Cardiac Arrhythmias

Front 1

Class I A drugs

Back 1

Quinidine, Procainamide, Disopyramide, Amiodarone

Front 2

Quinidine: MOA, Uses, Adverse

Back 2

MOA: binds open/inactivated Na channels preventing Na entry. Prevents rapid upstroke in phase 0 and decreases slope in phase 4.

Use: Atrial, junction, ventricular arrhythmias, prevents reentry, maintains normal sinus rhythm after cardioversion

Adverse: Exacerbate arrhythmia, cause SA/AV block, asystole. Hypokalemia worsens cardiotoxicity. Can increase Digoxin levels. CINCHONISM (blurred vision, tinnitus, headache)

Front 3

Procainamide:

Back 3

MOA: binds open/inactivated Na channels preventing Na entry. Prevents rapid upstroke in phase 0 and decreases slope in phase 4.

Uses: A. Fib, A. Flutter, Paroxysmal Atrial Tachycardia, V.Tach.

Kinetics: acetylated in liver, byproduct can prolong AP

Adverse: LUPUS LIKE SYNDROME

Front 4

Disopyramide

Back 4

Simiiary use to Quinidine and additionally negative inotropic effects/peripheral vasoconstriction. Has anticholingergic effects

Front 5

What arrhythmias can Class 1A drugs precipitate?

Back 5

Torsade de Pointes (long QT interval V Tach)

Front 6

Class IB drugs mentioned:

Back 6

Lidocaine, Mexiletine, Tocainide

Front 7

Lidocaine

Back 7

MOA: lidocain affects purkinje and ventricular tissue but not atrial tissue. No affects on normal cells. Shortens phase III repolarization and decreases duration of AP.

USES: For acute/life threatening ventricular arrhythmias. NOT effective in prophylaxis of arrhythmias in post MI.

Front 8

Mexiletine and Tocainaide

Back 8

Uses: Life threatening ventricular arrhythmias. Mexiletine: pain associated w/ diabetic

Adverse: rare topical/local anesthetic activity such as CNS stimulation including convulsions. May cause CV depression and allergies.
Tocainamide can cause FATAL hematological effects (agranulocytosis)

Front 9

Class IC drugs:

Back 9

Flecainide, Propafenone, Moricizine

Front 10

Flecainide

Back 10

Have effects on normal heart tissue.
MOA:diminishes phase 0 upstroke in purkinje and myocardial fibers.

Uses:REFRACTORY VENTRICULAR ARRHYTHMIAS.

Adverse: aggravate CHR.

Front 11

Class II (beta blockers) listed in class and general actions

Back 11

Propranolol, Emolol, Acebutolol, Meoprolol, Pindolol

Diminish phase IV depolarization. Decrease rate/force.

Front 12

Esmolol

Back 12

Uses: short acting, beta1 selective, used for arrhythmias occuring in surgery and ER. Used for acute control of hypertension or certain SVT's

Front 13

Propranolol/metoprolol

Back 13

Used as prophylactiv in pt's who had MI to prevent arrhythmias and sudden death.

Front 14

Toxicity associated w/ B Blockers

Back 14

Induced depression of cardiac output w/ more vulnerability to cardiac depression.

Front 15

Class III (K channel blockers):

Back 15

Amiodarone, Ibutilide, Dofetilide, Sotalol.

Class II drugs are not interchangable.

Front 16

Class III general effects

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Reduce outward potassium current during repolarization of cardiac cells. Prolong duration of AP w/out changing phase 0 depolarization or resting membrane potential. Prolong refractory period and the AP.

Front 17

Ibutilide

Back 17

Promotes influx of sodium thru slow inward sodium channels.

*****Ibutilide is indicated for rapid conversion of a fib and a flutter.

Front 18

Sotalol**

Back 18

B-BLOCKER w/ class II and II properties. NO intrinsic sympathomimetic activity or membrane stabilizing activity.

Uses: atrial arrhythmias or life threatening ventricular arrhythmias. Preventing reccurrent arrhythmias

Adverse: Increased risk for torsades de pointes.

Do NOT substitute Betapace for Betaepace AF

Front 19

Amiodarone:

Back 19

Has class I, II, III, and IV effects. Antianginal and Antiarrhythmic.

Uses: refractory SVT and Ventricular Tachyarrhythmia. Amiodarone prolongs AP duration and refractory period.

Adverse: pulmonary fibrosis, hyper or hypothyroidism, blue skin discoloration

Front 20

Class IV drugs mentioned (Calcium channel blockers)

Back 20

Verapamil, DIltiazem

Front 21

Verapamil and Diltiazem

Back 21

Treats angina, HTN, SVT. Effective in arrhythmias traverse AV node and when the heart isbeating rapidly

Verapamil is contraindicated in pt's w/ existing cardiac depression.

Front 22

Adenosine

Back 22

Purine Nucleoside
MOA: stimulates adenosine K channels in atrial and SA node. Outward flow of K causes a bradycardia. Good diagnostic aid.

Does NOT affect upstroke phase of AP. Short duration of action

Adverse: flushing, chest pain, hypotension.

Front 23

Digoxin

Back 23

Shortens refractory period in atrial/ventricular cells, prolongs refractory and diminishes conduction in purkinje.

Used for ventricular effects in A Fib and Flutter

Adverse: can cause ectopic beats (treated w/ lidocaine) when used in high doses.

Front 24

Potassium

Back 24

Hypokalemia causes arrhythmias in pt's getting digitalis.