733
edits
Infective Endocarditis: Difference between revisions
Jump to navigation
Jump to search
→Pathogenesis and Causes
| Line 6: | Line 6: | ||
==Pathogenesis and Causes== | ==Pathogenesis and Causes== | ||
[[Image:Heart1.JPG|thumb|300px|Large lesions on non coronary and left coronary cusps normal valves otherwise]] | |||
[[Image:Heart2.JPG|thumb|300px|Vegetations on tricuspid valve]] | |||
[[Image:Heart3.JPG|thumb|300px|Septic emboli to the conjunctiva]] | |||
Generally, endothelial damage to heart valves predisposes to bacterial infections as it is generally resistant to bacterial infections. This may be caused by turbulent blood flow in damaged valves, septal defects or instrumentation. Although, recent evidence suggests that A-type von Willebrand factor may contribute to S. aureus binding in endothelial intact valves<cite>v</cite>. Specifically, in patients with S. aureus bacteremia, native valve endocarditis was reported to be in 19% of patients, and 38% in those with prosthetic valves<cite>vi</cite>. | Generally, endothelial damage to heart valves predisposes to bacterial infections as it is generally resistant to bacterial infections. This may be caused by turbulent blood flow in damaged valves, septal defects or instrumentation. Although, recent evidence suggests that A-type von Willebrand factor may contribute to S. aureus binding in endothelial intact valves<cite>v</cite>. Specifically, in patients with S. aureus bacteremia, native valve endocarditis was reported to be in 19% of patients, and 38% in those with prosthetic valves<cite>vi</cite>. | ||
| Line 22: | Line 25: | ||
Gram negative bacilli IE is rather uncommon, the HACEK organisms (Haemophillus spp, Actinobacillus, Cardiobacterium hominis, Eikenella corrodens, Kingella spp) are responsible for approximately 3% of endocarditis cases and are the most common cause for gram negative endocarditis in non-intravenous drug users<cite>xi</cite>. Non-HACEK organisms are a rare cause for endocarditis and only account for <1-2% of causes. | Gram negative bacilli IE is rather uncommon, the HACEK organisms (Haemophillus spp, Actinobacillus, Cardiobacterium hominis, Eikenella corrodens, Kingella spp) are responsible for approximately 3% of endocarditis cases and are the most common cause for gram negative endocarditis in non-intravenous drug users<cite>xi</cite>. Non-HACEK organisms are a rare cause for endocarditis and only account for <1-2% of causes. | ||
Fungal endocarditis occurs in patients who receive prolonged parenteral nutrition or antibiotics through intravenous catheters. It has also been described in intravenous drug users. Patients are often immunocompromised. The most common organisms implicated are Candida species, Histoplasma capsulatum, and Aspergillus. Mortality rates associated with fungal endocarditis exceed 80%<cite>xii</cite>. | Fungal endocarditis occurs in patients who receive prolonged parenteral nutrition or antibiotics through intravenous catheters. It has also been described in intravenous drug users. Patients are often immunocompromised. The most common organisms implicated are Candida species, Histoplasma capsulatum, and Aspergillus. Mortality rates associated with fungal endocarditis exceed 80%<cite>xii</cite>. | ||
==Diagnosis== | ==Diagnosis== | ||