endocarditis(redirected from culture-negative endocarditis)
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endocarditis(ĕn'dōkärdī`tĭs), bacterial or fungal infection of the endocardium (inner lining of the heart) that can be either acute or subacute. In the acute form the symptoms (fever, malaise, fatigue, weight loss, anemia) are directly related to the presence of an active infection that runs its course within a few weeks. Acute endocarditis may follow respiratory infection, surgery, or other trauma; but in some cases the source of infection is unknown. A major cause of endocarditis is the use of contaminated intravenous needles by drug addicts. Bacterial endocarditis is an insidious, often progressive, disease that can lead to kidney failure and congestive heart failure. The causative agent in many cases of subacute disease is Streptococcus viridans. Endocarditis is often a complication of Lyme disease. A previously damaged valve increases the risk of infection tenfold. The most common diseases causing these predisposing valvular deformities are rheumatic feverrheumatic fever
, systemic inflammatory disease, extremely variable in its manifestation, severity, duration, and aftereffects. It is frequently followed by serious heart disease, especially when there are repeated attacks. Rheumatic fever usually affects children.
..... Click the link for more information. and congenital heart diseasecongenital heart disease,
any defect in the heart present at birth. There is evidence that some congenital heart defects are inherited, but the cause of most cases is unknown.
..... Click the link for more information. . Thrombi associated with the infection on the valve often dislodge and spread septic emboli throughout the body that may damage the kidney. Primary diagnostic symptoms are fever and a changing heart murmur. Physical diagnosis can be confirmed by the use of echocardiography (ultrasoundultrasound
in medicine, technique that uses sound waves to study and treat hard-to-reach body areas. In scanning with ultrasound, high-frequency sound waves are transmitted to the area of interest and the returning echoes recorded (for more detail, see
..... Click the link for more information. ). Treatment with high doses of antibiotics often kills the bacteria, but the damage to the valve may put an additional strain on the heart that can eventually lead to cardiac failure. However, it is sometimes possible through follow-up corrective surgery to repair or replace valves damaged by endocarditis.
inflammation of the inner membrane, or endocardium, of the heart. Endocarditis is caused chiefly by rheumatism and sepsis. It occurs occasionally in myocardial infarction, uremia, syphilis, tuberculosis, and other diseases. The disease is usually combined with myocarditis; less commonly it occurs with pericarditis. Valvular insufficiency occurs when mostly the endocardium of the heart valves is affected.
Subacute septic, or malignant, endocarditis is caused by Streptococcus viridans or, less often, by staphylococcal or other bacteria. Change in the body’s immunity is significant. Because penetration by microbes is facilitated by injury to the endocardium and by congenital structural defects of the heart, septic endocarditis can be “superposed” on rheumatic and congenital heart disease. The necrotic and ulcerative changes that take place in the endocardium often result in arterial embolism in the systemic circulation. Inflammatory and degenerative changes and hypersensitivity vasculitis arise in the myocardium, and capillary permeability increases. The disease is manifested by fever, chills, weakness, and pain in the joints and bones. Petechial hemorrhages appear on the mucous membranes and on the skin, which acquires a greenish brown color. The terminal phalanges of the fingers thicken, causing the fingers to look like drumsticks and the nails like watch glasses. Signs of valvular disease (generally incompetence of the aortic valve) and anemia appear, and the spleen and liver become enlarged. Hemorrhagic pleurisy, focal glomerulonephritis, and other diseases may develop. The causative agent of the disease can often be isolated from the blood.
Acute septic endocarditis is less common than the subacute form. It is usually caused by hemolytic streptococcus entering the blood from the primary septic focus. The disease has similar symptoms, but its course is more severe than that of acute septic endocarditis. Endocarditis is treated mainly by prolonged administration of fairly large doses of antibiotics. Prevention requires clinical follow-up of patients with rheumatic and congenital heart diseases, elimination of focuses of infection in the body, and hardening of the body.
REFERENCETeodori, M. I. Zatiazhnoi septicheskii endokardit. Moscow, 1965.
N. R. PALEEV and S. D. KAPANADZE