Drugs Acting on the Heart

Question 0

What condition is it where the heart is temporarily deprived of oxygen?

Answer 0

Angina

Question 1

What is a pro-drug?

Answer 1

One that needs to be metabolised to a different form in order to become active

Question 2

What happens when the heart rhythm is disturbed?

Answer 2

Dysrhythmia

Question 3

What condition is where the heart is deprived of oxygen?

Answer 3

Heart Attack (MI)

Question 4

What happens when the heart doesn’t pump properly?

Answer 4

Heart Failure

Question 5

What is coronary heart disease?

Answer 5

Thinning of coronary arteries due to fatty plaques

Question 6

What are the consequences of coronary artery disease?

Answer 6

It slows and restricts blood flow to the cardiac muscle. As it depends on oxygen and glucose, the muscle does not work properly, resulting in pain.
If this occurs for too long = heart muscle dies

Question 7

What 3 things can reduce coronary artery disease?

1 lifestyle, 2 are drugs

Answer 7

Lifestyle - diet, exercise, stopping smoking
Medication to reduce BP
Statins to reduce cholesterol

Question 8

What is the key drug to reduce cholesterol, to reverse the effects of coronary artery disease in its EARLY stages?

Answer 8

Statins

Question 9

What condition is a crushing pain in the chest that may radiate to arm, neck, or jaw and feel like a strangling of the chest, that only lasts short time?

Answer 9

Angina Pectoris

Question 10

What does the pain in angina pectoris result from?

Answer 10

Cardiac ischaemia - not enough oxygen reaching the heart to meet its demands

Question 11

What do you call angina experienced when exercising?

Answer 11

Angina of effort

Question 12

What are the 2 solutions for solving the problem of angina (too little oxygen getting to the cardiac muscle)?

Answer 12

Reducing oxygen demand (reduce workload)

Increasing oxygen supply (improve blood flow)

Question 13

What is an effective vasodilator that reduces the cardiac workload?

Answer 13

GTN/Glyceryl Trinitrate (nitroglycerin)

Question 14

Why can GTN not be taken orally?

Answer 14

It is a prodrug that needs to be converted to its active form.
This must be done close to the site of action - in the blood stream

Question 15

What is GTN/nitroglycerin converted to in the body?

Answer 15

Nitro oxide

Question 16

What do vasodilators do in relation to the heart/why is it useful that they dilate the peripheral blood vessels?

Answer 16

Heart does not have to push as hard

Less blood is returned to the heart: lower force of contraction

It DECREASES RESISTANCE and REDUCES WORKLOAD

Question 17

What is the best treatment for angina?

Answer 17

GTN

Question 18

What does GTN do?

Answer 18

Converts to nitro oxide and dilates peripheral blood vessels. Good for angina as decreases resistance of blood flow, thereby reducing cardiac workload and output.

Question 19

Name a beta-blocker beginning with A that improves blood supply to the heart, thereby reducing cardiac workload:

Answer 19

Atenolol

Question 20

Where does atenolol act in the heart?

Answer 20

B1 adrenoceptors

Question 21

Atenolol blocks the action of the sympathetic nervous system on the SA node. What does this achieve?

Answer 21

It stops the heart from pumping more forcefully and thus requiring more oxygen when the patient’s SNS is activated

Question 22

Which phase does atenolol prolong?

Answer 22

The diastole phase. This is when the heart is relaxed, so it gives the heart longer for the blood and oxygen to flow round the body before it contracts again

Question 23

What 2 mechanisms of action does atenolol have?

Answer 23

It acts on B1 adrenoceptors in the heart -

blocking SNS activation and prolonging the diastole phase

Question 24

What is similar to angina but with prolonged pain? | Why is the pain prolonged.

Answer 24

A heart attack. It hurts because the cardiac muscle is dying

Question 25

What is the process called where part of the cardiac muscle dies due to lack of oxygen?

