Electrocardiographic Criteria for Left Ventricular Hypertrophy in Children

Previous studies to determine the sensitivity of the electrocardiogram (ECG) for left ventricular hypertrophy (LVH) in children had their imperfections: they were not done on an unselected hospital population, several criteria used in adults were not applied to children, and obsolete limits of normal for the ECG parameters were used. Furthermore, left ventricular mass (LVM) was taken as the reference standard for LVH, with no regard for other clinical evidence. The study population consisted of 832 children from whom a 12-lead ECG and an M-mode echocardiogram were taken on the same day. The validity of the ECG criteria was judged on the basis of an abnormal LVM index, either alone or in combination with other clinical evidence. The ECG criteria were based on recently established age-dependent normal limits. At 95% specificity, the ECG criteria have low sensitivities (<25%) when an elevated LVM index is taken as the reference for LVH. When clinical evidence is also taken into account, the sensitivity improved considerably (<43%). Sensitivities could be further improved when ECG parameters were combined. The sensitivity of the pediatric ECG in detecting LVH is low but depends strongly on the definition of the reference used for validation.     

心电图在川崎病急性期的应用研究进展

川崎病是一种急性血管炎症性疾病,冠状动脉损伤及心肌炎是其常见的并发症,尤其在急性期可表现出不同程度的心肌损伤,在心电图上可表现出多种异常。心电图作为一种无创的电生理检查手段,对川崎病的早期诊断及治疗预后评估均有重要意义。随着研究的深入,川崎病早期的心电图表现及电生理意义逐渐被认识,现对近年来国内外研究川崎病急性期心电改变及临床意义进行回顾及总结,就心电图在川崎病诊治的应用进展进行综述。     

Are ECG abnormalities in Noonan syndrome characteristic for the syndrome?

Of all patients with Noonan syndrome, 50–90% have one or more congenital heart defects. The most frequent occurring are pulmonary stenosis (PS) and hypertrophic cardiomyopathy. The electrocardiogram (ECG) of a patient with Noonan syndrome often shows a characteristic pattern, with a left axis deviation, abnormal R/S ratio over the left precordium, and an abnormal Q wave. The objective of this study was to determine if these ECG characteristics are an independent feature of the Noonan syndrome or if they are related to the congenital heart defect. A cohort study was performed with 118 patients from two university hospitals in the United States and in The Netherlands. All patients were diagnosed with definite Noonan syndrome and had had an ECG and echocardiography. Sixty-nine patients (58%) had characteristic abnormalities of the ECG. In the patient group without a cardiac defect (n = 21), ten patients had a characteristic ECG abnormality. There was no statistical relationship between the presence of a characteristic ECG abnormality and the presence of a cardiac defect (p = 0.33). Patients with hypertrophic cardiomyopathy had more ECG abnormalities in total (p = 0.05), without correlation with a specific ECG abnormality. We conclude that the ECG features in patients with Noonan syndrome are characteristic for the syndrome and are not related to a specific cardiac defect. An ECG is very useful in the diagnosis of Noonan syndrome; every child with a Noonan phenotype should have an ECG and echocardiogram for evaluation.     

直立性高血压儿童卧位、立位心电图T波和ST段振幅变化及其临床意义

目的 探讨直立性高血压（OHT）儿童卧位与立位心电图T波和ST段振幅变化及其临床意义。方法 选取确诊为OHT患儿49例为OHT组，同期按年龄与性别匹配43例健康儿童为对照组。测量两组卧位与立位12导联心电图心率、各导联T波和ST段振幅，比较同组卧位和立位T波振幅、ST段振幅，并比较两组卧位、立位T波振幅差和ST段振幅差。结果 对照组aVR、V₁、V₄~V₆导联T波振幅立位较卧位降低（P < 0.05），V₄、V₅导联ST段振幅立位较卧位增加（P < 0.05）。OHT组Ⅱ、aVR、aVF、V₄~V₆导联T波振幅立位较卧位降低（P < 0.05），Ⅱ导联ST段振幅立位较卧位增加（P < 0.05）。OHT组Ⅱ、V₆导联立位、卧位T波振幅差较对照组增大（均P < 0.05）。V₆导联卧位、立位T波振幅差对OHT有诊断价值（P < 0.05），V₆导联T波振幅差最佳截断值为0.105 mV，灵敏度为72.10%，特异度为57.10%。结论 V₆导联卧位、立位T波振幅差对OHT儿童具有一定的诊断价值。     

Comparison between pulse oximetry and transthoracic impedance alarm traces during home monitoring.

