Characteristics of electrocardiographic changes with representative agents. (A) Control, (B) 10 min after doxapram hydrochloride administration, (C) 10 min after adrenaline administration, (D) just before the ventricular tachycardia, and (E) continuous electrocardiogram are migrating to bidirectional ventricular tachycardia and premature ventricular contraction from normal sinus rhythm.