Answer 25

Ischaemia

Question 26

What are the 5 types of heart dysrhythmia?

Answer 26

``` Atrial Fibrillation Supra-ventricular Tachycardia Ventricular Tachycardia Heart Block Ventricular Fibrillation ```

Question 27

What are the 2 best drugs for a heart attack that reduce workload and oxygen demand, improve blood flow through coronary arteries and reduce pain?

Answer 27

GTN and propranolol

Question 28

What is a tissue plasminogen activator? | In what time scale should it be used?

Answer 28

A 'clot busting drug' used during a heart attack to unblock an artery. It needs to be used within a few hours

Question 29

What is the name of a procedure where a vessel is reopened using a tiny balloon and stent?

Answer 29

Angioplasty

Question 30

What is heart failure?

Answer 30

When the heart does not pump efficiently enough to supply the body

Question 31

What are the two solutions for heart failure?

Answer 31

Reduce blood pressure to reduce demands on the heart Make the heart pump faster

Question 32

Name a positive intropic agent beginning with D

Answer 32

Digoxin

Question 33

What is a positive inotropic agent?

Answer 33

A drug that increases cardiac output/force of contraction

Question 34

Name a drug that increases cardiac output/force of contraction that is used for patients with heart failure, atrial fibrillation or for a very long time in sinus rhythm:

Answer 34

Digoxin

Question 35

What are the first 2 types of drugs that should be given to a patient with sinus rhythm before giving digoxin?

Answer 35

An ACE inhibitor and a diuretic

Question 36

Does digoxin reduce the mortality of patients with heart problems?

Answer 36

No

Question 37

What drug improves the symptoms, exercise tolerance and need for hospitalisation in patients with heart failure/atrial fibrillation?

Answer 37

Digoxin

Question 38

What does digoxin inhibit and increase? | What is the molecular mechanism of digoxin

Answer 38

It inhibits the Na/K ATPase - i.e. Sodium/Potassium pump | Increases the Calcium in stores

Question 39

Digoxin inhibits the sodium/potassium pump and increases calcium stores in which cells in the body?

Answer 39

Every single one = TOXIC

Question 40

What is the physiological effect of digoxin?

Answer 40

It increases the force of contraction (positive inotropic effect) without increasing oxygen consumption

Question 41

Why would digoxin not be the first choice drug?

Answer 41

Lots of interactions with other drugs Very toxic Better to reduce demands on heart than increase output

Question 42

What is a cardiac arrhythmia?

Answer 42

LACK of rhythm in the heart

Question 43

What is a cardiac dysrhythmia?

Answer 43

A disturbance of rhythm in the heart

Question 44

What are the 3 potential sites of origin for a cardiac dysrhythmia?

Answer 44

Atrial Supra-ventricular/Junctional Ventricular

Question 45

What is a true arrhythmia?

Answer 45

A very disorganised cardiac rhythm

Question 46

What is tachycardia?

Answer 46

Where the heart beats too fast

Question 47

What is the term for when the heart beats too slow?

Answer 47

Bradycardia

Question 48

What is the term for when cardiac tissue other than the SA node initiates heart beats?

Answer 48

Ectopic Pacemaker

Question 49

What is the term for a build up of calcium in cells that lead to a train of action potentials causing dysrhythmia in the heart?

Answer 49

Delayed after depolarisation

Question 50

What is the term used for tissue damage/abnormality causing action potentials to travel in circles in the heart?

Answer 50

Re-entry circuits

Question 51

What are additional conducting pathways connecting atria and ventricles in the heart?

Answer 51

Congenital abnormalities

Question 52

What is a HEART BLOCK?

Answer 52

Damage to conducting pathways in the heart disrupting atrial-ventricular signalling

Question 53

What disrupts atrial-ventricular signalling as a result of damage to conducting pathways?

Answer 53

Heart Block

Question 54

People with coronary heart disease, heart valve disorders and blood chemistry disorders (e.g. thyroid) are more at risk of what?

Answer 54

Cardiac DYSRHYTHMIA

Question 55

Beta blockers, psychotropics, sympathomimetics, caffeine, amphetamines, cocaine and some anti-dysrhythmic drugs can sometimes cause what?

Answer 55

Cardiac dysrhythmia

Question 56

What does ectopic focus look like on an ECG?

Answer 56

Extra P Waves. The atrial muscle is trying to initiate heart beats from another bit of tissue as well as the SA node = tachycardia

Question 57

When would you see extra P waves and no QRS wave on an ECG (bradycardia)

Answer 57

Atrio-ventricular block = impulse not going to ventricles

Question 58

What may require an electric shock to restore function and results in no QRS wave on an ECG?

Answer 58

Ventricular fibrillation

Question 59

What are the 3 treatment types for dysrhythmia?

Answer 59

Drug, Electrical, Surgery

Question 60

What classification system is flawed because: - it does not allow for drugs with multiple mechanisms of action - does not allow for drug action differing between diseased and healthy tissue - it excludes some potential sites of drug action?

Answer 60

The Vaughn-Williams classification

Question 61

What classification system do most clinic use for classifying anti-dysrhythmic drugs?

Answer 61

By clinical utility

Question 62

What are the 3 classification groups for classifying dysrhythmic drugs by clinical utility?

Answer 62

Supra-ventricular origin Supra-ventricular OR ventricular origin Ventricular origin

Question 63

What are the 5 classification groups in the Vaughn-Williams classification system?

Answer 63

