What is Endocarditis?

Endocarditis refers to an inflammatory disease caused by pathogenic microorganisms directly attacking the endocardium. The valve is the most commonly affected site, but infections can occur at the site of the ventricular septal defect, the chordae, and the endocardium. Infections in arteriovenous fistula, arterial fistula (such as open ductus arteriosus) or aortic stenosis are arterial endometritis, but clinical and pathological are similar to infective endocarditis.

Endocarditis refers to an inflammatory disease caused by pathogenic microorganisms directly attacking the endocardium. The valve is the most commonly affected site, but infections can occur at the site of the ventricular septal defect, the chordae, and the endocardium. Infections in arteriovenous fistula, arterial fistula (such as open ductus arteriosus) or aortic stenosis are arterial endometritis, but clinical and pathological are similar to infective endocarditis.

Causes of endocarditis

Factors that cause endocardial infections are:

1. Pathogens invade the bloodstream

Causes bacteremia, sepsis, or sepsis, and invades the endocardium.

2. Heart valve abnormalities

Conducive to the colonization of pathogenic microorganisms.

3. Inhibition of defense mechanisms

Cytotoxic drugs for tumor patients and immunosuppressants for organ transplant patients. The clinical process is related to pathogenic microorganisms, which include various bacteria and fungi. Traditions are divided into acute and subacute types, and their clinical course and pathological changes are different. Acute infective endocarditis is also referred to as ulcerative endocarditis due to the presence of ulcers in the affected endocardium. This kind of endocarditis has a sharp onset and is mostly caused by virulent pyogenic bacteria, most of which are Staphylococcus aureus, followed by Streptococcus pyogenes. Usually pathogenic bacteria first cause purulent inflammation (such as purulent osteomyelitis, diarrhea, puerperal fever, etc.) in a certain part of the body. When the body's resistance decreases (such as tumors, heart surgery, immunosuppression, etc.), the pathogens invade the bloodstream, causing Septicemia and invasion of the endocardium. This type of endocarditis mostly occurs on the normal endocardium, which mostly invades the aortic valve alone, or invades the mitral valve. Subacute cases mainly occur in organic heart disease, with heart valve disease first and congenital vascular disease.

Clinical manifestations of endocarditis

Onset is slow and symptoms vary. Most patients have an organic heart disease, and some have a history of dental caries, tonsillitis, intravenous intubation, interventional therapy, or intracardiac surgery before onset.

Infection symptoms

Fever is the most common symptom of endocarditis. Almost all patients have different degrees of fever, irregular heat patterns, longer heat courses, and individual patients have no fever. In addition, the patient has fatigue, night sweats, loss of appetite, weight loss, joint pain, pale skin and other symptoms, and the disease progresses slowly.

2. Heart symptoms

Heart murmurs can be heard in 80% to 85% of patients and can be caused by valve damage caused by underlying heart disease and / or endocarditis. The original heart murmur can be changed by the vegetation of the heart valve, and there are rough, loud, seagull-like or music-like murmurs. Music-like murmurs can occur in those who have no heart murmur. About half of the children have congestive heart failure due to heart valve disease, toxic myocarditis, etc., and have dull heart sounds and galloping rhythms.

3. Embolism symptoms

Different clinical manifestations occur depending on the location of the embolism, which usually occurs late in the course of the disease, but about 1/3 of the patients are the first symptoms. There are scattered small petechiae on the skin embolism. There may be small purple-red nodules on the flexion surface of the toes, with slight tenderness. This is Osler nodules. Visceral embolism can cause splenomegaly, abdominal pain, hematuria, blood in the stool, and sometimes splenomegaly. Very significant; pulmonary embolism may include chest pain, cough, hemoptysis, and lung murmur; cerebral arterial embolism includes headache, vomiting, hemiplegia, aphasia, convulsions, and even coma. Those with a long course of disease can see club-shaped fingers and toes, but no cyanosis.

There are not many typical patients with the above three symptoms at the same time, especially infants under 2 years old are mainly the symptoms of systemic infection, and only a few children have embolism symptoms and / or heart murmurs.

Endocarditis examination

Blood test

The common haematology is progressive anemia, mostly positive cell anemia and increased leukocyte count, increased neutrophils, increased erythrocyte sedimentation, and positive C-reactive protein. When combined with immune complex-mediated glomerulonephritis, severe heart failure, or hypoxia caused by increased red blood cell count, serum globulin often increases, and even the albumin and globulin ratios are inverted. Elevated immunoglobulin, elevated -globulin, elevated circulating immune complexes, and rheumatoid factor positive.

Blood culture

Positive blood bacterial culture is an important basis for the diagnosis of infective endocarditis. Anyone who has fever and body temperature of unknown cause and lasts for more than 1 week, and the original heart disease should actively and repeatedly perform blood culture to improve the positive rate. If the blood culture is positive, a drug sensitivity test should be done.

3. Urine test

There are often microscopic hematuria and mild proteinuria. Gross hematuria suggests renal infarction. Red blood cell casts and large amounts of proteinuria suggest diffuse glomerulonephritis.

4. ECG

Because the myocardium can have multiple pathological changes at the same time, fatal ventricular arrhythmias may occur. Atrial fibrillation indicates atrioventricular valve reflux. Complete atrioventricular block, right bundle branch block, left anterior or left posterior branch block have been reported, suggesting an increase in myocardial suppuration or inflammatory response.

5. Echocardiography

Echocardiography can detect neoplasms larger than 2mm in diameter, so it is very useful for diagnosing infective endocarditis. In addition, echocardiography can dynamically observe the size, shape, activity and valve function of neoplasms during treatment The status and understanding of the degree of valve damage are of reference value in deciding whether to perform valve replacement surgery. The test can also identify pre-existing heart conditions.

6.CT inspection

CT should be done in time for those with suspected intracranial lesions to understand the extent of the lesion.

Endocarditis diagnosis

Make a diagnosis based on clinical manifestations and related tests.

Endocarditis treatment

1. Application of antibiotics

The application of antibiotics is the most important measure for the treatment of endocarditis. The choice of antibiotics is based on the results of pathogenic cultures or sensitivity to antibiotics.

2. Surgical treatment

The following situations need to consider surgery:

(1) Valve perforation, rupture, chordae rupture, and refractory acute heart failure.

(2) Infection after valve replacement in workers cannot be controlled by medical treatment.

(3) Complicated rupture of bacterial aneurysm or embolization of aorta of extremities.

(4) In the case of infective endocarditis due to congenital heart disease, which cannot be controlled after systemic treatment, surgery should be performed as soon as possible under the control of enhanced supportive therapy and antibiotics.