Infective Endocarditis Lecture Notes PDF

Field of Medicine Medicine Program Lecture : (Infective Endocarditis ) Dr : (SANAA MAHMOUD ) Date :18/ 08 /2024 FIRST QUESTION IN OUR LECTURE : EXPLAIN DEFINITION, ETIOLOGY AND PATHOGENESIS OF INFECTIVE ENDOCARDITIS DEFINITION: Suppurative inflammation that affects endothelial s...

Field of Medicine Medicine Program Lecture : (Infective Endocarditis ) Dr : (SANAA MAHMOUD ) Date :18/ 08 /2024 FIRST QUESTION IN OUR LECTURE : EXPLAIN DEFINITION, ETIOLOGY AND PATHOGENESIS OF INFECTIVE ENDOCARDITIS DEFINITION: Suppurative inflammation that affects endothelial surface of heart. Organisms: Highly virulent as staph aureus, strept.hemoIytïcus and gonococci.  TYPES: *Acute: *Subacute: -Affects normal heart valves -Often affects damaged heart -Rapidly destructive valves -If not treated, usually fatal -Indolent nature within 6 weeks -If not treated, usually fatal by -Commonly Staph→ one year Metastatic foci -Commonly Streptococci viridans  Risk Factors: *Injection drug use Structural cardiac 100 times risk in young abnormality Staphylococcus aureus 75% of patients will have *Other risks: a preexisting structural 1.Poor dental hygiene cardiac abnormality. 2.Hemodialysis 10-20% have congenital 3.DM heart disease 4.HIV  Risk Factors ; Cardiac Abnormality HIGH RISK: MODERATE RISK: 1.Previous IE 4.5 Mitral Valve Prolapse or Mitral valve (2.5 to 9)% prolapse /thickened leaflets- 5 to 8 times (100/100 000 person years) 2.Aortic valve Mitral Stenosis disease12 to 30% Tricuspid valve 3.Rheumatic valve Pulmonary Stenosis disease Hypertrophic Obstructive 4.Prosthetic valve Cardiomyopathy (HOCM) 5.Coarctation 6.Complex cyanotic LOW/NO RISK ASD (secundum) congenital  Lesions: Mitral & aortic valves are most commonly affected. Tricuspid is affected in IV drug abusers. The mural endocardium may be also affected. The affected valve and mural endocardium show suppurative inflammation + vegetations.  Vegetations are: * N/E: multiple, large, yellowish, friable found anywhere on the cusps. ”M/P: the vegetations consist of platelet, fibrin, bacteria, numerous neutrophils & pus cells. Myocardial shows microabscesses. The pericardial sac is filled with pus. SECOND QUESTION IN OUR LECTURE : DESCRIBE C.P,COMPLICATIONS AND INVESTIGATIONS OF INFECTIVE ENDOCARDITIS ???  CLINICAL PICTURE: 1. Valvulitis: may result in changing cardiac auscultatory findings or the development of congestive heart failure. 2. In bacteremia or fungemia: fever (high in acute, mild in subacute ), fatigue, tachycardia , sweating , clubbing and weight loss (in subacute cases) are usually present. 3. Embolic manifestations: originate from a source of infection that becomes complicated with bloodstream infection: -Kidney→renal infarction/hemorrhages and crescentic glomerulonphritis may lead to renal failure -Spleen→splenic infarctions/hemorrhages/abscesses, splenomegaly. -Brain : aneurysms, stroke, deficit according to affected site. -Liver : pyogenic liver abscesses  CLINICAL PICTURE(CONT.): -Mesentric: Septic embolic occlusion, mycotic aneurysms of the superior mesenteric artery. -Skin : Janeway lesions: painless, small, erythematous macules in the palms or soles, occur in 6% of cases, denotes septic micro-emboli esp. in Staph aureus infection. -Lung:The right-sided endocarditis can be complicated by pulmonary injury→pulmonary embolism, empyema,lung abscess. 4.Immunological manifestations: *Skin: petechiae in skin or mucosal surfaces. *Eyes: subconjunctival hemorrhage, Roth spots on fundus EX (white-centered retinal hemorrhages). * S.C tissues:Splinter Hge under nails,Osler nodes are tender, purple-pink nodules with a pale center and an average diameter of 1 to 1.5 mm,caused by immune complex deposition and the resulting inflammatory response.  Investigations: 1. Blood CS :The hallmark of bacteremia in IE is demonstration of a continuous bacteremia via 2-3 sets of blood cultures. They identify the specific disease-causing bacteria and the best antibiotics to use against them. 2.Echocardiography: which uses ultrasound waves, can produce images showing heart valve vegetations and damage to the heart. 3. Other investigations: According to manifestations: -Urine analysis, CS -Abd US -Fundus EX -CT chest -CT brain LAST QUESTION IN OUR LECTURE: ENUMERATE PRVENTION AND TREATMENT STRATEGIES IN INFECTVE ENDOCARDITIS??  Prophylaxis : Antibiotic prophylaxis is strongly recommended in high-risk patients undergoing medical procedures with bacteraemia. -Prosthetic cardiac valve or prosthetic material used for cardiac valve repair -Prior infectious endocarditis -CHD Unrepaired cyanotic CHD, including palliative shunts and conduits Completely repaired CHD with prosthetic material or device ( 10mm, 7.or persistent sepsis despite adequate antibiotic therapy for more than 7 days.  Prognosis: The mortality rate within the first 30 days of infection has been reported to be ~20% but survival without antibiotic therapy is unlikely. Improved general health care, improved dental care, early treatment, and antibiotic prophylaxis have decreased the mortality rate.