Transient Fever Response After ECT in a Patient with Catatonic Schizophrenia: A Case Report. / Katatonik Sizofreni Hastasinda EKT Sonrasi Ortaya Çikan Geçici Ates Yaniti: Olgu Sunumu.

Electroconvulsive therapy (ECT) is an effective and safe treatment method for many psychiatric disorders. In general medical practice, ECT may cause side effects as most other treatment methods do. Headache, myalgia, nausea, vomiting, confusion, anterograde amnesia are common side effects of electroconvulsive therapy. Fever; in addition to general medical conditions such as infection, malignancy, connective tissue diseases, drug treatments, malignant hyperthermia, convulsions, it can also occur due to conditions such as neuroleptic malignant syndrome (NMS), serotonin syndrome, catatonia, malignant catatonia, which are frequently encountered in psychiatry clinics. In the literature, transient fever response due to electroconvulsive therapy application have been described, albeit rarely. Although there are many proposed mechanisms for the emergence of a fever response, regardless of its cause, it is still not understood why some fever responses occur. In this article, we present the differential diagnosis of the fever response, possible causes, and the mechanisms that may reveal the secondary fever response to electroconvulsive therapy in a case with a diagnosis of catatonic schizophrenia, who developed a fever response during electroconvulsive therapy sessions and no fever response was observed at times other than electroconvulsive therapy sessions. In this case, postictal benign fever response associated with electroconvulsive therapy was considered after excluding other medical conditions that may cause a fever response after electroconvulsive therapy. Keywords: ECT, Fever, Catatonia, NMS.

Magnetic Seizure Therapy vs Modified Electroconvulsive Therapy in Patients With Bipolar Mania: A Randomized Clinical Trial.

Importance: Bipolar mania is a common disabling illness. Electroconvulsive therapy (ECT) is an effective treatment for patients with severe mania, though it is limited by the risk of cognitive adverse effects. Magnetic seizure therapy (MST) as an alternative treatment to ECT for bipolar mania has not yet been reported. Objective: To compare the effectiveness and cognitive adverse effects of MST and ECT in bipolar mania. Design, Setting, and Participants: This randomized clinical trial was conducted at the Shanghai Mental Health Center from July 1, 2017, through April 26, 2021. Forty-eight patients with bipolar mania were recruited and randomly allocated to receive MST or ECT. The data analysis was performed from June 5, 2021, through August 30, 2023. Interventions: Patients completed 2 or 3 sessions of MST or ECT per week for a total of 8 to 10 sessions. The MST was delivered at 100% device output with a frequency of 75 Hz over the vertex. Main Outcomes and Measures: The primary outcomes were reduction of total Young Manic Rating Scale (YMRS) score and response rate (more than 50% reduction of the total YMRS score compared with baseline). An intention-to-treat (ITT) analysis and repeated-measures analyses of variance were conducted for the primary outcomes. Results: Twenty patients in the ECT group (mean [SD] age, 31.6 [8.6] years; 12 male [60.0%]) and 22 patients in the MST group (mean [SD] age, 34.8 [9.8] years; 15 male [68.2%]) were included in the ITT analysis. The response rates were 95.0% (95% CI, 85.4%-100%) in the ECT group and 86.4% (95% CI, 72.1%-100%) in the MST group. The YMRS reduction rate (z = -0.82; 95% CI, -0.05 to 0.10; P = .41) and response rate (χ2 = 0.18; 95% CI, -0.13 to 0.31; P = .67) were not significantly different between the groups. The time-by-group interaction was significant for the language domain (F1,24 = 7.17; P = .01), which was well preserved in patients receiving MST but worsened in patients receiving ECT. No serious adverse effects were reported in either group. Conclusions and Relevance: These findings suggest that MST is associated with a high response rate and fewer cognitive impairments in bipolar mania and that it might be an alternative therapy for the treatment of bipolar mania. Trial Registration: ClinicalTrials.gov Identifier: NCT03160664.

Exploring Brain and Heart Interactions during Electroconvulsive Therapy with Point-of-Care Ultrasound.

