Cardiology — Flashcards

Flashcard 2481: How do the following deficiencies/conditions affect platelet aggregation in response to ristocetin, and what diseases are they associated with? - Glycoprotein Ib receptors - Glycoprotein IIb-IIIa receptors - Hageman factor - Thromboxane A2 - von Willebrand factor

Answer: - **Glycoprotein Ib (GPIb) receptors:** Bernard-Soulier Syndrome. Ristocetin-induced aggregation is absent and does **not** correct with normal plasma (contains vWF but lacks receptor). Features: giant platelets, thrombocytopenia. - **Glycoprotein IIb-IIIa receptors:** Glanzmann Thrombasthenia. Ristocetin-induced aggregation is **normal** (interaction is via GPIb-vWF). - **Hageman factor (Factor XII):** Factor XII deficiency. Ristocetin test is normal. Presents with a prolonged aPTT but no clinical bleeding (thromboembolic risk). - **Thromboxane A2 (TXA2):** Aspirin effect (COX-1 inhibition). Ristocetin-induced aggregation is **normal**. - **von Willebrand factor (vWF):** von Willebrand Disease (vWD). Ristocetin-induced aggregation is absent but **corrects** with the addition of normal plasma (which provides vWF).

Flashcard 2482: What is the 1st line of Tx for acute gout.

Answer: NSAIDS

Flashcard 2483: 38 y/o patient present with hypercoagulability, paradoxical partial thromboplastin time (PTT) prolongation, and recurrent miscarriages. -What is the most likely antibody present and DX?

Answer: Antiphospholipid antibodies. Antiphospholipid syndrome. due to blood clots with recurrent miscarriage.

Flashcard 2484: Patient present with acute Gout, and renal disease. -What is the best line of Tx?

Answer: Glucocorticoids (e.g., oral Prednisone or intra-articular steroids)

Extra: NSAIDs are contraindicated in patients with renal disease (CKD). While Colchicine can be used with dose adjustment, Glucocorticoids are generally preferred and safer in the setting of significant renal impairment.

Flashcard 2485: 55 y/o man is found to have abnormal serum chemistries on lab testing. -He has history of hypertension, for which he's being treated with pharmacological therapy, weight reduction, & decreased sodium intake. -Lab results: Serum Na 134 K 3.8 BUN 18 Creatinine 0.8 Calcium 11 Blood Glucose 98 PTH: Decreased What is the most likely responsible for these findings? a. Familial hypocalciuric hypercalcemia b. Hypothyroidism c. Medication d. Primary hyperparathyroidism e. Secondary hyperparathyroidism

Answer: c. Medication (Thiazide diuretics) Thiazides increase renal calcium reabsorption in the distal tubule, leading to hypercalcemia which suppresses PTH secretion.

Flashcard 2486: A 54-year-old patient presents with an acute gouty attack. He has a history of recent epigastric pain and suspected peptic ulcer disease. What is the preferred treatment for his gout?

Answer: Colchicine NSAIDs are contraindicated in patients with peptic ulcer disease. Colchicine works by inhibiting microtubule polymerization, which interferes with neutrophil chemotaxis.

Flashcard 2487: Match the following markers/antigens to their clinical associations: - Centromeres - Citrullinated peptides - Double-stranded DNA - Fc portion of human IgG - Nuclear basic proteins - Phospholipids

Answer: - Centromeres: Associated with CREST syndrome (anti-centromere antibodies) - Citrullinated peptides: Rheumatoid arthritis (Anti-CCP; highly specific) - Double-stranded DNA: SLE (Anti-dsDNA; highly specific) - Fc portion of human IgG: Rheumatoid Factor (RF is an autoantibody, usually IgM, directed against the Fc portion of IgG) - Nuclear basic proteins: Antinuclear antibodies (ANA); associated with SLE and other connective tissue diseases - Phospholipids: Antiphospholipid syndrome, SLE

Flashcard 2488: 17 y/o girl comes for follow-up on anemia. - She has taken iron supplements regularly since being diagnosed with iron-deficiency anemia 3 months ago. - She has occasional gingival bleeding when brushing her teeth. - Heavy menses. - Further evaluation: patient's platelets do not aggregate appropriately in response to ristocetin. - When normal plasma is added to the solution of patient platelets and ristocetin, appropriate platelet aggregation occurs. - What is the most likely deficiency in this patient?

Answer: von Willebrand factor (vWF) When normal plasma (containing vWF) is added, appropriate aggregation occurs. Ristocetin activates vWF to bind to GpIb for platelets to aggregate. Rx: Desmopressin, as it stimulates vWF release from the endothelium (Weibel-Palade bodies).

Flashcard 2489: 40 y/o woman presents with a 3-month history of progressive fatigue and decreased exercise tolerance. - Physical exam: Conjunctival and palmar pallor. - Labs: Hemoglobin 9 g/dL, MCV 72 fL. - Bone marrow biopsy: Ring sideroblasts seen on Prussian blue stain. Decreased activity of what enzyme most likely explains this patient's anemia?

Answer: δ-Aminolevulinate synthase (ALA synthase)

Extra: Sideroblastic anemia results from defective heme synthesis. The rate-limiting step is catalyzed by ALA synthase, which requires Vitamin B6 (pyridoxine) as a cofactor. Key clinical features: - Microcytic anemia (sometimes dimorphic) - Increased serum iron and ferritin, decreased TIBC - Ring sideroblasts (iron-laden mitochondria surrounding the nucleus) on Prussian blue stain of bone marrow. Common causes: - Hereditary (X-linked) - Acquired: Lead poisoning, Isoniazid (B6 antagonist), Alcohol, Myelodysplastic syndrome.

Flashcard 2490: 47 y/o woman comes with joint pain and swelling in her hands for the past several months. -Complains of easy fatigability that has gradually worsened. -Morning activities are especially difficult for her due to prolonged stiffness. -Examination: joints reveals warmth, swelling & tenderness involving PIP joints, MCP joints, & wrists bilaterally. -Serum with high specificity for this patient's condition are most likely to react with what?

Answer: Citrullinated peptides. Very specific for Rheumatoid arthritis (95%-98%). More specific than Rheumatoid Factor (which reacts with the Fc portion of human IgG).