CVS: Ischemic Heart Disease

Question 1

Name the 3 types of angina.

Answer 1

Atherosclerotic angina
Vasospastic angina
Unstable angina

Question 2

What drugs can be used to treat angina?

Answer 2

Glyceryl trinitrate (GTN)/NG
Non-selective B blockers
Selective B1 blockers

Question 3

Pharmacokinetics of GTN/NG?

Answer 3

Nitroglycerin=glyceryl TRInitrate

Becomes glyceryl DInitrate then MONOnitrate, releasing an endogenous NO each time which allows for vasodilation.

Question 4

How can GTN/NG be administered?

Answer 4

Sublingual or transdermal.

They differ in their onset and duration of action. Sublingual has a faster onset, but a short duration of action (10-30min). Transdermal has a longer onset, but a duration of action of 7-10h. Therefore, the sublingual administration is a temporary measure - get to the hospital ASAP!

Question 5

What is the MOA of nitrates?

Answer 5

Release of NO results in the increase in activity of guanylyl cyclase, which converts GTP to cGMP. Myosin-LC will be dephosphorylated, and this results in the relaxation of muscles.

Question 6

Side effects of nitrates?

Answer 6

Tachycardia
Hypotension
Headache

Question 7

Clinical indications for nitrates?

Answer 7

Immediate relief for angina.

Not for maintenance therapy due to short duration of action.

Question 8

Effect of continuous nitrate use?

Answer 8

Tolerance develops with continuous exposure

Release of NO from tissues decreases due to systemic compensation. Water and salt increasingly retained to increase blood pressure.

Question 9

What is the cardiovascular effect of B-adrenoreceptors?

Answer 9

Diminishes phase 4 depolarisation.

Depresses automaticity, prolonging AV conduction.

Results in decreased heart rate and contractility.

Question 10

Where are the different B-adrenoreceptors located?

Answer 10

B1: heart
B2: vascular smooth muscles

Question 11

Name 4 non-selective B-blockers.

Answer 11

Propranolol
Timolol
Nadolol
Cateolol

Question 12

Name 4 selective B-blockers.

Answer 12

Atenolol
Metoprolol
Acebutol
Esmolol

Question 13

What is the MOA of B-blockers?

Answer 13

Block beta receptors, lowering the conversion of ATP to cAMP as second messenger.

Question 14

Side effects of B-blockers?

Answer 14

Bradycardia
CNS effects (mild selection, vivid dreams, depression-beta blocker blues)
Asthma
Withdrawal syndrome (due to upregulation of receptors/supersensitivity)

Question 15

Contraindications for non-selective B-blockers?

Answer 15

Contraindicated in

1. AV blockade, severe LV failure
2. T1DM, exacerbate hypoglycaemic episodes
3. Asthma, may exacerbate

Question 16

Name 3 Ca channel blockers.

Answer 16

Verapamil
Diltiazem
Nifedipine

Question 17

What are Ca channel blockers used for?

Answer 17

1. Lower BP (verapamil=diltiazem=nifedipine)
2. Vasodilator (nifedipine>diltiazem>verapamil)
3. Cardiac depressant (verapamil>diltiazem>nifedipine)

Question 18

Adverse effects of Ca channel blockers?

Answer 18

Cardiac depression: bradycardia, AV blocker, heart failure

Question 19

What is most effective, long term therapy to reduce the incidence and severity of the coronary vasospasm?

Answer 19

Ca channel blockers (e.g. diltiazem) > nitrates