week 4- hypertension

Question 1

hypertension

Answer 1

• sustained elevation of systemic arterial blood pressure (BP) and is the leading cause for visits to primary care physicians
• high BP is the most significant modifiable risk factor for cardiovascular disease and mortality in canada
• 140/90 mmHg< (180/120 is considered a HT crisis)

Question 2

prevalence of HT

Answer 2

• increases with age
• women with high BP have a greater risk for CVD
• indigenous people have a higher incidence of CVD than non-indigenous people in canada
• more prevalent in older women than in older men

Question 3

isolated systolic hypertension

Answer 3

• average SBP greater than or equal to 140 mmHg coupled with an average DBP less than 90 mm Hg
• more common in older
  adults

Question 4

stage 1 HT

Answer 4

130-139/80-89 mmHg

Question 5

stage 2 HT

Answer 5

140/90 mmHg<

Question 6

factors contributing to blood pressure

Answer 6

a) cardiac output: inc CO, inc bp
b) peripheral vascular resistance: inc PVR, inc bp
c) volume of circulating blood: inc vol, inc bp
d) viscosity of blood: inc viscosity, inc bp
e) elasticity of vessels walls: dec elasticity, inc bp

Question 7

cardiac output

Answer 7

the volume of blood ejected from the heart per minute
CO in L/min = stroke volume (SV) x HR

SV = the amount of blood pumped out of the left ventricle per beat

Question 8

factors that influence CO

Answer 8

a) increase in CO: sympathetic stimulation, the catecholamines epinephrine and norepinephrine, thyroid hormones, and increased calcium ion levels
b) decrease in CO: include parasympathetic stimulation, elevated or decreased potassium ion levels, decreased calcium levels, anoxia, and acidosis

Question 9

peripheral vascular resistence

Answer 9

• force opposing the movement of blood
  within the blood vessels
• when BV constrict, PVR increases
• when BV dilate, PVR decreases

Question 10

alpha 1 receptors

Answer 10

primarily found on vascular smooth muscle and are responsible for vasoconstriction when stimulated by catecholamines like norepinephrin

Question 11

alpha 2 receptors

Answer 11

• located in the brain and periphery
• modulate sympathetic outflow, potentially lowering blood pressure through mechanisms like reduced neurotransmitter release

Question 12

beta 1 receptors

Answer 12

• mainly located in the heart (and kidneys), increase heart rate and contractility when stimulated
• stimulation in the kidneys can lead to renin release

Question 13

beta 2 receptors

Answer 13

found in blood vessels and other organs, cause vasodilation when activated

Question 14

dopamine

Answer 14

• peripheral vasostimulant used to treat low blood pressure, low heart rate, and cardiac arrest
• intermediate infusion rates (from 2 to 10 micrograms/kg/min) stimulate myocardial contractility and increase electrical conductivity in the heart leading to increased cardiac output

Question 15

baroreceptors

Answer 15

• specialized nerve cells located in the carotid artery and the arch of the aorta, sense changes in BP
• when BP is increased, these receptors send inhibitory impulses to the sympathetic vasomotor centre in the brainstem resulting in decreased HR, decreased force of contraction, and vasodilation in peripheral
  arterioles

Question 16

SNS

Answer 16

activation increases heart rate (HR) and
cardiac contractility, produces widespread vasoconstriction in the peripheral arterioles and promotes the release of renin from the kidneys

Question 17

vascular endothelium

Answer 17

• the endothelium produces and releases a variety of molecules that affect blood vessel tone
• NO relaxes blood vessels and lowers blood pressure
• endothelin-1 constricts blood vessels and raises blood pressure

Question 18

how does RAAS increase BP?

Answer 18

• kidneys secrete renin, which initiates the RAAS cascade
• leads to the production of angiotensin II, which constricts blood vessels and increases blood pressure
• aldosterone is also released, which helps the kidneys retain sodium and water, further raising blood pressure
• kidneys also play a role inpressure natriuresis,the process of increasing sodium and water excretion when blood pressure rises (helps lower blood volume and blood pressure)

Question 19

how does the endocrine system regulate BP?

Answer 19

• adrenal medulla releases epinephrine in response to SNS stimulation.
• epinephrine activates β2-adrenergic receptors, causing vasodilation
• adrenal cortex is stimulated by angiotensin 2 to release aldosterone
• aldosterone stimulates the kidneys to retain sodium and water, increasing BP
• ADH is released from the posterior pituitary gland in response to an increased blood sodium and osmolarity level
• this promotes the reabsorption of water in the distal and collecting tubules of the
  kidneys, resulting in an increase in blood volume and BP

Question 20

etiology of HT

Answer 20

a) primary hypertension: elevated BP without an identified cause
- accounts for 90% to 95% of all cases of HTN
b) secondary hypertension: elevated BP with a specific cause that often can be identified and corrected
- accounts for 5% to 10% of HTN in adults, and more
than 80% of HTN in children

Question 21

causes of primary HT

Answer 21

• family history, ethnicity
• high sodium, low potassium intake
• diabetes mellitus or insulin resistance
• obesity
• excessive alcohol intake
• stress and inc SNS activity
• endothelial cell dysfunction (excess vasconstriction)
• altered RAAS system

Question 22

clinical signs of secondary hypertension

Answer 22

• unprovoked hypokalemia
• abdominal bruit
• variable pressures with history of tachycardia, sweating, and tremor
• family history of renal disease

Question 23

causes of secondary HT

Answer 23

• coarctation or congenital narrowing of the aorta
• renal disease such as renal artery stenosis and parenchymal disease
• endocrine disorders such as pheochromocytoma, Cushing’s syndrome, and hyperaldosteronism
• neurological disorders such as brain tumours, quadriplegia, and head injury
• sleep apnea
• medications
• pregnancy-induced hypertension

Question 25

symptoms of HT

Answer 25

- fatigue, reduced activity tolerance, dizziness, palpitations, angina, and dyspnea - sudden, severe headache can indicate a hypertensive crisis

Question 26

diagnostic tests of HT

Answer 26

a) lipid panel, metabolic panel and thyroid panel b) urinalysis:to check for protein in the urine (albumin-to-creatinine ratio) and hematuria (blood in the urine) c) ECG: assess heart rhythm and identify any signs of heart damage due to hypertension d) physical exam including eye exam, CV exam and abdominal exam

Question 27

ambulatory blood pressure monitoring

Answer 27

- monitoring takes dozens of readings over a continuous period - also calculates changes in BP and heart rate, BP distribution pattern - can be used to confirm a diagnosis of HT

Question 28

pharmacological management of HT

Answer 28

a) thiazide diuretics: encourage excretion of Na and water b) CCBs: relax BV by preventing calcium from entering the heart and blood vessel muscles c) ace inhibitors/ARBs: block the production of a hormone that narrows BV d) beta blocker e) renin inhibitors

Question 29

orthostatic hypotension

Answer 29

defined as a decrease of 20 mm Hg or more in SBP, a decrease of 10 mm Hg or more in DBP

Question 30

hypertensive crisis

Answer 30

- a severe and abrupt elevation in BP, arbitrarily defined as a DBP above 120 to 130 mm Hg - evidence of acute organ damage - requires immediate hospitalization and administration of IV antihypertenisive drugs | 180/120 mmHg <

Question 31

hypertensive urgency

Answer 31

- elevated blood pressure without acute organ damage, usually managed with oral medications and close follow-up - develops over days or weeks