心肌炎患儿与正常儿童心率及心率变异性比较分析

目的 研究不同年龄心肌炎患儿的心率及心率变异性(HRV)改变的特点和相关性.方法 对120例心肌炎患儿进行24 h全程动态心电图检查,与804例正常儿童的心率及HRV进行比较分析.结果 7岁以下患儿最慢心率较正常增快,最快心率比较变化无差异,7～18岁患儿心率监测指标均异常;3～7岁心肌炎患儿与正常儿童比较每5分钟R-R间期平均值的标准差(SDANN)无变化,各组其他HRV指标均降低.结论 心肌炎患儿的HRV普遍降低,提示心脏自主神经系统的总体功能受损,以迷走神经张力降低为主,交感神经张力相对增强.     

Vesicoureteric reflux and renal scars in asymptomatic siblings of children with reflux.

The purpose of the study was to determine the incidence of vesicoureteric reflux (VUR), renal scars and hypertension in asymptomatic siblings of children with VUR. The study comprised 105 siblings of patients with VUR. Their age ranged from 4 months to 6.3 years. All had a direct radionuclide voiding cystography (DRVC) performed, and VUR was detected in 47 of 105 (45%). High grade VUR in the first year of life had an incidence of 50% compared with a 9% incidence in siblings older than 2 years, while only one of the 27 siblings with a low VUR grade was younger than 1 year. In 43 of 47 siblings with VUR, a technetium-99m dimercaptosuccinic acid (99mTc-DMSA) scan was performed and renal scars were found in 10, which presents 23% of siblings with VUR who were scanned and 10% of all siblings studied. One child had hypertension. Identifying VUR among asymptomatic siblings could possibly prevent renal damage and its consequences. Thus, the predictive value of positive family history alone in identifying VUR was 45% while 23% of siblings had renal scars. This incidence justifies the routine investigation of asymptomatic siblings, by using DRVC at an early stage.     

正常儿童动态心电图窦性心率及心率变异分析

目的探讨正常儿童心率及心率变异性(HRV)特点。方法对804例正常儿童进行24h全程动态心电图检查,分析心率及HRV。结果不同年龄儿童窦性心率范围不同,年龄越小心率越快;儿童不同性别间HRV中24h内全部正常心动周期的标准差(SDNN)、24h内每5minNN间期标准差的平均值(SDNNindex)、NN50占所有N-N间期个数的百分数(PNN50)、极低频率(VLF)、低频(LF)差异有显著性;儿童不同年龄组间24h内5min节段平均心动周期的标准差(SDANN)、VLF、LF、全程相邻NN间期之间的均方根值(rMSSD)差异有显著性;儿童组与成人正常参考值中SDNN、SDANN、rMSSD差异有显著性,rMSSD儿童组中明显高于成人组。结论HRV是一种反映自主神经活性及其平衡的能定量、可重复的非侵入性的检测方法,是自主神经系统与心血管系统相互制约的结果。不同年龄、不同性别间儿童HRV存在显著差异;儿童组与成人参考值存在显著差异,尤其rMSSD儿童明显高于成人,提示儿童的自主神经功能较成人活跃,而随着年龄增长自主神经功能减退,尤其是迷走神经的紧张抑制功能明显减退。     

学龄期肥胖儿童胰岛素抵抗与心率变异性及心率减速力的相关性

目的探讨学龄期肥胖儿童胰岛素抵抗(IR)与心率变异性(HRV)、心率减速力(DC)及心率加速力(AC)之间的关系。方法选取学龄期6～10岁肥胖儿童83例,根据空腹血糖及空腹胰岛素值计算胰岛素抵抗指数(IRI),再根据IRI值将实验对象分为IR组45例和非IR组38例。在检测空腹血糖及空腹胰岛素同日行24小时动态心电图检查,计算出DC、AC、HRV各指标。比较IR组与非IR组DC、AC、HRV各指标,并进行相关性分析。结果 IR组DC、正常RR间期标准差(SDNN)、5分钟均值标准差(SDANN)、高频功率(HF)均低于非IR组,AC高于非IR组,差异均有统计学意义(P0.05)。肥胖儿童的IRI与DC、SDNN、SDANN、相邻RR间期差值的均方根(RMSSD)、低频功率(LF)、HF均呈显著负相关(r=-0.475～-0.249,P0.05),与AC呈显著正相关(r=0.488,P0.01)。结论 IR较非IR肥胖儿童的自主神经功能损伤严重,主要表现为迷走神经张力降低,且IRI越高,迷走神经张力越低。     

