Valvular heart disease

Question 1

Clinical presentation of calcific aortic stenosis

Answer 1

70s-90s

• Hypertrophied myocardium causes ischemia and angina pectoris
• Both systolic and diastolic function may be impaired
• Surgical valve replacement is necessary
• Age associated wear and tear
• Statins don’t help with valvular calcific degeneration

Question 2

Pathogenesis of calcific aortic stenosis

Answer 2

• If the valve is bicuspid, the issues precipitate faster
• Hydroxyapatite is the most common deposit
• Abnormal valves have cells that are like osteoblasts
• Chronic injury from hyperlipidemia, HTN, inflammation, atherosclerosis
• Left ventricular outflow obstruction leads to gradual narrowing of the valve orifice
• Increasing pressure gradient causes concentric LVH

Question 3

Morphology of calcific aortic stenosis

Answer 3

• Mounded calcified masses within the aortic cusps
• Prevent the cusps from opening fully
• Layered architecture of the valves are preserved
• Commissural fusion is not usually seen

Question 4

Clinical presentation of Calcific stenosis of congenitally bicuspid aortic valve

Answer 4

• Valves become incompetent due to aortic dilation, cusp prolapse, or infective endocarditis
• Usually asymptomatic early in life
• Aortic stenosis or regurgitation, infective endocarditis, and aortic dilation or dissection
• 50% of cases become calcified

Question 5

Pathogenesis of Calcific stenosis of congenitally bicuspid aortic valve

Answer 5

• Some show familial clustering with associated aorta or left ventricular outflow tract malformations
• NOTCH1 is strongly associated with these abnormalities

Question 6

Morphology of Calcific stenosis of congenitally bicuspid aortic valve

Answer 6

• Two functional cusps of unequal size, larger cusp has a midline raphe
• Raphe is a common site for the calcific deposits

Question 7

Clinical presentation of mitral annular calcification

Answer 7

-Women older than 60 or individuals with mitral valve prolapse

• Usually do not effect valvular function
• May cause: regurgitation, stenosis, or arrhythmias
• At a higher risk for embolic stroke
• Provides a location for infective endocarditis
• Visualized on echo or x ray by ring like opacities

Question 8

Pathogenesis of mitral annular calcification

Answer 8

-Calcific deposits in the mitral valve typically occur in the fibrous annulus

Question 9

Morphology of mitral annular calcification

Answer 9

-Irregular, stony hard, occasionally ulcerated nodules at the base of the leaflets

Question 10

Clinical presentation of Mitral valve prolapse (myxomatous degeneration)

Answer 10

Females

• Usually an incidental finding
• Mid-systolic clicks
• Minority display angina and dyspnea
• Serious complications: infective endocarditis, mitral insufficiency, stroke, arrhythmias
• Risk of serious complications is low but higher in men, older patients, and those with mitral regurgitation or arrhythmias

Most common cause of mitral valve surgery

Question 11

Pathogenesis of mitral valve prolapse (myxomatous degeneration)

Answer 11

-Sometimes associated with Marfan syndrome (fibrillin-1) and dysregulates TGF-B signaling

Question 12

Morphology of mitral valve prolapse (myxomatous degeneration)

Answer 12

• Leaflets are floppy and balloon back into the left atrium
• Interchordal ballooning (hooding) of the mitral leaflets that are enlarged, redundant, thick and rubbery
• Tendinous cords are elongated, thinned or even ruptured
• Myxomatous degeneration: thickening of the spongiosa layer from deposition of mucoid material
• Fibrous thickening of the leaflets, fibrous thickening of endocardium, thickening of the mural endocardium, thrombi on the leaflets, focal calcifications

Question 13

Clinical presentation of rheumatic heart disease

Answer 13

Children

Rate has declined due to increased diagnosis and treatment, and improved sanitation

• migratory polyarthritis, pancarditis, subq nodules, erythema marginatum, Sydenham chorea
• Acute: 10 days to 6 weeks after infection in children. Abs to streptolysin O and DNase B. Contain pericardial friction rubs, tachy, and arrhythmias
• After initial infection there is increased vulnerability to reactions with subsequent infections
• Damage to the valves is cumulative
• Surgical replacement of the valves

Rheumatic fever –> RHD

RHD only cause of mitral stenosis

Question 14

Pathogenesis of rheumatic heart disease

Answer 14

• Acute, immunologically mediated, multisystem inflammatory disease occurring a few weeks after an episode of group A strep pharyngitis
• RHD: deforming fibrotic valvular disease involving the mitral valve
• CD4 cells against M proteins recognize cardiac self antigens causing cytokine production and macrophage activation

