Rhythm In Children Research Articles

Torsades de Pointes Ventricular Tachycardia in a Pediatric Patient Treated with Fluconazole

Fluconazole is an antifungal medication that has been reported to cause prolongation of the QT interval and Torsades de Pointes (TdP) ventricular tachycardia in adults. We describe the case of an 11-year-old child treated with fluconazole who developed ventricular arrhythmia culminating in TdP. We discuss the possible roles played by genetic and environmental factors in this child's rhythm disturbances. After briefly summarizing similar cases from the adult literature, we outline the putative mechanism by which fluconazole may cause arrhythmia. This case should alert pediatricians to the possible risks of fluconazole use, especially in the presence of electrolyte abnormalities, diuretic use, therapy with other pro-arrhythmic agents, or suspicion of congenital Long-QT Syndrome.

Early Detection of Regional Myocardial Dysfunction in Paced Children With Congenital Complete Atrioventricular Block

Right ventricular apical pacing leads to global left ventricular dysfunction. Assessment of regional myocardial function may allow for earlier detection of pacing-induced myocardial remodeling. The aim of this study was to evaluate regional myocardial function in paced children with congenital complete atrioventricular block (CCAVB). We investigated regional myocardial function using strain echocardiography and tissue velocity imaging in 10 paced children with CCAVB and in 14 age-matched healthy children. Echocardiograms of the paced children were obtained during intrinsic junctional rhythm. All patients had normal biventricular size and global function. The time from R wave to peak regional strain rate and the time from R wave to peak regional myocardial tissue velocity were measured in nine segments. The differences between maximum and minimum values were used as a measure of contraction delay (dSR and dTV). Study group patients had significantly higher dSR and dTV values compared to the control group. Mean peak strain rates and peak tissue velocities obtained from same segments were significantly decreased in the study group compared to the control group. Regional dysfunction was more prominent in the areas of ventricular pacing. No significant correlation is found between the duration of pacing (2.5-18 years) and dSR, dTV, mean peak strain rates, or mean peak tissue velocities. Pacing leads to regional myocardial dysfunction that can be detected with strain echocardiography and tissue velocity imaging during intrinsic junctional rhythm in children with CCAVB. Pacing-induced regional myocardial remodeling does not seem to progress with long-term right ventricular pacing in children with CCAVB.

The effects of sevoflurane and desflurane anesthesia on QTc interval and cardiac rhythm in children

Inhalational anesthetics may prolong QTc interval (QT interval corrected for heart rate) of the ECG and cause life-threatening arrythmias. The effects of desflurane on QTc interval and cardiac rhythm have not been reported previously in children. We assessed the effects of desflurane anesthesia on QTc interval and cardiac rhythm and compared them with sevoflurane anesthesia in children. The study was performed on 20 children admitted for inguinal hernia repair, with normal QTc intervals. Anesthesia was induced with propofol and intubation was achieved with vecuronium. Anesthesia was maintained with 2% sevoflurane (group I, n = 11) or 6% desflurane (group II, n = 9) and 66% nitrous oxide in oxygen. Electrocardiogram recordings were obtained by Holter recorder. QTc intervals were measured at baseline, 5, 10, 15, and 30 min after inhalation. None of the patients had significant arrythmia with desflurane anesthesia. One patient in the sevoflurane group had single, bigemini and multiform ventricular extrasystoles. There was no statistically significant difference in the baseline QTc values of the groups. Desflurane significantly prolonged QTc interval 5 min after induction until 30 min of anesthesia compared with baseline values (P = 0.029), while no significant prolongation was observed with sevoflurane (P = 0.141). Use of 2% sevoflurane during maintenance of anesthesia does not significantly prolong QTc interval while 6% desflurane significantly prolonged QTc interval in children with normal QTc interval undergoing inguinal herniorrhaphy.