甲状腺功能亢进症儿童的甲状腺激素与心率减速力及心率变异性的相关性

目的 对甲状腺功能亢进症（简称“甲亢”）儿童的心率减速力（DC）、心率加速力（AC）、心率变异性（HRV）进行分析,并探讨甲亢儿童的血清甲状腺激素水平与DC、AC及HRV的关系。方法 选取甲亢儿童47例,另选取50例健康儿童为对照组,对所有受试者行24 h动态心电图检查,将甲亢组与对照组的DC、AC、心率（HR）及HRV各指标[RR间期总体标准差（SDNN）、RR间期平均值的标准差（SDANN）、相邻RR间期差值的均方根（RMSSD）、低频功率（LF）、高频功率（HF）]进行比较,并将甲亢儿童的甲状腺激素指标[游离三碘甲状腺原氨酸（FT3）、游离甲状腺素（FT4）]与DC、AC及HRV各指标进行相关性分析。结果 甲亢组的DC、SDNN、SDANN、RMSSD、LF、HF均低于对照组;AC和HR均高于对照组（P < 0.05）。甲亢儿童的血清FT3、FT4与DC、SDNN、SDANN、RMSSD、LF、HF均呈负相关（P < 0.05）;与AC和HR呈正相关（P < 0.05）。结论 甲亢儿童的心脏自主神经功能受损,表现为迷走神经张力降低。血清甲状腺激素水平越高,迷走神经张力越低,提示发生心血管疾病的危险性越大。     

Adherence in children with nocturnal enuresis

ObjectiveThe treatment of enuresis requires adherence to several guidelines often over a long period of time. The aims of this study were 1) to investigate adherence to the medical treatment regime for enuresis and its influence on therapeutic success, and 2) to gain insight into the socio-demographic, medical, familial and psychological predictors of adherence.Materials and methodsFor 41 children (6–12 years) with nocturnal enuresis, adherence to four common guidelines (drinking and voiding schedule, toilet posture and medication intake) was measured at 1, 3 and 5 months after treatment.Results and conclusionsMean adherence to the medical regime is about 70% according to both child and parent reports at the 24-h recall interview. Greater adherence, particularly to the drinking schedule, was associated with greater therapeutic success after 6 months. The best predictor of good adherence was a positive perception of one's physical appearance and to a lesser extent low levels of stress related to the treatment of the disorder.     

Elevated nocturnal blood pressure and heart rate in adolescent chronic fatigue syndrome

Aim: To compare ambulatory recordings of heart rate (HR) and blood pressure in adolescents with chronic fatigue syndrome (CFS) and healthy controls. We hypothesized both HR and blood pressure to be elevated among CFS patients. Methods: Forty‐four CFS patients aged 12–18 years were recruited from our paediatric outpatient clinic. The controls were 52 healthy adolescents having similar distribution of age and gender. 24‐h ambulatory blood pressure and HR were recorded using a validated, portable oscillometric device. Results: At night (sleep), HR, mean arterial blood pressure and diastolic blood pressure were significantly higher in CFS patients as compared with controls (p < 0.01). During daytime, HR was significantly higher among CFS patients (p < 0.05), whereas blood pressures were equal among the two groups. Conclusions: The findings support previous experimental evidence of sympathetic predominance of cardiovascular control in adolescent CFS patients. Also, the findings prompt increased focus on cardiovascular risk assessment and suggest a possible target for therapeutic intervention.     

SCUBA-dive-related changes in heart rate in children

The purpose of this study was to monitor heart rate (HR) and rhythm during open water SCUBA dives. Nine children performed 25-min open water SCUBA dives to 8 m depth. Before, during and after these dives, ECG was recorded. Compared with predive heart rate, heart rate declined by -24 ± 8% (range -36%; -15%) during the dive. In some children a further decline in HR was observed within the last minutes of the dive. Older and taller subjects and those with a high initial HR showed a more pronounced decline in HR. Furthermore singular supraventricular and ventricular extrasystoles were observed in some children. Immersion as well as facial and skin cooling presumably account for the initial decline in heart rate. A further drop in HR within the last minutes of the dive might be related to mild hypothermia. Single supraventricular and ventricular extrasystoles might occur in healthy children during dives.     

