Drug Treatments for CVD Part 1

Question 1

Hypertension and Regulation of BP

Answer 1

Persistently high BP, measured ABPM/HBPM
Treatment if mean BP > 150/95
BP = CO x TPR
CO = SV x HR

Question 2

Sympathetic Regulation of BP

Answer 2

Noradrenaline
Increased areterioconstriction (alpha1-R)
Increased afterload (alpha1-R)
Increased preload (alpha1-R)
Increased frequency (beta1-R)
Increased force of Contraction (beta-1-R)

Question 3

Extrinsic Regulation & Regulation of TPR

Answer 3

SNS: beta1 receptors -> cAMP -> increased Ca2+ -> increased rate and force of contraction
PNS: decreased cAMP -> M2 receptors
TPR: SNS -> noradrenaline -> alpha 1 -> inositol triphosphate -> Ca2+ -> constriction
PNS -> adrenaline -> beta2 -> CAMP -> relaxation

Question 4

Renin-Angiotensin-Aldosterone-System

Answer 4

Decreased CO -> decreased renal blood flow -> RAS -> angiotensin II -> venoconstriction -> increased preload -> increased BP.
RAS -> aldosterone -> Na+ and H2O retention -> increased preload -> increased BP.
Angiotensin II -> arterioconstriction -> increased afterload -> increased BP

Question 5

Aldosterone Sensitive Distal Nephron

Answer 5

Aldosterone activates cytoplasmic receptors which bind to the nucleus and increase the expression of Na+ channels & so aid Na+ and H2O retention

Question 6

Regulation of Preload by RAAS & Regulation for TPR

Answer 6

Preload:Constriction of venules via AT1-R (also facilitates Na+ and H2O retention)
TPR: Increase in Ang II -> IP3 -> increased intracellular Ca2+
Causes constriction of arterioles and an increase in TPR and in BP

Question 7

Drug Treatment

Answer 7

Depends on

a) age (>55 years old: ACE inhibitor/Angiotensin receptor blocker, >55 years old use Ca2+ channel blocker)
b) race (ACE inhibitors/Beta blockers less efficacious in black race)
c) coexisting diseases