Gp sent me home with an rx for prevacid (lansoprazole) for persistent chest pain, no questions asked. can acid reflux also lead to soreness in the left arm/shoulder?

Yes, but ask questio: Your GP should've asked questions or at least verified your symptoms, duration, & medical history to see what the likelihood is. Irritiation of the diaphragm from acid reflux in the stomach (or heart disease) can cause left arm / shoulder pain. However, is your family's tendency for heart attacks or reflux? Use HealthTap Prime if you don't get a satisfactory answer. Prevacid (lansoprazole) takes ~1 week to work.