Abstract: AIM: To evaluate effects of landiolol on heart rate variability (HRV) and QTc interval during tracheal intubation in patients with type Ⅱ diabetes.METHODS: Forty patients with type Ⅱ diabetes were randomly allocated either to landiolol group (group L) or to control group (group C). A bolus of 0.1 mg·kg^-1·min^-1 landiolol was administered to the group L for one minute at two minutes before tracheal intubation and followed by a continuous infusion at a rate of 0.04 mg·kg^-1·min^-1; group C received the same volume of saline. The changes in HRV and QT interval were recorded and compared between the two groups at following time points: preinduction (T₀),intubation(T₁)and 1min(T₂), 3 min(T₃), 5 min(T₄) after intubation.RESULTS: At T₁ to T₄, LF/HF were lower significantly in group L than those in group C. QT intervals were lengthened remarkably at T₁ to T₄ in the group C than those in the group L (P<0.05).CONCLUSION: Landiolol can inhibit effectively the sympathetic nervous system activity and improve the balance between the sympathetic and parasympathetic nervous system. Landiolol can also shorten the QT interval prolongation associated with tracheal intubation.

Key words: Landiolol, Diabetes mellitus, Endotracheal intubation, Heart rate variability, QT interval