Class 4&Misc. Anti-Arrhythmic Drugs

Question 1

What are the Class 4 drugs?

Answer 1

Verapamil

Diltiazem

Question 2

MOA for Class 4 drugs?

Answer 2

Block L-type Calcium channels

Question 3

What effects will Class 4 drugs have on the slope of phase 0 and threshold potential of the L-type calcium channels?

Answer 3

• Decrease slope of phase 0

- Increase threshold potential of L-type calcium channels

Question 4

Overall effects of Class 4 drugs on the nodal cells?

Answer 4

• Decrease HR at SA node

- Prolong conduction and refractory time in AV node

Question 5

Verapamil and Diltiazem are used to terminate, prevent and control?

Answer 5

Ventricular rate

Question 6

What adverse effects can Verapamil and Diltiazem result in?

Answer 6

Constipation

AV block and SA node arrest

Question 7

What is the Miscellaneous drug?

Answer 7

Adenosine

Question 8

MOA for Adenosine?

Answer 8

(+) A1 adenosine receptor coupled to Gi

=> enhances K+ current and (-) calcium and funny channels

Question 9

Overall MOA for Adenosine?

Answer 9

Hyperpolarization and suppression of action potentials

Question 10

What does Adenosine relieve rapidly?

Answer 10

Paroxysmal Supraventricular Tachycardia

Question 11

What does Adenosine relieve rapidly?

Answer 11

Paroxysmal Supraventricular Tachycardia

Question 12

What are some adverse effects seen with Adenosine use?

Answer 12

Shortness of breath and bronchoconstriction

Chest burning

Question 13

MOA for Adenosine?

Answer 13

• (+) A1 adenosine receptors coupled to Gi
• Enhances K+ current
• (-) Calcium and funny currents
  = Marked hyperpolarization and suppression of APs

Question 14

Results of the CAST trial?

Answer 14

Flecainide and other class 1C drugs caused increased mortality and proarrhythmias

Question 15

Results of CAST trial?

Answer 15

Flecainide and other class 1C drugs caused increased mortality and proarrhythmias

Question 16

Certain Anti-arrhythmic drugs can trigger fatal arrhythmias. Which classes of drugs can cause Torasade de pointes?

Answer 16

(slow conduction)

= Class 1A and 3

Question 17

Certain Anti-arrhythmic drugs can trigger fatal arrhythmias. Which drug classes can cause ventricular tachycardias?

Answer 17

(slow conduction)

= Class 1A and 1C

Question 18

Atrial Fibrillation is due to formation of?

Answer 18

Re-entry circuits

Question 19

Which drug classes can treat Afib by terminating re-entry circuits?

Answer 19

Class 1C and 3

Question 20

Which drug classes can treat Afib by terminating re-entry circuits?

Answer 20

Class 1C and 3

Question 21

Cardioversion converts back to?

Answer 21

Sinus rhythm

Question 22

In patients with structural heart disease, which 3 drugs can be considered for Afib/

Answer 22

Sotalol
Amiodarone
Dofetilide

Question 23

To control the rate with Afib, what drugs can be considered (generally)?

Answer 23

CCB, Beta blockers and amiodarone

Question 24

What is the most common type of Paroxysmal Supraventricular Tachycardia?

Answer 24

AVNRT

- Atrioventricular Nodal Re-entrant Tachycardia

Question 25

What is Paroxysmal Supraventricular Tachycardia subtype AVNRT?

Answer 25

Re-entry of impulses into AV node

Question 26

What can be used to Terminate AVNRT?

Answer 26

Adenosine, CCB, Beta blocker

Question 27

What can be used to prevent AVNRT?

Answer 27

CCB or beta blockers

Question 28

Torsade de pointes

Answer 28

Long QT interval

Question 29

Torsade de pointes is prolonged _____

Answer 29

Repolarization (QT interval)

Question 30

What classes of drugs often cause Torsade de pointes?

Answer 30

Class 1A and 3

Question 31

What medications for covid can cause Torsade de pointes?

Answer 31

Chloroquine and Azithromycin combo

Question 32

Besides meds, what can cause Torsade de pointes?

Answer 32

Electrolytes changes and decreased HR

Question 33

What are 3 treatments for Torsade de pointes?

Answer 33

• Treat electrolyte changes
• Magnesium sulfate
• Pacemaker/ Isoproterenol

Question 34

What are 3 treatments for Torsade de pointes?

Answer 34

• Correct electrolytes
• Magnesium sulfate
• Pacemaker/Isoproterenol