Vascular/Hematology High Yield Topics

Thrombocytopenia: Low platelet count (<150,000/ml). If 40k-60k, have increased risk of post-traumatic bleeding. If <20k, have increased risk of spontaneous bleeding. Manifests as microhemorrhage, mucous membrane bleeding, petechiae, purpura, elevated bleeding time. Can be due to decreased platelet production (aplastic anemia, malignancy, drugs, benzene, radiation), immune destruction (autoimmune ITP, heparin-induced HIT), non-immune consumptive destruction (DIC, TTP, HUS), or splenic sequestration.

Clotting Factor Deficiencies: deficiencies of factors II, V, VII, and X are inviable

Hemophilia A: factor VIII. X-linked. Delayed bleeding (2-3 days) into muscles, joints, mouth. Hemarthrosis destroys cartilage of joint space. Chronic arthropathy due to synovial neovascularization. CNS bleeding is most common cause of death. Elevated aPTT. Normal PT, BT, TCT.

Hemophilia B: factor IX. Clinically identical to hemophilia A.

Hemophilia C: factor XI. Autosomal recessive. Ashkenazi Jews. Less severe than hemophilia A or B.

Lymphoma & Leukemia: see First Aid, pages 239-241.

Mitral Stenosis: Caused primarily by rheumatic disease. Elevated LA pressure and volume. Pulmonary HTN leads to RV hypertrophy. Increased risk of atrial thrombi leading to embolic stroke. Loud S1, opening snap, diastolic rumble. Radio = 4-bump sign (double density), hockey-stick valves. Murmur intensifies with NTG (distinguish from AR).

Mitral Regurgitation: Disease of annulus, leaflet, or papillary muscle. Acute (due to endocarditis or chordae tendinae rupture) = elevated LA pressure with pulmonary edema. Chronic = normal LA pressure with dilated LA. Apical holosystolic murmur, widely split S2.

Aortic Stenosis: Causes = congenital dome, rheumatic disease, calcifications. Impeded LV outflow causes LV hypertrophy. Exertional symptoms = angina, syncope, dyspnea. Strong S4, crescendo-decrescendo systolic murmur. Death often within 2-5 years of symptom onset.

Aortic Regurgitation: Acute = elevated LV pressure, elevated LA pressure, pulmonary edema. Chronic = LV hypertrophy and dilatation. Wide pulse pressure. Decrescendo diastolic murmur (Austin Flint), S3. Murmur diminishes with NTG (distinguish from MS)

Tricuspid Regurgitation: Usually functional. Due to dilation of tricuspid annulus from RV dilatation. May be due to endocarditis from IV drug use. Jugular venous distension, systolic murmur at left sternal border. Enlarged RA and RV.

Thoracic Aortic Aneurysm: Due to atherosclerosis, Marfan’s, or cystic medial necrosis.

Abdominal Aortic Aneurysm: Majority of aortic aneurysms are infrarenal. Due to atherosclerosis. Usually asymptomatic, but may present with abdominal fullness, pulsation, or back pain.

Primary Polycythemia Vera: Chronic proliferative disorder of bone marrow. Increased erythroid cells (high levels of RBC, Hb, Hct). Increased blood viscosity leads to thrombosis or hemorrhage. Low EPO due to negative feedback. Treat with phlebotomy or myelosuppression (hydroxyurea).

Secondary Polycythemia: Chronic hypoxia (for example, COPD) causes increased EPO production from kidney, which stimulates RBC production from bone marrow.

Sources: class notes, Cecil’s