Endocrine and Cardiovascular Systems

Ms. J.S., a 52 yo white female with two children (16 and 14 yo) presents with history of fatigue, weight gain and muscle weakness over past two years. She initially thought it was caused by work stress and busy family life but has also noticed that she bruises more easily than in the past. She also noted purple lines (stretch marks) that you identified as striae . All of the above symptoms have been getting worse. Blood pressure is 170/110, respirations 12/min and some ankle edema (non-pitting) was noted. The limbs seem relatively thin and the trunk thickened, especially between the upper shoulder blades. Diagnosis was made of Cushing’s disease/syndrome. How could you differentiate between the two? Elevated levels of cortisol has two effects of plasma leading to increased volume: 1) up-regulation of receptors for aldosterone and 2) an increased effectiveness of ADH (either by centrally increasing ADH release or peripherally by increasing the cellular responsiveness).

1 What effects would these two changes (increased responsiveness to aldosterone and ADH) have on Na+, K+ and water levels in the plasma? (Endocrine Mod 3: MO2, MO3, CO2, CO3, CO4)

2 Where does cortisol secretion occur, and thus is a potential site of an over-secreting tumor? How else could someone develop Cushing syndrome if not by a tumor in that area? (Endocrine Mod 3: MO1, MO2, MO3, CO1, CO2, CO3, CO4, CO5)

3 Which of the following influences the secretion of ACTH? (Endocrine Mod 3: MO1, MO2, CO1, CO2, CO3)

1. Cortisol levels in the plasma 3 Corticotropin releasing hormone from the hypothalamus
2. Neuro-endocrine reflexes 4 All of the above

4 What is the most common cause of Cushing syndrome in the United States? (Endocrine Mod 3: MO1, MO2, MO3, CO1, CO2, CO3, CO4, CO5)

1. Adrenal tumors 3 Infections
2. Pituitary tumors 4 Glucocorticoids prescribed by healthcare workers

Mr. M.S., an overweight, 55 yo white male presents to your clinic with chest pains. He has a history of hypertension, alcohol use and does not restrict his diet. He is currently taking nitroglycerin tablets as needed for angina. This pain is worse and is not controlled by nitroglycerin. The pain is radiating down his left arm. The pain in the chest feels like pressure or heartburn. You hear inspiratory rales, consistent with pulmonary edema. His blood pressure is 100/75. He begins to have difficulty breathing, especially when lying down. EKG and serum enzymes suggest a left ventricular wall myocardial infarction. Cardiac catheterization reveals a pulmonary wedge pressure of 30 mm Hg (normal, 5 mm Hg) and two-dimensional echocardiography measured an ejection fraction of 0.35 (normal, 0.55). In the Coronary ICU, he was treated with thrombolytic agents (tPA), digitalis (a positive inotropic agent) and furosemide (Lasix, a loop diuretic)

5 What measures above helped you determine that the stroke volume (considering the measures that factor into it) was reduced? (Cardiovascular Alterations Mod 5: MO7, MO9, MO10, MO12, MO17, CO2, CO3, CO4, CO5)

6 Describe the mechanism of how digitalis (AKA Oubain) works at a molecular level to increase contractility (positive ionotrope)? Discuss the ion gradients, how they were created/maintained for a cell at resting membrane potential and the effects of this drug that lead to its action on muscle. (Cardiovascular Structure and Function Mod4: MO2, MO6, MO7, MO9, MO11, CO1, CO2, CO3)

7 Statins are commonly used to treat cardiovascular disease. Describe their effect and the mechanism of how that effect is brought about. Explain if men and women with similar cholesterol profiles are at similar risk for cardiovascular disease (i.e. are they equally predictive of cardiovascular risk for men and women). Supply a link to an article that supports your assertion and in a sentence or two, describe the “take home point(s)” of the article (Cardiovascular Structure and Function Mod 5: MO1, MO5, MO7, MO8, MO9 CO1, CO2, CO3)

8 Supply one link/web address/citation to an article that describes differences in either gender or race in the treatment or assessment of risk for cardiovascular disease and a statement of how that information will affect your assessment/treatment of patients in practice.