Antiarrhythmic drugs can help arrhythmias by doing which overall action?

A) Increasing preload only

B) Slowing heart firing

C) Increasing potassium loss

D) Increasing AV speed

B. Slowing heart firing

Which drug group slows heart firing according to the notes?

A) Class II beta blockers

B) Class IA sodium blockers

C) Class IB sodium blockers

D) Class IC sodium blockers

A. Class II beta blockers

Which drug listed can slow heart firing by blocking L-type calcium channels?

A) Flecainide

B) Lidocaine

C) Verapamil

D) Procainamide

C. Verapamil

Which non-Vaughan-Williams drug slows heart firing by affecting the AV node?

A) Adenosine

B) Quinidine

C) Mexiletine

D) Propafenone

A. Adenosine

Which drug from prior angina material is listed as slowing heart firing?

A) Dofetilide

B) Ivabradine

C) Disopyramide

D) Ibutilide

B. Ivabradine

Which antiarrhythmic goal means reducing how quickly impulses travel through the heart?

A) Increasing automaticity

B) Increasing contractility

C) Slowing conduction

D) Shortening refractoriness

C. Slowing conduction

Which class slows conduction by blocking sodium channels?

A) Class I

B) Class II

C) Class III

D) Class IV

A. Class I

Which drug class helps slow conduction through beta receptor blockade?

A) Class III

B) Class II

C) Class IB only

D) Class IA only

B. Class II

Which drug class slows conduction through L-type calcium channel blockade?

A) Class III

B) Class IC

C) Class IV

D) Class IB

C. Class IV

Which antiarrhythmic goal means cells must wait longer before firing again?

A) Shorter AP duration

B) Increased refractory period

C) Faster AV conduction

D) Higher excitability

B. Increased refractory period

Which classes are especially associated with making cells wait longer before firing again?

A) Class IA and III

B) Class IB and IC

C) Adenosine and magnesium

D) Potassium and lidocaine

A. Class IA and III

In the AV node, which classes can increase the waiting period before firing again?

A) Class IB and IC

B) Class II and IV

C) Class IA and IB

D) Class III and IC

B. Class II and IV

Which drugs are Class IA antiarrhythmics?

A) Procainamide, quinidine, disopyramide

B) Lidocaine, mexiletine, flecainide

C) Amiodarone, sotalol, dofetilide

D) Verapamil, diltiazem, adenosine

A. Procainamide, quinidine, disopyramide

Which drug is a Class IA antiarrhythmic?

A) Lidocaine

B) Procainamide

C) Metoprolol

D) Diltiazem

B. Procainamide

Which drug is a Class IA antiarrhythmic?

A) Quinidine

B) Mexiletine

C) Flecainide

D) Esmolol

A. Quinidine

Which drug is a Class IA antiarrhythmic?

A) Sotalol

B) Propafenone

C) Disopyramide

D) Adenosine

C. Disopyramide

Class IA drugs block which channels?

A) Calcium and chloride channels

B) Sodium and potassium channels

C) Beta and alpha receptors

D) BNP and D1 receptors

B. Sodium and potassium channels

What is the main electrophysiologic effect of Class IA drugs?

A) Shortened AP duration

B) Faster AV conduction

C) Prolonged AP duration

D) Increased ischemic firing

C. Prolonged AP duration

Class IA drugs prolong which cellular period?

A) Refractory period

B) Depolarization leak only

C) SA pacemaker slope only

D) AV nodal delay only

A. Refractory period

Class IA drugs are used for which arrhythmia types?

A) Only atrial arrhythmias

B) Only ventricular arrhythmias

C) Atrial and ventricular arrhythmias

D) Only digitalis arrhythmias

C. Atrial and ventricular arrhythmias

Which side effect is associated with Class IA drugs?

A) Bronchoconstriction only

B) QT prolongation/torsades

C) Severe cyanide toxicity

D) Thrombocytopenia only

B. QT prolongation/torsades

Which Class IA drug is linked to lupus-like syndrome?

A) Procainamide

B) Quinidine

C) Disopyramide

D) Lidocaine

A. Procainamide

Which drugs are Class IB antiarrhythmics?

A) Flecainide and propafenone

B) Lidocaine and mexiletine

C) Verapamil and diltiazem

D) Quinidine and disopyramide

B. Lidocaine and mexiletine

Which drug is a Class IB antiarrhythmic?

