Effect of Atracurium versus Cisatracurium on QT interval changes in patients undergoing cataract surgery: a randomized clinical trial.

Background: Muscle relaxants are used during surgery, but their impact on ECG may differ, potentially affecting cardiac safety. This study aimed to compare the effects of Atracurium versus Cisatracurium on QT interval changes in patients undergoing cataract surgery.

Method: This double-blind, parallel-group randomized clinical trial (RCT) was conducted in 2023 in Hamadan, Iran. A total of 80 patients undergoing cataract surgery under general anesthesia were randomly assigned to receive either Atracurium (n = 40) or Cisatracurium (n = 40). QT interval changes were measured at four time points to assess and compare the corrected QT interval (QTc) between the two groups. Data were analyzed using SPSS version 29, and a p-value < 0.05 was deemed significant.

Results: Cisatracurium demonstrated significant reductions in QTc from pre-anesthesia to post-anesthesia and through recovery, with values of -9.325 ms (P = 0.045), -9.925 ms (P = 0.038), and - 19.359 ms (P = 0.016), respectively. Atracurium also showed reductions but a notable increase in QTc after anesthesia to the end of surgery (32.322 ms, P = 0.0019). Throughout the procedure, Cisatracurium maintained shorter QTc intervals compared to Atracurium (e.g., T0: 420.07 ms vs. 434.75 ms, P = 0.03), but post-recovery, no significant differences were observed (Cisatracurium: 440.05 ms; Atracurium: 439.80 ms, P = 0.489).

Conclusions: Atracurium causes more QT prolongation than Cisatracurium. While both affect QTc intervals, Cisatracurium has a more stable impact on cardiac repolarization, making it safer for patients at risk of QT prolongation. Cisatracurium's minimal impact on cardiovascular function, especially in patients with low ejection fraction, makes it the preferred choice for maintaining cardiac stability.

Trial registration: IRCT20120215009014N441.