IHD Pharmacology I - Auchampach

Question 1

What causes ischemic heart disease?

Answer 1

An deficiency in oxygen supply relative to oxygen demand of the heart.

Question 2

What is the most probable cause of ischemic heart disease?

Answer 2

atherosclerosis of the coronary arteries

Question 3

How does ischemic heart disease usually present?

Answer 3

variable

pain in the chest, possibly radiating through the arms, jaw, and sternum

Question 4

What contributes to myocardial oxygen demand?

Answer 4

Wall Stress
Heart Rate
Contractility

Question 5

What contributes to myocardial oxygen supply? Which factor(s) are stable?

Answer 5

Oxygen content in blood is constant

Coronary blood flow is variable

Question 6

What is the relationship between coronary blood flow, perfusion pressure, and coronary vascular resistance?

Answer 6

Coronary blood flow= (perfusion pressure)/vascular resistance

Question 7

What determines the perfusion pressure in the coronary arteries?

Answer 7

the diastolic pressure

Question 8

When is coronary perfusion the lowest? Why?

Answer 8

Perfusion is lowest during systole; either because the leafs of the valve are blocking it OR because the muscle contraction closes the blood valve… neither makes complete sense

Question 9

What is an external factor that regulates coronary flow? What is an intrinsic factor?

Answer 9

Sympathetic receptors aplha1 cause constriction.

Adenosine and lactic acid released from the cardiomyocytes cause dialation

Question 10

What factors related to wall stress increase oxygen demand?

Answer 10

Increased ventricle volume

increase ventricle pressure

Question 11

What level of coronary obstruction causes a decrease in perfusion during resting flow? What about during increased demand?

Answer 11

90% obstruction is needed to lower resting perfusion

70% obstruction is needed to lower perfusion during increased demand

Question 12

Why is the subendothelium especially vulnerable to ischemia?

Answer 12

Increased ventricle muscle pressure during systole limits perfusion and during exercise diastole can be shortened, also limiting the perfusion.

Question 13

What EKG changes can be seen in subendocardial ischemia?

Answer 13

ST segment depression

T wave inversion

Question 14

What role does endothelial dysfunction play in ischemia?

Answer 14

Incorrect release of endothelial vasodilators

loss of anti-thrombotic properties

Question 15

What are three forms of chronic ischemic heart disease?

Answer 15

• stable angina (stable plaque that has not burst)
• variant angina/ prinzmetal’s angina (no plaque, vasospasm)
• syndrome X (normal coronary arteries, decreased blood flow)

Question 16

What is silent ischemia?

Answer 16

Episodes of ischemia that occur without any pain

Question 17

What is unstable angina?

Answer 17

A coronary artery plaque that has burst and has started a clotting cascade

Question 18

What disease is seen on an EKG with ST depression? T wave inversion? ST elevation?

Answer 18

ST depression- subendocardial ischemia
T wave inversion-subendocardial ischemia
ST elevation- transmural ischemia

Question 19

How can stable angina be diagnosed?

Answer 19

cardiovascular stress test, physical or pharmaceutical
OR
coronary angioplasty

Question 20

What therapies are recommended for acute episodes of ischemia?

Answer 20

Fast-acting nitrates

Question 21

What three drugs classes are used to prevent ischemia?

Answer 21

Long-acting nitrates
beta-adrenergic receptor blockers
calcium channel blockers

Question 22

How do long-acting nitrates act to prevent ischemia?

Answer 22

They are potent venous vasodilators, reducing pre-load. They increase production of NO.

Question 23

What are three nitrates? What are the pharmacokinetics of the each?

Answer 23

Nitroglycerin- low bioavailability, extensive first pass
Isosorbide dinitrate- metabolized to mononitrate
Isosorbide mononitrate-bioactive

Question 24

Why is nitroglycerin useful if it has an extensive first pass effect?

Answer 24

It is typically used in short-action situations, given sublingually, and has three nitrous groups

Question 25

What is a problem with using nitrates as a chronic therapy for ischemia?

Answer 25

tolerance

Question 26

What are adverse effects for nitrates?

Answer 26

Headache
Hypotension
Reflex tachycardia
Flushing

Question 27

Why are beta-adrenergic receptors useful for treating ischemia?

Answer 27

They decrease oxygen demand by decrease heart rate and pressure.

Question 28

What are the two classes of beta-adrenergic receptor blockers? What are the drugs in each class?

Answer 28

Non-specific 
-propanolol
-timolol
Specific
-atenolol
-metoprolol

Question 29

What are some adverse effects of beta-adrenergic receptor blockers?

Answer 29

fatigue
sexual dysfunction
airway constriction

Question 30

What are some contraindications for beta-blockers?

Answer 30

COPD/asthma
heart failure
bradycardia

Question 31

What are the two classes of calcium channel blockers? What are the drugs in each class?

Answer 31

Dihydropyridines

• Amlodipine
• Nifedipine

Non-dihydropyridines

• Diltiazem
• Verapamil

Question 32

Which class of calcium channel blocker treats prinzmetal angina?

Answer 32

Dihydropyridines are potent vasoconstrictors that counter-act the vasospasms seen in prinzmetal angina.

Question 33

What are some adverse effects of calcium channel blockers?

Answer 33

Headache, flushing
• Decrease contractility (V, D)
• Bradycardia (V, D)
• Edema (especially N, D)
• Constipation (especially V)

Question 34

What is Ranolazine?

Answer 34

a drug that inhibits late sodium current in the cardiomyocytes.