A Baltimore County Circuit Court judge dismissed Monday a defamation lawsuit filed by Dr. Mark Midei against St. Joseph Medical Center, barring the embattled cardiologist from seeking damages against his former hospital in the scandal over unnecessary heart stent procedures he's been accused of performing. The opinion by Judge Mickey Norman was not available, but electronic court records show that Midei's case was dismissed.Lawyers for Midei, St. Joseph and its corporate parent, Denver-based Catholic Health Initiatives, all declined to comment until they had read the ruling.