Maria Weis

Are affective disorders associated with alterations of heart rate variability

A standardized heart rate analysis was carried out in unmedicated patients with major depression, melancholic type (n = 16), panic disorder (n = 16), reactive depression with suicide attempts during the preceding 24 h (n = 16) and in 16 normal control subjects. The investigations included time- and frequency-derived measurements of heart rate variability. In the patients with reactive depression, no differences could be detected as compared with the control group. The patients with panic disorder showed a significantly increased low-frequency band of spectral analysis (P < 0.01) and a marginally significant increment of heart rate (P = 0.05), probably indicating predominance of sympathetic control of heart rate. In the patients with major depression, we found significantly lower values of hearts beat-to-beat intervals and of the high-frequency peak of spectral analysis than in the other groups (P < 0.025), indicating decreased parasympathetic activity.

Corticospinal conduction studied with magnetic double stimulation in the intact human

A group of 8 healthy normal subjects (24-36 years old, mean age 29 years) were investigated. Transcranial magnetic double stimulation of the motor cortex was carried out at different interstimulus intervals. With both stimuli suprathreshold, an attenuation of the test response was found at interstimulus intervals of less than 200 msec (target relaxed or contracted). The manifestation of this attenuation correlated with central signs in 31 patients with multiple sclerosis. This phenomenon is (at least at longer intervals) probably not a result of the refractory spinal motoneuron pool, but of a supraspinal inhibitory mechanism or lack of corticospinal drive caused otherwise. At interstimulus intervals between 10 and 30 msec, the test response increases significantly (magnetic double stimulation 10% suprathreshold, target relaxed). This result is also seen with voluntary muscle contraction and with vibration applied to a relaxed target muscle. The facilitatory effect is probably caused by slowly conducted corticospinal volleys enabling summation, with descending impulses generated by the test stimulus. With the conditioning stimulus subthreshold and target muscle relaxed an intracortical inhibition of the test response could be confirmed at short interstimulus intervals.

Heart rate variability in schizophrenic patients and changes of autonomic heart rate parameters during treatment with clozapine

We intented to determine the extent of autonomic cardiovascular side effects caused by clozapine. Furthermore, we investigated whether or not unmedicated paranoid schizophrenic patients show abnormalities in their heart rate analysis

Alterations of Autonomic Cardiac Control in Anorexia Nervosa

BACKGROUND The authors investigated autonomic cardiac function in anorexia nervosa. METHODS Forty-eight patients, who in the present or past met the DSM-III-R criteria for anorexia nervosa, and 16 normal control subjects participated in a standardized analysis of heart rate variability during supine and standing postures. RESULTS Several heart rate variability parameters showed an inverse correlation to the present weight of the anorexic subjects. The values of the spectral power analyses were significantly (p < .01) lower in patients (n = 18) weighing less than 75% of ideal weight when compared to the results found in the control group; however, the heart rate variability parameters of anorexic subjects with restored weight (n = 12) did not differ from those of the control subjects. CONCLUSIONS The obtained results provide evidence for autonomic cardiac dysfunction in acutely ill anorexic patients. Further research is required to elucidate possible clinical consequences of these findings.

Heart rate analysis in 24 patients treated with 150 mg amitriptyline per day.

Twenty-four patients treated with 150 mg amitriptyline per day for an episode of major depression underwent a standardized heart rate analysis (HRA) before therapy and after 14 days. The battery of cardiovascular reflex tests included the determination of the coefficient of variation (CV) while resting and during deep respiration, a spectral analysis of heart rate, the heart rate response to standing, and the Valsalva manoeuvre. The results of the initial HRA did not differ from a group of 24 normal control subjects matched for age and sex. On day 14 of treatment the patients showed significantly reduced values of heart rate variability in all tests (P<0.0001), probably due to the anticholinergic side effects of amitriptyline. Heart rate increased form 78.1 to 93.6 bpm on average (P<0.0001). Abnormal CV at rest was registered in 96% of the patients; during deep respiration 29% showed abnormal CV results. An abnormal spectral analysis was found in 100% of the cases (low frequency peak: 42%, mid-frequency peak: 100%, high frequency peak: 79%). The heart rate response to standing was abnormal in 75% and the Valsalva test in 33% of the cases. Eighty-eight percent of the patients fulfilled the criteria of a cardiovascular autonomic neuropathy under the conditions of amitriptyline therapy. As yet, the consequences of these changes for the patients have not been sufficiently elucidated.

