Actress Elizabeth Taylor said she was going into a hospital for heart surgery and asked for prayers.

Taylor, 77, was diagnosed with congestive heart failure five years ago and also has endured severe back problems and a benign brain tumor operation. She made the announcement on her Twitter page, saying she wanted to break the news herself before the media found out.

"Dear Friends, I would like to let you know before it gets in the papers that I am going into the hospital to have a procedure on my heart," Taylor wrote.

"It's very new and involves repairing my leaky valve using a clip device, without open heart surgery, so that my heart will function better. Any prayers you happen to have lying around I would dearly appreciate. I'll let you know when it's all over. Love you, Elizabeth," she said.

She often uses a wheelchair in her rare public appearances but has enthusiastically embraced Twitter in recent months as a way of communicating directly with her fans and the media.

Taylor's Hollywood publicist said he had nothing to add to her Twitter announcement.