Assessment of QT interval and QT dispersion during electroconvulsive therapy using computerized measurements

Effect of Remifentanil on the Tpeak-Tend Interval During Electroconvulsive Therapy

INTRODUCTION

QT interval dispersion, which reflects the regional heterogeneity of ventricular repolarization, increases during electroconvulsive therapy (ECT). Tpeak-Tend (TpTe) is considered a new marker of the transmural dispersion of ventricular repolarization (TDR). This study aimed to evaluate the effect of remifentanil on TpTe during ECT.

METHODS

Forty-two patients who were scheduled to undergo ECT with American Society of Anesthesiologists physical status I or II randomly received 0.1 μg/kg remifentanil (group R: n = 21) or saline (group C: n = 21). After the induction of general anesthesia, we measured the TpTe, TpTe/QT, TpTe/QTc, TpTe/RR, TpTe/√RR and TpTe/3√RR every minute during ECT (QT: QT interval, QTc: corrected QT interval, RR: RR interval). Statistical analysis was performed using two-way analysis of variance (ANOVA).

RESULTS

Immediately (T0) and 1 min (T1) after electrical stimulation, the RRs (group C: T0; 654.2 ± 145.9 ms, T1; 657.3 ± 114.8 ms, group R: T0; 849.6 ± 249.3 ms, T1; 885.4 ± 213.6 ms, p < 0.05) were significantly increased, while systolic (group C: T0; 177.1 ± 35 mmHg, group R: T0; 129 ± 27.2 mmHg, p < 0.05) and diastolic blood pressures (group C: T0; 107.1 ± 22.4 mmHg, T1; 101.3 ± 23.2 mmHg, group R: T0; 75.4 ± 19.3 mmHg, T1; 80.6 ± 18.3 mmHg, p < 0.05) were significantly decreased in group R compared to group C. The TpTe/RR was significantly lower at T1 in group R compared to group C (group C: 101.5 ± 28.2, group R: 76.8 ± 21.8, p < 0.05). However, there was no significant difference in TpTe, TpTe/QT, TpTe/QTc, TpTe/√RR or TpTe/3√RR between the two groups throughout the study.

CONCLUSION

Pretreatment with remifentanil suppressed the increase of TpTe/RR after electrical stimulation. Our results imply that remifentanil may lead to a decrease in TDR during ECT.

TRIAL REGISTRATION

This trial was registered with the University Hospital Medical Information Network (registration number: UMIN000051958).

Challenges during Electroconvulsive Therapy—A Review

Electroconvulsive therapy (ECT) is one of the most successful treatment techniques employed in psychiatric practice. ECT is usually administered as a last resort to a patient who fails to respond to medical management or on an urgent basis as a life-saving procedure when immediate response is desired. It is performed under general anesthesia and is often associated with autonomic changes. All attempts should be made to minimize the resulting hemodynamic disturbances in all the patients using various pharmacological methods. Anesthesiologists providing anesthesia for ECT frequently encounter patients with diverse risk factors. Concurrent cardiovascular, neurological, respiratory, and endocrine disorders may require modification of anesthetic technique. It is ideal to optimize patients before ECT. In this review, the authors discuss the optimization, management, and modification of anesthesia care for patients with various cardiac, neurological, respiratory, and endocrine disorders presenting for ECT to improve the safety of the procedure. It is not infrequent that an anesthesiologist also plays an important role in inducing a seizure. Proconvulsants such as caffeine, adjuvants like opioids, hyperventilation, and appropriate choice of anesthetic agent for induction such as etomidate or ketamine can help. The use of BIS monitoring to guide the timing of electric stimulation is also elaborated in this review.

The impact of electroconvulsive therapy on the spatial QRS-T angle and cardiac troponin T concentration in psychiatric patients

Background

Electroconvulsive therapy (ECT) is an effective treatment method used in psychiatry; however, its cardiac safety has not been clearly demonstrated. The aim of the study was evaluation of the ECT effects on the myocardium based on troponin T concentrations and the following ECG parameters: the spatial QRS-T angle (QRS-TA), QRS duration (QRSd) and the corrected QT interval (QTc).

Methods

In the study 44 patients (12 female and 32 male) were enrolled diagnosed with schizophrenia (n = 21) and major depressive disorders (n = 23), according to the DSM-IVR criteria. All cases were undergoing ECT procedures. The mean age of the patients was 36.9±16 years (range: 18–74). Resting ECG was recorded before performing ECG and 1 hour after. The spatial QRS-TA was reconstructed from 12-lead ECG using the inverse Dower method. Troponin T concentration was assessed before the procedure and 6 hours after ECT.