OBJECTIVE: To compare transthoracic impedance (TTI/ECG) and pulse oximetry alarm traces detected during home monitoring in infants at risk of apnoea, bradycardia and hypoxaemia. STUDY DESIGN: A retrospective evaluation of the monitor downloads of 67 infants who had undergone either TTI/ECG or pulse oximetry home monitoring using a device which can detect both parameters. METHODS: The patients were categorised as: apparent life-threatening events (n = 39), preterm infants (n = 21) and miscellaneous (n = 7). TTI/ECG and pulse oximetry alarm traces were scored as either true or false alarms. Classification criteria were based on visual analysis of the impedance and plethysmographic waveforms captured by the memory monitor every time alarm thresholds were violated. RESULTS: 5242 alarms occurred over 3452 days of monitoring: 4562 (87%) were false and 680 (13%) true. The mean duration of monitoring was 51 days (range 5-220 days). There were 2982 TTI/ECG false alarms (65% of the total) and 1580 pulse oximetry false alarms (35%) (p = 0.0042). Of the 680 true alarms, 507 (74%) were desaturations not attributable to central apnoea and 173 (26%) were true TTI/ECG alarms (p = 0.0013). CONCLUSIONS: Comparison of pulse oximetry and TTI/ECG alarm traces shows that true events were mostly attributable to desaturations, while false alarms were mainly provoked by TTI/ECG. The total number of false alarms is lower than reported in other studies using TTI/ECG only, thus indicating that monitoring using both pulse oximetry and TTI/ECG is suitable for home use. When the combination of both techniques is not feasible or not required, we recommend the use of motion resistant pulse oximetry alone.     

Psycho- and neurovegetative effects on the ECG of children and adolescents

In six patients between 10 and 21 years of age vegetative function disorders were diagnosed. All of them showed an inversion of T in lead II and/or III and in V4 to V6. After exercise-testing the ECG signs normalized. Other clinical investigations, echocardiography, and in one case heart-catheterization revealed no pathological findings. It is necessary to distinguish these rare ECG findings from pathological ECG changes.     

Can we prevent sudden cardiac death in young athletes: the debate about preparticipation sports screening

All high school athletes in the United States require a preparticipation screening examination. The American Heart Association recommends a focused history and physical examination. The European Society of Cardiology recommends that all examinations include an electrocardiogram (ECG). We review the risks and costs of screening, discuss legal ramifications and analyse the ethical implications of these considerations. There are too many unknown about ECG screening to require it as routine testing for all high school athletes. Conclusion: Doctors must inform young athletes and their parents about the option of ECG screening and about the debate over its efficacy. Patients and parents may then choose to have an ECG or not. Mandatory universal screening is not warranted at this time.     

多层螺旋CT血管造影在小儿复杂先天性心脏病中的临床应用价值

目的探讨多层螺旋CT血管造影（MSCTA）对小儿复杂性先天性心脏病的临床应用价值。方法回顾性分析12例复杂性先天性心脏病的MSCTA资料，并与超声心动图（ECG）及手术结果对照研究。结果12例经手术或多种影像学证实的心内外结构异常共57个，其中心内结构异常26个，心外结构异常31个。MSCTA、ECG对心内结构异常诊断的准确率为80．8％和100％；对心外结构异常的诊断准确率为100％和58．1％，总的诊断准确率为91．2％和77．2％。结论MSCTA对心外大血管结构异常的检出明显优于ECG，而对心内结构异常的检出稍逊于ECG。术前MSCTA检查有助于治疗方案的制定、降低手术风险，并可以方便的进行术后追踪随访。     

Ventricular arrhythmias and mitral valve prolapse in childhood

Although ventricular arrhythmias are well described in adults with mitral valve prolapse, this association remains controversial in children. To assess the incidence of ventricular premature complexes (VPCs), 103 consecutive children with mitral valve (MV) prolapse confirmed by echocardiography were evaluated prospectively by treadmill exercise and ambulatory ECG. A group of 50 normal children with clinical, ECG, or echocardiographic evidence of heart disease who had undergone treadmill exercise and ambulatory ECG served as controls. In the group with MV prolapse, 16 patients had VPCs with treadmill exercise and 39 had VPCs on ambulatory ECG. High-grade ventricular ectopy (multiform VPCs, couplets, or ventricular tachycardia) was recorded in four patients with MV prolapse during treadmill exercise and in eight during ambulatory ECG. In contrast, no control patient had a single VPC in response to treadmill exercise and only four control patients had rare uniform VPCs on ambulatory ECG. Neither physical examination findings, standard ECG results, nor symptoms could be correlated with VPCs in the patients with MV prolapse. Although the prognostic implications of these findings are uncertain, this study demonstrates that potentially serious ventricular arrhythmias are frequently observed in children with MV prolapse.     

