Ischeamic Heart Disease

Question 1

What are the 4 classes of drugs used to treat IHD?

Answer 1

1. Beta-blockers
2. DHP & non-DHP calcium channel blockers
3. Ivabradine
4. Nitrates

Question 2

Nitrates are ____________ that stimulate vascular smooth muscle relaxation, resulting in ____________This reduces ____________ and hence ____________, causing a decrease in the ____________ of the heart

Answer 2

Nitrates are nitric oxide donors that stimulate vascular smooth muscle relaxation, resulting in vasodilationThis reduces total peripheral resistance and hence afterload, causing a decrease in the O2 consumption of the heart

Question 3

What is the duration of action of Nitroglycerin?

Nitroglycerin = Glyceryl Trinitrate

Answer 3

10-30 min

Question 4

What is the fast-onset nitrate indicated in acute angina pectoris?

Answer 4

Nitroglycerin; 1-5 min

Question 5

Can nitroglycerin be administered transdermally?

Answer 5

Yes. Longer onset of action (30-60min) but longer duration of action also (7-10 hrs)

Question 6

What is the duration of action of ISDN?

Isorbide Dinitrate

Answer 6

8-12 hrs

Onset of action: 60 min

Question 7

What is the clinical use for ISDN/ISMN?

Answer 7

Angina pectoris prophylaxis + treatment of heart failure

Question 8

At what plasma concentrations does ISDN/ISMN cause arterial vasodilation?

Answer 8

High plasma conc.Venous vasodilation occurs at low plasma conc. –> increased venous pooling –> reduced venous return –> reduced preload

Question 9

What are the adverse effects of nitrates?

Answer 9

1. Hypotension
2. Reflex tachycardia
3. Headache

HHR

Question 10

How do ISDN/ISMN improve the subendocardial blood flow?

Answer 10

Reduces end-diastolic pressure and volume –> heart is less dilated –> lower intramural pressure –> coronary arteries dilate

The heart will be less dilated so it doesnt squash the coronary arteries during end diastole

Question 11

What is the MOA of beta-blockers in the therapy of angina/IHD?

Answer 11

Block beta-1 receptors in cardiac myocytes leading to decrease in contractility –> reduced O2 demand

Question 12

What are the adverse effects of DHP calcium channel blockers?

Answer 12

1. Hypotension (used for BP)
2. Heart failure
3. Myocardial infarction

Question 13

What are the clinical indications for DHP-calcium channel blockers?

Answer 13

1. Hypertension
2. Stable angina (amlodipine)
3. Reduced risk of AMI & stroke (amlodipine)

Question 14

What are the 2 DHP-calcium channel blockers?

Answer 14

Nifedipine
Amlodipine

Question 15

What are the non-DHP calcium channel blockers?

Answer 15

Verapamil
Diltiazem

Question 16

Which calcium channel blocker is the most potent cardiac depressant?

Answer 16

Verapamil > Diltiazem > Nifedipine

Question 17

Which calcium channel blocker is the most potent vasodilator?

V for vasodilator is a SCAM

Answer 17

Nifedipine > Diltiazem > Verapamil

Question 18

____________ inhibits ____________ current that controls the spontaneous diastolic depolatisation in the ____________. Heartrate will ____________, causing a reduction in cardiac workload & ____________## FootnoteWhich drug slows heart rate?

Answer 18

Ivabradine inhibits cardiac pacemaker I(f) current that controls the spontaneous diastolic depolarisation in the sinus node. Heartrate will decrease, causing a reduction in cardiac workload & myocardial O2 consumption

Question 19

What are the adverse effects of Ivabradine?

Answer 19

1. Visual problem; luminous phenomena
2. Dizziness
3. Other brachycardia-related symptoms - hypotension, fatigue, malaise

Question 20

Which drug causes ‘visual problems’ described as ‘luminous phenomena’?

Answer 20

Ivabradine