Valvular Heart Disease Flashcards
Valvular interstitial cells
-most abundant cells in heart valves, distributed throughout all layers, synthesize ECM and matrix matalloproteinases (MMPs)
Three types of valve pathology
- nodular calcification begins in interstitial cells: calcific aortic stenosis
- damage to collagen that weaken leaflets: mitral valve prolapse (MR)
- fibrotic thickening: key feature in rheumatic heart disease (MS)
Three types of valve disease
- stenosis: failure of valve to open completely, which impedes flow
- insufficiency (regurgitation or incompetence): primary-mitral valve prolapse, secondary-functional mitral regurgitation (normal leaflets, will improve w/ heart failure treatment/ischemia)
- combined stenosis & insufficiency
Valve issue seen in marfan sydrome
aortic regurgitaion
Acute and Chronic valve disease
- acute: severe or lethal, no time to adapt to hemodynamic changes
- chronic: better tolerated due to chamber adaptation
Result of mitral or aortic insufficiency
- volume overload
Result of aortic stenosis
- pressure overload
- cardiac hypertrophy
Calcific aortic stenosis
- most common valvular abnormality
- consequence of age “wear & tear”, hyperlipidemia, HTN, inflammation, atherosclerotic issues, deposition of hydroxyapatite
- SATINS NOT HELPFUL
- BICUSPID valves at increased risk, prone to endocarditis
Causes of valvular diseases
- acquired
- genetic
Genetics of AV stenosis
- 1%, possibly hereditary
- significant AS at age 50 (EARLIER THAN ACQUIRED)
Nonrheumatic AS feature
- free edge is NOT effected
LaPlces’s Law and AS
- in order to reduce stress of increased pressure ventricle wall must get thicker
Result of hypertrophic ventricle
- myocardium tends to be ischemic due to diminished microcirculatory perfusion/demand-supply missmatch
- ANGINA even in ABSENCE of CAD
Prognosis of AS (bicuspid/tricuspid)
- bicuspid AS progresses faster
- treatment is surgical valve replacement
Mitral annular calcification & swinging calcified amorphous tumors (CATs)
- calcific deposits develop in the FIBROUS ANNULUS
- usually DOES NOT AFFECT valvular function but can lead to: regurgitation, stenosis, arrhythmias (by calcium deposits penetrating deep to impinge on AV conduction system)
Large risk with swinging CATs and mitral annular calcification
- nodules provide site for thrombus formation
- increased risk of embolic stroke
- endocarditis
Acute rheumatic fever
- inflammatory disease occurring 10 days to 6 wks after episode of GROUP A STREP PHARYNGITIS
- acute rheumatic carditis is a common manifestation and may progress over time to rheumatic heart disease
Rheumatic heart disease
- fibrotic valvular disease, involving mitral valve leading to MITRAL VALVE STENOSIS
- result of RF acute rheumatic carditis progression
Pathogenesis of RF
- antigens to group A strep cross react with host proteins: antibodies against strep M proteins also recognize cardiac self-antigens
- antibody binding can activate complement, cytokine production stimulated by T cells leads to macrophage activation (ASCHOFF BODIES)
Clinical features of RF
- migratory polyArthritis of large joints
- panCarditis
- subcutaneous Nodules
- ERythema marginatum of the skin
- sydenham Chorea: involutary rapid, purposeless movements
Diagnostic ‘Jones criteria’
- evidence of preceding group A strep infection
- 2 major manifestations OR 1 major + 2 minor manifestations
Antibodies of two enzymes detected in RF patients due to strep
- steptolysin O
- DNase B
Acute carditis symptoms with RF
- pericardial friction rubs
- tachycardia & Afib
- functional mitral valve insufficiency due to cardiac dilation/CHF
- 1% die of fulminant RF involvement of heart
Recurrence of RF
- increased vulnerability w/ subsequent pharyngeal infections
- damage is cumulative
- clinical manifestations appear years or decades after initial episode of RF and depend on valve involved
Treatment for rheumatic heart disease
- favor percutaneous balloon valvuloplasty > surgery
- MITRAL VALVE=REPAIR, AORTIC VALVE=REPLACE
Different types of chronic rheumatic heart disease
- vegetative valve disease*
- RHD
- infective endocarditis
- nonbacterial thrombotic endocarditis
- libman sacks endocarditis (in patients with SLE)
Valves involved in chronic rheumatic heart disease
- mitral valve alone: 40%
- mitral & aortic: 40%
- aortic alone: 20%
- tricuspid: occasional
- pulmonic valve: NEVER INVOLVED
Characteristic feature of anterior MV leaflet on ultrasound
- ‘hockey stick’ (diastole)
Ventricle changes in chronic rheumatic heart disease
- congestive changes in lungs may induce pulmonary vascular/parenchymal changes; over time, these can lead to RIGHT ventricle hypertrophy
- left ventricle in unaffected by isolated mitral stenosis
Side of MV more effected in rheumatic heart disease
ventricular side
Appearance of MS in rheumatic heart disease
- fish mouth
- FREE EDGE IS EFFECED
- candle stick appearance
Major causes of mitral regurgitation
- degenerative mitral disease (MVP): 65%
- ischemic mitral regurgitation: 27%
Cause of mitral valve prolapse
- myxomatous degeneration of mitral valve
Mitral valve prolapse
- one or both leaflets are floppy and prolapse into the left atrium during SYSTOLE
- F:M=7:1 i.e. FEMALES MORE THAN MALES
- most often incidental finding
Histology of MVP
- thickening of spongiosa layer w/ deposition of mucoid (myxomatous) material, called MYXOMATOUS DEGENERATION
- attenuation of collagenous fibrosa layer
- thrombi on atrial surface
- calcifications at base of posterior MV leaflet
Clinical features of MVP
- usually anymptomatic, mid systolic click, murmur
- DIAGNOSIS IS CONFIRMED BY ECHO
Treatment of MVP
- most common cause for mitral valve surgery
- NATIVE valve repair over valve replacement
Carcinoid syndrome
- systemic disorder marked by flushing, diarrhea, dermatitis, & bronchoconstriction caused by bioactive serotonin released by carincoid tumors
Result of serotonin release
fibrosis
Carcinoid syndrome spread
- 50% of patients w/ liver metastasis will develop carcinoid heart disease
Parts of heart effected by carcinoid heart disease
- endocardium, & valves of RIGHT heart
- left heart can occur in setting of PFO & ASD and direct right to left flow
Plaque deposits in carcinoid heart disease similarities
- similar to lesions occurring in patients taking FENFLURAMINE (appetite suppressant) or ERGOT ALKALOIDS (migraines)
- agents also affect serotonin release
Clinical manifestation of carcinoid heart disease
- exam: elevated JVP, palpable RV impulse, murmurs of tricuspid & pulmonary valve regurgitation
Tri-layered structure of cardiac valves
- fibrosa: dense collagenous outflow surface, connected to supporting structures
- spongiosa: central core loose CT, proteoglycan rich
- ventricularis/atrialis(depending on chamber it faces): elastin rich layer on inflow surface
