Final answer:
The first treatment for paroxysmal supraventricular tachycardia (PSVT) at a rate of 170 beats per minute is usually a fast IV push of adenosine (Adenocard).
Step-by-step explanation:
The emergency department patient experiencing paroxysmal supraventricular tachycardia (PSVT) at a rate of 170 beats per minute would most likely be treated first with an adenosine (Adenocard) fast IV push. Adenosine's action includes slowing down the electrical conduction through the atrioventricular (AV) node, which can help to convert the heart rhythm back to normal. It is typically given quickly in an IV due to its very short half-life, allowing it to act rapidly. On the other hand, defibrillation is reserved for life-threatening arrhythmias such as ventricular fibrillation or pulseless ventricular tachycardia, where the heart's electrical activity becomes chaotic, preventing the effective pumping of blood. This is not the initial treatment for PSVT. Sotalol and digoxin are also not typically first-line treatments for an acute episode of PSVT.