10.2: Hypertension And Heart Failure

Question 1

When do the kidneys release renin?

Answer 1

When blood pressure is low, Renal perfusion drops and this is detected by the kidneys which cause them to release renin and activate the RAAS

Question 2

What are some causes of secondary hypertension?

Answer 2

Renal Disease 
Conns syndrome
Cushing’s 
Phaechromocytoma
Pregnancy

Question 3

For a hypertensive patient, what should the blood pressure aim to be less than?

Answer 3

<140/90

<130/80 if diabetic, <150/90 if aged >80

Question 4

How should hypertension be managed?

Answer 4

Treat cause if present

Conservative: smoking cessation, reduce salt, reduce alcohol, exercise, low fat diet)

If age < 55 1st line is ACEi
If aged > 55 or Afro-Caribbean, 1st line is CCB
2nd line = ACEi + CCB
3rd line = ACEi + CCB + thiazide diuretic

Question 5

What are some side effects of calcium channel blockers?

Answer 5

Flushing
Headaches
Gum hyperplasia
Constipation 
Oedema

Question 6

What type of drug is nifedipine?

Answer 6

Calcium channel blocker

Question 7

How do ACEi reduce blood pressure?

Answer 7

Inhibit conversion of angiotensin 1 to angiotensin 2
Reduce aldosterone
Hence vasodilation and less salt and water retention (less aldosterone so less upregulation of ENaC channels)

Question 8

What are some examples of ACEi?

Answer 8

Lisinopril

Ramipril

Question 9

What are some important side effects of ACEi?

Answer 9

Dry cough
Hyperkalaemia
Angiooedema
Renal failure

Question 10

What type of drugs are losartan and valsartan?

Answer 10

Angiontensin receptor blockers

Question 11

How do calcium channel blockers reduce blood pressure?

Answer 11

Bind to calcium channel to reduce cellular calcium entry to prevent smooth muscle contraction hence arteriolar vasodilator

Question 12

Why can dihydropiridine calcium channel blockers cause tachycardia?

Answer 12

As they activate the sympathetic nervous system

Question 13

How do phenylalkylamines eg verapamil work?

Answer 13

Impede Ca transport across myocardial and vascular SM membrane
Hence used as class IV anti arrhythmic as it prolongs the action potential (calcium plateau phase)

Question 14

Why can verapamil worsen heart failure?

Answer 14

As it reduces myocardial contractility

Also peripheral vasodilation lowers preload

Question 15

What is an example of a thiazide?

Answer 15

Bendroflumethiazide

Question 16

What channel do thiazides acts on in the nephron?

Answer 16

NCC

Question 17

What are some side effects of thiazides?

Answer 17

Hypokalaemia 
Gout
Erectile dysfunction
Impairs glucose tolerance
Raised cholesterol and TAG levels