditis (Herold 2022).

- Pharmaceutical-induced valvular changes:

These can be caused by, for example, Parkinson's drugs with dopamine agonistic effects such as cabergoline, pergolide. They lead to fibrotic heart valve damage. Similarly, ecstasy (MDMA) can cause changes in heart valves (Herold 2022).

- Endocardial fibroelastosis (EFE).

The exact cause has not yet been determined with certainty. Studies suggest that it is not an idiopathic event, but likely has a genetic component, probably x- chromosomal recessive (Sana 2022).

Other studies suggest a possible association with autoimmune processes, as maternal anti-La and anti-Ro antibodies are often detectable (Sana 2022).

EFE can occur alone, but is combined with other genetic disorders such as aortic stenosis, atresia, hypoplastic left heart syndrome in 20-50% of cases (Sana 2022).

- Infective endocarditis:

Most often, infection is preceded by subtle lesions of the endocardium. Thrombi form on these, leading to infection in the setting of bacteremia. This infection may lead to destruction of the valve apparatus and abscesses of the valve annulus. If detachment of the vegetations occurs, septic emboli in the brain, kidneys or coronary arteries occur (Renz- Polster 2008).

- Infective Endocarditis:

Infective endocarditis most commonly affects the mitral valve, followed by the aortic and tricuspid valves. Multiple valve involvement is found in approximately 25% of patients. The clinical course can be very variable, up to fulminant courses with septic clinical picture and signs of multi-organ failure (Renz- Polster 2008).

- E. rheumatica (verrucosa):

This is frequently found at the closure margins of the mitral and aortic valves. It represents a partial manifestation of pancreatitis and rheumatic fever(Herold 2022).

E. Libman- Sacks:

In this case, larger drops of fibrin are found on the mitral, aortic, and pulmonary valves. It is often accompanied by pleurisy and pericarditis (Herold 2022).

- Endomyocarditis eosinophilica:

It predominantly affects the endocardium of the right ventricle and may occur in bronchial asthma, Hodgkin's and non-Hodgkin's lymphomas, eosinophilic leukemia, idiopathic hypereosinophilia, polyarthritis nodosa, lung carcinoma, (Herold 2022).

- Infective endocarditis:

Here one differentiates between an acute and a subacute course.

- Acute course:

Pathogens are usually Staphylococcus aureus, pneumococci, gram-negative rods. The clinical picture is septic with rapid onset of heart failure and a heart murmur (Knirsch 2014).

- Subacute course, also known as endocarditis lenta:

Predominantly triggered by streptococci (44%), coagulase-negative staphylococci (27%), less frequently by enterococci, pathogens of the HACEK group such as Haemophilus / Aggregatibacter, Actinobacillus /Aggregatibacter, Cardiobacterium, Eikenella and Kingella or by fungi.

The subacute course shows an insidious course in 80 % with non-specific symptoms such as fever, fatigue, myalgias, arthralgias and clinical signs of heart failure.

In about 20%, specific symptoms are found in the form of a new-onset heart murmur and skin manifestations in the form of Roth's spots, splinter hemorrhages, Osler nodules (Knirsch 2014).

- EFE:

The children often show failure to thrive, difficulty eating, increased sweating, dyspnea, cough, cyanosis (Sana 2022).

- Infective endocarditis:

Repeated blood cultures must be taken both before the start of antibiotic treatment and during the course of targeted antibiotic treatment. The diagnosis is confirmed if blood cultures are positive and the same pathogen is detected several times and echocardiographic evidence of typical changes of endocarditis is available (Renz- Polster 2008).

- EFE:

In addition to the usual laboratory tests including an antibody profile, diagnostic gold standards include a chest X-ray, ECG, echocardiography, computed tomography, and biopsy of the endocardium. However, biopsy may not be the 1st choice because of associated complications (Sana 2022).

- Infective endocarditis:

Infectious endocarditis typically shows elevated inflammatory parameters such as CRP, ESR, leukocytes, and infectious anemia (Renz- Polster 2008).

Blood cultures are negative in 5-15% of patients (Kasper 2015).

- Endocardial fibroelastosis (EFE):

Antibody determination for maternal anti-La and anti-Ro antibodies (Sana 2022).

- Sepsis

- damage to the heart valves

- intracardiac abscesses

- cardiac arrhythmias

- heart failure

- arterial embolisms

- renal dysfunction (Hombach 2001)

- mycotic aneurysm (Kasper 2015)

- Infective endocarditis:

Treatment is always performed by an interdisciplinary team of cardiologists, cardiac surgeons, infectiologists and microbiologists, if necessary also together with neurosurgeons, neurologists and radiologists (Herold 2022).

If the pathogen is as yet unknown, therapy for community-acquired endocarditis and native valves and prosthetic valves > 12 mon postoperatively should consist of:

- Ampicillin 12 g / d i. v., distributed over 4 - 6 single doses (ED)

plus

- (Flu)cloxacillin or oxacillin 12 g / d i. v., distributed over 4 - 6 EDs

plus

- Gentamicin 3 mg / kg bw / d i. v. or i. m. as a single dose (Herold 2022).

The duration of therapy should be 4 - 6 weeks.

If the prosthetic heart valve surgery less than 12 mon. ago, recommend:

- Vancomycin 30 mg / kg bw / d i. v., distributed over 2 ED (duration of therapy ≥ 6 weeks).

plus

- Gentamicin 3 mg / kg bw / d i. v. or i. m. as a single dose (duration of therapy 2 weeks)

plus

- Rifampicin 900 - 1,200 mg /d i. v. or orally, divided into 2 - 3 ED (duration of therapy ≥ 6 weeks)

(Herold 2022)

- EFE:

In this case, symptomatic treatment with e.g. diuretics, digoxin, ACE- inhibitors is of primary importance. If maternal anti-Ro and anti-La antibodies are detected, the use of corticosteroids has proven effective. In the final stage of the disease, heart transplantation may be recommended (Sana 2022).

- Infective Endocarditis:

Before the era of antibiotics, bacterial endocarditis was almost always lethal. However, even today, the prognosis of endocarditis remains serious, as it is associated with significant morbidity and also lethality. In nearly half of the cases, cardiac surgery is required to prosthetically repair the valves (Lechner 2020).

According to Renz- Polster (2008), mortality is approximately 25% even with adequate treatment. Mortality can now be reduced to <10% by a multidisciplinary endocarditis team (Herold 2022).

Autoantibody-associated EFE, whether it develops in fetal or postnatal life, has a very high mortality rate. The 4-year survival rate is 77% (Sana 2022).

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