10c- Antiarrythmics + Rate Controllers

Question 1

What are the 2 most important parts of cardiac arrest management?

Answer 1

1. Defibrilation if indicated to converting rhythms
2. Continuous CPR that is good

Question 2

What are 3 things antiarrhythmic drugs do?

Answer 2

1. Slow down how fast electrical signals are conducted
2. Slow down how often those signals are produced
3. Slow down how quick a cardiac cell recovers after activation

Question 3

Where do dysrhythmias often generate? (3)

Answer 3

1. From a place outside the SA node
2. Electric signals going through diseased or damaged tissues
3. The signals re-entering back into cardiac tissue, causing one signal to cause 2 beats.

Question 4

What ions do antiarrhythmic drugs focus on influencing?

Answer 4

1. Na+ ions
2. K+ ions
3. Ca2+ ions

Question 5

What happens at stage 0 on this chart?

Answer 5

Na+ channels open –> Na+ goes into cell –> Initial depolarization occurs

Na+ Channel Blockers work here

Question 6

What does stage 1 represent?

Answer 6

Na+ channels close –> K+ and Cl- go out of cell slowly –> Initial repolarization (- charge reestablished in cell)

Question 7

What does stage 2 represent?

Ca+ Channel Blockers work here

Answer 7

Ca2+ comes in slowly, K+ goes out. Equilibrium for charge established.

Ca2+ Channel Blockers work here

Question 8

What does stage 3 represent?

Answer 8

Ca2+ movement stops –> K+ goes out –> Cell repolarizes b/c charge (-) again

K+ Channel Blockers work here

Question 9

What happens during stage 4?

Rectifier Stage!

Answer 9

Rectifier stage. Na/K pump maintains the repolarizing (-) charge so each of those ions can go in and out.

Beta Blockers work here!

Question 10

What are the 5 classes of antiarrhythmic drugs?

Some Bunnies Prefer Carrot Meals

Answer 10

1. Sodium Channel Blockers
2. Beta Blockers
3. K+ channel blockers
4. Ca2+ channel blockers
5. Miscellaneous

Question 11

Na+ Blockers

What is the goal of Na+ Channel Blockers?

Answer 11

Slow down initial depolarization + conduction of electric signals

Question 12

Drug: Xylocaine (Lidocaine)

What does this drug do?

Na+ Blocker

Answer 12

• Blocks Na+ Channels
• Treats Ventricular Tachycardia + Ventricular Fibrillation

Question 13

Na+ Blockers

These drugs can be **Pro-dysrhythmic ** vs other drugs. What does that mean?

Answer 13

They’re prone to causing dysrhythmias on their own

Question 14

Beta Blockers

What do beta blockers do?

Answer 14

Slow down creation of electrical signals, and their conduction.

Question 15

Beta Blockers

What are their 3 effects?

Answer 15

1. Negative chronotropic effects
2. Negative dromotropic effects
3. Negative inotropic effects

Question 16

Beta blockers

What do they primarily treat?

Answer 16

Atrial Tachycardias

Question 17

Beta blockers

What are 2 drugs commonly used by RTs in this category?

Answer 17

1. Labetalol
2. Metoprolol

Question 18

Labetalol

What is it?

Answer 18

A non-selective beta blocker used to treat hypertension + tachycardia

Question 19

Labetalol

What does it target?

Answer 19

• B1 + B2 receptors to block them
• a1 (very minimal, not that significant)

Question 21

Metoprolol

What is it?

Answer 21

A selective B1 blocker

Question 22

Metoprolol

What is it primarily used for? (2)

Answer 22

1. Helping treat supraventricular tachycardias
2. Reduce BP to treat hypertension

Question 23

K+ Channel Blockers

What’s their main objective?

Answer 23

• Slow down how fast a cardiac cell recovers after being activated.
• Helps lead to cardiac cells that are de-synched to re-synch

Question 24

K+ Blockers

What is the common drug in this category?

Answer 24

Amiodarone

Question 25

# Amiodarone? What do they do in addition to blocking K+ Channels?

Answer 25

1. Block Na+ Channels 2. Block Beta channels 3. Block Ca2+ Channels

Question 26

# Amiodarone Because of its special ability, what can it do?

Answer 26

Slow down both atrial + ventricular rates ## Footnote Needs loading dose to work quickly, followed up with infusion

Question 27

# Amiodarone Although very effective, what are its significant side effects?

Answer 27

1. Hepatoxicity 2. Bradycardia 3. Sking discolouration 4. Pulmonary fibrosis(*)

Question 28

# Amiodarone What are the potential reasons of this drug causing pulmonary fibrosis?

Answer 28

1. Directly increasing O2 production of free radicals 2. Indirectly affecting immune regulated reactions ## Footnote Hard to detect (months to years to develop)

Question 29

# Ca2+ Channel Blockers What is their goal?

Answer 29

Slow down conduction + creation of electric signals

Question 30

# Ca2+ Channel Blockers How do they primarily work?

Answer 30

1. Decrease A-V node conduction speed 2. Incrase A-V node refractory time 3. Decrease SA node automaticity

Question 31

# Ca2+ Channel Blockers What are they useful in treating?

Answer 31

Atrial (supraventricular) dysrhythmias

Question 32

# Ca2+ Channel Blockers What are the 2 drugs used by RTs in this category?

Answer 32

1. Diltiazem 2. Verapamil

Question 33

# Miscellaneous Drugs What are the 3 drugs that fall under this category?

Answer 33

1. Adenosine 2. Digoxin 3. Magnesium Sulphate

Question 34

# Adenosine What is it used for and how is it delivered?

Answer 34

- Used to treat atrial (supraventricular tachycardias) - Delivered via IV push ## Footnote No gurantee of it working though

Question 35

# Digoxin What does it do?

Answer 35

Slow down HR + Conduction speed through AV node

Question 36

# Digoxin What can it be used to treat?

Answer 36

Atrial dysrhythmias

Question 37

# Digoxin What are its 2 negatives?

Answer 37

1. Slower Onset Time 2. Lower Therapeutic Index ## Footnote Used at home, higher risk of overdosing

Question 38

# Magnesium Sulphate What is it used for?

Answer 38

- Treating specific dysrhythmias - Has significant effects on normal electrical activity if it is too low