antiarrhythmia drugs 2 Flashcards Preview

CV exam 1 wk 1 > antiarrhythmia drugs 2 > Flashcards

Flashcards in antiarrhythmia drugs 2 Deck (23):
1

direct results of block of L-type Ca2+ channels are?

1. Slowed upstroke
2. reduced AP amplitude

2

What results indirectly from L channel block?

Slowed repolarization (phase 3)

3

In SA and AV node, adenosine (via A1 adenosine receptor) works to?

1. ↑ K+ current
2. ↓ L-type Ca2+ current (dihydropyridine-sensitive, slow inward current)
3. ↓ If in SA and AV nodes

4

adenosine action

similar to β-adrenergic receptor blockers, but adenosine is not a β-blocker.

5

Adenosine-induced changes in membrane currents:

↓ SA node and AV node firing rate
↓ conduction rate in the AV node

6

Antiarrhythmic drugs are primary therapy for

1. atrial fibrillation only
2. Ablation or ICD equal or superior in management of all other arrhythmias

7

PSVT: tx acute with

adenosine (short half-life is advantageous)

8

PSVT: tx chronic with

1. AV nodal blockers
2. Class II (β-blockers)
3. Class IV (Ca2+ channel blockers)
4. Class III (amiodarone, sotalol)
5. catheter ablation of ectopic focus

9

Ventricular tachycardias/fibrillation pathophysiology via

afterdepolarizations + re-entry

10

Ventricular tachycardias/fibrillation: treat acute with

1. amiodarone
2. lidocaine

11

esmolol metabolize by

blood esterase

12

amiodarone side effects

1. heart block
2. thyroid dysfunction
3. corneal deposits
4. pulmonary fibrosis

13

Drug prevention of sudden cardiac death:
Proven benefit

1. β-blockers
2. angiotensin converting enzyme (ACE) inhibitors
3. aspirin
4. statins

14

Drug prevention of sudden cardiac death:
perhaps benefit

1. amiodarone
2. digoxin

15

Drug prevention of sudden cardiac death:
perhaps harmful

1. Class I drugs (Na+ channel blockers)
2. Class IV drugs (Ca2+ channel blockers)

16

Procainamide major side effect

1. Lupus syndrome (occurs in 1/3 of patients on long-term therapy).
2. class Ia

17

Lidocaine major side effects

1. Least cardiotoxic agent of Class I drugs.
2. Side effects: paresthesia, tremors, seizures, agitation, confusion.
3. class Ib

18

Flecainide and Propafenone Major side effects

1. Highly pro-arrhythmic, particularly with ventricular tachycardia.
2. class Ic

19

B-blocker major side effects

1. Hypotension
2. aggravation of heart failure
3. bronchospasm
4. impotence.

20

amiodarone major side effects

1. Cardiac problems include bradycardia and heart block.
2. Dose-related effects include:
a. thyroid dysfunction,
b. corneal deposits,
c. pulmonary fibrosis and
d. skin discoloration.
3. Problems with side effects are exacerbated by the very long half-life of amiodarone (13-100 days).
4. Class 3

21

sotalol major side effects

1. Structurally, this drug is a β-adrenergic receptor ligand.
2. Principal side effects are similar to those of the other β-blockers.
3. class 3

22

verapamil major side effects

1. The major adverse effect of these drugs is hypotension
(via action on vascular smooth muscle.)
2. Negative cardiac inotropy
3. class 4

23

what explains adenosine's side effects?

Adenosine action on coronary circulation