A) Lidocaine

B) Procainamide

C) Dofetilide

D) Metoprolol

A. Lidocaine

Which drug is a Class IB antiarrhythmic?

A) Flecainide

B) Mexiletine

C) Quinidine

D) Sotalol

B. Mexiletine

Class IB drugs block sodium channels especially in which tissue?

A) Healthy atrial tissue only

B) AV nodal tissue only

C) Damaged ischemic ventricular tissue

D) Normal SA nodal tissue

C. Damaged ischemic ventricular tissue

Class IB drugs have which effect on action potential duration?

A) Prolong AP duration

B) Shorten AP duration

C) No sodium effect

D) Prolong QT strongly

B. Shorten AP duration

Although Class IB drugs shorten AP duration, they suppress which activity?

A) Normal AV nodal delay

B) Abnormal ischemic ventricular activity

C) BNP receptor signaling

D) Aldosterone receptor activity

B. Abnormal ischemic ventricular activity

Which clinical use matches Class IB drugs?

A) Ventricular tachycardia

B) Chronic hypertension only

C) Stable angina only

D) Supraventricular arrhythmias only

A. Ventricular tachycardia

Class IB drugs can help prevent which rhythm after cardioversion?

A) Atrial flutter only

B) Ventricular fibrillation

C) Sinus bradycardia

D) AV block

B. Ventricular fibrillation

Which class is best for sodium channel blockade in damaged ischemic ventricular tissue?

A) Class IA

B) Class IB

C) Class IC

D) Class IV

B. Class IB

Which drug best matches “ventricular tachycardia after ischemic damage”?

A) Lidocaine

B) Diltiazem

C) Adenosine

D) Propranolol

A. Lidocaine

Which drugs are Class IC antiarrhythmics?

A) Lidocaine and mexiletine

B) Procainamide and quinidine

C) Flecainide and propafenone

D) Amiodarone and sotalol

C. Flecainide and propafenone

Which drug is a Class IC antiarrhythmic?

A) Flecainide

B) Lidocaine

C) Amiodarone

D) Verapamil

A. Flecainide

Which drug is a Class IC antiarrhythmic?

A) Procainamide

B) Propafenone

C) Mexiletine

D) Adenosine

B. Propafenone

Class IC drugs are defined by which major mechanism?

A) Strong Na+ channel blockade

B) Strong K+ channel blockade

C) L-type calcium blockade

D) Beta receptor activation

A. Strong Na+ channel blockade

Class IC drugs mainly slow which cardiac property?

A) Heart preload

B) Renal sodium excretion

C) Conduction

D) Contractility

C. Conduction

Slowed conduction from Class IC drugs prevents which problem?

A) Impulses spreading too quickly

B) Cells waiting too long

C) Calcium leaving cells

D) Venous return increasing

A. Impulses spreading too quickly

Class IC drugs are used for supraventricular arrhythmias in which patients?

A) Patients with normal hearts

B) Patients after MI

C) Patients with ischemic disease

D) Patients with torsades

A. Patients with normal hearts

What is the big warning for Class IC drugs?

A) Avoid in asthma

B) Avoid in post-MI disease

C) Avoid in hypokalemia only

D) Avoid in AVNRT only

B. Avoid in post-MI disease

Why should Class IC drugs be avoided in ischemic heart disease or post-MI patients?

A) They worsen arrhythmias

B) They cause lupus only

C) They reverse hypokalemia

D) They block BNP receptors

A. They worsen arrhythmias

A post-MI patient has arrhythmias. Which drug should be avoided because it can worsen arrhythmias?

A) Flecainide

B) Lidocaine

C) Magnesium

D) Adenosine

A. Flecainide

Which class strongly blocks sodium channels and is used only in normal hearts for supraventricular arrhythmias?

A) Class II

B) Class IC

C) Class IA

D) Class III

B. Class IC

Which drugs are Class II antiarrhythmics?

A) Propranolol, esmolol, metoprolol

B) Verapamil, diltiazem, adenosine

C) Lidocaine, mexiletine, flecainide

D) Amiodarone, dofetilide, ibutilide

A. Propranolol, esmolol, metoprolol

Class II antiarrhythmics are also known as which drug group?

