East must bid 2♥, showing 6-10 points, 5+ hearts and an unbalanced hand. (Balanced or semi-balanced East would have responded 1NT). Next
Comment As a general rule a 5-card suit should not be bid for a 2nd time !
But above example is a rare exception, when holding a 5-card suit in a weak (6-10), unbalanced hand.
With a stronger Responder's hand the bidding will continue, and the Opener will show delayed 3-card support at his next turn to bid.