FCCS FCCS Cardiovascular Emergencies 2 — Questions and Answers
Question 1: Which drug is the antidote for beta-blocker overdose causing bradycardia and hypotension?
- Atropine
- Glucagon (Correct answer)
- Calcium gluconate
- Sodium bicarbonate
Correct answer: Glucagon
Glucagon reverses beta-blocker toxicity by stimulating adenylate cyclase independently of beta receptors, increasing heart rate and contractility.
Question 2: Pulsus paradoxus greater than 10 mmHg is associated with which condition?
- Aortic stenosis
- Cardiac tamponade (Correct answer)
- Left ventricular failure
- Mitral regurgitation
Correct answer: Cardiac tamponade
Cardiac tamponade compresses the heart, causing exaggerated inspiratory drops in systolic BP exceeding 10 mmHg (pulsus paradoxus).
Question 3: In acute decompensated heart failure, what is the primary goal of IV nitroglycerin?
- Increase cardiac output directly
- Reduce preload and afterload to decrease pulmonary congestion (Correct answer)
- Increase heart rate
- Improve coronary perfusion only
Correct answer: Reduce preload and afterload to decrease pulmonary congestion
Nitroglycerin dilates venous and arterial beds, reducing both preload and afterload and rapidly relieving pulmonary congestion in acute heart failure.
Question 4: Narrow complex tachycardia at 150 bpm with a regular rhythm should prompt consideration of which diagnosis?
- Ventricular tachycardia
- Atrial flutter with 2:1 block (Correct answer)
- Multifocal atrial tachycardia
- Junctional escape rhythm
Correct answer: Atrial flutter with 2:1 block
Atrial flutter typically produces atrial rates of ~300 bpm; a ventricular rate of 150 bpm with regular rhythm suggests 2:1 AV conduction of flutter waves.
Question 5: Which intervention is indicated for hemodynamically unstable SVT unresponsive to adenosine?
- IV amiodarone infusion
- Synchronized cardioversion (Correct answer)
- Digoxin loading
- Oral beta-blocker
Correct answer: Synchronized cardioversion
Synchronized cardioversion is the immediate treatment for hemodynamically unstable SVT when pharmacologic therapy fails.
Question 6: What is the mechanism of action of adenosine in terminating SVT?
- Blocks calcium channels in ventricular muscle
- Transiently blocks AV nodal conduction, interrupting reentry circuits (Correct answer)
- Increases vagal tone chronically
- Prolongs ventricular action potential
Correct answer: Transiently blocks AV nodal conduction, interrupting reentry circuits
Adenosine causes transient AV nodal block by activating A1 receptors, interrupting the reentrant circuit responsible for most SVT.
FCCS FCCS Cardiovascular Emergencies 2
Which drug is the antidote for beta-blocker overdose causing bradycardia and hypotension?