A) Calcium channel blockers

B) Sodium channel blockers

C) Beta blockers

D) Potassium channel blockers

C. Beta blockers

Beta blockers help arrhythmias by decreasing which stimulation?

A) Sympathetic stimulation

B) Parasympathetic stimulation

C) BNP stimulation

D) Aldosterone stimulation

A. Sympathetic stimulation

Class II beta blockers slow firing in which cardiac node?

A) SA node

B) AV node only

C) Purkinje fibers only

D) Ventricular myocardium only

A. SA node

Class II beta blockers slow conduction through which cardiac node?

A) AV node

B) SA node only

C) Bundle branches only

D) Ventricular apex only

A. AV node

Which clinical use matches Class II beta blockers?

A) Atrial arrhythmias

B) Cyanide toxicity

C) Hypokalemia only

D) Lupus-like syndrome

A. Atrial arrhythmias

Beta blockers are useful for which arrhythmia treatment goal?

A) Rate control

B) QT shortening only

C) Cardioversion anesthesia

D) Potassium repletion

A. Rate control

Class II beta blockers help prevent which cardiac outcomes?

A) Recurrent MI/sudden death

B) Digitalis toxicity only

C) Torsades only

D) Lupus-like syndrome

A. Recurrent MI/sudden death

Which side effect is associated with Class II beta blockers?

A) Bradycardia

B) Cyanide toxicity

C) Gingival hyperplasia

D) Hearing loss

A. Bradycardia

Class II beta blockers can cause which conduction adverse effect?

A) AV block

B) QT shortening

C) SA node acceleration

D) Ventricular fibrillation prevention only

A. AV block

Which side effect is associated with beta blockers due to reduced sympathetic activity?

A) Fatigue

B) Constipation

C) Lupus-like syndrome

D) Visual brightness

A. Fatigue

Bronchoconstriction is especially associated with which beta blockers?

A) Nonselective beta blockers

B) Beta-1 selective blockers

C) Class III agents

D) Class IV agents

A. Nonselective beta blockers

A patient with asthma develops wheezing after propranolol. Which side effect explains this?

A) Bronchoconstriction

B) QT prolongation

C) Lupus-like syndrome D

) Torsades

A. Bronchoconstriction

Which drugs are Class III antiarrhythmics?

A) Amiodarone, dofetilide, sotalol

B) Propranolol, esmolol, metoprolol

C) Flecainide, propafenone, lidocaine

D) Verapamil, diltiazem, adenosine

A. Amiodarone, dofetilide, sotalol

Which drug is a Class III antiarrhythmic?

A) Amiodarone

B) Procainamide

C) Mexiletine

D) Verapamil

A. Amiodarone

Which drug is a Class III antiarrhythmic?

A) Dofetilide

B) Flecainide

C) Adenosine

D) Magnesium

A. Dofetilide

Which drug is a Class III antiarrhythmic?

A) Sotalol

B) Esmolol

C) Quinidine

D) Potassium

A. Sotalol

Which drug is a Class III antiarrhythmic?

A) Ibutilide

B) Lidocaine

C) Diltiazem

D) Propafenone

A. Ibutilide

Which drug is a Class III antiarrhythmic?

A) Dronedarone

B) Disopyramide

C) Metoprolol

D) Adenosine

A. Dronedarone

Class III drugs mainly block which channels?

A) Potassium channels

B) Sodium channels

C) Calcium channels

D) Chloride channels

A. Potassium channels

What is the main effect of Class III drugs?

A) Prolong AP and refractory period

B) Shorten AP and refractory period

C) Speed AV conduction D) Increase SA firing

A. Prolong AP and refractory period

Amiodarone has extra actions on which targets?

A) Na+, Ca2+, beta receptors

B) SGLT2, ACE, renin

C) BNP, D1, alpha-1

D) Aldosterone, GABA, NMDA

A. Na+, Ca2+, beta receptors

Class III drugs are used for which arrhythmias?

A) Serious ventricular and supraventricular

B) Hypokalemia only

C) AVNRT only

D) Digitalis toxicity only

A. Serious ventricular and supraventricular

Which side effect is associated with Class III drugs?

A) QT prolongation/torsades

B) Lupus-like syndrome only

C) Bronchoconstriction only

D) Thiocyanate toxicity

A. QT prolongation/torsades

A patient receiving dofetilide develops torsades de pointes. Which class toxicity is this?

