Does parasympathetic modulation prior to ECT treatment influence therapeutic outcome?

The Role of the Autonomic Nervous System in the Mediation of the Resolution of Suicidal Ideation With Electroconvulsive Therapy: A Hypothesis and Review of Heart Rate Variability Over a Course of Electroconvulsive Therapy

ABSTRACT

Longitudinal observational studies have shown a meaningful decrease in suicidal thinking and suicidal behavior after receipt of electroconvulsive therapy (ECT). The antisuicide effect of ECT may be related to success in the global relief of the presenting syndrome such as depressive or psychotic illness. However, it is possible that the antisuicide effect is specific to ECT per se, over and above the relief of the clinical syndrome. Electroconvulsive therapy is associated with many observable neurochemical and physiologic effects, and some of these may plausibly be specifically linked to an antisuicide effect. The phenomenon of physiologic hyperarousal has been named as a candidate mechanism driving the risk for suicide. Hyperarousal is associated with decreased neuropsychological executive function responsible for response inhibition and can lead to impulsive action. The level of arousal within the autonomic nervous system (ANS) can be assayed with the pupillary light reflex, electrodermal activity, or with heart rate variability (HRV). This article summarizes the literature on the effects of ECT on HRV 24 to 72 hours after a course of ECT and finds evidence for increases in HRV, which indicates lower levels of arousal in the ANS. This finding suggests that ECT-related reductions in ANS arousal, presumably with corresponding improvements in response inhibition, may be one mechanism whereby ECT reduces risk for suicide.

Intervention methods for improving reduced heart rate variability in patients with major depressive disorder: A systematic review and meta-analysis

INTRODUCTION

Several studies have demonstrated that patients with major depressive disorder (MDD) commonly show reductions in heart rate variability (HRV) parameters. Thus, interventions for the improvement of low HRV may be advantageous in treating MDD. This systematic review and meta-analysis aimed to explore the improvement effects of current clinical treatments on low HRV in patients with MDD.

METHODS

Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the PubMed, EMBASE, PsycINFO, and CNKI databases were searched for relevant literature. Interventional studies of patients with confirmed MDD, which included baseline and post-intervention data and at least one HRV parameter as an outcome indicator, were included for meta-analysis.

RESULTS

Twenty-one studies were included in the review. Several studies affirmed the role of psychotherapy in improving low HRV in patients with MDD showing a significant increase in high-frequency and low-frequency power after psychotherapy in the meta-analysis. However, both pharmacotherapy studies and physiotherapy studies included in the meta-analysis showed significant heterogeneity.

LIMITATIONS

The main limitation of this study was the relatively small samples for the meta-analysis, and more high-quality randomized controlled trials in this field are wanted.

CONCLUSIONS

Psychotherapy was effective for improving low HRV in patients with MDD. However, the effect of pharmacotherapy or physical therapy on low HRV in MDD remains unclear. Regarding research methods, it is necessary to formulate and standardize operational guidelines for future HRV measurements.

Higher Resting Cardiovagal Activity Predicts Larger Decrease of Depressive Symptoms in Inpatients Treated for Stress-Related Depression

Abstract. Depression is one of the most prevalent mental disorders, with treatment outcomes generally being unsatisfactory. The identification of outcome predictors could contribute to improving diagnosis, treatment, and outcome. Heart rate variability (HRV), an index of cardiovagal activity, has been proposed as a potential correlate of depression as well as a predictor of treatment effectiveness. The aim of the present study was to examine if HRV at baseline could predict the outcome of inpatient treatment for stress-related depressive disorder (SRDD). Depressive symptoms of n = 57 inpatients with an SRDD, who were treated in a specialized burnout ward, were assessed using the Beck Depression Inventory (BDI) at the beginning, the end of treatment, and at 3-month follow-up. HRV (i.e., RMSSD, the root mean square of successive RR interval differences) was determined from a five-minute measurement in the supine position. RMSSD was not significantly associated with the BDI score at the beginning, end, and follow-up. Higher RMSSD was revealed to be a significant predictor of a stronger decrease in depressive severity from the beginning to the end of the treatment. Thereby, the regression model explained 7.6% of the total variance in the BDI decrease. The results revealed initial HRV to predict a larger decrease in depressive severity. Therefore, resting HRV represents a physiological resource and index of successful neurovisceral interaction, which supports inpatients in benefitting from specialized treatment.