Sleep and circadian rhythms in children and adolescents with bipolar disorder

The aim of this paper is to highlight the importance of the sleep-wake cycle in children and adolescents with bipolar disorder. After presenting an overview of the measurement and function of human sleep, we describe changes in sleep and circadian functioning across the life cycle. We then review evidence that, in adults, sleep and/or circadian rhythms are of considerable influence in the multifactorial causal chain implicated in relapse in bipolar disorder, discussing relevant mechanisms. The latter include abnormalities in the amount and timing of sleep, the role of social zeitgebers, and the importance of sleep in regulating emotional responses and mood. We next present preliminary data indicating considerable sleep disturbance among children and adolescents with bipolar disorder. Given the considerable sleep disturbance evident among children and adolescents with bipolar disorder along with a key role for sleep in emotion regulation and learning, we conclude that sleep among children and adolescents with bipolar disorder is a critical domain for future research. An agenda for future research is presented that includes descriptive studies, investigations of causality, and treatment development research.

Melatonin rhythm in children with enuresis

To study the circadian rhythm of melatonin in children with enuresis. Twenty-five children, divided into two groups (enuretic patients and controls) were assessed; salivary samples were collected to measure melatonin by radioimmunoassay using commercial kits. Friedman two-way anova and Wilcoxon tests were used to assess the circadian rhythm of melatonin, and anova with between-patient factors and Mann-Whitney tests to compare melatonin values and groups. Both groups had statistically significant differences in melatonin concentration during the 24-h period (both P < 0.001), with a circadian rhythm; the highest values were always at approximately 04.00 hours. There were no significant differences overall in melatonin values between cases and controls, but patients had lower peak values than controls at 04.00 hours, and higher melatonin levels at 24.00 hours, but with no significant differences. There was some evidence for minor disturbances in the circadian rhythm of melatonin as a cause of enuresis, but the rhythm was not grossly disrupted.

Correlations between anthropometric data at birth and parameters of autonomic regulation of the heart rhythm in children under school age

Correlations between anthropometric data at birth and parameters of autonomic regulation of the heart rhythm in children under school age

Impairment of the melatonin rhythm in children with Sanfilippo syndrome

Impairment of the melatonin rhythm in children with Sanfilippo syndrome

WAITING FOR THE MESSIAH, A TAMBOURINE IN HER HAND

Between March and July of 1994, the period just before and after the death of the Lubavitcher Rebbe, Menachem Mendel Schneersohn, I was doing fieldwork among Lubavitch women in Crown Heights, New York, and in Morristown, New Jersey, home of the Lubavitch Rabbinical College. Most of the women I encountered said they believedor at least hopedthat their Rebbe would not die, but would rather emergerise up was the expression they usedas the Messiah. While attending their study sessions and prayer gatherings and visiting them in their homes, I inadvertently discovered that a new ritual object was emerging in the women's community: a Miriam's tambourine. Because a tambourine is a prosaic object, evoking folk concerts and children's rhythm training, it was not initially clear to me that this object, in the context of the Lubavitch women, possessed spiritual agency. In this essay, I attempt to narrate, in the form of a chronicle, various forms of spiritual work that the tambourine performed for Lubavitch women. Speaking broadly, I observed that the tambourine enabled the creation of women's bonds; it channeled anxiety and creative energy, and it released the women from boundaries of time and place as they identified with the biblical Miriam and the confident ancient Israelite women who had gracefully saved the day when their husbands quarreled, complained, despaired, and withdrew from procreation. The tambourine eased women across a threatening transition, guiding and assuring them, and creating a locus for divine-human intersection.

A Study of Spectral Characteristics of Cardiac Rhythm in Children of Primary School Age during Mental Work

Studies of the psychophysiological status and func� tional resources of schoolchildren have become very important under contemporary conditions of increasing education load and new technologies of education. The cardiovascular system is an indicator of the functional state of the human brain [4, 7, 9], while cardiac rhythm changes represent dynamics of nerve processes. Heart rate can be regarded as an indicator of socially important events, including educational efforts. The functional resources of the human body can be assessed using tests for variability of cardiac rhythm (VCR). Control over physiological reactions depends on the level of functional load [3]. Spectral analysis of car� diac rhythm reveals a correlation between spectral com� ponents and stages of the regulatory mechanism. Orthostatic tests are routinely used in most studies of functional resources [2, 6]. Postural tests are more appro� priate for studies of children’s adaptation to school con� ditions [1, 4, 10]. The goal of this work was to study spectral character� istics of cardiac rhythm in children of primary school age during mental activity. Primary school age is a critical period of development. It corresponds to qualitative rearrangement of many brain structures, physiological systems, and adaptive reactions. At early stages of devel� opment inconsistency between environmental factors and adaptive capacity is particularly detrimental [8].