A) Class III toxicity

B) Class IB toxicity

C) Class II toxicity

D) Class IV toxicity

A. Class III toxicity

Which class prolongs refractory period mainly by blocking potassium channels?

A) Class III

B) Class IB

C) Class IC

D) Class II

A. Class III

Which drugs are Class IV antiarrhythmics?

A) Verapamil and diltiazem

B) Propranolol and esmolol

C) Lidocaine and mexiletine

D) Flecainide and propafenone

A. Verapamil and diltiazem

Class IV drugs directly block which channels?

A) L-type Ca2+ channels

B) Fast Na+ channels

C) K+ channels

D) HCN pacemaker channels

A. L-type Ca2+ channels

Which drug is a Class IV antiarrhythmic?

A) Verapamil

B) Adenosine

C) Procainamide

D) Amiodarone

A. Verapamil

Which drug is a Class IV antiarrhythmic?

A) Diltiazem

B) Metoprolol

C) Mexiletine

D) Quinidine

A. Diltiazem

Class IV drugs are clinically used for which arrhythmia type?

A) Supraventricular tachycardias

B) Ventricular fibrillation after cardioversion

C) Digitalis-induced arrhythmias

D) Hypokalemia-associated arrhythmias

A. Supraventricular tachycardias

Besides arrhythmias, Class IV drugs are used for which condition?

A) Hypertension

B) Cyanide toxicity

C) Lupus-like syndrome

D) Thrombocytopenia

A. Hypertension

Besides arrhythmias and hypertension, Class IV drugs are used for which condition?

A) Angina

B) Asthma

C) Hypokalemia

D) Digitalis toxicity

A. Angina

Which side effect is associated with verapamil and diltiazem?

A) Bradycardia

B) Cyanide toxicity

C) Lupus-like syndrome

D) Ototoxicity

A. Bradycardia

Class IV calcium channel blockers can cause which conduction adverse effect?

A) AV block

B) Ventricular acceleration

C) QT shortening

D) Hyperkalemic arrest

A. AV block

Which gastrointestinal side effect is associated with Class IV drugs?

A) Constipation

B) Diarrhea

C) Metallic taste

D) Vomiting

A. Constipation

Which vascular side effect is associated with Class IV drugs?

A) Hypotension

B) Hypertension

C) Cyanosis

D) Pulmonary edema

A. Hypotension

Which side effect set best matches Class IV drugs?

A) Bradycardia, AV block, constipation

B) Torsades, lupus-like syndrome, cough

C) Cyanide toxicity, hypotension, fatigue

D) Arrhythmias, thrombocytopenia, flushing

A. Bradycardia, AV block, constipation

Adenosine acts primarily in which cardiac structure?

A) AV node

B) SA node only

C) Ventricular muscle only

D) Purkinje fibers only

A. AV node

Adenosine activates which current in the AV node?

A) Potassium current

B) Sodium current

C) Chloride current

D) Pacemaker current

A. Potassium current

Adenosine blocks which current in the AV node?

A) Calcium current

B) Potassium current

C) Chloride current

D) Sodium-glucose current

A. Calcium current

Adenosine is clinically used for which arrhythmia?

A) Paroxysmal supraventricular tachycardia

B) Ventricular tachycardia after ischemia

C) Digitalis-induced arrhythmia

D) Torsades de pointes

A. Paroxysmal supraventricular tachycardia

Which drug is used for paroxysmal supraventricular tachycardia by affecting AV nodal K+ and Ca2+ currents?

A) Adenosine

B) Lidocaine

C) Flecainide

D) Potassium

A. Adenosine

Magnesium helps arrhythmias by doing which general action

A) Stabilizes cardiac electrical activity

B) Blocks ACE

C) Releases nitric oxide

D) Blocks beta receptors

A. Stabilizes cardiac electrical activity

Magnesium interacts with what to stabilize cardiac electrical activity?

A) Ion channels

B) Aldosterone receptors

C) Beta receptors

D) BNP receptors

A. Ion channels

Magnesium is clinically used for which arrhythmia?

A) Torsades de pointes

B) Stable angina

C) Chronic hypertension

D) Recurrent MI prevention

A. Torsades de pointes

Magnesium is also used for arrhythmias caused by which drug toxicity?

