Final answer:
Dopamine is the first-line IV inotropic agent for cardiogenic shock, as it improves myocardial contractility and increases cardiac output.
Step-by-step explanation:
The first-line IV inotropic agent when dealing with cardiogenic shock is Dopamine. Dopamine is a synthetic drug that mimics the effects of epinephrine and norepinephrine by stimulating the influx of calcium ions into the cardiac muscle cells, increasing the strength of contraction. It is commonly used to improve myocardial contractility and increase cardiac output in patients with cardiogenic shock.