CARACAS, Venezuela (AP) _ Miguel Otero Silva, one of Venezuela's best known authors and journalists, died Wednesday in Caracas of a heart ailment. He was 76.

Mario Delfin Becerra, editor in chief of the daily newspaper El Nacional, said Otero Silva died in La Floresta medical clinic at 1:15 p.m. He was taken there that morning for treatment of a cardiac aneurism.

Born in the eastern state of Anzoategui on Oct. 26, 1908, Otero Silva was a member of one of Venezuela's most prominent families. He was imprisoned and exiled several times for his activities against dictatorial regimes.

Otero Silva, an avowed Marxist, served as a legislator in the democratic governments that have ruled Venezuela for the past 27 years. But he was best known for his activities as an author and journalist.

''You have to use all a journalist's tricks in order to put together a book,'' Otero Silva said in a 1983 interview.

Otero Silva founded El Nacional, the daily newspaper.

His most critically acclaimed novel, Casas Muertas (Dead Houses), describes the effect of a turn-of-the-century malaria epidemic on a small town. His last novel, La Piedra Que Era Cristo (The Rock That Was Christ), was published in 1984.

Otero Silva's books were translated into several languages, including Czechoslovakian and Russian. In 1980, he received the Lenin Prize from the Soviet Academy of Sciences.

Otero Silva is survived by his wife, Mercedes Baumester de Otero, and by two children from a previous marriage.