The Long Island heart doctor who was arrested last April for allegedly hiring two people to kill his former medical partner was slapped with a 77-count indictment on Monday, officials said.

At his arraignment, cardiologist Anthony Moschetto, 54, pleaded not guilty to the slew of charges, including arson, conspiracy, criminal possession of a weapon and criminal possession of a controlled substance.

After a falling-out with his business partner, Dr. Martin Handler, Moschetto allegedly hired two men to burn down the rival doc’s practice.

When that failed, he allegedly forked over blank prescription pads, guns and $500 to a confidential informant and an undercover cop, who he believed were goons, to murder Handler in May.

Moschetto is due back in court on Dec. 9.