Question 15

Morphology of rheumatic heart disease

Answer 15

Anitschkow cells: pathognomonic for RF. Caterpillar cells

• Aschoff bodies: distinctive lesions in the heart with T cells and anitschkov cells.
• Pancarditis: inflammation in any of the layers of the heart
• Fibrinoid necrosis in the cusps or tendinous cords
• Verrucae: vegetations along the lines of closure on the cusps
• MacCallum plaques develop in the left atrium due to regurgitant jets
• Mitral valve: leaflet thickening, commissural fusion, thickening and fusion of the tendinous cords
• Fish mouth or buttonhole stenoses
• Right ventricular hypertrophy and pulmonary vascular changes may occur

Question 16

Clinical presentation of infective endocarditis

Answer 16

• Acute: infection of a previously normal heart valve by staph aureus that destroys. Difficult to destroy with drugs alone. May need surgery
• Subacute: strep viridans. That are insidious and overall less destructive. Cures can be achieved over weeks to months. Abx.
• Abx prophylaxis is necessary after previous RHF
• Acute: rapidly developing fever, chills, weakness and loassitude
• Mumurs on 90% of individuals
• DUKE criteria
• Glomerulonephritis, microthromboemboli, Janeway lesions, Osler nodes, and Roth spots

Question 17

Pathogenesis of infective endocarditis

Answer 17

• Microbial infection of the heart valves or mural endocardium leading to the formation of vegetations of thrombotic debris and organisms
• Associated with the destruction of the underlying cardiac tissues
• Most common are bacterial
• Previously normal valves
• RHD may precede this but also mitral valve prolapse, degenerative calcific valvular stenosis, bicuspid aortic valve, artificial valves, and unrepaired and repaired congenital defects
• Microorganism seeding to bloodstream

Question 18

Morphology of infective endocarditis

Answer 18

• Vegetations on heart valves that are friable and bulky
• Aortic and mitral valves are most common
• Vegetations are prone to embolization
• Granulation tissue
• Fibrosis, calcification and a chronic inflammatory infiltrate develop over time

Question 19

Common organisms implicated in infective endocarditis

Answer 19

• S. viridans: after dental procedures
• S. aureus: acute and IV drug users
• S. Epidermidis: prosthetic valves

Question 20

Clinical presentation of nonbacterial thrombotic endocarditis

Answer 20

• Can cause infarcts in the brain, heart, or elsewhere
• Often in debilitated patients (marantic endocarditis)
• Concomitantly with DVT and PE
• Striking association with mucinous adenocarcinoma that also causes Trousseau syndrome
• Endocardial trauma may also cause this

Question 21

Pathogenesis of nonbacterial thrombotic endocarditis

Answer 21

• Deposition of small sterile thrombi on the leaflets of cardiac valves
• Develop on the line of closure of the leaflets or cusps

Question 22

Morphology of nonbacterial thrombotic endocarditis

Answer 22

• Bland thrombi that are loosely attached to the underlying valve
• Non-invasive vegetations
• Often track along pulmonary artery catheters

Question 23

Clinical presentation of endocarditis of SLE (Libman Sacks Disease)

Answer 23

• Steroids has decreased this risk
• Also can occur in the setting of antiphospholipid syndrome
• Mitral valve involvement is the most common

Question 24

Pathogenesis of endocarditis of SLE (Libman Sacks Disease)

Answer 24

-Mitral and tricuspid valvulitis with small, sterile vegetations

Question 25

Morphology of endocarditis of SLE (Libman Sacks Disease)

Answer 25

• Single or multiple, sterile, pink vegetations with a verrucous appearance
• Finely granular, fibrinous eosinophilic material
• Lesions also have fibrinous necrosis

Question 26

Clinical presentation of Carcinoid Syndrome

Answer 26

-Systemic disorder with flushing, diarrhea, dermatitis, and bronchoconstriction

Question 27

Pathogenesis of carcinoid syndrome

Answer 27

• Caused by release of serotonin from carcinoid tumors
• Cardiac lesions occur after there is a large hepatic metastatic burden
• Left side of the heart is protected from breakdown in the pulmonary vasculature
• Serotonin, kallikrein, bradykinin, histamine, prostaglandins, and tachykinins
• Levels of serotonin directly correlate to the severity of the cardiac lesions
• Similar lesions from taking fenfluramine or ergot alkaloids

Question 28

Morphology of carcinoid syndrome

Answer 28

• Endocardium and the valves of the right heart are most affected
• Distinctive, glistening white intimal plaquelike thickenings of the endocardial surfaces
• Composed of smooth muscle cells and sparse collagen fibers in an MPS rich matrix
• Tricuspid insufficiency and pulmonary stenosis