Arrhythmia Flashcards
Class 1 drugs?
Sodium channel blockers
Class 1A drugs?
Procainamide
Class 1B drugs?
Lidocaine
Class 1C drugs?
Flecainide
MOA of Procainide?
“1. Slows Phase 0 depolarization
2. Slows conductivity and automaticity
3. Increases ERP and APD
MOA of Lidocaine?
- Slow Phase 0 rise
- Shorten Phase 3 repolarization
- Lower Automaticity, little effect on conductivity
- Lower APD
- No change in ERP
MOA of Flecainide
- Lower rate of Phase 0 rise
- Shorten phase 3 repolarization
- Reduce conductivity + automaticity
- No/little effect on APD + ERP
Use of Flecainide?
Refractory Ventricular tachycardias that progress to VF
Beta blockers names?
Metoprolol
Propranolol
MOA of beta blockers?
“1. Block binding of Beta-1 ligand to Gs protein on myocyte surface
- Reduce Phase 4 depolarization
- Reduce Automaticity
- Prolong AV conduction
- Reduce HR + contractility
- No change to APD + ERP”
Uses of beta blockers?
- Tachycardia caused by sympathetic activation
- Atrial fibrillation
- AV nodal re-entrant tachycardia
- Reduce sudden arrhythmic death post-MI
What class is beta blockers?
Class 2
Class 3 drugs?
K channel blockers, Amiodarone
MOA of amiodarone
- Block I kr and I ks (III)
- Block sodium channels (I)
- Block adrenergic receptor (II)
- Block Calcium channels (IV)
- Prolong Phase 3 repolarization (no Phase 0 effect)
- Increase ERP + APD
ADR of amiodarone?
Symptomatic bradycardia
Heart block
Use of amiodarone?
Maintain normal sinus rhythm in patients with atrial fibrillation
Prevent re-entrant ventricular tachycardia”
Class 4 drugs?
Non-DHP calcium channel blockers
Name of class 4 drugs?
Verapamil
Diltiazem
MOA of Non-DHP calcium channel blockers?
“1. Prolong Phase 4 depolarization
2. Reduce conductivity on AV node
3. Raise ERP and APD”
Use of Class 4 drugs?
Supraventricular Tachycardia
Hypertension
Angina
ADR of Class 4 drugs?
Hypotension
Banned for patients with pre-existing depressed cardiac function
MOA of adenosine?
- Supress AV Nodal conduction
- Increase AV nodal refractory period
- Stimulate cardiac K channel
- Inhibit Calcium current
Use of Flecainide?
Refractory Ventricular tachycardias that tend to progress to VF
Use of beta blockers in arrhythmia?
Tachycardia caused by sympathetic activation
Atrial fibrillation
AV nodal re-entrant tachycardia
Reduce sudden arrhythmic death post-MI
Use of Amiodarone in arrhythmia?
Maintain normal sinus rhythm in patients with atrial fibrillation
Prevent re-entrant ventricular tachycardia
Use of Non-DHP Calcium channel blockers in arrhythmia?
Supraventricular tachycardia
Hypertension
Angina