Incidence of intra-operative bradycardia. Comparison of atracurium and vecuronium in gynaecological surgery

Intra-operative bradycardia is one of the most common cardiac arrhythmias observed in clinical anaesthetic practice and can lead to a potentially dangerous outcome. In a randomised double-blind trial, 50 female patients undergoing elective abdominal hysterectomy were divided into two groups. Group I received atracurium and group II received vecuronium as a neuromuscular blocking agent in a balanced anaesthetic technique. The incidence of bradycardia was compared among the two groups. Bradycardia was defined as a heart rate of less than 60 beat.min^-1. A heart rate of less than 45 beat.min^-1 was labelled as severe bradycardia and symptomatic bradycardia was defined as bradycardia associated with hypotension. The two groups were similar in their demographic characteristics. The results showed that there was no statistically significant difference among the two groups regarding the incidence of simple bradycardia. However, the incidence of severe bradycardia or symptomatic bradycardia requiring treatment was significantly higher in the vecuronium group.