arrhythmia Flashcards
disopyramide
class 1A Na channel blocker
heavy antimuscarinic effects -> tachy (bad)
atopine like effects = urinary retention, dry mouth, glaucoma
only approved for V arrythmias
flecainide
class 1C Na channel blocker, strong Na block
no QT prolongation (even though it does block K chans)
no antimuscarinic effects
oral admin
used to treat supraventricular arrythmias
very effective in supressing premature ventricular contractions
lidocaine
class 1B Na channel blocker
least cardiotoxic, can get seizures in elderly patienst with IV
no QT prolong
has to be given IV (high first pass met)
agent of choice for termination of vent tachy and to prevent V fib after cardioversion
mexiletine
class 1B Na channel blocker
lidocaine analog - can give it orally (resistant to first pass)
can be used off label to relive chonic pain (diabetic neuropathy)
procainamide
class 1A Na channel blocker
mild antimuscarinic and lupus like syndrome effects (lupus especially in patients with chronic arthritis
blocks K channels = QT prolong -> torades
extracardiac: reduce TPR = hypotension -> reflex tach (bad)
theapeutic use: most A and V arrythmias, short HL (take evey 6 hours) - less useful for long term treatment,
drug of second or thrid choice for sustained V arrythmias associated with MI (after lidocaine and amiodarone)
propafenone
class 1C Na channel blocker, strong Na block
no QT prolongation (even though it does block K chans)
no antimuscarinic effects
oral admin
used to treat supraventricular arrythmias
very effective in supressing premature ventricular contractions
has a metalic taste
Moriclizine
- class 1C
- Antiarrhytmic phenothiazine derivative
- Was used for ventricular arrythmiase
- Potent sodium channel blocker that does not prolong APD
- Withdrawn from US market
quinidine
class 1A Na channel blocker
medium antimuscarinic effects
blocks a-adrenergic receptors = vasodilation = hypotension = reflex tach (bad)
blocks K channels = QT prolong -> torades
increases plasma digoxin, thrombocytopenia, alpha blockade
not used freuqntly
acebutolol
class 2 beta 1 blocker
all beta blockers can prevent recurrent infarction and sudden death in patienst with acute MI
esmolol
class 2 beta 1 blockers
short acting - used for acute arrythmias during surgery
all beta blockers can prevent recurrent infarction and sudden death in patienst with acute MI
propranolol
class 2 non selective beta blocker
for supraventricular and ventricular arrythmia cuased by SYM stimulation
can prevent V fib
all beta blockers can prevent recurrent infarction and sudden death in patienst with acute MI
amiodarone
class 3 K channel blocker
maintain normal sinus rhythem in patients with A fib, or to prevent recurrent V tach
cuases peripheral vasodilation - especially after IV
biphaseic HL - rapid component followed by slow componenet
this is a good drug but has lots of long term side effects (treat kids with beta blockers, not amiodarone)
- Toxicity
- Asymptomatic bradycardia and AV block in patient with SA or AV node disease
- respiratory difficulties leading to fatal pulm fibrosis - in about 1% of patients
- Hepatitis
- Skin deposits resulting in photo dermatitis
- Corneal microdeposits - reduced visual accuity
- Blocks peripheral conversion of T4 to T3 (must check thyroid function before giving)
- There are some derivatives that don’t contain iodine that are being evaluated (dronaderone = only one FDA approved)
- Biphasic half life
- Rapid component (3-5 days) - 50% of drug
- Slow component - several weeks - tox may last long after the drug is discontinued
- Metabolized by CYP3A4
dronedarone
class 3 K channel blocker
amiodarone analog without the iodine = no thyroid dysfunction
worse liver toxicity than amiodarone
black box warning - increased risk of death/stroke/HR in patinets with decompensated HF or perminant A fib
sotalol
class 3 K channel blocker (its actually a beta blocker but i guess it also blocks K)
can prolong AP duration -> torsades
used for treatment of life threatining vent arrythmias
maintaining normal sinus rhythem in A fib
treatment of supraventricular and ventricular arrythmias in kids (less long term effects than amiodarone)
ibutilide
class 3 K channel blocker
- Block rapid component of delayed rectifier K current to slow cardiac repolarization
- Good to restore normal sinus rhythem in atrial fib or flutter
- Common SE: prolong QT (torsades) in up to 10% of patients