Predicting postictal suppression in electroconvulsive therapy using analysis of heart rate variability

BACKGROUND

Postictal suppression on an electroencephalogram (EEG) represents electrical silence during electroconvulsive therapy (ECT) and has been considered as a key feature associated with the efficacy of treatment. The present study aimed to predict postictal suppression using heart rate variability (HRV).

METHODS

Participants comprised 21 consecutive patients with depression who underwent bilateral pulse wave ECT. We analyzed the frequency domains of resting HRV before ECT. HRV indices such as the high-frequency component (HF) reflecting parasympathetic activity and the ratio of low-frequency component (LF)/HF reflecting sympathetic activity were natural log transformed for analysis. We evaluated ictal and peri-ictal EEG parameters and investigated their associations with HRV indices.

RESULTS

Postictal suppression and regularity were positively associated with ln[HF]. Postictal suppression remained significantly associated with ln[HF] after adjusting for age in multiple regression analysis of patients with depression.

LIMITATIONS

The present study could not examine the influence of diabetes mellitus, hypertension and polarity on HRV. In addition, the small sample size resulted in low statistical power.

CONCLUSIONS

These results suggested that ln[HF] before ECT could be utilized as a predictor of postictal suppression on EEG during ECT.

Changes in cardiac autonomic nervous system activity during a course of electroconvulsive therapy

AIM

Although electroencephalogram (EEG) seizure duration and seizure threshold change during a course of electroconvulsive therapy, the mechanisms by which these factors influence heart rate during subsequent electroconvulsive therapy sessions are currently unclear. In the current study, we investigated changes in heart rate during electroconvulsive therapy.

METHODS

We recorded electroencephalography and electrocardiography during electroconvulsive therapy in 12 patients with major depressive disorder. Baseline heart rate was defined as the mean heart rate in the 30 seconds prior to stimulus onset. The Time_Max peak refers to the maximum heart rate after stimulus onset. Time_1/2 points represent the time points at which the heart rate had decreased to a value midway between the baseline heart rate and the Time_Max peak. We examined the relationships between EEG seizure duration, Time_Max , and Time_1/2 throughout the course of electroconvulsive therapy.

RESULTS

Time_1/2 decreased as the number of electroconvulsive sessions increased. Time_1/2 was positively correlated with EEG seizure duration.

CONCLUSION

The duration in which electroconvulsive therapy-induced sympathetic nervous system activation returned halfway to baseline levels gradually shortened during the course of electroconvulsive therapy.

Clinical outcome of maintenance electroconvulsive therapy in comorbid Posttraumatic Stress Disorder and major depressive disorder

BACKGROUND

Post-traumatic stress disorder (PTSD) and major depressive disorder (MDD) are prevalent and frequently comorbid. Approximately 42-48% of patients with PTSD also meet diagnostic criteria for MDD. Maintenance electroconvulsive therapy (mECT) has been found to be efficacious for the prevention of recurrence of MDD. This study investigated the efficacy of mECT in the treatment of MDD with and without comorbid syndromal PTSD.

METHODS

This retrospective study includes 36 patients, 26 with MDD and 10 with comorbid MDD & PTSD receiving monthly mECT for a mean of 1.5 years. The mean age was 52 ± 14 years and 25% were female. The change in PTSD and MDD symptoms in response to mECT was assessed using Clinical Global Impression - Severity Scale (CGI-S). Heart rate variability (HRV), 12-month hospitalization rate, suicide rate and all-cause mortality in response to mECT were assessed and compared between groups using repeated generalized linear regression (GLM) analysis.

RESULTS

At mECT baseline, there were no statistically significant differences in CGI-S scores, HRV between patients with MDD alone and those with comorbid MDD and PTSD (P > 0.05). After 12-months of mECT, a significant increase in HRV (mean difference: 10.9 95%CI 4.8-20.3, p = 0.001) and decrease in CGI-S overall (mean difference: 3.5, 95% CI 3.3-3.6, p = 0.001)], PTSD (mean difference: 3.4, 95% CI 3.2-3.6, p = 0.001)], and MDD (mean difference: 3.8, 95% CI 3.5-3.9, p = 0.001)] symptoms in both groups were noted (p < 0.05). No psychiatric hospitalization or suicide occurred in any of the patients.

CONCLUSIONS

Maintenance ECT is associated with improved HRV, reduction of both major depression and PTSD symptoms, and a favorable clinical outcome.

Effect of Atropine Premedication on Cardiac Autonomic Function During Electroconvulsive Therapy: A Randomized Crossover Study

OBJECTIVES

Electroconvulsive therapy (ECT) results in significant cardiovascular changes. The acute cardiac autonomic changes during ECT remain unexplored. The primary objective of this study was to compare autonomic dysfunction with and without atropine premedication during ECT and secondarily to evaluate dysautonomia across psychiatric diagnoses before and after ECT.