Bull-neck, electrocardiographic changes and creatine phosphokinase blood levels in patients with diphtheria.

All paediatric patients with the diagnosis of diphtheria who were seen at the Department of Child Health Ujung Pandang General Hospital from October 1987 to October 1989 were evaluated for bull-neck, ECG patterns and serum creatine phosphokinase (CPK) values. Their ages ranged from 1 year and 2 months to 13 years with a mean of 6.54 +/- 3.09 years. Males and females were affected in a ratio of 1:1. Of 39 patients included in the trial, 28 were classified as having normal ECG and 11 as having abnormal ECG on admission. During hospitalization, 56.4% of cases showed ECG changes. All patients had raised serum CPK levels on admission. This increase was 14.6 times the normal level in cases with abnormal ECG and only 3.0 times in those with normal ECG (p < 0.01). The highest levels of serum CPK were noted in the first week, then returned to normal in the second week and decreased further in the third week. It became also evident that patients who developed abnormal ECG later on, had already demonstrated an increased serum CPK level of 5.2 times the normal levels on admission. Bull-neck appeared in 19 out of the 39 patients. Patients with bull-neck differed very significantly (p < 0.001) from those without bull-neck in either the frequency of the occurrence of abnormal ECG patterns or the mean CPK serum levels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Electrocardiogram shows reliable heart rates much earlier than pulse oximetry during neonatal resuscitation

Background: The aim of this study was to determine the usefulness of the three‐lead electrocardiogram (ECG) during neonatal resuscitation. Methods: Both pulse oximetry (PO) and ECG were applied immediately after delivery to measure heart rate (HR). We reviewed video recordings of the respective monitors, and checked the time at which each monitor started to display reliable rate values. Results: In 20 deliveries, ECG showed HR much earlier than PO (median 38 s vs 122 s after delivery). ECG displayed reliable HR throughout resuscitation. We were able to confirm the effectiveness of the initial respiratory support from the elevation in HR. Conclusions: ECG was a safe and reliable method for showing HR, and was used to determine the initiation and the effectiveness of resuscitation in the delivery room.     

无创性电生理检查在儿童阵发性室上性心动过速诊断中的应用价值

目的　评价无创伤性电生理检查在儿童室上性心动过速(PSVT)诊断中的应用价值。方法　2002年1月至 2003年 12月对广东省心血管研究所 58例室上性心动过速 (PSVT)患儿进行体表 12导联心电图检查(ECG)、食管电生理检查(TEAP),并与心内电生理检查 (EPS)结果进行比较。结果　ECG对房室折返性PSVT(AVRP)诊断敏感性为 100% ( 20 /20 );但对 5例P波不明显的房室结折返性PSVT(AVNRP)均漏诊;TEAP对AVRP和AVNRP总诊断敏感性为 90 3% (28 /31),对AVNRP无漏诊;ECG和TEAP对PSVT诊断符合率分别为80% (20 /25)和 91% (30 /33)。结论　联合应用ECG和TEAP等无创性电生理检查能对儿童PSVT作出正确诊断及分型,是一种安全可靠、无痛性的检查方法。     

动态心电图在心肌炎诊断中的应用价值

目的　探讨动态心电图监测24小时在心肌炎诊断中的应用价值。方法　对63例心肌炎或疑似心肌炎患儿3天内做动态心电图24小时监测及常规12导联心电图描记,两项结果做对比分析。结果　①常规心电图显示正常或窦性心律不齐的26例患儿中,动态监测检出各种心律失常22例;②常规心电图显示单源早搏,动态监测显示多源多型早搏或早搏白天多于夜间的现象;③动态心电图监测发现常规心电图正常的患儿有间歇性房室传导阻滞等一过性心电图改变。结论　动态心电图24小时监测提高了心律失常的检出率,对评价早搏的性质起决定性作用,可捕捉到一过性心电图改变,为心肌炎诊断提供可靠的依据。     

Are chest radiographs and electrocardiograms still valuable in evaluating new pediatric patients with heart murmurs or chest pain?

