Final answer:
The first line treatment for ACS (Acute Coronary Syndrome) is Nitroglycerin sublingual. It involves the release of nitric oxide to relax the smooth muscle in the coronary vessels.
Step-by-step explanation:
The first line treatment for ACS (Acute Coronary Syndrome) is Nitroglycerin is administered under the tongue to facilitate its absorption. It is believed to involve the release of nitric oxide, a known vasodilator, to relax the smooth muscle in the coronary vessels. Other immediate treatments for ACS include administering supplemental oxygen and aspirin to help break up clots.