Effects of Transcutaneous Electrical Nerve Stimulation (TENS) on Cognition, Behavior, and the Rest-Activity Rhythm in Children with Attention Deficit Hyperactivity Disorder, Combined Type

Objective. The aim of this study was to examine the effects of transcutaneous electrical nerve stimulation (TENS) on cognition, behavior, and the rest-activity rhythm in children with attention deficit hyperactivity disorder, combined type (ADHD-CT). Methods. Twenty-two children diagnosed with ADHD-CT received TENS treatment during 6 weeks, 2 times 30 min a day. Neuropsychological tests were administered to assess cognition, parent/teacher behavioral rating scales were used to measure behavior, and actigraphy was used to assess the rest-activity rhythm. Results. TENS appeared to have a moderate beneficial influence on cognitive functions that load particularly on executive function. There was also improvement in behavior as measured by parent/teacher behavioral rating scales. Moreover, motor restlessness during sleep and motor activity during the day decreased by TENS. Conclusions. The effects of TENS in children with ADHD are modest but encouraging and warrant further research.

Attenuated adult biphasic shocks for prolonged pediatric ventricular fibrillation: Support for pediatric automated defibrillators

To evaluate published data regarding the treatment of prolonged pediatric defibrillation, with special emphasis on the use of attenuated adult biphasic shocks for pediatric defibrillation. Review relevant human and animal literature. Rhythm analysis algorithms from two manufacturers of automated external defibrillators can accurately distinguish shockable from nonshockable rhythms in children. Theoretical considerations and transthoracic impedance data from animals and children suggest that pediatric defibrillation doses should not necessarily vary in a simple weight-based manner. Two piglet studies have established that an attenuated adult biphasic dosage can be successfully used for 3.5- to 24-kg animals in ventricular fibrillation. One study established that the attenuated adult biphasic dosage was at least as safe and effective as the standard monophasic weight-based dosing. This review supports the American Heart Association's new guidelines for pediatric automated external defibrillator usage: "Automated external defibrillators may be used for children 1 to 8 yrs of age who have no signs of circulation. Ideally the device should deliver a pediatric dose. The arrhythmia detection system used in the device should demonstrate high specificity for pediatric shockable rhythms, i.e., it will not recommend delivery of a shock for nonshockable rhythms."

Rest-Activity Cycles in Childhood and Adolescent Depression

To quantify circadian rhythms in rest-activity cycles in depressed children and adolescents. Rest-activity cycles were evaluated by actigraphy over five consecutive 24-hour periods in 100 children and adolescents, including 59 outpatients with major depressive disorder (MDD) and 41 healthy normal controls. Total activity, total light exposure, and time spent in light at more than 1,000 lux were averaged over the recording period for each participant. Time series analysis was used to determine the amplitude and period length of circadian rhythms in rest-activity. Overall, adolescents with MDD had lower activity levels, damped circadian amplitude, and lower light exposure and spent less time in bright light than healthy controls. Among children, those with MDD showed lower light exposure and spent less time in bright light, but only depressed girls showed damped circadian amplitude. The sex differences were substantially greater in the MDD group than in the normal control group. These results confirm damped circadian rhythms in children and adolescents with MDD and highlight the influence of gender and age on these measures.

Alterations in circadian and ultradian cardiovascular rhythms in children with chronic renal failure

P-177 Key Words: Circadian and Ultradian Rhythms, Chronic Renal Failure, Children

Prevalence of arrhythmias and conduction disturbances in large population-based samples of children.

