Zelandakh, on 2014-March-13, 06:54, said:
Would you splinter with a singleton ♠A or ♠K here, Andy?
Probably, yes. The reason for not splintering with a singleton ace or king is that it may be useful opposite some strength in partner's hand. In this sequence slam is likely to depend on the solidity of the heart and club suits, not on how well our spade honours mesh.
But even if you wouldn't splinter with that hand-type, it would be very wasteful to reserve the delayed 3♥ bid to show it. If you don't want to splinter, you may be able to bid 2♠ then 3♥ then 4♥.