East gave preference to hearts and 4 and 4 were cue bids. Once the spades were covered, West took a shot at six.
North leads the Q and the ace wins.
When you play A and a heart to the queen, North shows out on the second round. Plan the play. With a trump loser certain, West needs to make sure a diamond is not lost. Plan to ruff the fourth diamond in dummy. It will usually work to play a diamond to the ace, a diamond to the queen, followed by the third diamond from dummy.