BACKGROUND: Electroconvulsive therapy (ECT) is a procedure commonly used to treat a number of severe psychiatric disorders, including pharmacologic refractory depression, mania, and catatonia by purposefully inducing a generalized seizure that results in significant hemodynamic changes as a result of an initial transient parasympathetic response that is followed by a marked sympathetic response from a surge in catecholamine release. While the physiologic response of ECT on classic hemodynamic parameters such as heart rate and blood pressure has been described in the literature, real-time visualization of cardiac function using point-of-care ultrasound (POCUS) during ECT has never been reported. This study utilizes POCUS to examine cardiac function in two patients with different ages and cardiovascular risk profiles undergoing ECT. METHODS: Two patients, a 74-year-old male with significant cardiovascular risks and a 23-year-old female with no significant cardiovascular risks presenting for ECT treatment, were included in this study. A portable ultrasound device was used to obtain apical four-chamber images of the heart before ECT stimulation, after seizure induction, and 2 min after seizure resolution to assess qualitative cardiac function. Two physicians with expertise in echocardiography reviewed the studies. Hemodynamic parameters, ECT settings, and seizure duration were recorded. RESULTS: Cardiac standstill was observed in both patients during ECT stimulation. The 74-year-old patient with a significant cardiovascular risk profile exhibited a transient decline in cardiac function during ECT, while the 23-year-old patient showed no substantial worsening of cardiac function. These findings suggest that age and pre-existing cardiovascular conditions may influence the cardiac response to ECT. Other potential contributing factors to the cardiac effects of ECT include the parasympathetic and sympathetic responses, medication regimen, and seizure duration with ECT. This study also demonstrates the feasibility of using portable POCUS for real-time cardiac monitoring during ECT. CONCLUSION: This study reports for the first time cardiac standstill during ECT stimulation visualized using POCUS imaging. In addition, it reports on the potential differential impact of ECT on cardiac function based on patient-specific factors such as age and cardiovascular risks that may have implications for ECT and perioperative anesthetic management and optimization.

Development, validation and clinical utility of short-term adverse-effects of electroconvulsive therapy (SAVE) checklist.

Electroconvulsive therapy (ECT) is one of the most effective treatments in psychiatry. However, it has many cognitive and non-cognitive adverse effects (AEs). There are lacunae in the literature on systematic assessment of non-cognitive AEs. There is a need for a standard, comprehensive and specific clinical tool to evaluate this. Hence, a checklist of short-term AEs of ECT (SAVE) with a 2-phase assessment was developed. Content validation was done using 15 experts' ratings and predefined content validity ratio and index (CVR and CVI) in a two-stage modified Delphi method. The checklist had a good CVR and CVI with a final tool of 39 items. The tool was sensitive and identified the non-cognitive AEs after ECT. Cardiovascular and musculoskeletal systems displayed the highest incidence. Many participants exhibited delayed recovery in orientation, gait, and stance, highlighting a necessity for meticulous monitoring. SAVE is the first standardised tool to assess short-term ECT-related AEs systematically. This checklist likely identifies clinically significant incidences of adverse effects. Its regular use may enhance the safety of ECT and patient comfort by supporting early identification and intervention for AEs. However, given the transient nature of AEs, further studies are needed to determine their predictive validity for long-term consequences.

A woman with schizophrenia who died due to Takotsubo cardiomyopathy occurring after electroconvulsive therapy.

BACKGROUND: Electroconvulsive therapy (ECT) is a safe treatment for treatment-resistant schizophrenia. However, it has some side effects, and Takotsubo cardiomyopathy is considered one of the minor complications. Several cases of patients developing Takotsubo cardiomyopathy during a course of ECT have been reported, but none have died. We present a case of post-ECT Takotsubo cardiomyopathy that became fatal. CASE PRESENTATION: We experienced a case of a 67-year-old woman who had delusions and catatonic symptoms due to schizophrenia but was resistant to several medications. Her symptoms improved by conducting ECT, but she had difficulty maintaining her improvement, which caused her to receive multiple courses of ECT. 3 weeks after her 6th course of ECT, the patient was diagnosed with Takotsubo cardiomyopathy and had a fatal outcome. CONCLUSION: Our patient had numerous cases of aspiration pneumonia and malnutrition before ECT was performed, which might have made this case fatal. In conclusion, appropriate supplementation of nutrition and reduction of physical stressors are important to avoid death from Takotsubo cardiomyopathy caused by ECT. Prescribing clozapine was a solution in the present case, but there are some difficulties, such as the restriction against prescribing this drug in Japan.

