pathology III: hypertension

hypertension is elevated blood pressure, subcategorized in several different ways: primary hypertension is not caused by any underlying diseases, whereas secondary hypertension is caused by a number of factors such as renal disease or pulmonary disease. the severity of hypertension can be graded according to the blood pressure level; a diastolic pressure above 120 mmHg generally indicates a very severe case of hypertension. benign hypertension refers to the gradual elevation of blood pressure over time (a misnomer because it can cause an MI, stroke, renal disease, among other things) whereas accelerated is a sudden increase in blood pressure that could indicate an emergency situation. finally, labile hypertension, also known as "white coat" hypertension, is an inconsistent elevated BP that generally only appears when measured by a doctor.

there are several proposed mechanisms for hypertension: decreased Na/K ATPase activity and/or increased cell permeability to Na+, both which lead to increased intracellular Na+ which is thought to increase the sensitivity of cells to sympathetic stimulation, causing systemic vasoconstriction and therefore increased blood pressure. another theory is that Ca+ is the causative agent since Ca+ also follows Na+ into cells.

hypertension can lead to many other serious conditions related to vessel damage. an aneurysm is a ballooning out of a vessel due to decreased wall strength combined with increased blood pressure and generally occurs in the arteries, aorta and circle of willis. aortic dissection refers to high blood pressure infiltrating the media layer of arteries (generally the aorta), causing excruciating pain resistant to painkillers. people with marfan's syndrome have an increased susceptibility to this condition because of the connective tissue abnormalities that may occur in the blood vessels as part of this syndrome.

questions
hypertension introduction...
1. how is severe hypertension defined in terms of blood pressure levels?
2. long term effects of hypertension include...
3. what are some potential mechanisms for hypertension?
4. what is the relationship of calcium in the pathogenesis of hypertension?
5. hypertension is the leading cause of which prominent diseases?
6. what percentage of americans are affected by hypertension?
7. what are some demographic / racial trends related to hypertension within the united states?
8. what is the difference between primary and secondary hypertension and in what percentage does each occur?
9. how might renal disease contribute to hypertension?

types of hypertension...
10. what is labile hypertension?
11. labile hypertension is also related to what other condition?
12. what does benign hypertension refer to?
13. what is accelerated hypertension?

complications...
14. what is an aneurysm?
15. where are aneurysms most likely to occur?
16. what is aortic dissection?
17. how will a patient with aortic dissection present and what must be done immediately in terms of treatment?
18. what is marfan's syndrome and how does it relate to aortic dissection?

answers
1. diastolic pressure above 120 mmHg.
2. heart attack, stroke, renal failure.
3. defective Na/K pump or increased cellular permeability to Na+, both of which would increase intracellular sodium and therefore make cells more sensitive to sympathetic stimulation.
4. because Ca follows Na+ into cells, it is possible that increased intracellular calcium levels is what causes the increased sympathetic sensitivity, as opposed to Na+.
5. ischemic heart disease, peripheral vascular disease, cerebrovascular disease, ventricular hypertrophy, congestive heart failure.
6. 25%
7. african americans twice as likely to have hypertension compared to caucasians.
8. primary: 95%, no underlying disease. secondary: 5% due to multiple underlying factors.
9. hypertension can stimulate renin production which can result in increased salt retention and systemic vasoconstriction.

10. inconsistent BP elevation that generally occur only when measured by a doctor. also called white coat hypertension.
11. pheochromocytoma, which presents with paroxysmal headaches, sweats, palpitations.
12. BP that has has gradually been elevated over time but is relatively stable. may still result in serious conditions such as MI, stroke, renal disease.
13. marked increase in BP (emergency) that can cause acute organ damage and CNS symptoms.

14. ballooning out of a vessel due to underlying weakness of vessel wall combined with increased blood pressure.
15. arteries, aorta, circle of willis.
16. a severe complication of hypertension that results in blood traveling in the media of vessels in addition to the lumen. usually affects ascending aorta, aortic arch, descending aorta, and abdominal aorta.
17. patient will present with severe, excruciating pain that might not be relieved by painkillers-- blood pressure must be lowered if it is elevated.
18. a connective tissue disorder that can increase the likelihood for aortic dissection due to the connective tissue abnormalities that might appear in blood vessels.
19.