Anti-Arrhythmics Flashcards
Class 1A
Sodium channel blockers
Quinidine, Procainamide, Disopyramide
Increase AP duration, effective refractory period in vent AP, and QT interval
Atrial and vent arrhythmias-re-entrant and ectopic
Cinchonism (HA, tinnitus-quinidine), SLE-like syndrome, HF, thrombocytopenia, torsades
Class 1B
Na channel block
Lidocaine, Mexiletine
Decrease AP duration-ischemic or depolarized Purkinje and vent tissue
Acute vent arrhythmias, digitalis-induced arrhythmias, post-MI
CNS stimulation/depression, CV depression
Class 1C
Na Channel block
Flecainide, Propafenone
Prolongs effective refractory period in AV node and accessory bypass tracts- prolong QRS
SVTs including a-fib
Proarrhythmic, esp post-MI-contradindicated in structural and ischemic heart ds
Class II
B-Blockers-metoprolol, propranolol, esmolol, atenolol, timolol, carvedilol
Decrease SA and AV nodal activity-decrease cAMP, Ca currents; increase PR interval
SVT, vent rate control for a-fib and flutter
Class III
Potassium channel blockers-amiodarone, ibutilide, dofetilide, sotalol
Increase AP duration, effective refractory period, QT interval
A-fib, flutter, V-tach (amiodarone and sotalol)
Sotalol-torsades, B blockade; Ibutilide-torsades; Amiodarone-pulm fibrosis, hepatotoxicity, hypo/hyper-thyroid, hapten, neuro effects, constipation, CV effects
Class IV
Calcium channel blocker-verapamil, diltiazem
Decrease conduction velocity, increase effective refractory period, PR interval
Prevent nodal arrhythmias, rate control a-fib
constipation, flushing, edema, CV effects
Adenosine
K+ out of cell-> hyperpolarize-> decrease Ca current
Dx/terminate SVT
Short acting
Flushing, hypotension, chest pain, sense of impending doom, bronchospasm
Magnesium
Torsades, digoxin toxicity
Digoxin
Cardiac glycoside
Inhibit Na/K ATPase-> indirect inhibition of Na/Ca exchanger-> inotropic; stimulates vagus nerve-decrease HR
HF, a-fib
Cholinergic SE, hyperkalemia; careful if renal failure, hypokalemia, decreased clearance
