Dr. Douglas Schreck is a supporting character portrayed by Matthew Sussman.
Douglas Schreck is DiMeo boss Junior Soprano's cardiologist at Saint Barnabas Medical Center in Livingston, New Jersey. He allowed Junior to use his office to conduct meetings while under the pretense of coming in for medical appointments. Due to the physician-patient privilege clause that denies the FBI and authorities to listening in on their conversations, meeting with associates including DiMeo street boss Tony Soprano and capo Richie Aprile.
Junior mentions that Douglas is the son of Monty Schreck, a book maker in New Jersey who is known to the DiMeo crime family.