Arrhythmia - Antiarrhythmic drugs

Question 1

Classification of antiarrhythmic drugs?

Answer 1

Class I - acts on phase O

Class II- on Phase 4

Class III on 3

class IV on phase 2

Question 2

What is proarrhythmia?

Answer 2

Question 2

subcategory of class I that can prolong QTc

Answer 2

Class Ia - prolongs Qtc

***class III can also prolong QTc

Question 2

Mechanism of proarrhythmia?

Answer 2

slowed conduction by Class 1c agents
(reentry)

prolong repolarization by Class III
(EAD)

Calcium overload by Digoxin
(DAD)

Question 3

Example of prolonged repolarization by EAD

Answer 3

precipitated by bradycardia

Question 4

cause of delayed afterdepolarization

Answer 4

high intracellular calcium

Question 5

arrhythmia by which DAD is the mechanism

Answer 5

• Digoxin induced
• Catecholamine Polymorphic VT
• Bidirectional VT

Question 6

drug of choice for catecholamine polymorphic VT

Answer 6

Flecainide

Question 7

Effects/arrhythmias associated with Digoxin toxicty

Answer 7

• High grade AV block with accelerated junctional rhythm
• Focal atrial tachycardia
• Bi-directional VT

Question 8

question?

Answer 8

B

Question 9

Question?

Answer 9

3

Question 10

Question? started with flecainide

Answer 10

A

Question 11

Use-dependent channel block vs reverse use-dependent channel block

Answer 11

Use-dependence in CLASS Ic

reverse use-dependence in Class III

Question 12

in patient taking Class Ic, what will you monitor in the ECG?

Answer 12

monitor for QRS widening with stress test

• ECG +/- exercise stress test after 1 week after initiation.

stop agent if QRS prolongs >15-20% form the baseline

***exercise will use the use-dependence

Question 12

in patient taking Class III, what will you monitor in the ECG?

Answer 12

QT prolongation at rest

potential for PAUSE-dependent polymorphic VT

Question 12

pro-arrhythmic action of Class I and III

Answer 12

Class I - promote reentry

Class III - EAD/TdP

Question 13

AAD that is renally excreted

Answer 13

DDS

Digoxin
Dofetilide
Sotalol

Question 14

safer SSRIs with coadministered with Class Ia and III

Answer 14

Fluoxetine

Question 15

Drug for maintenance of sinu rhythm for Afib

Answer 15

depends if with structural heart disease

Question 16

Drugs of choice for VT

Answer 16

Question 17

what to monitor in pt with Class Ic

Answer 17

QRS widening

class III - QTc prolongation

Question 18

Amiodarone monitoring: TSH

Answer 18

initiation, at 3 months then every 6 months

can cause both hypo- and hyperthyroidism

Question 19

Question?

Answer 19

5

Question 19

question?

Answer 19

4

Question 20

Question?

Answer 20

2

Question 21

Monitoring with amiodarone: Ocular effects - Corneal microdeposits

Answer 21

yearly

Question 21

Monitoring with amiodarone: Pulmonary: most common is Interstitial Pneumonitis

Answer 21

baseline: CXR yearly CXR for asymptomatic CXR and PFT for symptomatic: dyspnea