The effects of intravenous anesthetics on QT interval during anesthetic induction with sevoflurane

The effect of anesthesia depth on radiofrequency catheter ablation of ventricular tachycardia: a retrospective study

Background

Radiofrequency catheter ablation (RFCA) as a safe and effective method has been widely used in ventricular tachycardia (VT) patients, and with which anesthesiologists frequently manage their perioperative care. The aim of this study was to investigate the effects of different anesthetic depths on perioperative RFCA and recurrence in patients who with intractable VT and could not tolerate an awake procedure.

Methods

We reviewed electronic medical records of patients with VT who underwent RFCA by general anesthesia from January 2014 to March 2019. According to intraoperative VT induction, they were divided into two groups: non-inducible group (group N) and inducible group (group I). We constructed several multivariable regression models, in which covariates included patient characteristics, comorbidities, protopathy and bispectral index (BIS) value.

Results

One hundred one patients were analyzed. Twenty-nine patients (28.7%) experienced VT no induction, and 26 patients (25.7%) relapsed within 1 year. Compared with group I, the proportion of patients with arrhythmogenic right ventricular cardiomyopathy in group N were higher (P < 0.05), and the recurrence rate of VT was significantly higher (51.7% vs 15.3%) (P < 0.05). The BIS value in group N was significantly lower (P < 0.01), in addition, the BIS < 40 was associated with elevated odds of VT no induction compared with a BIS > 50 (odds ratio, 6.92; 95% confidence interval, 1.47–32.56; P = 0.01). VT no induction was an independent predictor of recurrence after RFCA (odds ratio, 5.01; 95% confidence interval, 1.88–13.83; P < 0.01).

Conclusion

Lower BIS value during VT induction in RFCA operation was associated with high risk of VT no induction, which affects postoperative outcomes. We proposed that appropriate depth of anesthesia should be maintained during the process of VT induction.

Propofol abolishes torsade de pointes in different models of acquired long QT syndrome

There is conflicting evidence regarding the impact of propofol on cardiac repolarization and the risk of torsade de pointes (TdP). The purpose of this study was to elucidate the risk of propofol-induced TdP and to investigate the impact of propofol in drug-induced long QT syndrome. 35 rabbit hearts were perfused employing a Langendorff-setup. 10 hearts were perfused with increasing concentrations of propofol (50, 75, 100 µM). Propofol abbreviated action potential duration (APD₉₀) in a concentration-dependent manner without altering spatial dispersion of repolarization (SDR). Consequently, no proarrhythmic effects of propofol were observed. In 12 further hearts, erythromycin was employed to induce prolongation of cardiac repolarization. Erythromycin led to an amplification of SDR and triggered 36 episodes of TdP. Additional infusion of propofol abbreviated repolarization and reduced SDR. No episodes of TdP were observed with propofol. Similarly, ondansetron prolonged cardiac repolarization in another 13 hearts. SDR was increased and 36 episodes of TdP occurred. With additional propofol infusion, repolarization was abbreviated, SDR reduced and triggered activity abolished. In this experimental whole-heart study, propofol abbreviated repolarization without triggering TdP. On the contrary, propofol reversed prolongation of repolarization caused by erythromycin or ondansetron, reduced SDR and thereby eliminated drug-induced TdP.

Comparison of General Anesthesia (Sevoflurane) and Spinal Anesthesia (Levobupivacaine) Methods on QT Dispersion in Inguinal Hernia Operations

Introduction Arrhythmias are one of the most frequently seen issues during surgical operations. In this study, we investigated and compared the effects on the QT dispersion of patients when using a method of volatile inhalation mask anesthesia with sevoflurane (VIMA: Group I) and when spinal anesthesia was performed with levobupivacaine (Group II). Methods The study included 40 patients who had American Society of Anesthesiology scores of I-II (ASA I-II), were aged from 18 to 65 years, and were scheduled for inguinal hernia operations. Approval of the university ethics committee was obtained before the study began. All patients had measurements taken for non-invasive blood pressure, including systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP), heart rate (HR), and oxygen saturation (SO2) values. The QT intervals were measured using the 12-derivation electrocardiogram (ECG) device (Cardiofax V). Our study was performed with randomization using the closed envelope method. Results When the percentage differences of the HR values from the initial period in both groups were compared, we observed significant differences between the groups, with increases in the VIMA group at the second period as well as increases in the VIMA group at the fourth, fifth, sixth, seventh, and ninth periods but decreases in the spinal anesthesia group for these periods. There were statistically significant differences between the two groups at the third and fifth periods when the percentage differences of the QTc values from the initial period were compared. We observed increases in the spinal anesthesia group. Conclusion In our study, we suggest that the tendency toward arrhythmia may be reduced by choosing general anesthesia with sevoflurane rather than levobupivacaine in patients with cardiac complaints who are undergoing regional anesthesia and/or taking medication that affects QT intervals.

The effects of intravenous anesthetics on QT interval during anesthetic induction with desflurane

Introduction

This study aimed to determine the effects of the interaction between intravenous anesthetics and desflurane on the QT interval.

Methods

Fifty patients who underwent lumbar spine surgery were included. The patients received 3 μg/kg fentanyl and were randomly divided into two groups: group P patients received 1.5 mg/kg propofol and group T patients received 5 mg/kg thiamylal 2 min after fentanyl injection. All patients received rocuronium and desflurane (6% inhaled concentration) after loss of consciousness. Tracheal intubation was performed 3 min after rocuronium injection. Heart rate (HR), mean arterial pressure (MAP), bispectral index score (BIS), and the heart rate-corrected QT (QTc) interval on a 12-lead electrocardiograms were recorded before fentanyl injection (T1), 2 min after fentanyl injection (T2), 1 min after propofol or thiamylal injection (T3), immediately before intubation (T4), and 2 min after intubation (T5).

Results

There were no significant intergroup differences in patient characteristics. BIS and MAP decreased after anesthesia induction in both groups. MAP values at T3, T4, and T5 in group T were higher than those in group P. HR did not change over time or differ between the groups. The QTc intervals at T4 and T5 in group T were longer than those at T1. In group P, the QTc interval at T3 was significantly shorter than that at T1. The QTc intervals at T3, T4, and T5 in group T were significantly longer than those in group P.

Conclusions

A propofol injection could counteract the QTc interval prolongation during desflurane anesthesia induction.

Trial registration

UMIN Clinical Trials Registry database reference number: UMIN000023707. This study was registered on August 21, 2016.

Anesthetic Management In Electrophysiology Laboratory: A Multidisciplinary Review

Many clinical challenges have been encountered in electrophysiology laboratories (EP) while implanting intracardiac defibrillators for lethal arrhythmias, using pacemakers for bradyarrhythmias, placing pacemakers with multiple leads in patients with heart failure and cardiac ablation procedures. In this environment, anesthesiology plays a very critical role to ensure patients comfort, as well as maintains operator's convenience and facilitate management of undesired situations. EP laboratories are mostly used for diagnosis of certain heart diseases. Meanwhile, with the exponential increase in interventional procedures in our decade, electrophysiologists' need to cooperate with the anesthesiologists more frequently. The literature is still unclear about the effects of anesthetic agents on cardiac conduction pathways, but as we know with our previous data, the most agents we are using currently have more or less effect on the cardiac conduction systems. In this review, we aimed to describe the safe anesthesia methods in cardiac diagnostic procedures and have a closer look up the anesthetic outcomes of these procedures. This article comprehensively reviews the anesthesia practice encountered in electrophysiology laboratories.