What is causing pvcs/pacs from slouching, lying down, quickly standing or stopping. theyve been cleared benign but what's causes this from these stance?

Usually : no cause: In the majority of cases, no cause can be found. That said, check your electrolytes for deficiency: magnesium and potassium. Avoid stimulants: nicotine and caffeine. Check thyroid (TSH). Get plenty of rest. Avoid stress. If all those fail, they'll either go away by themselves (they often do) or you'll need medication to help.