Katzung Chapter 14 Agents Used in Cardiac Arrhythmias

Propranolol

Beta adrenergic antagonist, non selective

Metoprolol

Beta adrenergic antagonist, beta 1 selective

Atenolol

Beta adrenergic antagonist, beta 1 selective

Esmolol

Beta adrenergic antagonist, beta 1 selective, short-acting

Verapamil

Calcium channel blockers (L-type channels), has the greatest effect on the heart and may decrease heart rate and cardiac output

Diltiazem

Calcium channel blockers (L-type channels), depresses heart, intermediate effect on heart

Quinidine

Anti-arrhythmic, blocks activated sodium channels and lengthens the duration of the action potential

Procainamide

Anti-arrhythmic, blocks activated sodium channels and lengthens the duration of the action potential, may cause a lupus erythramatosus-like syndrome

Disopyramide

Anti-arrhythmic, blocks activated sodium channels and lengthens the duration of the action potential, antimuscarinic side effects limit its use

Lidocaine

Anti-arrhythmic, blocks activated and inactivated sodium channels and shortens the duration of the action potential, only given by IV often after an MI

Mexiletine

Anti-arrhythmic, blocks activated and inactivated sodium channels and shortens the duration of the action potential, congener of lidocaine, can be given orally

Flecainide

Anti-arrhythmic, blocks sodium and potassium channels

Propafenone

Anti-arrhythmic, blocks sodium and weak beta-blocker

Amiodarone

Anti-arrhythmic, blocks inactivated sodium channels, lengthens action potential by blocking potassium channels, weak calcium channel blocker, beta-blocker, prolongs QT duration and increases refractory period

Arrhythmias

Cardiac depolarizations that are abnormal in the site of origin, rate or conduction

Asynchronous

Cardiac depolarizations without rhythm

Cardioversion

Tachycardia or other arrhythmia is converted to a normal rhythm using electricity or drugs.

Catheter ablation

Minimally invasive procedure in which the doctor advances a flexible thin tube through the blood vessels to your heart to destroy the tissue that is causing an arrhythmia

Ectopic pacemaker cells

Excitable group of cells that causes a premature heart beat outside the normally functioning SA node of the heart.

Hypokalemia

Increase of pacemaker discharge

Hyperkalemia

Decrease of pacemaker discharge

Reentry

One impulse reenters and excites areas of the heart more than once resulting in a few extra beats or sustained tachycardia

Long QT-related arrhythmias

Delayed repolarization increases the time interval between depolarization and repolarization of the ventricle, can lead to potentially life-threatening arrhythmias, symptoms include fainitng seizures and sudden death

Bretylium

Antiarrhythic, Class III- interferes with normal release of catecholamines

Sotalol

Antiarrhythic, Class III- prolongs action potential and is a non-selective beta blocker

Ibutilide

Antiarrhythic, Class III- enhances inward sodium current

Dofetilide

Antiarrhythic, Class III- blocks a K channel