Tennessee executed death row inmate Byron Black on Tuesday despite raised concerns about his implanted heart device, which could cause a "prolonged and torturous execution."

Tennessee is scheduled to execute death row inmate Byron Black on Tuesday morning despite concerns his heart implant will shock him repeatedly during the lethal injection. Black, 69, is one of the longest residents on the state's death row.

Byron Black is scheduled to be given a lethal injection after a legal battle about whether a working defibrillator in his chest would cause him pain.