Dysrhythmias Flashcards
ventricular arrhythmias
tachycardia, fibrillation
atrial arrhythmias
flutter, fibrillation
AV junction arrhythmias
AV nodal reentry, acute SVT
Class I actions
all block sodium
IA- slows phase 0 depol
IB- shortens phase 3 repol
IC- markedly slows phase 0 depol
class II actions
B Blocker
suppress phase 4 depol
class III actions
K blocker
prolongs phase 3 repol
class IV actions
Ca blocker
shortens AP
indicated for atrial and vent arrhythmias, used to maintain rhythm post cardioversion. Class IA
quinidine
contraindicated in heart block, SA node dysfunction, cardiogenic shock, severe uncompensated HF, SLE
class IA antiarrhythmics (quinidine)
ADRs include arrhythmias, N/V/D, cinchonism,
class IA antiarrhythmics (quinidine)
drug metab inhibited by cimetidine. Induced by phenytoin, rifampin, barbiturates. Decreases digoxin clearance
class IA antiarrhythmics (quinidine)
metabolized to N-acetylprocainamide, which prolongs duration of AP
procainamide
ADRs: hypotension, lupus erythematosus like syndrome, aystole or ventricular arrhythmias, depression, hallucinations, psychosis
procainamide
produces negative inotropic effect- contraindicated in HF, causes peripheral vasoconstriction
disopyramide
ADRs- anticholinergic, proarrhythmic
disopyramide
prototype and DOC for emergency treatment of cardiac arrhythmias post mI. No negative inotropic effect, no impairment of LV dysfunction
lidocaine
extensive 1st pass metabolism, dose adjustment in liver failure
lidocaine
contraindicated in SA disorders, AV block
lidocaine
ADRs- confusion, slurred speech, drowsiness, parasthesias, agitation, cardiac arrhythmias
lidocaine
used in chronic vent arrhythmias associated with previous MIs
mexiletine, tocainide
associated with pulmonary toxicity that can lead to fibrosis
tocainide
questionable safety- blocks Na channels, indicated for refractory ventricular arrhythmias (PVCs)
flecainide
have negative inotropic effects (not used in CHF). ADRs include dizziness, blurred vision, HA, nausea, can aggravate pre-existing arrhythmias or induce life threatening vent tachy
class IC- flecainide
indicated post MI vent arrhythmias, tachyarrhythmias caused by increased sympathetic activity, atrial flutter and fib, AV nodal reentrant tachycardia
class II- B Blockers
block potassium channels, prolonging repolarization and duration or AP. Indicated in vent and supraventricular arrhythmias
class II- B Blockers
effective in preventing arrhythmia recurrence and decreasing mortality in patients with sustained VTACH
sotalol
ADR includes torsade de pointes
sotalol
has class I, II, III, and IV actions (dominant class III). Antianginal and antiarrhythmic activity
amiodarone
indicated for refractory SVT and ventricular tachyarrhythmias
amiodarone
Long half life. ADRs include pulmonary fibrosis, GI intolerance, tremor, ataxia, hyper/hypo thyroidism, neuropathy, muscle weakness, blue skin discoloration
amiodarone
slowed phase 4 spontaneous depol and slowed conduction in tissues dependent on calcium currents (AV node)
CCBs
indicated for atrial arrhythmias, reentrant suprevent tachy, reducing vent rate in atrial flutter and fib, HTN, angina
CCB
ADRs: hypotension. Contraindicated in pts with preexisting depressed cardiac function due to its negative inotropic properties
CCB
endogenous nucleoside that acts at tissues in lungs, afferent nerves, and platelets
adenosine
has a short DOA. Decreases conduction velocity, prolongs the refractory period and decreases automaticity in the AV node
adenosine
contraindicated in 2nd and 3rd degree heart block
adenosine
DOC for abolishing supraventricular tachycardia
adenosine
ADRs- transient facial flushing, chest pain, dyspnea, bronchospasm
adenosine
shortens refractory period in atrial/vent cells while prolonging effective refractory period and decreasing conduction velocity in purkinje fibers
digoxin
indicated to control vent rate in Afib and Aflutter. ADRs include ectopic vent beats- VTACH and VFIN
digoxin
this should be considered in all afib patients who are severely symptomatic or hemodynamically unstable
immediate DCC
all afib patients need
anticoagulation
ventricular rate control
restoration of normal sinus rhythm
when would you chose long term pharm rate control (rather than cardioversion)
no deterioration in sx w afib and HR controlled
normal LV function
duration of afib > 1 year
failure to maintain NSR despite cardioversion
when would you chose cardioversion
symptomatic with NSR
LVH
duration of afib < 1 year
young, active patients
