Question | Answer |
disopyramide | Class 1A |
procainamide | Class 1A |
quinidine | Class 1A |
class 1A effect on SA nodal cells | block Na+ channels, prolong phase 4, inc threshold for AP |
class 1A effect on myocytes | block Na+ channels, prolong depolarization, inhibit K+, inc AP duration |
class 1A effect on EKG | prolong QRS and QT |
uses of class 1A drugs | A fib/flutter, paroxysmal SVT |
signs of class 1A toxicity | torsade de points, syncope |
use with caution in pts w/LV dysfunction | Class 1A |
byproduct that causes QT prolongation | NAPA- product of procainamide |
produces NAPA | liver |
most effective for new onset A fib | IV ibutilide |
used for atrial arrhythmias, new onset A fib, VT, and to dec occurrence of reentry arrhythmias | procainamide |
type of procainamide to treat VT | Slow IV |
signs of procainamide toxicity | SLE-like sx, hypotension, ND, rash, fever, hepatitis, agranulocytosis |
procainamide effects that cause hypotension | ganglionic blocking effects |
action of NAPA | pure class 3 action |
caused by NAPA in renal insufficiency | torsade de points |
dec dose in pts w/heart failure | procainamide |
eliminates NAPA | kidneys |
quinidine effect on AV node | inc conduction |
quinidine effects that cause hypotension | anti-alpha effects |
use with caution in pts w/implanted defibrillators | Class 1A |
quidine effects that cause inc AV conduction | anti-cholinergic effects |
often administered w/beta blockers, verapamil, digoxin, or diltiazem | quinidine |
signs of quinidine toxicity | QT prolongation, tinnitus, GI disturbances, immunological effects |
contraindicated in long QT, SSS, BBB, MG, and liver failure | quinidine |
type of disopyramide used for life-threatening ventricular arrhythmias | oral |
anti-muscarinic effects exceed those of quinidine | disopyramide |
strong negative ionotropi effect | disopyramide |
disopyramide effects that cause urinary retention, dry mouth, blurred vision | anti-muscarinic effects |
contraindicated in heart failure, LV dysfunction, obstructive uropathy, glaucoma, conduction block, and SA nodal dysfunction | disopyramide |
used for atrial tachycardia, hypertrophic obstructive cardiomyopathy, and neurocardiogenic syncope | disopyramide |
norpace | disopyramide |
lidocaine | Class 1b |
mexiletine | class 1b |
phenytoin | class 1b |
not effective in a flutter, a fib, or SVTAs | class 1b |
used to treat ventricular arrhythmias | class 1b |
used as prophylaxis for V fib after DC conversion in an ischemic setting | lidocaine |
DOC for acute suppression of acute ventricular arrhythmias | lidocaine |
type of lidocaine used in heart failure pts | low dose |
signs of lidocaine toxicity | confusion, dizziness, seizures |
may cause lidocaine to accumulate | beta blocker |
phenytoin MOA | blocks Na+ channels |
induces CYP450 3A4 | phenytoin |
affects metabolism of lidocaine, mexiletine, and quinidine | phenytoin |
signs of phenytoin toxicity | gingival hyperplasia, horizontal gaze nystagmus, increased suicidal ideation |
used to treat seizures, congenital long QT, vent tachycardia, digoxin-induced arrhythmias | phenytoin |
useful in pt population with concurrent seizures and ventricular arrhythmias | phenytoin |
flecainide | group 1C |
propafenone | group 1C |
must have normal EF to be used | group 1C |
analog of lidocaine | mexiletine |
used for life-threatening vent arrhythmias, peripheral neuropathy pain | mexiletine |
may improve mexiletine side effects | taking with food |
signs of mexiletine toxicity | dizziness, tremor, slurred speech, NV |
class 1C effect on conduction velocity | decreased in all |
class 1C effect on refractory period | inc in AV node and accessory bypass tracts |
used for SVTA in non-MI pts and APCs | group 1C |
