"Two Hearts Beat in 3/4 Time" was recorded by Frank Patterson.

Lawrence Welk recorded "Two Hearts in 3/4 Time." On Welk's album, the authors credited are "Lackenbach/Stoltz/Young." (I suspect a misspelling; it might be Stolz.)

The Middle Spunk Creek Boys recorded "Our Hearts Beat in 3/4 Time" and the author credited is "Kreitzer."

There is a German version: "Zwei Herzen in 3/4 Takt." A German film by that name was released in 1930. Marek Weber & His Orchestra recorded it about that time.

BMI lists a song "Our Hearts Beat In Three Quart[ers Time]" and lists Mark Allen Kreitzer as the author.

My hunch is that the German version was the original, and the various ways of translating it into English account for the varying titles in English.