Week 8 Cardiovascular 3 Flashcards
What is Endocarditis?
Inflammation of the endocardium of the heart
Prototypical lesion = “vegetation” on valves
What are the two main forms of endocarditis?
Infective endocarditis
Clinically important
Non-infective endocarditis
Nonbacterial thrombotic endocarditis (NBTE)
Endocarditis of SLE (Libman-Sacks Disease)
Is infective endocarditis serious?
Clinically serious infection!!!
Colonization / invasion of heart valves or heart chamber endocardium by a microbe
What caues the vegetation of the valves in endocarditis?
Mixture of thrombotic debris and microorganisms
Invade and destroy underlying cardiac tissues
What is the cause of infective endocarditiis?
Most cases caused by bacterial infection
Fungi
How does acute infective endocarditis occur and what is the cause?
Can occur with infection of a previously normal healthy valve
Caused by highly virulent organisms
What is the consequence of acute infetive endocarditis?
Necrotizing, ulcerative, destructive lesions
What is the treatment of acute infective endocarditis
Difficult to cure with antibiotics and usually require surgery
Death frequent days to weeks despite aggressive treatment
What is more common acute or sub acute infective endocarditis?
Sub-acute
What is the cause and outcome of sub acute infective endocarditis?
Organisms of lower virulence
Insidious infections of deformed valves
Vague symptoms –> fever and maybe a murmur
Less destructive
What is the treatment of sub-acute infective endocarditis?
Protracted “wax and wane” course of weeks to months
Cured with antibiotics
What are the causes of infective endocarditis?
Mitral valave prolapse Valvular stenosis (calcification etc) Artificial (prosthetic) valves Unrepaired and repaired congenital defects Bicuspid AV
What disease use to be a major cause of infective endocarditis but not a problem as much any more?
Rheumatic heart disease
What are the different routes a bacteria can get into the blood stream and infected the heart?
Dental abnormalities, IVDU, wounds, bowel cancer
How does Streptococcus viridans affect the heart?
From the heart which cause damage/abnormal valves
50-60% cases
What bacteria on the skin can cause infection endocarditiis?
S.aureus–> 10% to 20% of cases overall esp in IVDU as they damage the skin
What bacteria commonly infects prosthetic heart valves?
Coagulase-negative staphylococci
What is appearance of vegetation in acute IE and what is effected?
Friable, bulky, potentially destructive
Often more than one valve –> AV,MV and the right heart (especially in IVDUS)
What effect does vegetation of acute IE have on the heart?
Can erode the myocardium and cause abscess
What are the clinical features of infective endocarditis?
Fever
Most consistent sign
Rapidly developing fever, chills, weakness
Can be slight or absent, particularly in the elderly
Non-specific symptoms
May be only presentation
Loss of weight / flu-like syndrome.
Murmurs
90% of patients with left-sided IE can be a new defect or a pre-existing condition
New valvular defect or represent a pre-existing abnormality.
What are the complications of Infective endocarditis?
Immunologically mediated conditions e.g. glomerulonephritis
What are the clinical manifestations of infective endocarditis?
Splinter / subungual hemorrhages
Janeway lesions
Erythematous or haemorrhagic non-tender lesions on the palms or soles
Osler’s nodes
Subcutaneous nodules in the pulp of the digits
Roth spots
Retinal haemorrhages in the eyes
What type of patients will commonly have non-bacterial thrombotic endocarditis?
Occurs in debilitated patients (e.g. cancer or sepsis)
What is Non-bacterial thrombotic endocarditis (NBTE) assoicated with?
Assoicated with hypercoagulable state
Hence DVT, PE and mucinous adenocarcinomas!
Pro-coagulant effects of tumour-derived mucin or tissue factor