The Canadian says it's not the first time he experienced issues with an elevated heart rate.
No. 11 seed aims high in New York.
Djokovic, Federer, Sharapova and Wozniacki all on tap for Day 2 in NYC.
Former Wimbledon winner joins Czech's team.
Two-time mahor champion's expectations are modest in New York.
Dunlop will be the official ball of Oz starting in January.
World No. 1 on why major first rounds can pose major problems.
