Valvular Heart Disease Flashcards
Describe the main causes of valvular heart disease
- Rheumatic heart disease
- Calcific aortic disease – most common in Western countries
- Valve ring dilation and leaflet degeneration
- Infective endocarditis
- Congenital heart disease
- Acquired stenoses of the aortic and mitral valves account for approximately two-thirds of all valve disease and virtually always a chronic process
Rheumatic fever
“Licks the joint, but bites the whole heart”
William Boyd
A sore throat can lead to a broken heart
RF is a
It is a systemic, post streptococcal, non suppurative inflammatory disease affecting the heart and extra- cardiac sites (joints, brain, skin etc.)
RF epidemiology
The incidence of RF is still high in developing countries
The disease affects children and young adults (5-15years)
The disease follows 10 days to 6 weeks after upper respiratory infection or via skin infection with Group A Beta hemolytic streptococci
RF caused by _____________
Group A Beta hemolytic streptococci
GABHS
Presence of GABHS is shown by
streptolysin O and DNAse B, in sera of most patients
Theories of Pathogenesis of RF
Induction of hypersensitivity & autoimmunity
Toxic products of streptococci
Sensitized T-lymphocytes may lead to cardiac injury
Note: Not by direct infection of Streptococci.
It is thought that antibodies directed against the M proteins of certain strains of streptococci cross-react with glycoprotein antigens in the heart, joints, and other tissues.
Migratory (Poly)Arthritis
Most common (75%) – and earliest manifestation
Involves larger joints: knees, ankles, wrists and elbows in a fleeting way
The pain can precede and appear to be disproportionate to the other findings
An inverse relationship between the severity of arthritis and the severity of cardiac involvement
Sydenham’s Chorea
St Vitus’ dance – jerky, involuntary movements
Often in prepubertal girls (8-12 years old)
Neuropsychiatric disorder
emotional lability and other personality changes.
Choreiform movements can affect the whole body, or just one side
Chorea disappears with sleep and is made more pronounced by purposeful movements
Subcutaneous Nodules
Firm, painless lumps, mainly on the hands, feet, occiput and back
Usually 0.5 to 2 cm in diameter and often found in crops of about three
Appearing two to three weeks after the onset of fever
Erythema Marginatum
Not itchy
Redness which gradually spreads out and the skin in the center of lesions returns to normal
Usually on the front of the abdomen and chest/back – it can develop on the limbs but almost never on the face
Tends to come and go lasting from one or two days to months or years
Carditis
Most serious manifestation
Accounts for essentially all of the associated morbidity and mortality
Isolated mitral valvular disease (90%) or combined aortic and mitral valvular disease
ASCHOFF’s BODIES formed in RHD – inflammation –foci of heart disease
Chronic Rheumatic Valvular Disease
Mitral & Aortic Valves pathology:
Thickening of valve leaflet, especially along the lines of closure
Fusion of commissures
Result is mitral or aortic stenosis, insufficiency, or both
Usually no clinical manifestations even for decades after Rheumatic fever
Small vegetations are formed at injured parts
2 types of endocarditis
infective = acute + subacute
non infective = rheumatic + non-bacterial thrombotic + Libman-Sacks
What is Infective Endocarditis?
An infection involving the inner layer of the heart – typically the heart valves
All of which can either have an acute presentation or a subacute presentation
4 types of
infective endocarditis
- native valve IE
- Prosthetic valve IE
- IV drug abuse IE
- Nosocomial IE
ACUTE vs SUBACUTE IE
ACUTE:
- affects NORMAL heart valves
- rapidly destructive
- metastatic foci
- commonly Staph
- untreated –> fatal within 6 weeks
SUBACUTE:
- affects damaged heart valves
- slow nature
- evidence of healing
- less virulent organism
- if not treated usually fatal by one year
Predisposing factor for (systemic) acute cases of IE
- Neutropenia
- Immunodeficiency
- Malignancy
- Diabetes mellitus
- Alcohol or intravenous drug abuse
- Indwelling vascular catheters
Predisposing factor (CARDIAC) => subacute cases of IE
- Rheumatic Heart Disease
- Myxomatous mitral valve
- Degenerative calcific valvular stenosis
- Bicuspid aortic valve (whether calcified or not)
- Artificial (prosthetic) valves
Describe the pathophysiology of infective endocarditis
The ability of an organism to cause endocarditis is the result of an interplay between the predisposing structural abnormalities of the cardiac valve for bacterial adherence, the adhesion of circulating bacteria to the valvular surface, and the ability of the adherent bacteria to survive on the surface and propagate as embolism
Describe the clinical manifestations of infective endocarditis
CARDIAC
Murmurs
Heart failure etc
NON CARDIAC
Embolic phenomena
Immune complex deposition
Septic signs
Symptoms of IE
ACUTE High grade fever and chills Shortness of breath, cover Painful joints and muscles Abdominal pain Pleuritic chest pain Back pain
SUBACUTE Low grade fever Anorexia, weight loss Painful joints and muscles Abdominal pain Fatigue Nausea/Vomiting
Signs of IE
Signs Septic Signs: • Fever • Weight loss • Pallor • Clubbing • Splenomegaly Immune complex deposition: • Inflammation may affect any vessel: vasculitis • Glomerular nephritis-proteinuria, hematuria • Osler’s nodes • Roth spots • Rheumatoid factor positive
Embolic phenomena:
• Septic embolism: infracts, abscess, gangrene in any organ
• Splinter hemorrhages: conjunctival and subungual
• Janeway lesions
• Mycotic aneurysm
• Petechaie
Cardiac Manifeatations
New regurgitant murmurs- 30-35% or change in pre existing murmur
Most commonly mitral or aortic valve is involved
Right sided valves are involved in IV drug abusers
Pericarditis Cardiac arrhythmia maybe heart block Valvular insufficiency leading to CHF Aortic root or myocardial abscesses Arterial emboli, infarcts, mycotic aneurysms
SKIN MANIFESTATIONS OF IE
JANEWAY LESIONS (embolic phenomena)
+
OSLERS NODES
(immune complex deposition)
Osler’s Nodes
More specific
Painful and erythematous nodules
Located on pulp of fingers and toes
More common in subacute IE
Janeway Lesions
More specific
Erythematous, blanching macules
No pain
Located on palms and soles
Non – specific skin manifestations of IE
Petechiae (Often located on extremities or mucous membranes)
Splinter Haemorrhages (under nail bed)
Roth spots
(Seen most commonly in acute bacterial endocarditis.
A red spot (caused by hemorrhage) with a characteristic pale white center.
This white center usually representsfibrin-platelet plugs)
Diagnosing IE
Major criteria:
- blood culture positive
- endocardial involvement evidence
Minor criteria:
- predisposing factor
- temperature of body
- vascular phenomena
- immunologic phenomena
- microbiologic evidence
Cardiomyopathy
Cardiomyopathy is a disease of the heart muscle – which can affect any age group
Two types of Cardiomyopathy
- Primary
Develops all by itself (intrinsically) – can be genetic, mixed or acquired - Secondary
Develops as a way to compensate for an underlying disease (extrinsic cause) – such as hypertension, valvular diseases, infections etc.
e.g. “Ischaemic cardiomyopathy”
3 Major classes of cardiomyopathies
- DILATED - 90%
- HYPERTROPHIC
- RESTRICTIVE
