According to multiple sources, Philadelphia Flyers forward Scott Hartnell received clearance to resume skating and participate in games by a cardiologist after undergoing a stress test Tuesday morning.Hartnell, 29, was examined after being diagnosed with an elevated heart rate between the second and third periods of Friday's preseason game in Detroit. Hartnell informed the training staff of odd twitching in his right arm between periods, and when he was examined, an abnormal heart rate was discovered.According to Sam Carchidi of Philly.com and Tim Panaccio of CSNPhilly.com, Hartnell was on the ice practicing with the Flyers on Tuesday and said he will be available for Thursday's preseason game against the New Jersey Devils at Wells Fargo Center.Hartnell had skipped Sunday's practice and did not play in Monday's preseason game against the Rangers."I feel fine," he told NHL.com on Monday during the announcement of the 2012 Bridgestone NHL Winter Classic. "Last game in Detroit, my heart rate wouldn't settle down as it usually does. Arms were shaking a little bit. Just more precautionary, stay off the ice for a couple days."