Valvular Heart Disease Pathology

Question 1

microscopic appearance of the myofibers in the setting of cardiac myocyte hypertrophy

Answer 1

Hypertrophy and disarray of fibers

Same # of myocytes, increased # of sarcomeres

Question 2

most common form of hypertension, and the effects of chronic hypertension on the appearance and function of the heart

Answer 2

Essential/primary (idiopathic/rule out other possible causes)

• sustained pressure overload on the LV leads to concentric hypertrophy of myofibers
• additional sarcomeres/myofibrils added to existing cardiomyocytes
• complications
  1. atherosclerosis/ aneurysm
  2. cerebral vascular disease
  3. kidney disease
  4. CHF

Question 3

Define cor pulmonale and give examples of underlying causes (excluding left heart failure).

Answer 3

• alteration in the structure and function of the RV caused by a primary disorder of the respiratory system
• causes: pulm HTN, pulmonary parenchyma disease, pulmonary vessel disease, chest movement alterations

Question 4

Describe the key features of rheumatic heart disease with respect to the valve leaflets, chordae tendinae, and the effects on the functionality of the valve

Answer 4

• endocarditis: inflammation of the endocardium valaves and eventual fibrosis
• valve leaflets and cusps: fibrosis, fusion, calcification
• chordae tendinae: fibrosis, fusion and shortening
• valves can’t open or close normally

Question 5

List several complications of rheumatic heart disease

Answer 5

• valves can’t open or close normally -> HF

- susceptibility to infective endocarditis

Question 6

most commonly affected valves in rheumatic heart disease

Answer 6

Mitral valve and aortic valve (usually with the mitral valve too)

Question 7

two major classes of cardiac valve vegetations and their causes

Answer 7

1. sterile/Marantic/Non-Bacterial Thrombotic Endocarditis (thrombus formation on valve)
   - -due to damaged valve (RHD or Lupus), normal valve at a hypercoaguable state
2. infective endocarditis (primary infection of normal or damaged valve)
   - -due to bacteria (skin, oral flora, GI trace)

Question 8

bacteria commonly associated with infectious endocarditis

Answer 8

• Normal: s. aureus or other virulent organisms

- Abnormal: s. vidrians, other relatively benign bacgtyeria or virulent organisms

Question 9

how bacteria may gain access to the valves

Answer 9

• bacteremic episodes allow organisms to be implanted on the valve/endocardial surfaces (i.e. dental procedures, surgeries, venous access for IV, cath, IV drug use)
• mucosal injuries (i.e. diverticulitis)
• skin injuries

Question 10

possible complications of cardiac valve vegetations

Answer 10

Sterile: embolism, valve fn deficits, potential to become infected
Infective: septic emboli (to heart, various organs, skin) and compromised valve function due to damage by bacteria and inflammatory response