Search PubMed⌕ Search

Biomedical subjects

Richard Balon

Publications and source records attributed to Richard Balon.

36 records · Page 2Linked to original sources
PubMed2003

Effect of fluoxetine, pemoline and placebo on heart period and QT variability in normal humans.

OBJECTIVE: To measure the effects of fluoxetine and pemoline on heart period and QT variability. METHODS: Healthy volunteers were randomly assigned treatment with 20 mg daily of fluoxetine (n=7), 56.25 mg of pemoline (n=7) or placebo (n=9). Twenty-four-hour Holter ECGs were obtained before and after approximately 8 weeks of double-blind treatment. RESULTS: There were no significant changes in the fluoxetine group. Pemoline was associated with a significant decrease in the high frequency (HF) power (0.15-0.5 Hz, P=.02) and fractal dimension of RR time series (P=.03). QTvi, a measure of QT interval variability, increased in the pemoline group (P=.05). CONCLUSION: Pemoline, but not fluoxetine, decreases heart period variability (HPV) in the HF power, suggesting a vagolytic effect on cardiac autonomic function. Pemoline is also associated with an increase in QT interval variability, a measure that is sensitive to adrenergic agonists.

Adult↗
PubMed2003

Approximate entropy of symptoms of mood: an effective technique to quantify regularity of mood.

OBJECTIVES: Several psychiatric conditions are associated with lability of affect. In this study, we investigated regularity of mood using APEN (Approximate Entropy) on daily subjective ratings using a Visual Analog Scale with 11 items pertaining to mood. METHODS: APEN was applied to the data in a double-blind placebo controlled investigation on the effects of fluoxetine (n=19), pemoline (n=18) and placebo (n=20) in normal controls. These subjects rated their subjective feelings daily at the end of each day. We analysed 56 data point time series (each value was obtained on each day) after the three experimental conditions. RESULTS: While the mean or the SD of all the 56 points was not significantly different among the three conditions, APEN was highly and significantly lower for pemoline compared with fluoxetine and placebo. There was no significant correlation between average APEN and mean or SD (standard deviation). The one symptom that explained most of this difference among the groups after drug administration was the feeling of 'happiness'. CONCLUSIONS: This result indicates that there was a more consistent subjective sense of happiness during the 8-week period of pemoline administration compared with the other two drugs. Though this study was not designed to address the efficacy of mood stabilizing drugs, such daily subjective ratings may be useful in future studies that evaluate the stability of mood. APEN has been used in several different fields of research with small data sets and this study extends its possible use to evaluate changes in mood in certain populations such as patients with bipolar disorders.

Adult↗
PubMed2002

Diminished chaos of heart rate time series in patients with major depression.

BACKGROUND: Depression and anxiety have been linked to serious cardiovascular events in patients with preexisting cardiac illness. A decrease in cardiac vagal function as suggested by a decrease in heart rate (HR) variability has been linked to sudden death. METHODS: We compared LLE and nonlinearity scores of the unfiltered (UF) and filtered time series (very low, low, and high frequency; VLF, LF and HF) of HR between patients with depression (n = 14) and healthy control subjects (n = 18). RESULTS: We found significantly lower LLE of the unfiltered series in either posture, and HF series in patients with major depression in supine posture (p <.002). LLE (LF/UF), which may indicate relative sympathetic activity was also significantly higher in supine and standing postures in patients (p <.05); LF/HF (LLE) was also higher in patients (p <.05) in either posture. CONCLUSIONS: These findings suggest that major depression is associated with decreased cardiac vagal function and a relative increase in sympathetic function, which may be related to the higher risk of cardiovascular mortality in this group and illustrates the usefulness of nonlinear measures of chaos such as LLE in addition to the commonly used spectral measures.

Adult↗
PubMed2002

Heart rate time series: decreased chaos after intravenous lactate and increased non-linearity after isoproterenol in normal subjects.

In this study, we reanalyzed our previous heart rate time series data on the effects of intravenous sodium lactate (n=9) and intravenous isoproterenol (n=11) using non-linear techniques. Our prior findings of significantly higher baseline non-linear scores (NL: S(netGS)) and significantly lower largest Lyapunov exponents in supine posture in patients with panic disorder compared to control subjects prompted this study. We obtained the largest Lyapunov exponent (LLE), and a measure of non-linearity (NL: S(netGS)) of heart rate time series. LLE quantifies predictability and NL quantifies the deviation from linear processes. There was a significant increase in NL score, (S(netGS)) after isoproterenol infusions and a significant decrease in LLE (an increase in predictability indicating decreased chaos), after intravenous lactate in supine posture in normal control subjects. Increased NL scores in supine posture after intravenous isoproterenol may be due to a relative increase in cardiac sympathetic activity or a decrease in vagal activity at least in certain circumstances, and an overall decrease in LLE may indicate an impaired cardiac autonomic flexibility after intravenous sodium lactate, as LLE is diminished by autonomic blockade by atropine. Band analysis of LLE (LF/HF) (LF: 0.04-0.15 Hz and HF: 0.15-0.5 Hz) showed an increase of these ratios during either condition with a higher sympathovagal interaction after the drug administration. These findings may throw new light on the association of anxiety and significant cardiovascular events.