The aim of our study is to provide data on the prevalence of disturbances of rhythm in the general population of children. Accurate estimates of true prevalence of such disturbances of rhythm from large samples are mandatory if we are to interpret properly electrocardiographic abnormalities. We analysed prevalence of disturbances of rhythm in a population of 152,322, comprised of 71,855 elementary school students, 36,692 males and 35,163 females, aged from 5 to 6 years, and 80,467 students of junior high school, 41,842 males and 38,625 females, aged from 12 to 13 years. We analysed the prevalence of premature atrial and ventricular contractions, first, second and third degree atrioventricular block, incomplete and complete right bundle branch block, Wolff-Parkinson-White syndrome, and prolongation of the QT interval. The prevalence of disturbances of rhythm in total rose with age, being found in 1.25% of elementary school students and 2.32% of junior high school students, and was higher in males than females, at 2.00% as opposed to 1.38%, both values being statistically significant at a level of less than 0.0001. Prevalences of all types of rhythmic disturbances were higher in junior high school students than elementary school students (p < 0.0001). Premature atrial and ventricular contractions and prolongation of the QT interval were higher in female than male students, at percentages of 0.089, 0.497, and 0.02 for males, and 0.123, 0.534 and 0.027 in females (p < 0.0001). In contrast, incomplete and complete right bundle branch blocks were higher in males than females, at 0.983% and 0.083% in males versus 0.410% and 0.161% in females (p < 0.0001). Disturbances of rhythm increased with age, and conduction disturbances were higher in male students than female, although premature atrial and ventricular contractions and prolongation of the QT interval were more frequent in female. These data may be useful for future comparative studies of disturbance of rhythm in children.

Melatonin Improves Health Status and Sleep in Children With Idiopathic Chronic Sleep-Onset Insomnia: A Randomized Placebo-Controlled Trial

To investigate the effect of melatonin treatment on health status and sleep in children with idiopathic sleep-onset insomnia. A randomized, double-blind, placebo-controlled trial was conducted in a Dutch sleep center, involving 62 children, 6 to 12 years of age, who suffered more than 1 year from idiopathic chronic sleep-onset insomnia. Patients received either 5 mg melatonin or placebo at 7 pm. The study consisted of a 1-week baseline period, followed by a 4-week treatment. Health status was measured with the RAND General Health Rating Index (RAND-GHRI) and Functional Status II (FS-II) questionnaires. Lights-off time, sleep onset, and wake-up time were recorded in a diary, and endogenous dim light melatonin onset was measured in saliva. The total scores of the RAND-GHRI and FS-II improved significantly more during melatonin treatment compared to placebo. The magnitude of change was much higher in the melatonin group than in the placebo group, with standardized response means for the RAND-GHRI of 0.69 versus 0.07 and for the FS-II of 1.61 versus 0.64. Melatonin treatment also significantly advanced sleep onset by 57 minutes, sleep offset by 9 minutes, and melatonin onset by 82 minutes, and decreased sleep latency by 17 minutes. Lights-off time and total sleep time did not change. Melatonin improves health status and advances the sleep-wake rhythm in children with idiopathic chronic sleep-onset insomnia.

Automated External Defibrillator Use In Children

Automated External Defibrillator Use In Children

Specificity and sensitivity of automated external defibrillator rhythm analysis in infants and children

