Jessica Kettlewell Heart Hormone Case Study 09/11/2023 1. What is the mean arterial pressure (MAP) and why is it important? Answer: The mean arterial pressure is also known as the average blood pressure within the cardiovascular system. Blood volume as well as cardiac output and peripheral resistance determine the MAP. Maintaining and adequate MAP prevents organ shutdown. Source: case study reading material. 2. Identify three factors that maintain MAP: Answer: 1) Cardiac output 2) Heart rate 3) Resistance to blood flow in the vessels Source: https://emtprep.com/resources/article/map-understanding-mean-arterialpressure 3. What role does the heart play in regulating MAP? Answer: the heart plays a role in regulating MAP by varying its cardiac output, which could be altered through stroke volume and heart rate. By increasing the cardiac output the heart increases MAP, and by decreasing it, the heart decreases MAP Source: https://emtprep.com/resources/article/map-understanding-mean-arterialpressure 4. What role does peripheral resistance play in maintaining MAP? Answer: the relationship between MAP and resistance is direct. If resistance increase so will MAP and vice versa Source: case study reading material 5. What effect would acute heart failure have on MAP? Answer: Acute heart failure would reduce the heart’s ability to pump, which would decrease the mean arterial pressure. Source: https://www.studocu.com/en-ca/document/university-of-ontario-instituteof-technology/animal-physiology/cardiovascular-system-worksheet/13657179 6. What effect does angiotensin II of RAAS have on blood volume and pressure and how does it achieve this? Answer: angiotensin II causes the muscular walls of small arteries to constrict, which increases blood pressure. It also triggers the adrenal glands to release aldosterone and the pituitary gland to release ADH. Source: https://my.clevelandclinic.org/health/articles/24175-renin-angiotensinaldosterone-systemraas#:~:text=Angiotensin%20II%20causes%20the%20muscular,(ADH%2C%20o r%20vasopressin). 7. What is antidiuretic hormone (ADH)? What effect does it have on blood volume and pressure, and what stimulates its secretion and what are its actions? Answer: ADH helps regulate the amount of water in your body. It works to control the amount of water your kidneys reabsorb as they filter the waste out of our blood. If your body would produce too much adh it would lead to water retention and blood volume would increase. The hypothalamus produces adh but it is stored and released by the pituitary gland Jessica Kettlewell Heart Hormone Case Study 09/11/2023 Source: https://www.webmd.com/a-to-z-guides/what-to-know-about-antidiuretichormone-adh 8. What effect would the change in MAP due to heart failure have on RAAS and ADH? How and why? Answer: due to Mark’s left ventricular heart failure, they left ventricle of the heart muscle ends up having a reduced ability to pump. This would cause the MAP to decrease. A decreased MAP triggers the RAAS to activate and also triggers the release of ADH. Source: case study reading material 9. What effect would activation of angiotensin II and ADH have on blood flow to the heart and pressure in the heart chambers? Answer: activation of both angiotensin II and ADH would increase the blood flow to the heart therefore increasing the pressure inside the chambers of the heart Source: https://www.studocu.com/en-ca/document/university-of-ontario-instituteof-technology/animal-physiology/cardiovascular-system-worksheet/13657179 10. There are many factors that can contribute to left ventricle heart failure. Based on what you have read above and after reviewing Mark’s history, lifestyle, and physical examination, what risk factors do you think are contributing to Mark’s heart failure and should be addressed as treatment? Answer: Contributing factors include Mark’s weight, smoking, drinking, lack of exercise, high blood pressure, age, and being a male. Treatment could address his weight, BP, and exercise. He should eliminate tobacco and alcohol use Source: case study reading material 11. The echocardiogram reveals a low ejection fraction and dilated left ventricle. What do the results of this test tell you about the efficiency of the heart? Answer: a low ejection fraction can mean the heart isn’t pumping enough blood. It can also be an indicator of heart failure. A dilated left ventricle cause the muscular wall of the ventricle to stretch which will make if thinner and weaker, causing the heart to not be able to pump enough oxygen rich blood to the rest of the body. Source: https://www.pennmedicine.org/updates/blogs/heart-and-vascularblog/2022/april/ejection-fraction-what-the-numbersmean#:~:text=An%20ejection%20fraction%20below%2040,Irregular%20heartbe at ; https://www.pennmedicine.org/for-patients-and-visitors/patientinformation/conditions-treated-a-to-z/dilatedcardiomyopathy#:~:text=Dilated%20cardiomyopathy%20(DCM)%20is%20a,the %20rest%20of%20the%20body. 12. The x-ray shows and enlarged heart and edema around the lungs. What is the cause of the edema of the lungs and throughout the body? Answer: the edema around the lungs and throughout the rest of the body is possibly caused by congestive heart failure Source: case study reading material 13. Why would a change in MAP and blood distribution due to heart failure cause body fatigue? Answer: when the heart failure becomes more severe, the heart is unable to pump the amount of blood required to meet all of the bodys needs. When this happens Jessica Kettlewell Heart Hormone Case Study 09/11/2023 the blood is diverted away from arms and legs in order to supply the heart and brain with enough blood Source: https://www.ucsfhealth.org/conditions/heartfailure#:~:text=Fatigue%20As%20heart%20failure%20becomes,supply%20the% 20heart%20and%20brain. 14. BNP is elevated in Mark’s blood. What effect does BNP have on blood volume and pressure and how does it achieve this? Answer: BNP can reduce preload and afterload in normal and failing hearts. It can reduce blood volume in the short term by isolating plasma and long term by promoting salt and water excretion Source: https://pubmed.ncbi.nlm.nih.gov/15566395/#:~:text=Atrial%20natriuretic%20pep tide%20and%20BNP,aldosterone%20system%20at%20many%20levels. 15. Sacubitril is used to keep brain natriuretic peptide (BNP) levels in the blood elevated. What beneficial effect does sacubitril have on a person with left ventricular heart failure? Answer: it improves the left ventricular ejection fraction in heart failure patients Source: https://www.jacc.org/doi/10.1016/j.jchf.2022.09.009#:~:text=Background,%2Dde fibrillator%20(ICD)%20placement. 16. Valsartan is used to inhibit the release of angiotensin II. Why would you want to inhibit the production of angiotensin II by valsartan in a person with left ventricular heart failure? Answer: valsartan will help expand the blood vessels which will lower the blood pressure and make it easier for the heart to pump blood Source: https://www.webmd.com/heart-disease/heart-failure/heart-failureangiotensinii#:~:text=Angiotensin%20II%20receptor%20blockers%20(also,the%20heart%20 to%20pump%20blood. 17. What role do the kidneys play in the RAAS and BNP system? Answer: through the RAAS and BNP system the kidneys control blood pressure and volume Source: https://opentextbc.ca/biology/chapter/22-5-hormonal-control-ofosmoregulatoryfunctions/#:~:text=The%20renin%2Dangiotensin%2Daldosterone%20system%20 acts%20through%20several%20steps%20to,blood%20pressure%20and%20volum e%20directly.descri 18. Describe the homeostatic mechanism in this patient with acute heart failure. Answer: in heart failure, the homeostatic mechanisms preserve blood flow to the brain and heart which takes blood away from the skeletal muscles, skin, kidneys and other organs. Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5286912/#:~:text=In%20heart%2 0failure%2C%20these%20homeostatic,%2C%20splanchnic%20organs%2C%20a nd%20kidneys.
