انت هنا الان : شبكة جامعة بابل > موقع الكلية > نظام التعليم الالكتروني > مشاهدة المحاضرة
الكلية كلية طب الاسنان
القسم العلوم الاساسية
المرحلة 3
أستاذ المادة علي زكي ناجي الاسدي
5/31/2011 8:16:46 AM
Infective endocarditis
• It is one of the most serious infections, it characterized by colonization or invasion of the heart valves, the mural endocardium, or other cardiovascular sites by a microbiologic agent.
• leading to the formation of bulky, friable vegetations composed of thrombotic debris and organisms, often associated with destruction .
• Acute endocarditis describes a destructive, infection, frequently of a previously normal heart valve with a highly virulent organism, that leads to death within days to weeks of more than 50% of patients despite antibiotics and surgery.
• Subacute endocarditis , in contrast, organisms of low virulence can cause infection in a previously abnormal heart, particularly on deformed valves. Most patients with subacute infective endocarditis recover after appropriate therapy.
Causes:
• alpha-hemolytic (viridans) streptococci (subacute).
• Virulent Staphylococcus aureus (acute).
• Prosthetic valve endocarditis is caused most commonly by coagulase-negative staphylococci (e.g., Staphylococcus epidermidis).
• Other agents causing endocarditis include gram-negative bacilli and fungi.
Risk factors:
• In years past, rheumatic heart disease.
• more common is mitral valve prolapse.
• degenerative calcific valvular stenosis.
• bicuspid aortic valve.
• artificial (prosthetic) valves.
• intravascular devices such as pacing leads and vascular grafts.
• poor dental hygiene, immunodeficiency, therapeutic immunosuppression, diabetes mellitus, and alcohol or intravenous drug abuse.
Gross appearance:
• friable, bulky, and potentially destructive vegetations containing fibrin, inflammatory cells, and bacteria or other organisms, most commonly on the heart valves.
• The appearance of the vegetations is influenced by the type of organism responsible, the degree of host reaction to the infection, and previous antibiotic therapy. Fungal endocarditis
Microscopical appearance:
• Vegetations of typical subacute infective endocarditis often have granulation tissue at their bases.
• With the passage of time, fibrosis, calcification, and a chronic inflammatory infiltrate may develop.
Clinical features:
1-Fever is the most consistent sign of infective endocarditis. With subacute disease, however, particularly in the elderly, fever may be slight or absent, and the only manifestations are sometimes nonspecific fatigue, loss of weight, and a flu like syndrome. 2-Murmurs are present in 90% of patients with left-sided lesions but may merely relate to the preexisting cardiac abnormality predisposing to endocarditis.
3- Petechiae, subungual hemorrhages, and Roth spots in the eyes (secondary to retinal microemboli) have now become uncommon owing to the shortened clinical course of the disease as a result of antibiotic therapy.
Complications:
• Cardiac complications:
• Valvular insufficiency or stenosis with cardiac failure.
• Myocardial ring abscess
• Suppurative pericarditis.
• artificial valves, partial dehiscence with paravalvular leak
• Embolic complications:
• left-sided lesions lead to embolization to the brain (cerebral infarct or abscess, meningitis), heart (MI), spleen (abscess), kidneys (abscess), other sites
• right-sided lesions lead to embolization to the lungs (infarct, abscess, pneumonia).
• Other complications:
1-Splenomegaly.
2-Anemia.
3-Hematuria.
4-clubbing of fingers with splinter hemorrhage.
5- glomerulonephritis
Pericarditis:
• It is an inflammatory reaction involving the visceral and / or parietal pericardial layer.
Clinical features:
• Chest pain, a pericardial friction rub is a characteristic feature of acute fibrinous pericarditis.
• Large pericardial effusion leads to dullness percussion, and heart sound may be diminished
Causes:
• viral pericarditis (coxsackie virus, herpis simplx, and influenza).
• Myocardial infarction.
• Uremia. • Bacterial pericarditis.
• Post-cardiac surgery.
• Malignancy and T.B.
Morphological types:
• Fibrinous and Serofibrinous Pericarditis.
• Purulent or Suppurative Pericarditis.
• Hemorrhagic Pericarditis.
• Caseous Pericarditis.
• Healed Pericarditis
Myocarditis :
• Causes: viral (coxsackie, influenza, and H.I.V), Bacterial infection, (diphtheria, meningococuss), Parasites, trypanoasomiasis, Radiation, and Drugs.
• Clinicpathological Features: In most patients, the myocarditis is a self limiting condition with only mild chest pain. The biopsy shows lymphocytic infiltrate, with myocyte necrosis
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
|