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Flashcards in Angina - Howlett 2 Deck (18)
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1

Angina pectoris

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

2

Myocardial infarction

Plaque ruptures

3

Treatment of myocardial infarction

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

4

Treatment of Angina

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

5

Drug therapy

Aims to improve balance between O2 supply and demand by:
1. Improving O2 supply
2. Decreasing O2 demand by decreasing the work of heart

6

Improving O2 supply

1. Dilate vessels
2. Prevent vasospasm

7

Reduce O2 demand

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

8

Organic nitrates

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

9

Nitroglycerin

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

10

Sildenafil

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

11

Nitrate metabolism

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

12

Beta-adrenergic blockers

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

13

Synergistic drug combination of beta-adrenergic blockers and nitrates

Nitrates cause drop in BP and increase HR as reflex
Beta blockers block increase of HR

14

Calcium channel blockers

Nifedipine, verapamil, diltiazem

15

Nifedipine

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

16

Verapamil

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

17

Newer agents

pFOX inhibitor
Selective cardiac rate inhibitors

18

pFOX inhibitor

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