Pharm Block 2 Anti-As and Angina Flashcards
What are the 3 ions that regulate the heart?
Na K Ca
What are the names of the five AP phases?
Upstroke Early-fast repolarization Plateau Repolarization Diastole
Arrhythmias can result from one of what three issues?
Abnormal Automaticity (impulse formation) Abnormal Impulse Conduction- development of short-circuit pathway Re-Entry Phenomenon- impaired conduction
How do antiarrhythmics exert their effect on the heart?
Inhibits K channels to widen AP causing prolonged QT interval
Excessive prolongation of QT interval can results in ?
Torsades de Pointes- ventricular tachyarrhthmia
QT interval prolongation is usually caused by ? but can be caused by what three things?
Drug induced
Can be from ischemia, hypoK, genetics
Torsades de Pointes typically occurs when QT intervals exceed what time and can be caused by ?
> 500 milliseconds
Hypo K, Mag, drugs
Define Supraventricular arrhythmias
Originate in Atria and AV nodes
What type of arrhythmia can lead to HF or ischemic stroke?
A-Fib
Define Re-Entrant rhythm
Atrial flutter- signals travel in circle and not across the atria
Define PSVT
HR above 100 bpm originating superior to ventricles when atria contract prematurely
Define PACs and what type of arrhythmia are they?
Transient ryhthm when extra beat originates in atria
PSVT
What can cause PVCs to develop?
Structural HD
Electrolyte imbalance
ETOH
Stimulants
CAST was tested with what two meds?
Encainide
Flecainide
What is the most common classification of antiarrhythmic drugs and what are they based upon?
Vaughn-Williams System
Effect on Purkinje fibers
Supra/Ventricular arrhythmias are treated with what class of drugs? Ventricular arrhythmias are treated with what class of drugs?
Class 3
Class 1A
Class 1C
Class 1B
Supraventricular arrhythmias are treated with what drugs?
Adenosine
Digoxin
Verapamil
Stress induced arrhythmias are treated with what class of drugs?
Class 2: BBs, propranol, atenolol
What classes of drugs are used for Rate, Rhythm or Both control?
Class 1- rhythm
Class 2- rate
Class 3- both (rate- Am, So, Dr)
Class 4- rate
What drug was the prototype of Class 1A drugs?
What is the most frequently used 1A drug?
Quinine
Procainamide
What happens if Quinidine is given in high doses?
Cinchonism
Can exacerbate myasthenia gravis
Procainamide is the 2/3 choice drug for ventricular arrhythmias associated with MI after what two drugs have been used?
Lidocaine
Amiodarone
What two drugs can produce the Lupus macular-like rash?
Hydralazine
Procainamide
Disopyramide has what added benefit on top of it’s Class 1A effects?
Class 3- K blocking, prolong repolarization
Disopyramide is reserved for treatment of what type of PT?
Ventricular arrhythmia that are refractory/intolerant to Quinidine or Procainamide
Class 1B drugs have what effect on the electrical process?
Shortens Phase 3 repolarization
What are the 3 uses of Lidocaine?
When must the dose be adjusted?
Shortens V-tach with pulse
Prevents V-tach after conversion
Alternate for PVT/VF if amiodarone is not available
Hepatic Dz and/or CHF
What is the least cardio toxic Na Channel blocker?
When is it contraindicated?
What can it interact with?
Lidocaine
3* block
Amiodarone inc lidocaine levels
What is Mexiletine used in the treatment of?
What is it contraindicated in?
Ventricular arrhythmias associated with previous MI
Off label- diabetic neuropathy
3* block
What is the MOA of Class 1C agents?
Slows conduction velocity w/ little effect on refractory period of Supraventricular/Ventricular arrhythmia
When are Class 1C drugs used?
PTs with normal hearts but have supraventricular arrhythmia
Avoid Class 1C drugs in what PTs?
Post MI
HF
Class 1C drugs have what effect on the electrical process?
Slows conduction velocity with little effect on refractory period
What Class 1C drug possesses negative ionotropic effects and can exacerbate HF?
Flecainide
What are the two uses of Flecainide?
Sinus rhythm maintenance of A-fib w/out structural HD
Life threatening V-tach, refractory
What are the 3 contraindications for Felainide?
HF
VD
CAD
What are the three uses of Propafenone?
Supraventricular arrhythmia w/out structural HD
Rhythm control of A-fib/flutter
Life threatening V-tach
What are the DOC in A-fib/flutter?
BBs
A-fib PTs should be started on what additional medication on top of the BB?
Anticoagulation
Of the anti-arrhythmic BBs, which one is non-selective?
Propranolol
What is Esmolol used for?
Intraoperative BP/HR control and acute arrhythmia
What drug has zero drug interactions due to being metabolized in RBCs?
Esmolol
What is the MOA of Class 3 drugs?
Prolong phase 3, refractory period in ventricle/supraventricle tissue
Amiodarone has what three effects?
BB
Anti-angina
Vasodilation
What is the DOC of PVT/VF
Amiodarone
What type of PTs is Amiodarone used in?
A-fib conversion
Suppression of arrhythmias in PTs with implanted defibrilators
Preferred agent for PTs with LVD/HF
What is the derivative of Amiodarone that doesn’t contain iodine?
Dronedarone
What is the clinical use of Dronedarone
How is it’s bioavailability increased?
Maintain sinus rhythm in A-fib/flutter w/ history of paroxysmal/persistent A-fib
Taken with food
What is Sotalol used for?
Treatment of Supra/Ventricular arrhythmias in Peds
Maintenance of sinus rhythm in PTs with A-fib
What is the MOA of Ibutilide?
Class 3 that prolongs AP duration that slows sinus rat and AV conduction velocity
What is Ibutailide used for?
Rapid conversion of A-fib/flutter to normal sinus
More effective if onset is less than 90 days
What is Dofetilide used for?
Conversion of A-fib/flutter
Maintenance of sinus in PTs with arrhythmias lasting greater than a week
What effect do Class 4 drugs have on the SA and AV nodes?
Slows Ca conduction in AV (most important)
SA- Slow depolarization and decrease HR
What are Class 4 drugs beneficial against?
Atrial arrhythmias
Re-entrant supraventricular tachy
Which Non-DHP has grater action on the heart?
Verapamil
Which Non-DHP is more potent vasodilator than Verapamil?
Diltiazem
What is the MOA of Digoxin?
Cardiac glycoside, inhibits Na/K pump in cardiac membrane dec K and inc Na/Ca