DRUGS USED FOR ARRHYTHMIAS

Question 1

What is the most common cause of arrhythmias?

Answer 1

Reentry

Question 2

How do anti-arrhythmic drugs prevent reentry?

Answer 2

By slowing conduction (Class I drugs) and/or increasing the refractory period (Class III drugs)

Question 3

What class of anti-arrhythmic drugs act by blocking voltage-sensitive sodium (Na+) channels via the same mechanism as local anesthetics?

Answer 3

Class 1

Question 4

Which type of Class 1 agent causes a MODERATE block of Na channels that INCREASES AP duration?

Answer 4

Class Ia

Question 5

Which type of Class 1 agent causes a MILD block of Na channels and DECREASES AP?

Answer 5

Class Ib

Question 6

Which type of Class 1 agent causes a MARKED block of Na channels and does not affect AP?

Answer 6

Class Ic

Question 7

What class 1A drug is used to maintain sinus rhythm after atrial flutter or fibrillation and to prevent frequent ventricular tachycardia?

Answer 7

Quinidine

Question 8

What class 1A drug is a derivative of the local anesthetic procaine and causes less prolongation of the QT interval?

Answer 8

Procainamide

Question 9

What class 1A drug causes peripheral vasoconstriction?

Answer 9

Disopyramide

Question 10

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?

Answer 10

Lidocaine

Question 11

What class 1B drug is used for CHRONIC treatment of ventricular arrhythmias associated with previous myocardial infarction?

Answer 11

Mexiletine

Question 12

What class 1B drug is used for treatment of ventricular tachyarrhythmia’s?

Answer 12

Tocainide

Question 13

What class 1C drug is useful in suppressing premature ventricular contraction?

Answer 13

Flecainide

Question 14

What class 1C drug slows conduction in all cardiac tissues and is considered to be a broad-spectrum antiarrhythmic agent?

Answer 14

Propafenone

Question 15

What class are β-adrenergic antagonists and are useful in treating tachyarrhythmia’s?

Answer 15

Class II agents

Question 16

What class II drug reduces the incidence of SUDDEN ARRHYTHMIC DEATH after myocardial infarction?

Answer 16

Propranolol

Question 17

What class II drug reduces the risk of BRONCHOSPASM and is most widely used in the treatment of cardiac arrhythmias?

Answer 17

Metoprolol

Question 18

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?

Answer 18

Esmolol

Question 19

What class blocks potassium (K+) channels and have the potential to INDUCE arrhythmias?

Answer 19

Class III agents

Question 20

What class III drug is a primary drug for VENTRICULAR FIBRILLATION and is the most commonly employed anti-arrhythmic?

Answer 20

Amiodarone

Question 21

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?

Answer 21

Dofetilide

Question 22

What class of drugs are calcium-channel blockers?

Answer 22

Class IV agents

Question 23

What 2 class IV drugs are more effective against atrial than against ventricular arrhythmias?

Answer 23

Verapamil and diltiazem