Adrenergic beta-Agonists↗
PubMed2002

Sleep in posttraumatic stress disorder.

Posttraumatic stress disorder (PTSD) is often associated with sleep disturbances. In this review, we focus on the published literature on subjective and objective findings of sleep in patients with PTSD. Insomnia and nightmares are most commonly reported subjective sleep disturbances. Polysomnographic investigations have frequently reported rapid eye movement (REM) sleep abnormalities in PTSD. However, studies have not been consistent about the type of REM sleep dysfunction in PTSD patients. Antidepressants such as nefazodone, trazodone, fluvoxamine, and imagery rehearsal therapy are found to be beneficial in the treatment of PTSD associated sleep disturbances as well as core symptoms of this anxiety disorder. We propose use of such modalities of treatment in PTSD patients with predominant sleep disturbances. Further studies are required to clarify polysomnographic sleep changes especially role of REM sleep dysregulation and treatment of sleep disturbances in PTSD.

Antidepressive Agents↗
PubMed2002

Twenty-four-hour QT interval variability: increased QT variability during sleep in patients with panic disorder.

Recent studies on beat-to-beat QT interval variability (QTV) have shown that it can be used as a noninvasive measure of cardiac repolarization lability. It is also a predictor of sudden cardiac death and is higher in patients with anxiety and depression. This study examined the diurnal measures in QTV in 32 normal adults and 22 patients using 24-hour electrocardiogram records. We obtained 8 5-min segments of ECG sampled at 1,000 Hz from the 24-hour records. Our results show that QTV measures at nighttime are significantly higher in patients with panic disorder compared with controls. These findings demonstrate blunted diurnal changes in ventricular repolarization lability in patients resulting in a higher QT variability index during sleep. We speculate that these effects may relate to a relative increase in cardiac sympathetic activity in patients with panic disorder, and may contribute to the increased risk for cardiac mortality in patients with anxiety.

Adult↗
PubMedDate not supplied

Alternate methods of teaching psychopharmacology.

OBJECTIVE: This article reviews methods used to teach psychopharmacology to psychiatry residents that utilize principles of adult learning, enlist active participation of residents, and provide faculty with skills to seek, analyze, and use new information over the course of their careers. METHODS: The pros and cons of five "nonlecture" methods of teaching are reviewed: 1) journal clubs, 2) problem-based learning, 3) formalized patient-centered training, 4) games, and 5) the use of modern technology. RESULTS: Several programs are beginning to find novel methods of teaching psychopharmacology that are effective and well received by trainees and faculty. CONCLUSION: Programs need to go beyond the traditional lecture and apprenticeship model of psychopharmacology education to help make learning more fun, useful, relevant and self-sustaining.

Curriculum↗
PubMedDate not supplied

Medical school research pipeline: medical student research experience in psychiatry.

OBJECTIVE: The authors discuss the importance of introducing research training in psychiatry and neurosciences to medical students. METHODS: A review of existing models of research training in psychiatry with focus on those providing research training to medical students is presented. RESULTS: Two research-training models for medical students that are easy to adopt and have possible nationwide applicability are identified, along with other useful research-training models. CONCLUSION: Specific recommendations on how to foster research training in psychiatry and neurosciences for medical students throughout the U.S. are presented.

Humans↗
PubMedDate not supplied

Comparison of burnout among medical residents before and after the implementation of work hours limits.

OBJECTIVE: The authors assess whether implementation of work hour limits is associated with a lower prevalence of medical resident burnout. METHOD: A survey was mailed to medical residents in different medical specialties at one university. RESULTS: Somewhat lower burnout prevalence was reported among residents after implementation of work hour limits compared with the rates prior to the implementation period. The decrease in burnout prevalence occurred primarily among PGY-1 residents. Prevalence of burnout increased with hours worked. CONCLUSIONS: Implementing work hour limits appeared to reduce burnout prevalence.

Burnout, Professional↗