Pharmacological Agents for Arrhythmias

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Which class of antiarrhythmic drugs is known for having alpha adrenergic blockade and vagolytic actions?

Class IC

Class IA (correct)

Class IB

Class II

Why is disopyramide not recommended for use?

High cost and limited availability

Lack of efficacy and toxicity (correct)

Potential for drug interactions

Low bioavailability and rapid metabolism

Which Class IC drug is highly effective at converting atrial fibrillation (AF) to sinus rhythm?

Flecainide (correct)

Propafenone

Mexiletine

Lidocaine

Why are beta-blockers (Class II) used in antiarrhythmic therapy?

To decrease automaticity of the SA node Signup and view all the answers

What is a significant limitation of using procainamide for atrial fibrillation (AF) treatment?

Potential for severe gastrointestinal side effects Signup and view all the answers

Why is the use of encapsulated oral mexiletine for recurrent ventricular tachycardia (VT) prevention not recommended?

Lack of improved outcomes Signup and view all the answers

Which class of antiarrhythmic drugs works by blocking the effects of catecholamines at beta-adrenergic receptors in the heart?

Class II Signup and view all the answers

Which class of antiarrhythmic drugs has a low ability to block sodium channels and is used to treat acute ventricular arrhythmias?

Class IB Signup and view all the answers

What is the main adverse effect associated with class IA antiarrhythmics?

Torsades de pointes Signup and view all the answers

Which type of blockade is state dependent for lidocaine-like agents in class IB antiarrhythmics?

Open state blockade Signup and view all the answers

What is the mechanism of action of class II antiarrhythmics in treating arrhythmias?

Mimicking sympathetic stimulation by inhibiting beta-1 and beta-2 receptors Signup and view all the answers

Which effect do beta blockers cause in the heart, leading to a reduction in the heart's oxygen demand?

Lower heart rate and force of contraction Signup and view all the answers

What is the main limitation of Vaughan Williams' classification system for antiarrhythmic drugs?

Variations in effect between patients Signup and view all the answers

What is the primary use of Class IB antiarrhythmics like Lidocaine?

Treating acute ventricular arrhythmias Signup and view all the answers

Why are beta blockers used under careful observation for changes in rhythm?

To increase the incidence of triggered activity in the ventricles. Signup and view all the answers

Which class of antiarrhythmic drugs is contraindicated following myocardial infarction (MI)?

Class IA Signup and view all the answers

What is the primary concern with class II antiarrhythmic agents?

Excessive depression of cardiac function Signup and view all the answers

Which class of antiarrhythmic drugs is known to delay repolarization?

Class III Signup and view all the answers

Which antiarrhythmic drug is considered most effective for atrial fibrillation?

Amiodarone Signup and view all the answers

What is the primary mechanism of action of Class IV antiarrhythmics?

Inhibiting the flow of calcium ions through calcium channels Signup and view all the answers

Why are beta blockers considered a first-line treatment for myocardial infarction patients?

To prevent ventricular arrhythmias Signup and view all the answers

Which action characterizes the effect of Class III antiarrhythmics on myocytes?

Prolonging repolarization Signup and view all the answers

Why are Class IV antiarrhythmics generally contraindicated in patients with left ventricular dysfunction?

To prevent side effects like heart failure Signup and view all the answers

What is the primary concern with using Amiodarone for atrial fibrillation?

Potential for toxicity Signup and view all the answers

Which drug has a decreased usage due to proarrhythmic effects and perception changes about risks and benefits?

Sotalol Signup and view all the answers

Why are Class III antiarrhythmics considered less susceptible to proarrhythmia compared to Class I agents?

They prolong repolarization Signup and view all the answers

What is the mechanism of action of Beta-blockers in arrhythmias?

Suppressing triggered activity and stabilizing membranes Signup and view all the answers

How do Calcium Channel Blockers affect the AV node in arrhythmias?

Suppress automaticity Signup and view all the answers

What is the primary mechanism of action of Digoxin in supraventricular arrhythmias?

Inhibiting sodium/potassium ATPase Signup and view all the answers

Why are Potassium Channel Blockers classified as Class III antiarrhythmic drugs?

They accelerate repolarization Signup and view all the answers

What is a common limitation of Beta-blockers in acute arrhythmias?

Slow onset of action Signup and view all the answers

How do Calcium Channel Blockers affect myocardial contractility?

Decrease it by inhibiting calcium movement Signup and view all the answers