The impact of fever on myocardial repolarization parameters

The Effect of Low-Flow and Normal-Flow Desflurane Anesthesia on the Frontal QRS-T Angle in Patients Undergoing Rhinoplasty Operation: A Randomized Prospective Study

Introduction: Low-flow anesthesia (LFA) has gained more interest worldwide owing to its economic and ecological advantages compared to normal-flow anesthesia (NFA). Desflurane is one of the commonly used anesthetic agents for LFA, but it may prolong myocardial repolarization. Frontal QRS-T angle (f[QRS-T]a) is a novel marker of myocardial repolarization. To our knowledge, no study has compared the effect of LFA and NFA on f(QRS-T)a. In this study, we aimed to compare the effect of the LFA and NFA with desflurane on f(QRS-T)a in patients undergoing rhinoplasty operation.

Methods: A total of 80 patients undergoing rhinoplasty operations were included in this prospective study. The patients were randomized into two groups as follows: LFA (n = 40) and NFA (n = 40). The frontal QRS-T angle was calculated from the automatic report of the electrocardiography device (Nihon Kohden, Tokyo, Japan). It was recorded at the following time points: T1: preoperative (basal), T2: immediately after anesthesia induction, T3: immediately after endotracheal intubation, T4: 5 min after endotracheal intubation, T5: 15 min after endotracheal intubation, T6: 30 min after endotracheal intubation, T7: 60 min after endotracheal intubation, T8: end of the operation, T9: 15 min after the end of the operation.

Results: Baseline clinical characteristics and laboratory parameters were similar between the two groups. In the LFA group, f(QRS-T)a was significantly increased at only the T3 time point when compared to T1 (P = 0.003). However, in the NFA group, f(QRS-T)a was significantly increased at T3, T4, T5, T6, T7, T8, and T9 time points when compared to the T1 value (P < 0.05, for all). On the other hand, fQRS-Ta was significantly higher in the NFA group than in the LFA group at T4, T5, and T6 time points. 

Conclusion: In our study, we have shown for the first time that NFA significantly increased the f(QRS-T)a, whereas LFA did not significantly increase the f(QRS-T)a except for immediately after the endotracheal intubation. It was also detected that f(QRS-T)a was significantly higher in the NFA group compared to that in the LFA group. Therefore, it can be concluded that LFA has more protective effects on myocardial repolarization than NFA.

Examination of ECG characteristics of patients admitted to emergency department with conversive attack

OBJECTIVE

Conversion disorder is defined as a disorder with one or more neurological symptoms that accompany psychological conflict, suggesting a physical disorder. It has been shown that patients with conversion disorder have an imbalance in the autonomic nervous system. There are only a limited number of studies that have examined how conversion disorder is related with surface ECG parameters. The present study aimed to investigate the effects of conversion disorder on the surface ECG parameters of patients with conversion disorder admitted to the emergency department.

METHODS

This cross-sectional case-control study included 98 patients who were admitted to the emergency department and diagnosed with conversion disorder and 56 healthy volunteers. All patients underwent 12-derivation ECG. PR interval, P wave dispersion, duration of QRS complex, QT interval, QTc interval, frontal QRS-T angle values were calculated for all individuals.

RESULTS

When compared with the control group, the conversion disorder group revealed a significant difference in terms of PWD [60 (40-80) vs. 40 (40-60) P = 0.01], QT [385 (364-410) vs. 378 (354-394), P = 0.048], QTc [420 (405-430) vs. 406 (397-429), P = 0.039], and frontal QRS-T angle [25 (15-33) vs. 20 (8-35), P = 0.018]. In the multivariate linear regression analysis, conversion disorder was found to be an independent predictor for both PWD (β = 0.196, P = 0.014) and frontal QRS-T angle (β = 0.258, P = 0.011).

CONCLUSION

This study is the first to show that conversion disorder significantly increases QT, QTc, P wave dispersion, and frontal QRS-T angle.