140 Antiarrhythmic Drug Therapy Flashcards
Mechanisms/Classifications of Bradyarrhythmias
- Diminished automaticity
- Block
Mechanisms of Tachyarrhythmias
- Enhanced automaticity
- Increased phase 4 depol
- Make threshold more negative
- Renentry
- Triggered activity
- Early after depols
- •During Phase 2, 3 of AP
- Early after depols
- Ca2+ current Dependent
- Occurs in setting of prolonged APD (prolonged QT interval)
- Delayed afterdepols
- During Phase 4 of AP
- Delayed afterdepols
Associated with high Ca2+ (eg digoxin toxicity)
Supraventricular tachyarrhythmias list
oSinus Tachycardia
oAtrial Premature Beats
oParoxysmal Supraventricular Tachycardia
(aka Supraventricular Tachycardia aka SVT)
oAtrioventricular Nodal Reentrant Tachycardia (AVNRT)
oAtrioventricular Reentrant Tachycardia (AVRT)
oEctopic Atrial Tachycardia
oAtrial Flutter
oAtrial Fibrillation
oMultifocal Atrial Tachycardia
Ventricular tachyarrhythmias list
AV Nodal Reentrant Tachycardia (AVNRT)
Atrioventricular Reentrant Tachycardia (AVRT)
Atrial Flutter
Atrial Fibrillation
Ventricular Tachycardia
Polymorphic Ventricular Tachycardia
Ventricular Fibrillation
Treating Enhanced Automaticity (theory)
- •Make maximum diastolic potential more negative
- •Reduce slope of phase 4 depolarization
- •Make the threshold potential more positive
Treating Reentry (theory)
Disrupt the Balance
- e.g. slow the “slow conduction” even more so it blocks
- supress premature beats which often set up slow conduction
Treating Triggered Activity (theory)
Rate Control vs. Rhythm Control in Atrial Fibrillation
Vaughan-Williams Classification
Na+-Channel Blockers Mechanism
Na+-Channel Blockers: Effect on Phase 0
Na+-Channel Blockers: Effect on Action Potential Duration