WRITTEN BY: Thaer Al-qatish & Sarah Awaisheh

Transcription

1 WRITTEN BY: Thaer Al-qatish & Sarah Awaisheh

2 Not all informations in the slides are included in this sheet so please study the slides. 3 kinds of Intracardiac infections: -endocarditis(inflammation of the inner layer of the heart) -thrombophlebitis (Inflammation of the viens) -endarteritis (Inflammation of the arteries) (slide 4) *these Intracardiac infection are caused mainly by bacteria but sometimes can be cause by fungi & viruses Endocarditis is characterized by lesions, known as vegetations ( )تنبتا ا انتفاخا *vegetation its like a layer formed on the inner layer of the heart made from a mass of platlets, fibrin, M.O. colonies, and inflammatory cells *Infective endocarditis it's caused mainly by bacteria (bacterial endocarditis) and sometimes may be caused by other M.O. *Non-infective endocarditis inflammation that is not caused by M.O. *Most infection occurs on the cardiac valves (mainly mitral & aortic valves) but can also develop on septal defects, or the mural endocardium. Factors that increase the susceptibility of endocarditis and result in infection: 1-Alteration of endothelium (any factors that make changes on the endothelium layer like truama or inflammation) 2-Transient bacteremia( moving of bacteria through the blood can accelerate the process of endocarditis) (slide 5) The organisms responsible for transient bacteremia are the common surface normal flora such as Viridans Streptococci (α - hemolytic streptococcus).. Viridans Streptococci are normal flora of the oropharynx region. α - hemolysis: Incomplete lysis of erythrocytes β - hemolysis: Complete lysis of erythrocytes γ- hemolysis: nonhemolytic *Intravenous drug abuse may lead to transient bacteremia with Staphylococcus aureus or a variety of Gram-negative aerobic and anaerobic bacteria *M.O. have capsules that protect them from phagocytosis (cellular immune defenses) *humoral immune defence (AB, cytokines, complement system) (slide 6) *Vegetations may break off and produce Emboli in a process called (embolization)... emboli any material that blocks or slows the blood flow in vessels like platlets, fibrin, foreign material *immune complexes (AB with antigen) flow through blood and can deposit in certain tissues this process will activate the complement system that will lysis these complexes and cause inflammation in these tissues like nephritis, arthritis, and cutaneous vascular lesions.

3 (slide 7) Stimulus of the humoral & cellular immunity for long time (more than 2 weeks) cause : 1-Hyperglobulinemia : increase production of immunoglobin 2. Splenomegaly 3. Appearance of MQs(macrophages) in the peripheral blood. Some patients develop circulating rheumatoid factor *rheumatoid factor "RF" (is the autoantibody this means the antibody is directed against an organism's own tissues ) : sometimes modification happens to IgG and the body will produce immunoglobin against the IgG and its mainly the IgM... so IgM against IgG (IgM anti-igg antibody) the cause of IgG modification( change in shape or structure) is unknown it may be caused by bacteria, viruses, or other factors. *Anti-nuclear-Antibody(ANA) : AB attacks cell's nucleus (slide 8) *bacteria adherence to the inflamed or injured surface of the heart valve proliferation of bacteria dissemination (embolization of the vegetations) (Slide 9) *Why the inflammations occurs mostly in the heart valves? The valves of the heart do not receive any dedicated blood supply. As a result, defensive immune system mechanisms (such as WBCs) cannot directly reach the valves via the bloodstream. If an organism (such as bacteria) attaches to a valve surface and forms a vegetation, the host's immune response is blunted. (Slide 10) Infective endocarditis has often been classified to: -Acute endocarditis mainly caused by S. aureus -Subacute endocarditis mainly caused by Viridans Streptococci (Slide 12) -Left-sided endocarditis can lead to oro ary artery e olizatio a d y oti aneurysms (bulge " "انتفاخ in the wall of a blood vessel occurs mostly in coronary artiries a d rai arteries) "ليس ألن ا من الفطريا بل ألن شكل االنتفاخ يك ن مغزلي mycotic" تسم - Right-sided endocarditis often causes embolization and infarction or infection in the lung. (Slide 13) *Streptococci are most common cause of infective endocarditis Gram-negative Bacilli (HACEK group) - Haemophilus aphrophilus, - Aggregatibacter (Actinobacillus )

4 - Cardiobacterium hominis, - Eikenella corrodens - Kingella kingae. (Slide 15) *Negative cultures means after we take the blood specimen and cultures it we can't find infective agent such as bacteria or fungi. بعد ما نزرع عين الد ما بنالقي ا مستعمرا ل بكتريا ا الفطريا (Slide 17) Libman Sacks endocarditis :Is a form of Nonbacterial endocarditis that is seen in association with systemic lupus erythematosus "SLE"( autoimmune disease)... adverse affect of procainamide ( (اخذناها بالفارما *To make thing more clear SLE disease can cause Libman Sacks endocarditis ( a kind of endocarditis that is not caused by bacteria) In Libman Sacks endocarditis there are vegetations made of (fibrin, neutrophils, lymphocytes, and histiocytes but no M.O. colonies unlike infective endocarditis) Libman-Sacks vegetations(lesions) rarely embolize. **This video may be helpful (Slide 18) * Its recommended to take more than one blood specimen... the sensitivity if we take 3 blood specimen will increase to 99% of detecting the infectious agent. its prefered to take 10ml in each blood specimen so the sum is 30 ml but most labroteries takes 20 ml of blood because its hard to take 30 ml from the patient blood. I Hope this was helpful Good luck Done by: Thaer Omar Qatish

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