The effect of transcranial direct current stimulation (tDCS) on cognitive function recovery in patients with depression following electroconvulsive therapy (ECT): protocol for a randomized controlled trial.

BACKGROUND: Electroconvulsive therapy (ECT) is a highly effective treatment for depressive disorder. However, the use of ECT is limited by its cognitive side effects (CSEs), and no specific intervention has been developed to address this problem. As transcranial direct current stimulation (tDCS) is a safe and useful tool for improving cognitive function, the main objective of this study was to explore the ability to use tDCS after ECT to ameliorate the cognitive side effects. METHODS: 60 eligible participants will be recruited within two days after completing ECT course and randomly assigned to receive either active or sham stimulation in a blinded, parallel-design trial and continue their usual pharmacotherapy. The tDCS protocol consists of 30-min sessions at 2 mA, 5 times per week for 2 consecutive weeks, applied through 15-cm2 electrodes. An anode will be placed over the left dorsolateral prefrontal cortex (DLPFC), and a cathode will be placed over the right supraorbital cortex. Cognitive function and depressive symptoms will be assessed before the first stimulation (T0), after the final stimulation (T1), 2 weeks after the final stimulation (T2), and 4 weeks after the final stimulation (T3) using the Cambridge Neuropsychological Test Automated Battery (CANTAB). DISCUSSION: We describe a novel clinical trial to explore whether the administration of tDCS after completing ECT course can accelerates recovery from the CSEs. We hypothesized that the active group would recover faster from the CSEs and be superior to the sham group. If our hypothesis is supported, the use of tDCS could benefit eligible patients who are reluctant to receive ECT and reduce the risk of self-inflicted or suicide due to delays in treatment. TRIAL REGISTRATION DETAILS: The trial protocol is registered with https://www.chictr.org.cn/ under protocol registration number ChiCTR2300071147 (date of registration: 05.06.2023). Recruitment will start in November 2023.

Unmasking patient diversity: Exploring cognitive and antidepressive effects of electroconvulsive therapy.

BACKGROUND: Electroconvulsive therapy (ECT) is an established treatment for depression, but more data on effectiveness and safety in clinical practice is needed. The aim of this register-based study was to investigate short-term effectiveness and cognitive safety after ECT, evaluated by clinicians and patients. Secondary, we investigated predictors for remission and cognitive decline. METHODS: The study included 392 patients from the Regional Register for Neurostimulation Treatment in Western Norway. Depressive symptoms and cognitive function were assessed with Montgomery-Åsberg Depression Rating Scale and Mini-Mental State Examination (clinician-rated) and Beck Depression Inventory and Everyday Memory Questionnaire (patient-rated). Assessments were done prior to ECT-series and a mean of 1.7 days after (range 6 days before and 12 days after) end of ECT-series. Paired samples t-tests were extended by detailed, clinically relevant subgroups. Predictors were examined using logistic regression. RESULTS: Clinician- and patient-rated remission rates were 49.5 and 41.0%, respectively. There was a large reduction in depressive symptoms and a small improvement in cognition after ECT, but we also identified subgroups with non-response of ECT in combination with cognitive decline (4.6% clinician-rated, 15.7% patient-rated). Positive predictors for patient- and clinician-rated remission were increasing age, shorter duration of depressive episode, and psychotic features. Antipsychotic medication at the commencement of treatment and previous ECT-treatment gave higher odds of clinician-rated remission, whereas higher pretreatment subjective depression level was associated with lower odds for patient-rated remission. Clinician-rated cognitive decline was predicted by higher pretreatment MMSE scores, whereas psychotic features, increasing age, and greater pretreatment subjective memory concerns were associated with lower odds for patient-rated cognitive decline. CONCLUSIONS: Our study supports ECT as an effective and safe treatment, although subgroups have a less favorable outcome. ECT should be considered at an early stage for older patients suffering from depression with psychotic features. Providing comprehensive and balanced information from clinicians and patients perspectives on effects and side effects, may assist in a joint consent process.

