Complex sentence: He currently holds the American record in the 50m butterfly (25m course) at 22.46, which he set at the 2012 Fina World Championships in Istanbul and shares the American record for the 200y butterfly with Michael Phelps at 1:39.65, set at the 2013 NCAA Championships.
Split into simpler sentences: He currently holds the American record in the 50-meter butterfly (short course) at 22.46, which he set at the 2012 FINA World Championships. He also shares the American record for the 200-yard butterfly with Michael Phelps at 1:39.65, set at the 2013 NCAA Championships.