小儿扩张型心肌病心率变异性分析

目的分析扩张型心肌病(DCM)儿童的心率变异性(HRV)。方法DCM儿童23例(研究组),匹配健康儿童23例为对照(对照组)。采用康泰TLC3000A12通道动态心电图(EKG)分析系统描记24hEKG,分析心率、HRV的时域指标和频域指标。应用SPSS11.0软件进行统计学处理。结果与对照组比较,研究组最低心率明显增高(P<0.05),最高心率稍增高(P>0.05);HRV时域指标SDNN、SDANN、pNN50明显降低(P<0.05),rMSSD稍降低(P>0.05);HRV频域指标TP、ULF明显降低(P<0.05),VLF、LF、HF、LF/HF稍增高(P>0.05)。结论DCM儿童自主神经功能明显受损。     

血管迷走性晕厥儿童心率变异性分析

目的探讨血管迷走性晕厥(VVS)儿童的心率变异性(HRV)。方法对27例不明原因晕厥患儿经直立倾斜试验(HUTT)检查阳性并诊断为VVS的HRV进行分析(研究组),并将29例健康儿童作为对照(对照组)。采用康泰TLC3000A12通道动态心电图分析系统描记未发生晕厥时24h心电图,分析时域指标和频域指标,应用SPSS11.0软件进行统计学处理。结果研究组低频功率(LF)与对照组比较明显降低(P<0.05);频域指标与时域指标在不同年龄段差别不明显(P>0.05);女性时域指标中SDANN及VLF、LF较男性明显降低(P<0.05);血管抑制型与混合型VVS的HRV指标差异不明显。结论VVS儿童基础自主神经功能发生改变;HRV主要受性别影响,而年龄影响不明显;HUTT不同反应类型VVS的HRV不存在差别。     

99mTc-EC肾动态显像在儿童肾瘢痕诊断中的价值

目的探讨99mTc-EC肾动态显像在尿路感染患儿肾瘢痕诊断中的价值。方法回顾性分析同期行99mTc-EC肾动态显像和99mTc-DMSA肾静态显像的67例尿路感染患儿的显像资料,以99mTc-DMSA肾静态显像结果为金标准,分析比较99mTc-EC肾动态显像与尿路感染、肾积水与肾瘢痕的关系。结果99mTc-EC肾动态图起始2 min叠加图像诊断肾瘢痕的灵敏性是80.28%,特异性是88.89%,阳性似然比为7.23。采用99mTc-DMSA肾静态显像诊断肾瘢痕,发现与上尿路排泄通畅和排泄延缓的患儿相比,上尿路排泄梗阻患儿的肾瘢痕形成概率较高,差异有统计学意义(P0.05);但积水程度不同患儿的肾瘢痕发生概率的差异无统计学意义(P0.05)。结论对尿路感染患儿,99mTc-EC肾动态显像早期叠加图像诊断肾瘢痕形成的灵敏性和特异性均较高,99mTc-EC肾动态显像提供的上尿路排泄情况对肾瘢痕形成的诊断具有一定价值。     

Hypercalciuria in children with monosymptomatic nocturnal enuresis

ObjectiveThe aim of this study was to measure the 24 h urinary calcium content in children with monosymptomatic nocturnal enuresis (MNE) and compare with those in healthy children to investigate whether there is any relation with enuresis and hypercalciuria.Material and methodsThis study included 120 children and adolescents with MNE aged between 7 and 14 years. Eighty age- and sex-matched healthy children served as a control group. To determine urinary calcium excretion, 24 h urine samples were collected. The children with enuresis were divided into two sub-groups as hypercalciuric and normocalciuric groups according to the amount of urinary calcium excretion.ResultsHypercalciuria was found in 27 (23%) of the MNE patients compared with two (4%) of continent children (p < 0.001). In addition, the mean 24 h urine calcium/body weight ratio was higher in the enuresis group than in the control group, 2.94 ± 2.42 versus 1.59 ± 1.72, respectively (p = 0.002). When the children with enuresis were divided into two groups as normokalsiuric and hypercalciuric, the hypercalciuric children were younger and the majority of this group were boys..ConclusionsOur study showed that hypercalciuria is common in children with MNE, so we suggested measuring urine calcium levels in NE patients. However, further studies are needed to clarify the relationship between hypercalciuria and NE in larger series..     