Pre-treatment predictors of cognitive side-effects after treatment with electroconvulsive therapy in patients with depression: A multicenter study.

BACKGROUND: Electroconvulsive therapy (ECT) is a highly effective treatment for major depressive episodes (MDE). However, ECT-induced cognitive side-effects remain a concern. Identification of pre-treatment predictors that contribute to these side-effects remain unclear. We examined cognitive performance and individual cognitive profiles over time (up to six months) following ECT and investigated possible pre-treatment clinical and demographic predictors of cognitive decline shortly after ECT. METHODS: 634 patients with MDE from five sites were included with recruitment periods between 2001 and 2020. Linear mixed models were used to examine how cognitive performance, assessed with an extensive neuropsychological test battery, evolved over time following ECT. Next, possible pre-treatment predictors of cognitive side-effects directly after ECT were examined using linear regression. RESULTS: Directly after ECT, only verbal fluency (animal and letter; p < 0.0001; Cohen's d: -0.25 and -0.29 respectively) and verbal recall (p < 0.0001; Cohen's d: -0.26) significantly declined. However, during three and six months of follow-up, cognitive performance across all domains significantly improved, even outperforming baseline levels. No other pre-treatment factor than a younger age predicted a larger deterioration in cognitive performance shortly after ECT. LIMITATIONS: There was a substantial amount of missing data especially at 6 months follow-up. CONCLUSIONS: Our findings show that verbal fluency and memory retention are temporarily affected immediately after ECT. Younger patients may be more susceptible to experiencing these acute cognitive side-effects, which seems to be mostly due to a more intact cognitive functioning prior to ECT. These findings could contribute to decision-making regarding treatment selection, psychoeducation, and guidance during an ECT course.

Comparative efficacy and tolerability of different anesthetics in electroconvulsive therapy for major depressive disorder: A systematic review and network meta-analysis.

Electroconvulsive therapy (ECT) is one of the most effective treatments for major depressive disorder. Modern ECT is conducted with anesthesia, however, the optimal anesthetic agent for ECT is yet to be understood. This study is aimed to compare the effects of different anesthetic agents on antidepressant efficacy and tolerability in depressed individuals undergoing ECT. We searched MEDLINE, EMBASE, the CENTRAL and PsycINFO for randomized controlled trials from database inception until Nov 13, 2022 (PROSPERO: CRD42022375407). Global and local inconsistencies, heterogeneity and publication bias were assessed. Rankings were calculated with the surface under the cumulative ranking curve. A total of 33 studies involving 1898 patients were enrolled. Remission rates were higher for ketamine anesthesia as compared to adjunctive ketamine and propofol. In terms of ranking, ketamine was found to be first in terms of response/remission rates and depressive scores after the 1st, 3rd and 6th ECT and at the end of ECT session, while a higher incidence of adverse events was also observed. No significant advantage of any anesthetic was revealed for the cognitive function after ECT. In summary, based on current evidence, no specific anesthetic is recommended for ECT anesthesia. However, despite more side effects, ketamine monoanesthesia seems to reveal a potential benefit in improving antidepressant efficacy of ECT, and further studies are needed to investigate the relationship between anesthetic agents and the therapeutic effect of ECT.

Association between pulse width and health-related quality of life after electroconvulsive therapy in patients with unipolar or bipolar depression: an observational register-based study.

