Would a paramedic resuscitate someone with a lacerated coronary artery in neck if the patient has lost too much blood and his heart has stopped beating?

No, because the coronary arteries are in the heart, not the neck. Did you mean carrotid artery? ---- If a person did have a lacerated coronary artery, which, by the way, is located in the heart, they would be close to death depending on the timing. Of course you would try to resuscitate that person, but in that case, with a heart that has stopped beating, the chance of surviving would be very slim. ~Blood Red Vampress