METHODS

In this crossover study, 41 psychiatric patients were monitored during 82 ECT sessions. Patients were randomized either to receive atropine or not to receive atropine during their second ECT session and were crossed over during their third session. Heart rate, blood pressure, and oxygen saturation were continuously monitored from stimulus application until 300 seconds after ECT. Demographic characteristics and ANSiscope indices derived pre- and post-ECT were collected.

RESULTS

Autonomic dysfunction (%) before ECT was similar between atropine and no-atropine sessions (32.4 ± 15.7 vs 32.8 ± 16.7; 95% confidence interval, -7.6 to 6.7; P = 0.90) but increased significantly after ECT to 60.9 ± 16.3 and to 47.0 ± 17.3, respectively, and this difference was significant (95% confidence interval, 6.5-21.3; P < 0.001). There was no difference in the autonomic function across psychiatric diagnoses both before (P = 0.07) and after ECT (P = 0.12).

CONCLUSIONS

Cardiac autonomic dysfunction worsens after ECT in patients with psychiatric illnesses and to a significantly greater extent with atropine premedication. The degree of dysautonomia is similar across various psychiatric diagnoses both before and after ECT. Atropine premedication during ECT should be restricted to select patients susceptible to bradyarrhythmia and could be avoided in others.

The use of ECT and MST in treating depression

Electroconvulsive therapy (ECT) has been used clinically since 1938. Its most common use is in the treatment of depression: first line treatment where rapid recovery is a priority, but more frequently as an effective treatment for patients who do not respond to pharmacological and psychological approaches. Whilst it is widely hailed as an effective treatment, concerns about its effect on cognition remain. The development of magnetic seizure therapy (MST) over the past decade has attempted to devise a therapy with comparable efficacy to ECT, but without the associated cognitive side effects. The rationale for this is that MST uses magnetic fields to induce seizures in the cortex, without electrical stimulation of brain structures involved with memory. MST has been used successfully in the treatment of depression, yet there is a dearth of literature in comparison with ECT. We present a systematic review of the literature on ECT (from 2009-2011) and MST (from 2001-2011).

Autonomic modulation in healthy first-degree relatives of patients with major depressive disorder

BACKGROUND

Cardiac mortality is known to be increased in patients with major depression. Several studies have reported an imbalance within the autonomic nervous system (ANS) of patients with major depressive disorder (MDD) as one putative cause. Since a heritability of autonomic modulation was demonstrated in healthy subjects, we aimed to investigate autonomic modulation in first-degree relatives of patients with MDD to find potential autonomic imbalances.

METHODS

We included 30 patients with MDD, 30 of their first-degree relatives (siblings or offspring) and 30 matched healthy controls in our study. We obtained a high resolution electrocardiogram and beat to beat blood pressure measurements for 30 min at rest. Linear and nonlinear parameters of heart rate variability (HRV) and baroreflex sensitivity (BRS) were calculated.

RESULTS

Parameters of HRV and BRS did not differ significantly between relatives and controls. We found significant differences between patients and controls for some HRV and BRS parameters confirming results of previous studies.

DISCUSSION

Findings of our study suggest that an imbalance of autonomic function is related to patients with depression and not to first-degree relatives. Thus, a genetic background for autonomic dysfunction is rather unlikely.

Gender-dependent impact of major depression on autonomic cardiovascular modulation

Depression has been shown to increase the risk for cardiovascular disease (CVD) more strongly in women than in men. Although the underlying mechanisms are unknown, a putative role of increased sympathetic modulation has been suggested for the association of CVD and depression. The aim of this study was to investigate possible gender-associated differences of autonomic function in healthy volunteers and patients suffering from major depressive disorder (MDD). Linear as well as non-linear measures of heart rate variability (HRV), blood pressure variability (BPV) and baroreflex sensitivity (BRS) were obtained in each 18 male and 18 female unmedicated patients and respective control subjects. Gender differences were detectable in healthy subjects showing predominant sympathetic modulation in males. This was most obvious in BPV analysis. These gender differences were abolished in patients suffering from MDD, mainly due to altered autonomic modulation in female patients. Our results indicate that BPV is more sensitive to reveal depression-associated changes of autonomic function as compared to HRV. Moreover, female patients contribute most to the overall difference between patients and controls. The shift in the balance of autonomic function in women might account for the increased prevalence of CVD in these patients.