OBJECTIVES: To determine the usefulness of electrocardiography (ECG) and chest radiography (CXR) in evaluation of patients referred to the pediatric cardiologist for the evaluation of heart murmur or chest pain. DESIGN: In this prospective study, 106 consecutive outpatients were categorized with no heart disease, possible heart disease, or definite heart disease based on history and physical examination; they then underwent ECG and CXR. Studies were reviewed and the examining cardiologist could change the diagnosis and order an echocardiogram. SETTING: Academic pediatric cardiology practice. RESULTS: In patients thought to have no heart disease, the diagnosis was changed to definite heart disease in four solely on the basis of abnormal CXR or ECG. In 25 patients thought to have possible heart disease, the diagnosis was changed to no heart disease (7) or definite heart disease (5) after review of the CXR and ECG. All 25 patients diagnosed with definite heart disease had this confirmed by abnormal CXR (2), ECG (3), both abnormal CXR and ECG, or echocardiogram (18). CONCLUSIONS: ECG and CXR helped diagnose heart disease in four patients thought to have no heart disease, helped to rule out lesions in seven patients with possible heart disease, helped diagnose heart disease in five patients thought to have possible heart disease, and helped confirm heart disease in nine patients. In these days of cost containment, routine ECG and CXR continue to be valuable tools for the pediatric cardiologist in evaluation of patients with heart murmurs or chest pain.     

Hand and ECG tremor in spinal muscular atrophy.

The presence of hand and electrocardiogram (ECG) tremor was studied in 31 children with severe, intermediate, or mild form of spinal muscular atrophy. Clinical tremor of the hands was seen in 16 (59%) of 27 patients, all with benign forms of the disease. Nineteen patients had ECG tremors, of whom 17 had the mild or intermediate form. With the exception of one, all patients in the mild or intermediate group had hand or ECG tremor. Hand and ECG tremor are valuable in the diagnosis of the benign forms of spinal muscular atrophy; they are of no value in diagnosis of the severe infantile type.     

Arrhythmia in children with dilated cardiomyopathy (data of 24-hour ECG monitoring)

The authors demonstrate potentialities of long-term ECG monitoring in the diagnosis of heart rhythm and conduction disturbances in children with dilated cardiomyopathy. Provide the results of comparative studies of routine and 24-hour ECG monitoring in children with dilated cardiomyopathy under every-day life conditions. Show that during 24-hour ECG monitoring, all the children with the above pathology manifest heart rhythm and conduction disturbances of varying intensity and prognostic significance.     

Electrocardiographic pattern of typhoid fever in children

Of 87 children with typhoid fever, from age ranging in 2.5 to 14 years, 62.0% showed ECG changes. Sinus tachycardia and left ventricular hypertrophy were the two most frequent abnormalities. The majority of ECG changes occurred in the first week of admission and return to normal two weeks thereafter. There were no significant differences in the frequency of abnormal ECG pattern by sex, age, and nutritional state.     

Macroscopic T wave alternans in long QT syndrome

A 6 year old girl was admitted with recurrent episodes of loss of consciousness. ECG showed prolonged QT interval and macroscopic T Wave alternans. Identification of this ECG pattern is important since it can lead to potentially lethal arrhythmias.     

Cardiac syncope in children]

Syncope is a frequent problem in childhood; generally, it is an isolated event and the common causes are benign. However, in some circumstances, syncope can herald a potentially lethal problem, especially when occurring during exercise. Routine evaluation includes history, physical examination and a 12-lead standard ECG should be performed in all cases. Worrying features which should be an indication for further investigation include syncope during exercise, collapse in a swimming pool, history of familial sudden death, and abnormalities on clinical exam or ECG. Structural cardiac abnormalities that may cause syncope and sudden death include aortic stenosis, hypertrophic cardiomyopathy and coronary malformations. All children with unrepaired or repaired congenital heart disease who experienced a syncope should be referred to a specialist. Primary arrhythmias that are easily diagnosed on ECG are the long QT syndrome, complete atrio-ventricular block and Wolff-Parkinson-White syndrome; ST elevation in V1-V3 may reveal a Brugada syndrome. Another arrhythmia which is known to be potentially fatal if undiagnosed is the catecholaminergic ventricular tachycardia; the baseline ECG is normal but the arrhythmia is easily reproduced during exercise testing. Finally, vasovagal syncope is the most likely cause of syncope in the young and it usually easily recognized.