That if you double "no-trumps" your partner will lead you his best heart.
THE LEAD WHEN PARTNER HAS DOUBLED
When your partner has doubled, the opening lead must depend greatly on the scheme you adopt for the play of your hand. It is a mistake to suppose your partner wishes a trump led EVERY time he doubles. On the contrary, spades—when doubled—are seldom led by good players, unless with a strong hand, until they have gained information to justify the trump lead.
The majority of hands will be covered by the following rules:
If spades have been doubled and you hold four or more trumps you should usually lead trumps.
It is fair to assume that your partner has doubled with a good suit hand. Lead trumps if you are weak in spades, but hold a strong suit hand. Your partner has probably doubled with trump strength.
If hearts, diamonds, or clubs have been doubled and dummy is the "maker" it is usually good play to lead trumps; that is, when you have no short suit and so are unable to use your trumps for ruffing.
If possible lead to take the first trick. After you have seen the dummy you are in a position to judge as to the advisability of the trump lead.
When hearts, diamonds, or clubs have been doubled and the dealer is the maker, it is not sound play to lead trumps. You would place your partner in a bad position by leading up to the dealer's declared strength.
When leading trumps always lead the top of two or three and the lowest of four.