Acquired Valvular and Endocardial Disease Flashcards
What are other terms for retrograde blood flow through a valve?
Valvular regurgitation/insufficiency
What does stenosis of a cardiac valve generally lead to?
Pressure overload hypertrophy of the myocardium proximal to the obstruction. Once compensatory mechanisms are exhausted, dilation and fialure of the chamber proximal to the valve occurs
What does valvular regurgitation lead to?
Hypertrophy and dilation of the chamber proximal to the valve
What is the common infecting agent in rheumatic fever?
Streptococcus pyogenes (group A Beta-hemolytic Streptococcus)
What is the pathogenesis triad of rheumatic fever?
- genetically susceptible host
- rheumatogenic strain of of GAS
- abnormal host immune response
What regions of the heart are affected in acute rheumatic heart disease?
Endocardium, myocardium, pericardium (pancarditis);
What are changes that occur in the myocardium in rheumatic heart disease?
Aschoff bodies, Anitschkow cells
What are Aschoff bodies? What are Anitschkow cells?
- AB - Characteristic granulomatous lesion of rheumatic myocarditis
- AC - Cells w/i the Aschoff bodies whose nuclei have an “owl eye” appearance in cross section and appear as caterpillars in longitudinal cuts
What are the characteristic changes that occur in the pericardium during Rheumatic Fever?
Pericarditis with fibrin deposits between parietal and visceral pericardium (“Bread and butter pericarditis”)
The biopsy of a heart is shown. What are the distinct findings in this biopsy? What is your Dx?
Anitschkow cells within Aschoff bodies; Rheumatic Fever
What are the criteria to Dx Rheumatic Fever?
The Jones Criteria
Either two major criteria or one major and two minor criteria
- Major criteria - carditis (murmurs, cardiomeg., pericarditis, CHF), polyarthritis, chorea, erythema marginatum, subcutaneous nodules
- Minor criteria - Previous Hx of RF, arthralgia, fever, certain lab tests indicating inflamm process, EKG changes
What tests are indicative of a Streptococcus infection?
Serum Abs to:
- Streptolysin O
- DNAase B
- hyaluronidase
What are recurrent attacks of Rheumatic Fever associated with?
Different types of GAS to which the patient has not yet been exposed
What is the most commonly and severely affected valve in chronic rheumatic disease?
Mitral
Which valve is second most commonly involved in rheumatic heart disease?
The aortic valve
What are 4 major complications of rheumatic heart disease?
- Bacterial endocarditis
- Mural thrombi
- Congestive HF
- Adhesion Pericarditis
Why is there an increased risk of bacterial endocarditis in patient swith chronic RHD?
Scarred valves of rheumatic hear disease provide an attractive envrionment for bacteria
A patient expires and their mitral valve is shown at autopsy. Verrucous vegetations are shown on the leaflets of the mitral valve. What is you Dx? What other conditions did the patient likely have? What is the most common lesion associated in this scenario?
Libman-Sacks Endocarditis; SLE; Fibrinous pericarditis
In patients with Ankylosing Spondylitis, what is the primary pathology that occurs?
Inflammation particularly near the vavle ring resulting in aortic regurgitation
What is the general cardiac pathogenesis that occurs in scleroderma (progressive systemic sclerosis)?
Intimal sclerosis of small arteries -> small infarcts -> patchy fibrosis -> CHF, arrhythmias
What are the complications of polyarteritis nodosa?
Necrotizing lesions in the branches of the coronaries resulting in MI, arrhythmias, and HB
What bugs generally cause acute bac endocarditis? Subacute bac endocarditis?
S. aureus/S. pyogenes; S. viridans/S. epidermidis
What is the most common predisposing condition for bac endocarditis in children?
Congenital heart disease
What are the most common predisposing bases for bac endocarditis in adults?
Mitral valve prolapse and congenital heart disease
What bug is most commonly found to cause bac endocarditis in IV drug users?
S. aureus
What are 7 RFs for bac endocarditis?
- Rheumatic Heart Disease
- IV Drug Users
- Prosthetic Valves
- Transient Bacteremia
- Elderly
- Diabetes
- Pregnancy
Describe the molecular pathogenesis of bacterial endocarditis
- High sheer flow rates of blood dunude valuve endothelial surfaces
- Endothelium become activated and produce vascular cell adhesion molecule 1 (VCAM1), Intracellular Adhesion molecule 1 (ICAM1)
- Platelets adhere to the valves
- Bacteria can proliferate in the valves
Where do valvular vegetations occur in the heart?
On inflow surfaces (atrial portion of AV valves and ventricular portion of semilunar valves)
What causes “flea-bitten kidneys”?
Infective endocarditis resulting in immune complex deposition in glomeruli causing patchy hemorrhagic appearance of kidneys
What are the early symptoms and progressive Syx of bacterial endocarditis?
- Early - low grade fever, fatigue, anorexia, weight loss
- Murmurs, splenomegaly. petechia, finger clubbing, neurologic dysfunction
What is the most serious complication of bacterial endocarditis?
Congestive HF due to destruction of a valve
A mitral valve with destructive vegetations is shown below. What is the Dx?
Bacterial Endocarditis
A patient’s mitral valve is shown at autopsy. The mitral valve is intact. What is the Dx? What other valve is commonly affected? What conditions are associated with this disease? What is the major risk of this disease?
Marantic Endocarditis; Aortic; Cancer, DIC; Embolization to distant organs
What is calcific aortic stenosis?
Narrowing of the aortic valve orifice due to calcium deposition in the valve cusps and ring
What are the three main causes of calcific aortic stenosis?
- Rheumatic aortic valvular disease
- Degenerative (senile) calcific stenosis
- Congenital bicuspid aortic stenosis
Describe the process of dystrophic calcification of the aortic valve
- Valvular interstitial cells modulate from wild type phenotype to an osteoblastic phenotype
What are the effects of calcific aortic stenosis on the myocardium?
Marked concentric left ventricular hypertrophy
What are the symptoms of mitral valve annulus calcification?
Generally asymptomatic!
A patients heart is shown at autopsy. What is your Dx? Describe the findings in this heart. What conditions are associated?
Mitral valve prolapse; Mitral valve becomes enlarged and redundant. Chordae tendinae enlongate and thin allowing the mitral valve to prolapse in systole; Marfan Syndrome, Ehlers-Danlos Syndrome
The biopsy of a mitral valve is shown below. What are the histologic findings? What is the Dx? What clinical features would expect to find in a patient with this condition?
Myxomatous connective tissue, accumulation of mucopolysaccharides; Mitral valve prolapse; Generally asymptomatic but a mid to late systolic click caused by the prolapse will be heard on auscultation
What is the most common cause of papillary muscle dysfunction? What can this result in?
Ischemia!; Mitral regurgitation
A heart is shown at autopsy. What is your Dx? What part of the heart does this condition affect? What does it lead to? What is this condition associated with?
Carcinoid heart disease; Uniquely affects right side of heart leading to tricuspid regurgitation and pulmonary stenosis; Carcinoid tumors that metastasize from SI to liver (Right heart), Enfluramine-phentermine, Ergot Alkaloids (Left heart)
What is the typical description of the valves on the right side of the heart in Carcinoid Heart Disease?
Leaflets with plaque-like, pearly, gray, fibrous tissue. The leaflets become “stuck down”. This results in tricuspid insufficiency and
