When watching the heartbeat, after House finds an immobile part of the heart, Chase says he found an "arrhythmia" and House corrects him saying it not an arrhythmia, it's a no-rythmia. The prefix a- means literally no in medicine, so "arrhythmia" literally means "no-rhytmia"
Neither House nor anyone on his team is qualified to perform brain surgery.
When comparing the DNA of the healthy and unhealthy parts of Clancy's heart, the title of both images contains a misspelled common word: "DNA Specimin [sic]..."
Chase tells the kid after the successful surgery that he'll be "normal again." The kid was never "normal" because of the cause of his condition.