Hypertension Flashcards
Define primary and secondary hypertension Outline there mechanisms underlying a1 adrenoreceptor antagonist, angiotensin converting enzyme inhibitor, calcium channel blocker, diuretic and B1 adrenoreceptor atagonist List the side effects associated with the above
Define primary (essential) hypertension:
A blood pressure that is associated with significant cardiovascular risk - no single factor causing it
Define secondary hypertension:
Associated with other conditions such as renal diseases. Caused by a primary source.
What is optimal blood pressure?
120/80
How can you practically manage hypertension? (4)
140/90 are low risk patients so lifestyle changes will help Diet Exercise No smoking NO alcohol
What is the equation for blood pressure?
BP = Cardiac output x total peripheral resistance
How can you reduce TPR? (3)
Reduce vasoconstriction by relaxing smooth muscle:
Block a-adrenoreceptors (vasodilation)
Inhibit Angiotensin 2 (vasodilation)
Calcium channel blocks (vasodilation)
How can you reduce sympathetic vasoconstriction? (3)
noradrenaline -> a-adrenoreceptors -> vasoconstriction
Therefore you need to block a-adrenoreceptors
a-blockers (phentolamine and prazosin)
What are the side effects of A1 and A2 adrenoreceptor antagonists? (4)
Postural hypertension
High heart rate
Angina
Cold extremities
Why do these side effects occur from adrenoreceptor blockers?
It blocks the a-1 and a-2 on the arteriole so reduces vasoconstriction but also blocks the a-2 receptor on the nerve terminal for uptake to monitor the noradrenaline use
What is angiotensin 2, what inhibits it and what is its side effect?
Angiotensin 2 is a vasoconstrictor.
It is inhibited by angiotensin converting enzyme which reduces vasoconstriction and reduces aldosterone release
Major side effect is a cough due to bradykinin breakdown
How do calcium channel blockers work and what is their effect?
They prevent the release of calcium stores into the cell cytosol
Increases vasodilation and decrease BP
What are the negative side effects of calcium channel blockers? (3)
Conduction in the heart - arrhythmia/heart block
Myocardial effects - hypotension/heart failure
Vascular effects - flushing/headaches
How do you reduce cardiac output? (2)
Reduce blood volume (leech)
Reduce cardiac force
What can you use to reduce cardiac output? (3)
Diuretics - promote urine production
Promotes salt loss
Reduces co and blood volume
Which receptors are affected to reduce CO?
B blockers - B1 in the heart, B2 in lungs and blood vessels
