DRUGS USED FOR ARRHYTHMIAS Flashcards
What is the most common cause of arrhythmias?
Reentry
How do anti-arrhythmic drugs prevent reentry?
By slowing conduction (Class I drugs) and/or increasing the refractory period (Class III drugs)
What class of anti-arrhythmic drugs act by blocking voltage-sensitive sodium (Na+) channels via the same mechanism as local anesthetics?
Class 1
Which type of Class 1 agent causes a MODERATE block of Na channels that INCREASES AP duration?
Class Ia
Which type of Class 1 agent causes a MILD block of Na channels and DECREASES AP?
Class Ib
Which type of Class 1 agent causes a MARKED block of Na channels and does not affect AP?
Class Ic
What class 1A drug is used to maintain sinus rhythm after atrial flutter or fibrillation and to prevent frequent ventricular tachycardia?
Quinidine
What class 1A drug is a derivative of the local anesthetic procaine and causes less prolongation of the QT interval?
Procainamide
What class 1A drug causes peripheral vasoconstriction?
Disopyramide
What class 1B drug was the drug of choice for emergency treatment of cardiac arrhythmias and is useful in treating ventricular arrhythmias arising during myocardial ischemia, such as that experienced during a myocardial infarction?
Lidocaine
What class 1B drug is used for CHRONIC treatment of ventricular arrhythmias associated with previous myocardial infarction?
Mexiletine
What class 1B drug is used for treatment of ventricular tachyarrhythmia’s?
Tocainide
What class 1C drug is useful in suppressing premature ventricular contraction?
Flecainide
What class 1C drug slows conduction in all cardiac tissues and is considered to be a broad-spectrum antiarrhythmic agent?
Propafenone
What class are β-adrenergic antagonists and are useful in treating tachyarrhythmia’s?
Class II agents
What class II drug reduces the incidence of SUDDEN ARRHYTHMIC DEATH after myocardial infarction?
Propranolol
What class II drug reduces the risk of BRONCHOSPASM and is most widely used in the treatment of cardiac arrhythmias?
Metoprolol
What class II drug is a very SHORT-ACTING β-blocker used for IV ADMINISTRATION in acute arrhythmias that occur DURING SURGERY or emergency situation?
Esmolol
What class blocks potassium (K+) channels and have the potential to INDUCE arrhythmias?
Class III agents
What class III drug is a primary drug for VENTRICULAR FIBRILLATION and is the most commonly employed anti-arrhythmic?
Amiodarone
What class III drug is used as a first-line antiarrhythmic agent in patients with persistent atrial fibrillation and heart failure or in those with coronary artery disease with impaired left ventricular function?
Dofetilide
What class of drugs are calcium-channel blockers?
Class IV agents
What 2 class IV drugs are more effective against atrial than against ventricular arrhythmias?
Verapamil and diltiazem
