Changes in Cardiac Variability after REM Sleep Deprivation in Recurrent Nightmares

Sleep Research Center, Hôpital du Sacré-Coeur de Montréal, Québec, Canada.
Sleep (Impact Factor: 4.59). 01/2010; 33(1):113-22.
Source: PubMed


To assess whether dysfunctional autonomic regulation during REM sleep as indexed by heart rate variability (HRV) is a pathophysiological factor in frequent nightmares (NMs).
Monitoring with polysomnography (PSG) and electrocardiography (ECG) for 3 consecutive nights: Night 1 (N1), adaptation night; N2, administration of partial REM sleep deprivation; N3, recovery night. Differences between NM and control (CTL) groups assessed for ECG measures drawn from wakefulness, REM sleep, and Stage 2 sleep on both N1 and N3.
Hospital-based sleep laboratory.
Sixteen subjects with frequent NMs (> or = 1 NM/week; mean age = 26.1 +/- 8.7 years) but no other medical or psychiatric disorders and 11 healthy comparison subjects ( < 1 NM/month; mean age = 27.1+/- 5.6 years).
NM and CTL groups differed on 2 REM sleep measures only on N1; the NM group had longer REM latencies and REM/NREM cycle durations than did the CTL group. No differences were found on time domain and absolute frequency domain ECG measures for either N1 or N3. However, altered HRV for the NM group was suggested by significantly higher LFnu, lower HFnu, and higher LF/HF ratio than for the CTL group.
Results are consistent with a higher than normal sympathetic drive among NM subjects which is unmasked by high REM sleep propensity. Results also support a growing literature linking anxiety disorders of several types (panic disorder, posttraumatic stress disorder (PTSD), generalized anxiety disorder) to altered HR variability.

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Available from: Elizaveta Solomonova
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    • "different pathways of action may be responsible for the observed effects . Another limitation is the use of one standard - ized dosage of ESC only . However , the ESC plasma levels meas - ured were within the range recommended for treatment of affective disorders . Furthermore , as disturbed sleep is also associated with auto - nomic alterations ( Nielsen et al . , 2010 ) , it is important to note that we did not determine sleep quality in our initial assess - ments and can herewith not exclude sleep quality – related bias , although we did not encounter complaints about altered sleep patterns . In order to rule out conditioning effects of repeated CCK - 4 administration ( Hinkelmann , Yassouridis , et"
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    ABSTRACT: BACKGROUND: Central serotonergic pathways influence brain areas involved in vagal cardiovascular regulation and thereby influence sympathetic efferent activity. Selective serotonin reuptake inhibitors (SSRIs) affect multiple serotonergic pathways including central autonomic pathways. However, only few studies assessed SSRI-mediated effects on autonomic reactivity in healthy individuals using heart rate variability (HRV). METHODS: The present study assessed the influence of long-term treatment with escitalopram (ESC) on autonomic reactivity to an intravenous application of 50 µg cholecystokinin tetrapeptide (CCK-4) in 30 healthy young men using a double-blind, placebo (PLA)-controlled, randomized, within-subject cross-over design. Main outcome measures were time and frequency domain HRV parameters assessed at both baseline and immediately after CCK-4 application. RESULTS: Results showed substantial effects for the treatment × CCK-4 challenge interaction with respect to HR (p < .001; pη2 = .499), SDNN (p < .001; pη2 = 576), RMSSD (p = .015; pη2 = 194), NN50(%) (p = .008; pη2 = .224), LF(%) (p = .014; pη2 = .196) and moderate effects with respect to HF(%) (p = .099; pη2 = .094), with PLA subjects showing a higher increase in HR and SDNN and a higher decrease in RMSSD, NN50(%), LF(%) and HF (%) than in the ESC condition. Thus, ESC treatment significantly blunted the autonomic reactivity to CCK-4 challenge compared to PLA. Secondary analysis indicated no effect of 5-HTTLPR polymorphism on CCK-4-induced autonomic response. Conclusions: Our results support findings suggesting an effect of SSRI treatment on autonomic regulation and provide evidence that ESC treatment is associated with blunted autonomic reactivity in healthy men.
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    • "Thus, the effects still need to be determined in women as gender differences cannot be ruled out. Furthermore, as disturbed sleep is also associated with autonomic alterations (Nielsen et al., 2010), it is important to note that we unfortunately did not include sleep quality in our initial assessments and can herewith not exclude sleep quality-related bias. Finally, our study did not assess data on cardiac recovery after the stress challenge, which is also a major indicator of cardiac reactivity (Salomon et al., 2009). "
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    ABSTRACT: Abnormal serotonin transporter (5-HTT) function and autonomic nervous system (ANS) dysregulation has been proposed in panic disorder. However, in contrast to hypothalamo-pituitary-adrenocortical (HPA) functioning, ANS reactivity during panic response has yet not been investigated in humans with respect to the 5-HTT genotype. The present study assessed the influence of challenging by cholecystokinin tetrapeptide (CCK-4) on heart rate variability (HRV) measures, to monitor autonomic reactivity and its relationship to 5-HTT-linked polymorphic region (5-HTTLPR) genotypes. We hypothesized substantial effects of the 5-HTTLPR genotype on autonomic reactivity. We studied 30 healthy young men, 15 of each with the long/long (l/l) or short/short (s/s) genotype for the 5-HTTLPR. All participants received an intravenous application of 50 μg CCK-4. HRV measures were assessed in both groups at baseline and immediately after CCK-4 application. Our results indicated lower parasympathetic activity in s/s carriers during baseline, time and frequency domain measures. CCK-4 application significantly enhanced the sympathetic tone in both groups, leading to diminished group differences. A significant treatment by genotype effect indicated reduced autonomic reactivity to CCK-4 challenge in the s/s compared to l/l carriers. Our findings show enhanced sympathetic and/or diminished cardiac vagal activity under basal conditions and blunted autonomic reactivity in s/s vs. l/l carriers. Our study provides novel data supporting claims that the s/s genotype represents a genetic vulnerability factor associated with inadequate hyporeactivity to stress and extends current knowledge on the impact of the central serotonergic activity on the sympathoadrenal pathway.
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    • "These important exclusion criteria contributed to the small sample size. Since disturbed sleep is also associated with autonomic alterations (Nielsen et al. 2010), it is important to emphasize that the higher HR of PTSD subjects during the night was probably not attributable to disturbed sleep, as there were no significant differences in sleep time and duration between the two groups, and the relevant group differences remained only modestly changed after adjustment for age, combat exposure, activity, and sleep. Our groups significantly differed with respect to the HDRS, while HDRS scores also correlated significantly with the LF/HF ratio and the a fast day coefficient, thus suggesting a potential confounding role of depressive symptoms in our results. "
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