pathophysiology + treatment of hypertension

Question 1

what is the equation for mean arterial pressure?

Answer 1

MAP (mean arterial pressure) = CO (cardiac output) x TPR (total peripheral resistance)

Question 2

what is the equation for MAP involving systolic and diastolic pressure?

Answer 2

MAP = DP + 1/3(SP - DP)

Question 3

what is the equation for cardiac output?

Answer 3

CO = SV (stroke volume) x HR (heart rate)

Question 4

define cardiac output

Answer 4

amount of blood for heart can pump out in one minute

Question 5

define stroke volume

Answer 5

amount of blood that can be effectively pumped out of the heart via the left ventricle

Question 6

equation for stroke volume

Answer 6

SV = preload (vol of blood at the end - diastole) x afterload (resistance heart much overcome to pump) x contractility (inherent strength of the heart’s contraction)

Question 7

define total peripheral resistance

Answer 7

resistance arteries and cells have against blood being pumped through them

Question 8

how is TPR increased?

Answer 8

vasoconstriction

Question 9

name the 3 hypertensive drug categories

Answer 9

ace inhibitors or angiotensin II receptor blockers (ARBs) calcium channel blockers diuretics

Question 10

list the main side effects of ACE inhibitors

Answer 10

angiodema cough alopecia angina nausea chest pain

Question 11

how do ACE inhibitors help relieve hypertension?

Answer 11

inhibit conversion of angiotensin I to angiotensin II, which reduces vasoconstriction

Question 12

how do ARBs help relieve hypertension?

Answer 12

selective competitive blockers of angiotensin II at the AT1 receptor

Question 13

when should you be cautious about prescribing ARBs? (specifically losartan)

Answer 13

severe hepatic impairment severe cardiac failue pregnancy

Question 14

list main side effects of ARBs

Answer 14

abdominal pain hyperkalaemia hypotension renal impairment anaemia (losartan specific)

Question 15

when should you be cautious about prescribing ACE inhibitors?

Answer 15

renal impairment

Question 16

list main side effects of calcium channel blockers

Answer 16

peripheral oedema tachycardia dizziness palpitations

Question 17

when should you be cautious about prescribing calcium channel blockers?

Answer 17

cardiogenic shock hepatic impairment (may need dose reduction

Question 18

when should you be cautious about prescribing diuretics?

Answer 18

diabetes eletrolyte balance addison’s disease elderly

Question 19

list main side effects of diuretics

Answer 19

kypokalaemia constipation electrolyte imbalance

Question 20

how do diuretics help relieve hypertension?

Answer 20

Inhibition of Na+ and Cl- reabsorption from distal convoluted tubules by blocking Na+ Cl- symporter – stop reabsorption of water lower doses can also cause vasodilation

Question 21

how do calcium channel blockers help relieve hypertension?

Answer 21

inhibit influx of calcium ions

Question 22

what do calcium channel blockers act on?

Answer 22

Myocardial muscle – inhibit contractility (how well heart pumps – reducing stroke volume and therefore cardiac output) Vascular smooth muscle – coronary or systemic vascular tone reduced (vasodilation)

Question 23

define ARTERIOsclerosis

Answer 23

thickening, hardening and loss of elasticity of arteries which gradually restricts blood flow to tissues

Question 24

define ATHEROsclerosis

Answer 24

form of arteriosclerosis where there is development of fatty plaques and cholesterol in the wall of arteries as part of an inflammatory response

Question 25

what are the parameters for the different stages of hypertension?

Question 26

what are the contraindications for ACE inhibitors?

Answer 26

combination with aliskiren (renin inhibitor) in patients w eGFR (glomerular filtration rate)

diabetes mellitus

Question 27

what are the contraindications for ABRs?

Answer 27

combination w renin inhibitor in pateints w reduced eGFR

diabetes mellitus

Question 28

what are the contraindications with calcium channel blockers?

Answer 28

cardiogenic shock

significant aortic valve disease (stenosis)

unstable angina

hepatic impairment - may need dose reduction due to prolonged half-life

Question 29

what are contraindications for diuretics?

Answer 29

addison’s disease

electrolyte imbalance