Angina - Howlett 2

Question 1

Angina pectoris

Answer 1

Chest pain caused by coronary artery disease due to schema (low blood flow)
Usually caused by atherosclerosis in the coronary arteries
Vasospasm can occur
Low O2 supply, causing pain

Question 2

Myocardial infarction

Answer 2

Plaque ruptures

Question 3

Treatment of myocardial infarction

Answer 3

1. Aspirin
2. Statins
3. Beta-blockers
4. ACE inhibitors

Question 4

Treatment of Angina

Answer 4

1. Decrease risk factors/alter lifestyle
2. Bypass surgery, angioplasty or stent
3. Drug therapy

Question 5

Drug therapy

Answer 5

Aims to improve balance between O2 supply and demand by:

1. Improving O2 supply
2. Decreasing O2 demand by decreasing the work of heart

Question 6

Improving O2 supply

Answer 6

1. Dilate vessels

2. Prevent vasospasm

Question 7

Reduce O2 demand

Answer 7

1. Reduce afterload (decrease PR and dilating vessels)
2. Reduce preload
3. Reduce contractility
4. Reduce HR

Question 8

Organic nitrates

Answer 8

Relax smooth muscle
Converted into NO which activates guanylyl cyclase which dephosphorylates myosin light chains causing relaxation of VSM
1. Decrease preload by dilating vessels more than arteries to cause pooling
2. Redistribute blood flow to ischemic area (dilate coronary arteries)
3. Prevent coronary spasms
Can become tolerant

Question 9

Nitroglycerin

Answer 9

Formulations used in medicine are not explosive
Nitrate patches
First used for angina in 1860s

Question 10

Sildenafil

Answer 10

Used for erectile dysfunction
Inhibits phosphodiesterase
Build up of cGMP
Cannot be used with nitrates as medication 
(Demographic)

Question 11

Nitrate metabolism

Answer 11

Taken orally, goes to liver after being absorbed where it is mostly broken down
First pass effect
Sublingual (quick, during attach) and patch delivery

Question 12

Beta-adrenergic blockers

Answer 12

Propranolol and metoprolol
Block beta receptors in SNS
Lower BP, decrease HR, decrease force of contraction of heart, decrease after load
Frequently used
Used in combination with nitrates
Synergistic drug combination

Question 13

Synergistic drug combination of beta-adrenergic blockers and nitrates

Answer 13

Nitrates cause drop in BP and increase HR as reflex

Beta blockers block increase of HR

Question 14

Calcium channel blockers

Answer 14

Nifedipine, verapamil, diltiazem

Question 15

Nifedipine

Answer 15

Acts on VSN only
Blocks Ca influx into cells
Cases vasodilation, decreased vasospasm and decreased afterload

Question 16

Verapamil

Answer 16

+ Diltiazem
Block calcium influx into heart cells (decreases force of contraction of heart)
Block calcium influx into VSM (same as nifedipine)

Question 17

Newer agents

Answer 17

pFOX inhibitor

Selective cardiac rate inhibitors

Question 18

pFOX inhibitor

Answer 18

Partial fatty acid oxidation inhibitor
Shifts the way the heart uses energy
Inhibits FA oxidation in ischemic heart and shifts metabolism to glucose oxidation
Loss O2 is needed for glucose oxidation