NTA Pharmacology and Medications Flashcards

What is the primary cardiac action of atropine?

Answer: Increases heart rate by blocking parasympathetic (vagal) tone

Atropine blocks the parasympathetic muscarinic receptors on the SA node, removing vagal slowing and increasing heart rate — making it the first-line drug for symptomatic bradycardia.

Which drug is the first-line pharmacologic treatment for terminating supraventricular tachycardia (SVT)?

Answer: Adenosine

Adenosine transiently blocks AV node conduction to interrupt the reentrant circuit driving SVT, and must be given as a rapid IV bolus due to its extremely short half-life.

Which ECG finding is characteristic of digoxin toxicity?

Answer: Prolonged PR interval and scooped ST depression

Digoxin toxicity produces a prolonged PR interval and the classic scooped or 'Salvador Dali mustache' ST depression pattern on ECG.

Amiodarone exerts its antiarrhythmic effect through which mechanism?

Answer: Blocks sodium, potassium, and calcium channels while also having beta-blocking properties

Amiodarone is a broad-spectrum Class III antiarrhythmic that blocks multiple ion channels and has alpha- and beta-blocking properties, making it effective for a wide range of arrhythmias.

What is the first-line vasopressor used during ACLS for ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT)?

Answer: Epinephrine

Epinephrine 1 mg IV every 3–5 minutes is the first-line vasopressor in the ACLS VF/pVT algorithm, improving coronary and cerebral perfusion pressure during resuscitation.

How do beta-blocker medications affect heart rate?

Answer: Decrease heart rate by blocking beta-1 adrenergic receptors

Beta-blockers competitively block beta-1 receptors, reducing the response to catecholamines and lowering both resting and exertional heart rate.