Few thought Paul Schrader would ever match the success of his early scripts for "Taxi Driver" and "Raging Bull".

 But suddenly, in his seventies, the writer-director is back at the top of his game.

His fear now, as he appeared at the Venice Film Festival with his latest movie "Master Gardener".

 Starring Sigourney Weaver and Joel Edgerton, is whether he will ever be able to make another.

"I can't breathe," the 76-year-old bluntly told AFP at the festival, visibly struggling,

The mysterious illness -- doctors are unsure whether it is his lungs or his heart.

"When I got to hospital, it turned out I'd been directing for a week with influenza -- at night in Louisiana," he said. 

The film follows a gardener with an extremely dark past, trapped in a love triangle with powerful racial overtones.

"We don't think of Paul Schrader as writing big parts for women. But he's created, at this time in his life, two very red-blooded, sexual women," Weaver told AFP.