``` Sodium Channels Beta 1 Adrenoceptor Potassium Channels Calcium Channels Unclassified ``` Vaughan Said Bullying Peter Causes Upset

Question 64

Where does Lidocaine target when used for a heart condition?

Answer 64

Sodium Channels

Question 65

Where does Atenolol target?

Answer 65

Beta 1 adrenoceptors

Question 66

Where does amiodarone target?

Answer 66

Potassium channels

Question 67

Where does verapamil target?

Answer 67

Calcium channels

Question 68

What category in the VW classification system does Adenosine and digoxin fit into?

Answer 68

Unclassified. It has more than one mechanism of action.

Question 69

What do V-W class 1 drugs target?

Answer 69

Sodium Channels

Question 70

What do Class 2 V-W drugs target?

Answer 70

Beta 1 Adrenoceptors

Question 71

What do Class 3 V-W drugs target?

Answer 71

Potassium Channels - prolonging action potentials

Question 72

What do Class 4 V-W drugs target?

Answer 72

Calcium channels

Question 73

Digoxin is used to treat cardiac failure. It is also a positive inotropic agent. True or False?

Answer 73

True

Question 74

Organic nitrates such as nitroglycerin are useful in the treatment of what?

Answer 74

Angina

Question 75

The component of the cardiac cycle during which blood flow to cardiac muscle occurs is:

Answer 75

diastole

Question 76

An abnormality in the atria that can produce extra P waves in an ECG and that can result the heart rate speeding up is:

Answer 76

An ectopic focus

Question 77

Lidocaine exerts its antidysrhythmic action by blocking: a. calcium channels b. chloride channels c. potassium channels d. sodium channels

Answer 77

Sodium channels

Question 78

Atenolol exerts its therapeutic effect in angina by: a. decreasing the force of heart contraction b. improving blood supply to the heart c. slowing the heart rate d. all of the above

Answer 78

All of the above

Question 79

Select a pro-drug a. atenolol b. glyceryl trinitrate c. lidocaine d. verapamil

Answer 79

GTN

Question 80

Select a drug that is usually given in a sublingual, buccal spray or patch form: a. atenolol b. glyceryl trinitrate c. lidocaine d. verapamil

Answer 80

GTN

Question 81

Digoxin acts on: a. beta adrenoceptors b. calcium channels c. sodium channels d. sodium potassium ATPase

Answer 81

Sodium Potassium Pump