Flashcards in 46 anti arrhythmic drugs Deck (31)
cardiac arrhythmias are categorized by what?
location of origin
What are the 2 types of supra ventricular arrhythmias?
atrial and nodal
Is torsades de pointes a supraventricular or a ventricular arrhythmias?
What is the goal of drug therapy for abnormal automaticity cause of arrhythmia?
reduce ectopic pacemaker activity
What is the goal of drug therapy for abnormal impulse conduction cause of arrhythmia?
modify conduction or refractoriness in reentry circuits
What drugs [decrease? but he changed to increase] phase 4 slope?
beta and Ca channel blockers
What drugs increase maximum diastolic potential?
What drugs increase the threshold?
Na and Ca channel blockers
What drugs increase action potential duration?
k channel blockers
Drugs can abolish re-entry by what 2 mechanisms?
1. Further slowing depressed conduction (Na or Ca channel block)
2. lengthening refractory period
What 2 mechanisms to lengthen refractory period?
Na channel and K channel blockers
What is a smart drug?
state and use dependent block
TF- depolarization of resting membrane decreases lidocaine block?
False- increases it
T-F-- tachycardia increases lidocaine block?
Class I anti arrhythmic mechanism?
Na channel-slow phase 0 depolarization slow conduction
Class II anti arrhythmic mechanism?
beta adrenergic receptor block
Class III anti arrhythmic mechanism?
K channel block
Class IV anti arrhythmic mechanism?
Ca2+ channel block
Class IA, IB, IC are unbound with what rate of kinetics? and do what to the action potential?
1. Medium, fast, slow
2. prolong, shorten, minimal effect
Class IA drugs also block what?
Procainamide metabolite predisposes to what?
Action potential prolongation, EADS, arrhythmias
What patients should we avoid using class IC antiarrhymic drugs?
underlying structural heart disease or post-myocardial infarction
What class I anti-arrythmic is a IV only drug?
What class II anti-arrythmic is a IV only drug?
What class III anti-arrythmic is a IV only drug?
Which Class III anti-arrythmic drug does not need to be started in a hospital, what is unique about it? why do we start them in hospitals?
1. amiodarone- does require regular monitoring! accumulates in tissues lipid soluble
2. monitor for acute QT prolongation -torsade de pointes
What does dronedarone lack?
lack thyroid and pulmonary toxicity of amiodarone
What do Ca channel blockers do to the QRS complex?
slow rate and reduce maximal height
What is a strong drug to break up AV node arrhythmia?
verapamil and diltiazem