Anti-arrhythmic drugs Flashcards Preview

Pharm Block 1 > Anti-arrhythmic drugs > Flashcards

Flashcards in Anti-arrhythmic drugs Deck (23):
1

What is the major cardiovascular danger of anti-arrhythmic drugs (especially class III agents)?

Anti-arrythmic drugs (especially class III agents) can significantly prolong repolarization (QT) and therefore can result in Torsade de Pointe as a form of Proarrhythmia.

2

What is the only anti-arrythmic that has been shown to improve mortality in the post infarct patient?

Beta blocker

3

What is the preferred therapy for high risk arrhythmia patients (low EF <35% or sustained VT/VF)?

Implantable Cardioverter Defibrillator

4

What are class I anti-arrhythmic drug agents?

Class I => are Na channel blockers

- Class Ia => moderate Na channel blocker (prolongs conduction and repolarization) and increases effective refractory period

- Class Ib => weak Na channel blocker and decreases effective refractory period

- Class Ic => strong Na channel blocker and maintains effective refractory period

5

What are some examples of Class Ia anti-arrhythmic drugs?

Quinidine

6

What are some examples of Class Ib anti-arrhythmic drugs?

Lidocaine

7

What are some examples of Class Ic anti-arrhythmic drugs?

Flecainide

8

What are class II anti-arrhythmic drug agents?

Class II => Beta Blockers

9

How do class III anti-arrhythmic drug agents act?

Class III => K channel blockers that delay depolarization

10

Why is Ibutilide a pseudo class III anti-arrhythmic drug?

Ibutilide causes a slow inward Na current that also delays depolarization

11

What are examples of class III anti-arrhythmic drug agents?

Sotalol, Dofetilide, Amiodarone, Dronedarone

12

How do class IV anti-arrhythmic drug agents act?

Act primarily on slow response cells (SA & AV node), which are dependent on Ca2+ influx for Phase 0 of the action potential.

13

What are 3 examples of class IV anti-arrhythmic drug agents?

Diltiazem

Verapamil

Adenosine

14

How does adenosine work to prevent arrhythmia?

- Blocks A1 receptor

- Prolongs AV conduction by causing cell hyperpolarization and reduces catacholamine stimulation

15

What drugs are used to treat SVT?

Adenosine

Beta blockers

Calcium Channel Blockers

Digoxin

16

What steps are taken if the routine SVT drugs do not work?

- IV: Ibutilide, Quinidine, Procainamide, Amiodarone

- PO: Quinidine, Procainamide, Amiodarone, Disopyramide, Flecainide, Propafenone, Sotalol, Dofetilide, Dronedarone

- DC cardioversion

- Ablation => now generally replaced traditional anti-arrhythmic therapy

17

When does ablation NOT work better than "traditional" anti-arrhythmic therapy?

Atrial fibrillation

18

Which drugs improve survival chances after MI?

Beta blocker (Class II) => propanolol

*Amiodarone (Class III) appears to increase the probability of survival but actually increases cumulative risk => pro-arrhythmia

19

Which drug classes can cause Torsades from Early Afterdepolarization (EAD)?

Class III (K+ blockers)

Class Ia (Na + blockers)

20

How do class Ic anti-arrhythmic drugs cause incessant monomorphic VT?

REMEMBER => Type 1C (Na+ blockers) delay conduction

-Slowing of conduction in limb 1 allows limb 2 to recover by the time the retrograde wavefront arrives at 2; thus facilitating reentry

A image thumb
21

What drugs should be used in acute VT?

IV Lidocaine or Amiodarone till definitive therapy can be instituted 

22

Which drugs should be used in sustained VT?

Amiodarone

Sotalol

*However, ICDs are superior

23

What is the most effective treatment strategy for reducing mortality in a patient with a low ejection fraction, and sustained ventricular tachycardia or cardiac arrest?

Empiric ICD