In economically distressed northeastern Pennsylvania, Community Health Systems Inc is investing heavily in more than half a dozen hospitals it has bought in the last three years. At Wilkes-Barre General, the company is spending $53 million to build a new emergency room that doubles the size of the previous ER and a Heart and Vascular Institute where heart problems are diagnosed and treated. In Scranton, it plans to spend $128 million over the next five years to upgrade five facilities.