consequences. It was reported that sudden bradycardia was often caused by an abrupt activation of vagal reflex, and it could be treated by atropine administration. [ 10 ] Atropine was proposed to treat bradycardia by blocking cardiac parasympathetic nerve. [ 11 , 12 ] In our case, we observed a sudden drop in HR from 60 bpm to 39 bpm and injected atropine 0.5 mg instantly. Unfortunately, HR increased significantly and premature ventricular contraction occurred in the monitor, ultimately developing ventricular tachycardia (HR: 160 bpm). Previous reports presented 3 cases of tachyarrhythmias induced by atropine, [ 13 – 15 ] and the results were shown in Table 1 . However, none of these case reports occurred during laparoscopic surgery. Although there were numerous reports on tachyarrhythmias after the administration of atropine, the precise mechanism remains ambiguous. Table 1. Previous cases of ventricular arrhythmia induced by atropine in the treatment of bradycardia. First author HR before atropine treatment Type of arrhythmia The dosage of atropine Operation procedure Lunde [ 13 ] Between 30 and 35 bpm Ventricular fibrillation 0.5 mg - Cooper [ 14 ] Between 45 and 55 bpm Ventricular fibrillation 0.5 mg - Lee [ 15 ] Between 42 and 45 bpm Ventricular tachycardia 0.5 mg A varicosectomy Open in a new tab bpm = beats per minute, HR = heart rate. Several studies demonstrated that he imbalance of autonomic nervous system was responsible for ventricular tachyarrhythmias after atropine therapy. [ 16 , 17 ] In recent decades, heart rate variability analysis was widely used to evaluate the sympathovagal balance. [ 18 ] In a previous case report we presented, heart rate variability analysis showed that there was an increase in sympathetic activity and a decrease in parasympathetic activity after atropine was injected. [ 19 ] Another case report indicated that atropine-related ventricular tachycardia might be attributed to a decrease in parasympathetic activity and then elite