AIMS: To examine the association between pulse width and HRQoL measured within one week after electroconvulsive therapy (ECT) and at six-month follow-up in patients with unipolar or bipolar depression. METHODS: This was an observational register study using data from the Swedish National Quality Registry for ECT (2011-2019). Inclusion criteria were: age ≥18 years; index treatment for unipolar/bipolar depression; unilateral electrode placement; information on pulse width; EQ-5D measurements before and after ECT. Multiple linear regressions were performed to investigate the association between pulse width (<0.5 ms; 0.5 ms; >0.5 ms) and HRQoL (EQ-5D-3L index; EQ VAS) one week after ECT (primary outcome) and six months after ECT (secondary outcome). RESULTS: The sample included 5,046 patients with unipolar (82%) or bipolar (18%) depression. At first ECT session, 741 patients (14.7%) had pulse width <0.5 ms, 3,639 (72.1%) had 0.5 ms, and 666 (13.2%) had >0.5 ms. There were no statistically significant associations between pulse width and HRQoL one week after ECT. In the subsample of patients with an EQ-5D index recorded six months after ECT (n = 730), patients receiving 0.5 ms had significantly lower HRQoL (-0.089) compared to <0.5 ms, after adjusting for demographic and clinical characteristics (p = .011). The corresponding analysis for EQ VAS did not show any statistically significant associations. CONCLUSION: No robust associations were observed between pulse width and HRQoL after ECT. On average, significant improvements in HRQoL were observed one week and six months after ECT for patients with unipolar or bipolar disease, independent of the pulse width received.

Safety of electroconvulsive therapy (ECT) in pregnancy: a systematic review of case reports and case series.

Pregnancy and the immediate postpartum period are considered at high risk for women who have already received a previous psychiatric diagnosis and might represent a stressful event favoring the onset of new psychiatric disorders. The electroconvulsive therapy (ECT) is effective for the treatment of severe, treatment-resistant mental disorders, and it could represent a therapeutic choice for psychiatric conditions during pregnancy. The purpose of this systematic review is to evaluate the safety of ECT during pregnancy and to update the state of the art of its use. An extensive literature search on PubMed, APA PsycInfo, and Scopus databases for relevant articles published from inception to September 2023 has been performed. A final number of 45 articles (34 case reports and 11 case series, for a total of 130 pregnant women) were included in the present review. The limited evidence confirmed that ECT is effective in determining a partial remission of symptoms in women suffering from severe mental disorders, especially in the presence of suicidal ideation or psychosis, during all pregnancy epochs. However, ECT is not free from side effects, although the majority of possible complications were of low- or moderate-grade and not life-threatening for the women. Exposure to pharmacological treatment before or during the ECT or to the anesthetic during ECT might have contributed to the onset of these complications. ECT techniques evolved over years, increasing the degree of its safety, and according to our review it appears to be relatively safe and effective during pregnancy in the majority of cases.

Changes in postictal cerebral perfusion are related to the duration of electroconvulsive therapy-induced seizures.

OBJECTIVE: Postictal symptoms may result from cerebral hypoperfusion, which is possibly a consequence of seizure-induced vasoconstriction. Longer seizures have previously been shown to cause more severe postictal hypoperfusion in rats and epilepsy patients. We studied cerebral perfusion after generalized seizures elicited by electroconvulsive therapy (ECT) and its relation to seizure duration. METHODS: Patients with a major depressive episode who underwent ECT were included. During treatment, 21-channel continuous electroencephalogram (EEG) was recorded. Arterial spin labeling magnetic resonance imaging scans were acquired before the ECT course (baseline) and approximately 1 h after an ECT-induced seizure (postictal) to quantify global and regional gray matter cerebral blood flow (CBF). Seizure duration was assessed from the period of epileptiform discharges on the EEG. Healthy controls were scanned twice to assess test-retest variability. We performed hypothesis-driven Bayesian analyses to study the relation between global and regional perfusion changes and seizure duration. RESULTS: Twenty-four patients and 27 healthy controls were included. Changes in postictal global and regional CBF were correlated with seizure duration. In patients with longer seizure durations, global decrease in CBF reached values up to 28 mL/100 g/min. Regional reductions in CBF were most prominent in the inferior frontal gyrus, cingulate gyrus, and insula (up to 35 mL/100 g/min). In patients with shorter seizures, global and regional perfusion increased (up to 20 mL/100 g/min). These perfusion changes were larger than changes observed in healthy controls, with a maximum median global CBF increase of 12 mL/100 g/min and a maximum median global CBF decrease of 20 mL/100 g/min. SIGNIFICANCE: Seizure duration is a key factor determining postictal perfusion changes. In future studies, seizure duration needs to be considered as a confounding factor due to its opposite effect on postictal perfusion.