Study objective: The rhythm detection algorithms of automated external defibrillators have been derived from adult rhythms, and their ability to discriminate between shockable and nonshockable rhythms in children is largely unknown. This study evaluates the performance of 1 automated external defibrillator algorithm in infants and children and evaluates algorithm performance with anterior-posterior versus sternal-apex lead placement. Methods: We enrolled pediatric patients in a critical care unit, an electrophysiology laboratory, and a cardiac operating room. A monitor-defibrillator recorded ECGs by means of standard defibrillation-monitor pads. Selected 15-second rhythm samples were played into a LIFEPAK 500 automated external defibrillator, and the automated external defibrillator “shock/no shock” decision was documented. To determine sensitivity and specificity, the automated external defibrillator decision was compared with the “shockable” versus “nonshockable” rhythm classification provided by 3 expert clinicians who were blinded to the automated external defibrillator decision. Results: We recorded 1,561 rhythm samples from 203 pediatric patients (median age 11 months; range, day of birth to 7 years). The automated external defibrillator recommended a shock for 72 of 73 rhythm samples classified as coarse ventricular fibrillation by expert review (sensitivity 99%; 95% confidence interval [CI] 93% to 100%); and correctly reached a “no shock advised” decision for 1,465 of 1,472 rhythm samples classified as nonshockable by experts (specificity 99.5%). Specificity was 99.1% (95% CI 97.8% to 99.8%) with the sternal-apex lead and 99.4% (95% CI 98.1% to 99.9%) with the anterior-posterior lead. Conclusion: This automated external defibrillator algorithm has high specificity and sensitivity when used in infants and children with either sternal-apex or anterior-posterior lead placement. [Ann Emerg Med. 2003;42:185-196.]

Oh, Boy! (Oh, Boy!): mutual desirability and musical structure in the buddy group

If rock'n'roll represented new, sexualised gender identities for the teenagers of the late 1950s, why (and how) were such identities constructed through the multiple voices of the group? In Buddy Holly's ‘Oh, Boy!’ the chorus plays a prominent supportive role in relation to the lead singer; but its continual echoing of the singer's ‘Oh boy!’ allows also for a literal hearing of cries of mutual desire and admiration between two men. This representation of the ‘buddy group’ has continuities with other group, or dual representations of male identity, where mutual, male selves and desires are constructed around an imagined, comforting woman. The presence of traces of the maternal body (Kristeva's ‘semiotic’ sphere) is audible in ‘Oh, Boy!’ through the chorus's separation of rhythm and melody, and in particular, its use of ‘children's rhythms’, consistent with those analysed by the musicologist Constantin Brailoiu as a cross-cultural phenomenon. In ‘Oh, Boy!’ children's rhythms are reworked in a dialogue between singer and chorus, and between guitar and chorus in the instrumental break, in such a way that after the break the singer is able to resolve the rhythmic tensions introduced in the first half of the song and get ‘everything right’. The new symbolic identity of male adolescent independence is audibly structured by the semiotic, so reversing the surface hearing of the song as involving the subordination of the chorus to lead singer in the consensual hierarchy of ‘buddy’ relations. The relationship of Buddy Holly to Bo Diddley adds a further dimension to this structure, where ostensible equality cannot mask the uncomfortable social hierarchy of the white rock star and black mentor, and where an appeal to the other as ‘boy’ would evoke not the buddy group, but slavery.

Age-related Features of Circadian Dynamics of Velocity of Reaction to Visual Stimuli in 8- to 14-Year-Old Boys

Studying individual circadian psychophysiological rhythms in children and adolescents, the authors showed that different rhythmological indices, such as fluctuation amplitude, mean level, and rhythm phase, change with age in different manners. Changes in one or more of these indices reflect a complex stagewise process of the formation of functions in human ontogeny. Additionally, a mismatch between individual and social (school load) rhythms may result in desynchronosis.

Mechanisms and clinical significance of circadian rhythms in children.

Circadian rhythms are endogenously generated rhythms with a period length of about 24 hours. A biologic clock in the hypothalamic suprachiasmatic nuclei is responsible for the generation of circadian rhythms. Notable examples of the circadian rhythms include the sleep-wake cycle and rhythms in hormone production. Abnormalities of the circadian system include biologic clock lesions that result in arrhythmic behavior and irregular sleep patterns. Abnormalities of the circadian system also occur when there is desynchronization of clock phase with that of the outside world, resulting in conditions such as "jet-lag." Numerous aspects of human physiology are greatly influenced by the time of day, as is the pathogenesis of illness. During development, the circadian system becomes functional at early stages and is regulated by photic information. With the continued elucidation of circadian system influences on human physiology and illness, it is anticipated that circadian biology will have an increasingly important impact on the clinical care of children.