When a vacancy in the office of trial judge exists by reason of death, permanent insanity as evidenced by adjudication, impeachment and conviction under Tenn. Const. art. V, or removal under Tenn. Const. art. VI, § 6, after verdict, but before the hearing of the motion for new trial, the trial judge's successor shall rule on the defendant's motion for new trial after the successor judge has reviewed the transcript and entire record of the trial.