A Novel Approach to Monitoring Cognitive Adverse Events for Interventional Studies Involving Advanced Dementia Patients: Insights From the Electroconvulsive Therapy for Agitation in Dementia Study.

OBJECTIVE: To develop an individualized method for detecting cognitive adverse events (CAEs) in the context of an ongoing trial of electroconvulsive therapy for refractory agitation and aggression for advanced dementia (ECT-AD study). METHODS: Literature search aimed at identifying (a) cognitive measures appropriate for patients with advanced dementia, (b) functional scales to use as a proxy for cognitive status in patients with floor effects on baseline cognitive testing, and (c) statistical approaches for defining a CAE, to develop CAEs monitoring plan specifically for the ECT-AD study. RESULTS: Using the Severe Impairment Battery-8 (SIB-8), baseline floor effects are defined as a score of ≤5/16. For patients without floor effects, a decline of ≥6 points is considered a CAE. For patients with floor effects, a decline of ≥30 points from baseline on the Barthel Index is considered a CAE. These values were derived using the standard deviation index (SDI) approach to measuring reliable change. CONCLUSIONS: The proposed plan accounts for practical and statistical challenges in detecting CAEs in patients with advanced dementia. While this protocol was developed in the context of the ECT-AD study, the general approach can potentially be applied to other interventional neuropsychiatric studies that carry the risk of CAEs in patients with advanced dementia.

A Retrospective Matched Comparison Study of Prolonged Seizures in ECT.

OBJECTIVE: This study assessed the incidence of and risk factors for prolonged seizures (>180 sec) in electroconvulsive therapy (ECT). METHOD: In 611 adult patients undergoing 6697 ECT treatments administered over a 2.5-year study period, 29 individuals experienced 42 prolonged seizures. A comparison sample (n = 29) was matched on sex, age, and treatment, and compared on psychiatric and medical diagnoses, as well as current medications. To examine the association between the characteristics and prolonged seizure, conditional logistic regression models or exact McNemar tests were conducted. RESULTS: Prolonged seizures occurred on average in 1 of every 167 treatments. No specific psychiatric disorders or medical conditions were associated with the prolonged seizure group. Antipsychotic drugs were used in a higher proportion of the comparison group than in the prolonged seizure group, suggesting a protective effect. Atropine was used in a lower proportion of the long seizure group than in the comparison group. No untoward sequelae occurred, and no progression to status epilepticus was observed. CONCLUSIONS: Prolonged seizures appear to be an uncommon complication of ECT in adults. The characteristics examined in this study suggest limited association of psychotropic medications with prolonged seizures. Treatment of prolonged seizures was straightforward. Prolonged seizures had no impact on the course of treatment. Further exploration of prolonged seizures would enhance the generalizability of the findings from this single site study.

Electroconvulsive Therapy in Heart Transplant Patients: To Avoid or Embrace?

ABSTRACT: Patients with heart disease are at an increased risk of depression. Electroconvulsive therapy (ECT) is a highly effective treatment for severe depressive episodes. However, ECT may increase the risk for adverse outcomes in certain patients because of changes in blood pressure and heart rate secondary to an initial parasympathetic surge followed by a sympathetic surge and peripheral catecholamine release. In post-cardiac transplant patients, these acute hemodynamic changes on a denervated heart may bring clinical challenges. The available data on ECT in heart transplant patients are limited. The authors of this article present a summary of the available literature relating to ECT in heart transplant patients.The authors performed a literature search of 6 online databases yielding 6 English-language case reports of ECT in cardiac transplant patients. All patients experienced changes in hemodynamic variables during and immediately after ECT, ranging from moderate decrease in blood pressure to extreme hypertension. The cases did not report any serious cardiac complications during the course of ECT. In the 5 patients whose psychiatric responses to treatment were detailed, all had improvement in their depressive symptoms. Electroconvulsive therapy may be considered for severe cases of depression in patients with a history of cardiac transplant, but the potential benefit of ECT needs to be weighed against risks. In the limited number of cases reported in the literature, ECT seems to have been relatively safe and effective.

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).