Flashcards in L66 – Valvular Heart Diseases Deck (48):
What is the valvular response to mechanical injury- e.g. wear and tear, excessive blood flow?
Damages endothelial layer
>> superficial fibrous
thickening (= scar) over preserved architecture
What is the valvular response to Inflammation?
1. Vascularisation of structure
>> Decrease in size / surface area
What is the valvular response to Degenerative changes?
Distortion and increase in size
Due to deposition of calcium salts, cholesterol... etc
What are the 3 effects of valvular disease?
Describe valve stenosis?
Tightening of the valvular opening
Resulting in decreased forward flow of blood through the opening
Describe Incompetence of valves?
Incomplete closure of the valvular opening, allowing backflow of blood through valvular opening
How does Mitral valve stenosis lead to atrial dilatation?
Mitral stenosis > Decreased outflow from Left atrium to Left Ventricle
> Increase atrial volume and pressure > Atrial dilatation
How does Left Atrial dilatation lead to right heart hypertrophy?
LA dilatation > Increased blood volume and pressure in pulmonary vessels
> Congestion of lungs > pulmonary hypertension
> Right heart hypertrophy
How does Mitral stenosis lead to systemic embolisation?
Mitral stenosis >>> Atrial dilatation
Turbulent blood flow > Atrial thrombus > Systemic thrombus
What is the treatment for valve stenosis?
How does aortic stenosis lead to MI?
Aortic stenosis obstructs left ventricular outflow
LV systolic pressure increases > LV Hypertrophy
> Increase myocardial O2 consumption cannot be met > Myocardial infarction
What is the treatment for valve incompetence?
Name the three common valvular diseases?
Rheumatic fever/ heart disease
What are the 3 subtypes of degenerative, common valvular diseases?
Calcific aortic stenosis
Mitral annular calcification
Myxomatous degeneration of mitral valves (Mitral valve prolapse)
Which valvular abnormality is the most frequent?
Calcific aortic stenosis
What causes the differences in age of onset of calcific aortic stenosis?
Onset in elderly:
individuals: 50’s and 60’s
Previous normal valves: 70’s, 80’s
Why is the age of onset of calcific aortic stenosis earlier in congenital bicuspid valve patients>?
stress on 2 instead of 3 valves >> more easily worn out
What causes calcific aortic stenosis?
Wear and tear induces
calcification >> formation of hard, heaped up calcified mass on valve surface
>> valves become difficult to open
Asymptomatic period for calcific aortic stenosis?
What are some general symptoms of calcific aortic stenosis?
Decreasing physical activity
Syncope during exertion
What are some specific symptoms of calcific aortic stenosis?
What are the signs of calcific aortic stenosis?
Small amplitude/ weak pulse
Displaced apex beat
Systolic thrill + ejection murmur
What is the normal architecture of aortic valve?
3 valvular cusps and 3 distinct commissures
Describe Mitral annular calcification?
Degenerative calcific deposits in the RING** (atrio-ventricular junction) of mitral valve
What are the risk factors of Mitral annular calcification?
Source of thrombi and emboli
Prone to Infective endocarditis
Prone to mitral regurgitation
What group in the population is most affected by Mitral annular calcification?
Women over 60
What are the clinical features of Mitral annular calcification?
Systolic murmur (in half of patients)
Develop into HF alongside existing cardiac diseases
Associated with hypertension
What is another name for mitral valve prolapse?
Myxomatous degeneration of valve
Describe the characteristics of mitral valve prolapse?
"Tenting"/ ballooning of valvular cusps (insertion / deposit of mucopolysaccharides)
>> affected leaflets become thickened, rubbery, fail to fit into AV junction
What causes mitral valve prolapse?
Developmental anomaly of connective tissue
Associated with Marfan's syndrome
What are the general clinical features of mitral valve prolapse?
*Could be asymptomatic altogether*
What are the specific clinical features of mitral valve prolapse?
Stroke (rare in young patients)
Describe Rheumatic fever?
acute, immunologically-mediated, multi-system inflammatory disease
What causes rheumatic fever?
Group A (ß-hemolytic) streptococcal pharyngitis
>> immune response: B lymphocytes in lymph node develops antistreptolysin O (ASO) antibodies
>> cross-react to attacks own body tissue
Duration of onset of rheumatic fever?
Occurs a few weeks after an episode of Group A streptococcal pharyngitis
What is the histology of acute phase rheumatic heart disease?
Foci of fibrinoid degeneration surrounded by lymphocytes
>> ASCHOFF BODIES distinctively in heart, but can disseminate
What is the most important consequence of rhuematic fever>?
Chronic Rheumatic Valvular Heart Disease
What occurs in Chronic Rheumatic Valvular Heart Disease ?
Inflammatory deformit of valves
Mostly mitral or aortic valves affected
What are the characteristics of Rheumatic Valvular Heart Disease?
Leaflets thicken (replaced by fibrous tissue)
Chordae tendinae shorten, thicken, fuse (tighten)
What causes pancarditis and what are its effects?
Acute rheumatic heart disease:
Pancarditis >> pathology in all three layers of the heart (endocardium, Myocardium, Pericardium)
Explain how each heart layer changes in Pancarditis?
1. Endocarditis: verrucae vegetations
2. Myocarditis: myocardial
Aschoff body >> diagnostic
of acute rheumatic carditis
3. Pericarditis: fibrinous
What is the most common site of Infective endocarditis?
Most common sites = left heart valves
Tricuspid valve endocarditis occurs in which patient groups?
Intravenous drug abusers
What are some complications of bacterial endocarditis?
What cardiac vegetation affects debilitated patients?
Nonbacterial thrombotic endocarditis
seen in patients with terminal illness (e.g. cancer)
Explain the effects of Libman Sacks Endocarditis?
Mitral, tricuspid valvulitis in
patients with Systemic Lupus Erythematosis (SLE)
change valve shape, damage chordae tendinae
Vegetation on both surfaces of valves
What are the 3 risks of prosthetic valves?
-Structural failure (time dependent
-Bacterial endocarditis (coagulase negative Staphylococcus)