A) Digitalis-induced arrhythmias

B) Beta blocker-induced fatigue

C) Procainamide-induced lupus

D) Nitroprusside cyanide toxicity

A. Digitalis-induced arrhythmias

Which agent is used for torsades de pointes?

A) Magnesium

B) Flecainide

C) Ivabradine

D) Diltiazem

A. Magnesium

Which agent can treat digitalis-induced arrhythmias by stabilizing electrical activity?

A) Magnesium

B) Propranolol

C) Quinidine

D) Adenosine

A. Magnesium

Potassium helps arrhythmias by correcting which abnormality

A) Hypokalemia

B) Hypercalcemia

C) Hypernatremia

D) Hypoglycemia

A. Hypokalemia

Why can hypokalemia promote arrhythmias?

A) Cells become too excitable

B) Cells stop conducting completely

C) BNP receptors activate

D) AV node calcium rises

A. Cells become too excitable

Potassium is clinically used for arrhythmias associated with which condition?

A) Hypokalemia

B) Hyperkalemia

C) Hypertension only

D) Angina only

A. Hypokalemia

Potassium can be used for arrhythmias caused by which drug toxicity?

A) Digitalis-induced arrhythmias

B) Beta blocker fatigue

C) Calcium blocker constipation

D) Procainamide lupus

A. Digitalis-induced arrhythmias

Which electrolyte correction reduces abnormal rhythm risk from overly excitable cells?

A) Potassium correction

B) Sodium restriction

C) Chloride loading

D) Glucose infusion

A. Potassium correction

A patient with hypokalemia develops abnormal rhythms. Which agent directly addresses the cause?

A) Potassium

B) Adenosine

C) Flecainide

D) Verapamil

A. Potassium

Compared with procainamide, disopyramide has which pharmacokinetic feature?

A) Shorter duration

B) No oral activity

C) Longer duration

D) No cardiac effect

C. Longer duration

Which toxicity is associated with disopyramide?

A) Antimuscarinic effects

B) Cinchonism

C) Tendon rupture

D) Methemoglobinemia

A. Antimuscarinic effects

Disopyramide can worsen which cardiac condition?

A) Hypertension

B) Atrial flutter

C) Angina

D) Heart failure

D. Heart failure

A patient taking disopyramide develops dry mouth, urinary retention, and blurry vision. Which toxicity explains this?

A) Beta blockade

B) Antimuscarinic effects

C) Calcium toxicity

D) Folate blockade

B. Antimuscarinic effects

Which side effect pair best matches disopyramide?

A) Tinnitus and vertigo

B) Rash and fever

C) Antimuscarinic effects and heart failure

D) Tendonitis and neurotoxicity

C. Antimuscarinic effects and heart failure

Compared with procainamide, quinidine is described as having what?

A) Less toxicity

B) No toxicity

C) Only renal toxicity

D) Greater toxicity

D. Greater toxicity

Which symptom set best matches quinidine cinchonism?

A) Dry mouth, urinary retention

B) Tinnitus, vertigo, headache

C) Cough, angioedema, rash

D) Wheezing, fatigue, bradycardia

B. Tinnitus, vertigo, headache

Which side effect set best matches quinidine?

A) Tendonitis, neurotoxicity, GI upset

B) Cinchonism, GI disturbance, thrombocytopenia

C) Methemoglobinemia, pulmonary irritation, hypotension

D) Antimuscarinic effects, heart failure only

B. Cinchonism, GI disturbance, thrombocytopenia

Compared with lidocaine, mexiletine has which pharmacokinetic feature?

A) Shorter duration

B) Longer duration

C) No absorption

D) IV use only

B. Longer duration

Which statement best describes mexiletine?

A) Similar to lidocaine, oral

B) Similar to quinidine, shorter

C) Similar to verapamil, IV only

D) Similar to adenosine, AV node

A. Similar to lidocaine, oral

A patient needs an orally active Class IB-like drug for ventricular arrhythmia. Which drug fits best?

A) Lidocaine

B) Mexiletine

C) Procainamide

D) Diltiazem

B. Mexiletine

Which drug is similar to lidocaine but has longer duration and neuropathic pain use?