Clinical and haemodynamic correlates of heart rate variability in children with congenital heart disease

Heart rate variability (HRV) represents a noninvasive parameter for studying the autonomic control of the heart. Cardiac patients have a complex autonomic disturbance. The relation of HRV to this abnormality in children with congenital heart disease (CHD) has not yet been examined. The present study examined HRV indices from 24 h Holter recordings in 258 children with an operated or non-operated CHD, to determine their differences as an indicator of the severity of heart disease. The latter was defined clinically as New York Heart Association (NYHA) functional class I to IV and haemodynamically by invasive parameters. Five time-domain measures (SDNN, SDNNi, SDANNi, rMSSD and pNN50) and three frequency-domain measures (LF, HF and balance LF/HF) were compared with normal ranges. HRV was reduced in children with CHD, except in patients of NYHA class I. The level of reduction depended on the NYHA functional class. None of the measures was significantly related to haemodynamic data. Conclusion Heart rate variability is reduced in children with Congenital heart disease depending on the functional limitation but not on haemodynamic disturbances. Heart rate variability indices are sensitive markers of the clinical state. Received: 3 December 1997 / Accepted in revised form: 22 June 1998     

Glomerular filtration rate in children following renal transplantation

Most studies evaluating renal function post-renal transplantation in children have used serum creatinine (S(Cr)) or estimates of its clearance (C(SCH)). When renal function is impaired both S(Cr) and the C(SCH) overestimate glomerular filtration rate (GFR), especially during cyclosporine therapy. This study measured GFR in 64 children (age range: 4-19 years) with stable renal function who received renal allografts at the Childrens Medical Center of Dallas, 31 from live related donors (LRD) and 33 from cadaveric donors (CAD). 125I-iothalamate clearance (C(IO)) was used as the reference standard for measuring GFR. Data from 100 C(IO) studies, were analyzed and results reported as mean +/- S.E.M. C(IO) performed during the first year after renal transplantation in 23 children who received allografts from LRD was 72.4+/-5.5 ml/min per 1.73 m2 compared to 50.4+/-7.4 ml/min per 1.73 m2 in 18 children who received allografts from CAD (p<0.05). Beyond the first year post-renal transplantation there was no difference in C(IO) between LRD and CAD allografts. When S(Cr) was compared to C(IO), the relationship was nonlinear. C(IO) was also compared to the simultaneous estimation of creatinine clearance by C(SCH). The overestimation of GFR by C(SCH) was inversely proportional to the level of renal function. When renal function was normal or mildly reduced (C(IO) > 50 ml/min per 1.73 m2), C(SCH) closely approximated C(IO). When renal function was moderately to severely curtailed (C(IO) < or = 50 ml/min per 1.73 m2), C(SCH) overestimated C(IO) by 43.6+/-5.6%. The study concludes that in children with renal transplant: 1) C(IO) is higher in allografts from LRD compared to CAD kidneys only in the first 12 months following renal transplantation; 2) S(Cr) is a poor predictor of C(IO); and 3) C(SCH) consistently overestimates GFR children following renal transplantation unless renal function is normal or only mildly decreased.     

肥胖儿童心率变异性分析

目的 了解肥胖儿童心率变异性的特征。方法 用Holter对62例单纯性肥胖儿童和61例非肥胖儿童连续记录24h心电信号，进行心率变异性分析。结果 肥胖儿童心率变异性的时域指标：窦性心律RR问期标准差(SDNN)和相邻窦性心律RR问期差的均方根(rMSSD)低于非肥胖儿童；频域指标：高频功率(HF)和低频功率(LF)低于非肥胖儿童，结果有统计学意义。结论 肥胖儿童心率变异性减小，迷走神经功能降低。