The subject of corporate medical injustice is overdue for a good honest muckraker, but Nick Cassavetes’ movie doesn’t explore injustice — it exploits it. Informed that his company insurance plan won’t cover a heart transplant for his son, John Q. Archibald (Denzel Washington) is forced to come up with $250,000. Unable to pay, he takes everyone in the emergency room hostage. Cassavetes thinks he’s making Dog Day Afternoon with a cause, but the movie is a shrill, didactic cartoon. Anne Heche plays the head administrator as a particularly clipped breed of fascist android, and James Woods, as a heart surgeon, looks and sounds about as compassionate as a man ordering a lap dance.