Path: Valvular Disease Flashcards
What is heart valve stenosis?
Slow onset of an inability of a valve to open completely due to leaflet distortion, fibrosis or calcification.
What is heart valve insufficiency?
Slow or Rapid onset of an inability to close a valve completely leading to regurgitation. Caused by cusp disease or damage to associated valve structures.
Which two organs are most commonly affected secondary to valvular disease?
Lungs and Liver due to blood congestion
Complication of a congenital bicuspid aortic valve.
Rapid onset of calcification and stenosis
What is the normal pressure gradient in the aortic valve area and the pressure gradient in a stenotic valve?
Normal: zero
Stenotic: any pressure gradient, disease becomes serious around 50mmHg.
What is the cause of Senlle degenerative calcific aortic stenosis?
Normal wear and tear on the valve.
-senile means a condition that occurs as people age
Characteristic of calcific aortic stenosis on biopsy.
Osseous metaplasia: the tissue looks like bone
Morphological change of the heart with aortic valve insufficiency.
Left Ventricular Hypertrophy: the regurgitated blood increases afterload (end diastolic volume) and the ventricle dilates and contract with greater force due to increased blood volume.
What are 4 general causes of aortic insufficiency?
- Aortic Root dilation: syphilis, marfan, ankylosing spondylitis
- Aortic Cusp Abnormality: arthritis, marfan, HTN
- Increased Afterload: supravalvular aortic stenosis (coarctation), systemic HTN
- Pharmacologic: Phentermine-Fenfluramine (caused pulmonary HTN).
What are two general causes of mitral valve insufficiency?
- Abnormalities of leaflets and/or commissures.
- prolapse, inflammation, infection - Abnormalities of the Tensor Apparatus.
- papillary muscles, chordae tendinae, mitral annulus, calcification
Most common cause of mitral valve prolapse.
Hereditary Connective Tissue Disorder
-Marfan, Ehlers-Danlos
What changes occur to the tissue structure of a Floppy Mitral Valve (type of mitral valve prolapse)?
Valve leaflets become thick and rubbery allowing “billowing up” of valve into the LA. The chordae tendinae elongate and thin out.
What microscopic tissue type is lost in mitral valve prolapse?
Type III collagen leading to loss of structural integrity.
How can mitral valve prolapse lead to infective endocarditis?
Changes in valve morphology alter the normal flow of blood in the area allowing stasis and a reservoir for bacterial colonization.
How can mitral valve prolapse lead to stroke or systemic infarct.
Changes in valve morphology alter the normal flow of blood in the area allowing stasis and thrombus formation which can embolize to other sites in the body.
What is Mitral Annular Calcification?
Buildup of calcium nodules on the valve leaflets. Calcium nodules anywhere can lead to thrombus formation or allow bacterial growth.
Major cause of Mitral Valve Stenosis.
Rheumatic Fever
Major cause of Acute Infective Endocarditis
Staph aureus: very fast progression (days to weeks)
Major cause of Subacute Infective Endocarditis
Viridans Strep family: slow progression (weeks to months)
What else should a physician worry about in a patient that is diagnosed with endocarditis caused by Strep. bovis?
GI malignancy: this bug is part of normal GI flora and usually only undergoes hematogenous spread with tumor invasion of colon mucosa.
Main pathogen that causes infective endocarditis in debilitated alcoholics.
Strep. pneumoniae
Main bug that causes IE in IV drug abusers.
Staph aureus
Main bugs that cause IE in patients with prosthetic heart valves.
Early: Staph epidermidis
Late: Streptococci sp.
What is the difference in the valve tissue in acute IE vs. Subacute IE?
The valve tissue does not have to be damaged for bacteria to infect in acute, however, the valves must be damaged in Subacute.
How does Subacute IE progress?
- Valves are damaged
- Thrombi form (non-bacterial thrombotic endocarditis)
- bacteria colonize thrombotic valve
Which population developed mostly Right Heart IE?
IV drug users
-acute IE caused by S. aureus
Which side of the valves do most IE vegetations form?
Atrial Side of AV valves
Ventricular side of Semilunar Valves
(vegetations consist of fibrin and bacteria)
Name 4 sites of complications that arise from left-sided IE.
- Brain: abscess, infarct, meningitis
- Heart: MI
- Spleen: abscess
- Kidneys: abscess
Name the site of complication of right-sided IE.
Lungs: abscess, infarct, pneumonia
How can IE lead to glomerulonephritis?
Buildup of Ag-Ab complexes in the glomerulus
Two most common organisms that cause fungal IE.
- Candida
2. Aspergillus
Only type of Vegetation to extend to the Chordae Tendinae.
IE
Only type of Vegetation to extend to both sides of the valves.
Libman Sacks Endocarditis (LSE)
-complication of SLE
Complications of vegetations that form due to Antiphospholipid Syndrome.
Hypercoagulable State: Pregnancy Loss (thrombi occlude placental blood flow)
Thrombocytopenia (many clots form leading to low platelet counts and inability to clot should an actual injury occur)
2 major complications of heart valve replacement.
Hemolysis: prosthetic valves alter blood flow thru the area and can increase shear force on RBCs leading to lysis.
Valve Stenosis: exuberant healing of tissue can overgrow around the valve and block it.
