Anti-Arrhythmics Flashcards
Class 1B
VT
- lidocaine - POST MI
- mexiletine - LONG QT
UP K+ out = shorter AP duration
Class 1C
VT»>SVT
- Flecainide =
- IF NO HX OF ISCHEMIC DZ
- RHYTHM CONTROL
STRONG Phase 0 block
NO POST MI
ATAXIA S.E>.
Class 1A
VT»>SVT (RHYTHM CONTROL)
- Quinidine = SUPPRESS AFIB (W/ BB/CCB)
- Procainamide
- Disopyramide
DOWN K+ out = AP duration longer
S.E = anticholinergic (quinidine more), Torsades de Pointe (long QT), lupus-like syndr, IN HOSPITAL ONLY
Class 3
K+
VT + SVT
*amiodarone, dronedarone
*Sotalol, ibutalide
Class 4
Ca2+ block in AV node(L type) (rate control)
SVT
*verapamil
*Diltiazem
- slow pacemaker current
- slow conduction velocity
- longer ERP
Careful CHF = less cardio muscle contract
Class 2
Beta (rate control)
SVT
*metoprolol
- DOWN AV NODE conduction
- DOWN excitability (ectopic pace)
Post MI reduce mortality
Other
SVT
- digoxin
- adenosine
Interfere with Na+ channels
Rx
- lidocaine, Mexiletine
- flecainide
- quinidine, procainamide, disopyramide
Cause long QT
- quinidine, procainamide, disopyramide
* Amiodarone, dronedarone, sotalol, ibutalide
Rhythm control
- flecainide
- quinidine, procainamide, disopyramide
- amiodarone, dronedarone, sotalol, ibutalide
Rate control
- Verapamil, diltaziem
- Metoprolol
- digoxin, adenosine
General concepts
- antiarrythmics = possibly pro-arrythmic
- dirty rx (synergistic, too many S.E.)
- Tx of CHOICE = procedure (not Rx)
- Tx tachs that are SYMPTOMATIC
Action potential duration
Start of AP to end
Refractory period duration =
Action potential duration
Sodium channels work best + recover quicker at
Depolarized (-) state
Explain why RPD has no APs
Phase 0 Na+ voltage channels depolarizing
- Quick open/quick close
* Affect Velocity + ERP
Phase 2-3 Ca++ in channel depolarizing
- slow open/close
* affects AP duration
Just VT
Rx
Lidocaine, mexiletine
VT»>SVT
Rx
- Flecainide
- Quinidine
- Procainamide, disopyramide
VT + SVT
- Amiodarone, dronedarone
* Sotalol, Ibutalide
SVT
Rx
- Verapamil, Diltiazem
- metoprolol
- digoxin, adenosine
Phase 2-3 K+ (TEA) out channel repolarizing
- delayed rectifier
* affects AP duration
Phase 4 Na+ in channels depolarizing
- pacemaker
* affects heart rate (automaticity)