propafenon effect on APs | does not prolong |
primarily used for SVTAs | propafenone |
signs of propafenone toxicity | metallic taste, constipation, bradycardia, bronchospasm |
beta blockers | Class 2 |
most useful anti-arrhythmic drugs | class 2 |
used for atrial arrhythmia, recurrent MI, exercise induced arrhythmia | class 2 |
signs of class 2 toxicity | bronchospasm, cold extremities, impotence, negative ionotropic effect, AV blockade, acute HR, sleep disturbance/depression |
amiodarone | class 3 |
bretylium | class 3 |
dronedarone | class 3 |
sotalol | class 3 |
dofetilide | class 3 |
ibutilide | class 3 |
class 3 effect on repolarization | block K+ current |
class 3 effect on AP | prolong in Purkinje and ventricular muscle fibers |
class 3 effect on phase 0 | none |
class 3 effect on conduction velocity | none |
used for vent arrhythmias and SV arrhythmias | amiodarone |
used for maintenance/restoration of sinus rhymthm in a fib | class 3 |
signs of class 3 toxicity | bradycardia, heart block, torsade de pointes |
amiodarone effects on AP and refractories | prolongs both |
amiodarone effects on depolarization (phase 0) | blocks Na+ and Ca++ channels, dec slope of phase 0 |
amiodarone effects on HR | slows |
amiodarone effects on AV conduction | decreases |
amiodarone effects on alpha and beta channels | blocks both |
DOC for vent arrhythmias in pts w/recent MI | amiodarone |
signs of amiodarone toxicity | pneuomonitis, bradycardia, vision issues, long QT, hypotension, hepatic toxicity, thyroid issues, blue skin, NV, constipation |
type of amiodarone that can cause heart failure | IV |
causes Smurf Syndrome | amiodarone |
increases activity of warfarin and digoxin | amiodarone |
used w/caution in pts w/SSS | amiodarone |
structural analog of amiodarone | dronedarone |
non selective beta blocker | sotalol |
inhibits conduction in accessory bypass tracts | sotalol |
excreted solely by kidneys | sotalol |
can cause orthostatic hypotension | bretylium |
prevents NE release | bretylium |
bretylium effect on atrial tissues | none |
used to treat life-threatening v tachycardia when all else has failed | bretylium |
dofetilide effect on K+ current | blocks delayed K+ |
given w/EKG monitoring | dofetillide |
contraindicated in pts w/hypokalemia or bradycardia | dofetillide |
dose depends on creatinine clearance | dofetillide |
verapamil | class 4 |
diltiazem | class 4 |
most potent in SA/AV nodes | class 4 |
contraindicated in SSS and AV block | class 4 |
used for SVTA, reentry SVT, hypertension, and prinzmetal angina | class 4 |
class 4 effects on threshold potential | elevates |
class 4 effects on AP | prolongs |
class 4 effects on refractory pd | prolongs in AV |
class 4 effects on conduction | decreases |
signs of class 4 toxicity | hypotension, constipation, bradyarrhythmias |
use caution w/beta blockers and Ca++ channel blockers | class 4 |
adenosine effect on K+ | increases outward current via G-pro coupled channels |
effects inhibited by caffeine and theophylline | adenosine |
DOC for rapid termination of narrow-complex PSVT | adenosine |
signs of adenosine toxicity | flushing, SOB, chest burning sensation |
digoxin MOA | vagal stimulation |
digoxin effect on conduction | slows through AV node and His bundle |
signs of digoxin toxicity | bradycardia, AV block, V-bigeminy |
toxicity exacerbated by low K+ | digoxin |
Mg MOA | influences Na/K ATPase, Na+, K+, and Ca++ channels |
used for digitalis-induced arrhythmias, torsade de pointes | Mg |
prevents ibutilide-induced VT/VF | Mg |
can cause AV block | Mg |
increases risk of EAD/DADs and ectopic pacemaker activity | hypokalemia |
decreases ectopic pacemaker activity, suppresses SA node | hyperkalemia |
hyperkalemia changes on EKG | peak T waves and slurred QRSs |