Autonomic cardiac abnormalities in alcohol-dependent patients admitted to a psychiatric department

Standardized heart rate analyses were performed in 60 drug-free patients with alcohol dependence, who were admitted consecutively to a psychiatric department, and in 60 healthy normal matched subjects. The procedure included time and frequency derived measurements of heart rate variability (HRV). The investigations were carried out 3 weeks after admission and treatment on a closed ward to avoid autonomic hyperexcitability during withdrawal or relapse.The patients showed a significantly increased heart rate (p<0.05), a significant reduction in the coefficient of variation while resting (p<0.01) and a significant decrease of the high frequency power of spectral analysis (p<0.01) compared with the normal subjects. Cardiovascular autonomic dysfunction was found in 12 of the patients, but in only one of the normal subjects (p<0.01). The results indicated moderate parasympathetic (vagal) alteration in alcohol-dependent patients treated in a psychiatric department. This may have implications for psychotherapeutic or psychopharmacological treatment strategies and prognosis in such patients with alcohol dependence.

Influence of repetitive magnetic stimuli on verbal comprehension.

The influence of repetitive magnetic transcranial stimulation over the temporo-parietal cortex on verbal comprehension was investigated in 44 healthy subjects. In right-handed subjects, trains of 50 Hz magnetic stimuli over the left hemisphere produced more errors than stimulation over the right hemisphere. The result is not very clearcut, however; thus the test cannot be used for diagnostic investigation of language dominance.

Correlation between plasma clozapine concentration and heart rate variability in schizophrenic patients

Abstract Forty schizophrenic patients treated with 50–600 mg/day of clozapine as monotherapy and 40 normal control subjects were tested for heart rate variability (HRV) which is mediated by the vagus nerve using acetylcholine as neurotransmitter. As compared to the control subjects, the patients showed essentially reduced HRV parameters which were negatively correlated with the plasma clozapine levels. Therefore, clozapine’s anticholinergic effect is correlated to the plasma clozapine level when measured by the decrease of HRV. We suggest that HRV data might be useful as a predictor for plasma clozapine levels.

Is diurnal variation of mood associated with parasympathetic activity

18 patients with distinct improvement of mood in the evening and 18 patients without, both suffering from major depression and equally treated with tricyclic antidepressants (TCA), and an age- and sex-matched group of 18 normal control subjects underwent a standardized heart-rate (HR) analysis (HRA) in the morning (08:00) and 12 h later in the evening (20:00). The battery of cardiovascular reflex tests included the determination of HR variability (HRV) while resting and during deep breathing, and a spectral HRA. The depressed patients with diurnal variation of mood showed significantly decreased HR and significantly increased HRV parameters while resting and during deep respiration in the evening. On the contrary, patients without diurnal changes of mood just showed a significant HRV increase during deep respiration in the evening. No statistically significant changes of these parameters were detected in the healthy subjects. It is not known if the observed changes of HR parameters representing increment of parasympathetic tone are intrinsically related to the mood swings or if this rhythm just becomes visible under the circumstances of depression. Also, the impact of TCA treatment upon the results remains to be elucidated.

Decreased heart rate variability parameters in amitriptyline treated depressed patients: biological and clinical significance

One hundred-four depressed patients treated with amitriptyline (mean dosage: 163 mg/d; mean plasma level: 239 ng/ml) and 52 normal control subjects matched for age and sex underwent a standardized cardiovascular test battery (various autonomic cardiac parameters, which are largely independent from heart rate, namely the coefficients of variation (CV) while resting and during deep respiration, a spectral analysis of heart rate, the Valsalva ratio, and a posture index were determined). The tests included the determination of time and frequency-derived measurements of heart rate variability (HRV), which is rather independent from heart rate. As compared to the controls the patients showed a significant plasma concentration-dependent decrease of R-R variation in the electrocardiogram (p < 0.0001), while their heart rate was significantly elevated (p < 0.0001). The markedly reduced parameters of sinus arrhythmia in amitriptyline treated patients are suggested to be mainly due to the anticholinergic effect of this drug, although it can not be excluded that the affective disorder itself might be associated with low heart rate variability. The results indicate that autonomic heart rate parameters are a valuable tool for the detection of tricyclic antidepressant (TCA) intake in unconscious patients, especially in intensive care and emergency wards.