FCCS Cardiovascular Emergencies Flashcards

Which drug is the antidote for beta-blocker overdose causing bradycardia and hypotension?

Answer: Glucagon

Glucagon reverses beta-blocker toxicity by stimulating adenylate cyclase independently of beta receptors, increasing heart rate and contractility.

Pulsus paradoxus greater than 10 mmHg is associated with which condition?

Answer: Cardiac tamponade

Cardiac tamponade compresses the heart, causing exaggerated inspiratory drops in systolic BP exceeding 10 mmHg (pulsus paradoxus).

In acute decompensated heart failure, what is the primary goal of IV nitroglycerin?

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.

Narrow complex tachycardia at 150 bpm with a regular rhythm should prompt consideration of which diagnosis?

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.

Which intervention is indicated for hemodynamically unstable SVT unresponsive to adenosine?

Answer: Synchronized cardioversion

Synchronized cardioversion is the immediate treatment for hemodynamically unstable SVT when pharmacologic therapy fails.

What is the mechanism of action of adenosine in terminating SVT?

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.