Results

No significant changes to troponin T concentrations were observed during the ECT series. The pre-ECT value of the spatial QRS-TA was 41.1±18.9°. The follow-up examinations did not reveal any significant increase of this parameter (p = 0.09) in any of the consecutive measurements. There were no significant changes in the QTc interval duration or the QRS complex duration demonstrated before the third, fifth and last procedure in the cycle (p>0.05). No significant changes to troponin T concentrations were observed during the ECT series.

Conclusions

Our findings indicate a lack of negative ECT effects on the risk of adverse cardiovascular events measured by the spatial QRS-T angle and cardiac troponin T concentration.

Effect of spinal anesthesia on the QT interval in term and post-term pregnancies scheduled for elective cesarean section: a prospective study

Objectives: In this study, we aimed to investigate the effects of spinal anesthesia on the QT interval in patients with term and post-term pregnancy that were scheduled for elective cesarean section.Materials and methods: Forty pregnant women scheduled for elective cesarean section under spinal anesthesia were assigned into two groups: Post-term group (Group P) (n = 20) and Term group (Group T) (n = 20). After entering the operation room, standard monitoring [electrocardiography (ECG), noninvasive blood pressure, heart rate, respiratory rate, and peripheral oxygen saturation] was performed. The patient was placed in the sitting position and spinal anesthesia was performed with a median approach at the L3-L4a level using a 25G Quincke-type spinal needle. After cerebrospinal fluid was viewed, 12.5 mg (2.5 mL) hyperbaric bupivacaine was administered intrathecally over 1 min. Other ECG records were made at min 1 (T1), 5 (T2), and 10 (T3) after the induction of spinal anesthesia and after skin closure (T4). QT and QT dispersion were measured from ECG. Heart rate-corrected QT (QTc) and QT dispersion (QTcd) values were calculated using the Bazett formula.Results: Demographic characteristics of the patients were similar in both groups. Postoperative QTc, QTd, and QTcd values were significantly increased in Group P compared to those in Group T (p < .05).Conclusion: Spinal anesthesia led to increased postoperative QTc, QTd, and QTcd values in the patients with a gestational age of ≥42 weeks who underwent cesarean section. Accordingly, it is advisable to perform postoperative strict cardiac monitoring particularly in post-term pregnant women undergoing spinal anesthesia.

QT dispersion and rate-corrected QT dispersion during electroconvulsive therapy in elderly patients

BACKGROUND

Electroconvulsive therapy (ECT) induces increase of QT dispersion (QTD) and the rate-corrected QTD (QTcD), which are associated with increased risk of ventricular arrhythmias and cardiovascular mortality. The effects of electrical stimulus during ECT on QTD and QTcD in elderly patients are of considerable interest.

OBJECTIVE

The purpose of this study was to clarify the differential effects of electrical stimulus caused by ECT on interbeat interval, QT interval, the rate-corrected QT (QTc) interval, QTD, and the QTcD under propofol anesthesia between younger and elderly patients with major depression.

METHODS

Twenty younger psychiatric patients (aged 30-40 years) and 20 elderly patients (aged 65-75 years) scheduled for ECT were studied under propofol anesthesia. A 12-lead electrocardiogram was monitored to measure parameters. Muscle paralysis was achieved by administering 1-mg/kg succinylcholine intravenously, and the efficacy of ECT was determined by the tourniquet technique.

RESULTS

The mean arterial pressure in the elderly was significantly higher than that of the younger patients from immediately to 2 minutes after electrical stimulus. The interbeat interval in the elderly was significantly lower than that of the younger patients from immediately to 1 minute after electrical stimulus. There was no statistically significant difference in the QT interval between the groups. The baseline value of QTc interval was higher than the normal limits, and the QTc interval in the elderly was significantly lower than that of the younger patients from immediately to 1 minute after electrical stimulus. The baseline value of QTD was higher than the normal limits, and the QTD in the elderly was significantly higher than that of the younger patients from immediately to 7 minutes after electrical stimulus. The baseline value of QTcD was higher than the normal limits, and the QTcD in the elderly was significantly higher than that of the younger patients from immediately to 7 minutes after electrical stimulus.

CONCLUSIONS

The QTc interval, QTD, and QTcD may be higher than the normal limits before anesthesia in patients with major depression. The QTD and QTcD in the elderly, which are associated with increased risks of ventricular arrhythmias, are higher than those of the younger patients after electrical stimulus during ECT. Electrical stimulus may induce further increased risks of cardiac events in elderly patients.