A) Quinidine

B) Disopyramide

C) Mexiletine

D) Esmolol

C. Mexiletine

Esmolol is also used for arrhythmias associated with which condition?

A) Hypokalemia

B) Thyrotoxicosis

C) Heart failure only

D) Toxoplasmosis

B. Thyrotoxicosis

A patient with thyrotoxicosis develops tachyarrhythmia. Which drug from the notes is especially useful?

A) Disopyramide

B) Quinidine

C) Esmolol

D) Nifedipine

C. Esmolol

Which statement best describes esmolol use?

A) Neuropathic pain treatment

B) Toxoplasmosis folate blockade

C) Pulmonary hypertension therapy

D) Perioperative and thyrotoxicosis arrhythmias

D. Perioperative and thyrotoxicosis arrhythmias

Dihydropyridine calcium channel blockers may sometimes do what to arrhythmias?

A) Cure all arrhythmias

B) Prevent digitalis toxicity

C) Shorten QT only

D) Precipitate arrhythmias

D. Precipitate arrhythmias

Which statement best contrasts dihydropyridines with verapamil/diltiazem?

A) Dihydropyridines are arrhythmia drugs

B) Dihydropyridines are not useful

C) Verapamil cannot affect AV node

D) Diltiazem causes cinchonism

B. Dihydropyridines are not useful

In deciding on a treatment regimen with procainamide
for this patient, which of the following statements is most
correct?
(A) A probable drug interaction with digoxin suggests that
digoxin blood levels should be obtained before and after
starting procainamide.
(B) Hyperkalemia should be avoided to reduce the likelihood of procainamide toxicity.
(C) Procainamide cannot be used if the patient has asthma
because it has a β-blocking effect.
(D) Procainamide cannot be used if the patient has angina
because it has a β-agonist effect.
(E) Procainamide is not active by the oral route.

(B) Hyperkalemia should be avoided to reduce the likelihood of procainamide toxicity.

If this patient should take an overdose and manifest severe
acute procainamide toxicity with markedly prolonged QRS,
which of the following should be given immediately?
(A) A calcium chelator such as EDTA
(B) Adenosine
(C) Nitroprusside
(D) Potassium chloride
(E) Sodium lactate

(E) Sodium lactate

The most effective therapy for procainamide (and quinidine)
toxicity appears to be concentrated sodium lactate.

Amiodarone:
(A) Decreases PR interval in normal sinus rhythm
(B) Increases action potential duration
(C) Increases contractility
(D) Often causes liver function abnormalities
(E) Reduces resting potential

(B) Increases action potential duration

A 36-year-old woman with a history of poorly controlled
thyrotoxicosis has recurrent episodes of tachycardia with
severe shortness of breath. During elective surgery to remove
her thyroid, she develops a heart rate of 200 with a slightly
decreased blood pressure. Which of the following drugs
would be most suitable?
(A) Amiodarone
(B) Disopyramide
(C) Esmolol
(D) Quinidine
(E) Verapamil

(C) Esmolol

A 55-year-old man is admitted to the emergency department
and is found to have an abnormal ECG. Overdose of an anti-arrhythmic drug is considered. Which of the following drugs
is correctly paired with its ECG effects?
(A) Quinidine: Increased PR and decreased QT intervals
(B) Flecainide: Increased QRS interval
(C) Verapamil: Decreased PR interval
(D) Lidocaine: Decreased QRS and PR interval
(E) Metoprolol: Increased QRS duration

(B) Flecainide: Increased QRS interval

A 60-year-old woman comes to the emergency department
with atypical chest pain. Her ECG reveals ventricular tachycardia with rare normal sinus beats, and ST-segment elevation. Troponin C levels are markedly increased, suggesting myocardial damage. A diagnosis of myocardial infarction is
made, and the woman is admitted to the cardiac intensive
care unit. Her arrhythmia will probably be treated initially
with
(A) Adenosine
(B) Digoxin
(C) Lidocaine
(D) Quinidine
(E) Verapamil

Lidocaine has limited applications as an antiarrhythmic drug,
but emergency treatment of myocardial infarction arrhythmias is one of the most important.

Which of the following drugs slows conduction through the
AV node and has a duration of action of 10–20 seconds?
(A) Adenosine
(B) Amiodarone
(C) Diltiazem
(D) Esmolol
(E) Flecainide

(A) Adenosine