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Biomedical subjects

R Balon

Publications and source records attributed to R Balon.

At least 163 records · Page 9Linked to original sources

The beta-receptor: isoproterenol anxiety states.

To learn the effect of isoproterenol on patients meeting Research Diagnostic Criteria (RDC) for panic disorder, we administered isoproterenol, racemic sodium lactate, and glucose to them and to nonpsychiatric control subjects. Each subject received all 3 infusions, double-blind in random order. A 21-item self-rating panic scale was constructed from the RDC for panic disorder and was used to identify RDC panic attacks. The results of this study and the preliminary results from the infusions after treatment with imipramine are discussed in the text, and the results from the first patient to be reinfused after treatment are presented graphically.

Adolescent↗

[Comparison between the effectiveness of fluphenazine decanoate and oxyprothepin decanoate in schizophrenia (double-blind crossover study)].

The efficacy of the long-acting neuroleptic oxyprothepin decanoate (HD), a new Czechoslovak drug, was evaluated in comparison with that of fluphenazine decanoate (FD). Within a year two groups consisting, respectively, of 19 and 17 patients were treated. The patients of the first group received FD for 6 months and then HD for the next 6 months. The patients of the second group received the same drugs, but in the reverse order (cross-testing). The degree of the psychic disturbances was assessed according to a special scale (Brief Psychiatric Rating Scale) with subsequent determination of the statistical significance of the differences revealed. As regards the efficacy HD appeared to be close to FD. No statistically significant differences between them were noted. The seeming superiority of HD over FD disappeared on introducing the correction for the order of their administration (the drug administered first produced a more marked therapeutic effect). Side effects due to both drugs were minor, however HD caused them in a far lesser number of patients than FD.

Adult↗

Relationship between age and heart rate variability in supine and standing postures: a study of spectral analysis of heart rate.

We compared heart rate variability measures of 11 normal children (4-12 years) to 23 normal adults (21-43 years) to study the effect of age on heart rate variability measures. Children had a significantly higher supine and standing heart rate and lower supine and standing systolic and diastolic blood pressure. Children also had a significantly higher supine standard deviation of HR, supine low frequency (0.01-0.05 Hz) (p < 0.005), supine high frequency (0.2-0.5 Hz) (p < 0.001), and standing high frequency powers (p < 0.005) compared to adults. The ratio of mid frequency (0.07-0.15 Hz) to high frequency power (0.2-0.5 Hz) upon standing was significantly lower in children (p < 0.005). While there was a significant increase of the mid frequency power from supine to standing posture in the adult group (p < 0.02), there was no such significant increase in children. There were also significant negative correlations between age and supine low frequency, mid frequency, and high frequency powers, and standing high frequency power. These findings illustrate a decrease of cholinergic and an increase of adrenergic modulation of heart rate variability with age (4-43 years).

Adrenergic Fibers↗

Effect of age on diurnal changes of 24-hour QT interval variability.

QT interval on the surface electrocardiogram (ECG) reflects the time for repolarization of myocardium and prolongation of QTc is strongly associated with sudden cardiac death. Studies using novel techniques on beat-to-beat QT interval variability (QTV) have shown that it is influenced by the autonomic nervous system and is a predictor of sudden cardiac death. In this study, we examined the awake and sleep changes in QTV in 39 normal adults (mean age, 35 years) and 10 children (mean age, 11 years) using 24-hour ECG records. We obtained eight 5-minute segments of ECG sampled at 1000 Hz from the 24-hour records. Our results show that there is a diurnal variation of QTvm, detrended QT interval variance corrected for mean QT, and QTvi, an index of QTvm divided by heart rate variability corrected for mean heart rate. There was a significant increase in mean QT during sleep, whereas there was a significant decrease in QTvm and QTvi. QTvi significantly increased during the early morning hours. There were significant but modest correlations between the average 24-hour and awake QTvi and age (p < 0.01). There were also decreased low-frequency and high-frequency powers of QT during sleep. Coherence between heart rate and QT interval fluctuations in the range of 0-0.5 Hz, and especially in the high-frequency range (0.15-0.5 Hz), was significantly lower in adults than in children (p < 0.0002). These findings demonstrate diurnal fluctuations in ventricular repolarization lability. We speculate that these effects may relate to changes in cardiac autonomic function and may contribute to the well-known diurnal variation in the incidence of ventricular arrhythmias.

Adolescent↗

Effect of age on QT variability.

Heart rate variability is influenced significantly by age. Recent studies have shown the utility of QT variability to study temporal repolarization lability, and increased QT variability is reportedly associated with sudden death. Because beat-to-beat QT interval variability appears to closely follow heart rate variability, this study investigated the relationship between age and QT variability. We obtained QT variability measures in 34 adults (22-55 years of age) and 15 children (6-14 years of age) using a novel algorithm to compute beat-to-beat QT intervals. QT variability corrected for mean QT interval was significantly inversely correlated with age. Coherence in the band of 0 to 0.5 Hz and high-frequency coherence (0.15-0.5 Hz) were also significantly inversely correlated with age. QTvi (QT variability corrected for mean QT interval over heart rate variability corrected for mean heart rate) was not significantly related to age in supine posture during spontaneous or controlled breathing, whereas there was a modest negative relationship in standing posture. These findings suggest that coherence between QT and heart rate time series appears to be modulated by cardiac vagal activity.

Adolescent↗