The impact of midazolam used in cataract surgery sedation on frontal QRS-T angle

Midazolam is one of the most commonly used drugs in procedures requiring sedoanalgesia. It affects the myocardium's ventricular depolarization and repolarization. Previous studies examining the arrhythmogenic effects of midazolam yielded conclusive results. These studies are based on QT and Tp -e distances. The frontal QRS-T angle (f-[QRS-T]a) is a new electro cardiac parameter that shows the heterogeneity of ventricular electrical activity. This study aims to examine the effect of midazolam on f-(QRS- T)a and other depolarization-repolarization parameters in patients who have had cataract surgery.

The study included 177 patients administered midazolam as a sedoanalgesia during cataract surgery. The sedative effect was evaluated 2-3 minutes after a 0.05 mg/kg dose of midazolam was given. Sedation was assessed again by giving 0.5 mg every 2-3 minutes until the desired level of sedation was achieved. 12-lead electrocardiogram (ECG) recordings of all patients were taken just before and immediately after surgery. ECGs were used to calculate the QT interval, QTc interval, Tp -e interval, Tp -e/QT, Tp -e/ QTc ratios and f-(QRS-T)a.

After cataract surgery, f-(QRS-T)a was unchanged compared to presurgery (29.14 ± 4.52 vs. 29.18 ± 5.39, p = 0.852). In addition, no significant change in QT(351.32 ± 21.98 vs. 351.94 ± 22.44, p = 0.091), QTc (384.05 ± 24.52 vs. 385.19 ± 26.12, p = 0.819), Tp -e interval (93.12 ± 9.60 vs. 94.44 ± 8.82, p = 0.179) and Tp -e/QT (0.27 ± 0.02 vs. 0.28 ± 0.03, p = 0.664), Tp -e/ QTc ratios (0.28 ± 0.02 vs. 0.29 ± 0.03, p = 0.655) was observed after surgery when compared to presurgery values. Significant ventricular and supraventricular arrhythmias were not observed in any patient during the operation.

Midazolam did not affect f -(QRS-T) with classical repolarization parameters in patients who underwent cataract surgery, according to this study. Midazolam has been found to be safe for the heart in sedoanalgesia. These results show that sedation with midazolam can be performed without electrocardiogram monitoring.