Doppler Echocardiographic Evaluation of Right Ventricular Diastolic Function in Children

Right ventricular diastolic function was evaluated by flow velocity pattern in the right ventricular inflow tract by means of pulsed Doppler echocardiography. Traditionally used to evaluate this function are peak velocities obtained during early diastole (peak E wave) and during atrial contraction (peak A wave), their ratio (peak E/A ratio), and the deceleration half-time. We conducted pulsed Doppler echocardiographic studies of right ventricular inflow and outflow patterns in 171 children (105 normal children and 66 children who were undergoing total surgical repair of congenital heart defects without sequelae). Results showed that summation flow was present in the right ventricular inflow tract in 43 (25%) of the 171 subjects, which made it difficult to separate the peak E wave from the peak A wave. We noted the presence of antegrade late diastolic flow (DW) in the right ventricular outflow tract of all subjects. DW, measured in 121 subjects in whom both E and A waves were detected in the right ventricular inflow tract, showed a highly significant correlation (p < 0.0001) with A waves in the right ventricular inflow tract. The ratio of DW to right ventricular outflow tract velocities during systole (SW) showed a highly significant (p < 0.0001) correlation with E/A ratio. When evaluating right ventricular diastolic function by pulsed Doppler, especially in children, the analysis of right ventricular outflow tract patterns is helpful in addition to that of inflow tract patterns. The DW and DW/SW ratio may present good alternatives to traditional parameters in children.     

Assessment of Ventricular Functions by Tissue Doppler Echocardiography in Children with Asthma

Patients with asthma develop pulmonary hypertension due to recurrent hypoxia and chronic inflammation, leading to right heart enlargement with ventricular hypertrophy. Patients with severe asthma can experience cor pulmonale later in life, but little is known about ventricular function during the early stages of the disease. This study aimed to investigate ventricular functions in asymptomatic children with asthma as detected by conventional echocardiography and tissue Doppler echocardiography (TDE). Fifty-one pediatric patients (mean age 10.4 ± 2.2 years) with asthma and 46 age- and sex-matched healthy children (mean age 10.9 ± 2.4 years) were studied. All subjects were examined by conventional echocardiography and TDE, and they had pulmonary function tests on spirometry. The right-ventricular (RV) wall was statistically (p = 0.01) thicker among asthmatic patients (4.7 ± 1.5 mm) compared with healthy children (3.6 ± 0.4 mm). However, conventional pulsed-Doppler indices of both ventricles did not differ significantly between asthmatic patients and healthy children (p > 0.05). The results of TDE examining RV diastolic function showed that annular peak velocity during early diastole (E′), annular peak velocity during late diastole (A′) (16.4 ± 1.8 and 5.1 ± 1.4 cm/s, respectively), E′/A′ ratio (3.2 ± 0.7), isovolumetric relaxation time (67.7 ± 10.2 ms) and myocardial performance index (48.1 % ± 7.0 %) of the lateral tricuspid annulus among asthmatic patients differed significantly (p = 0.01) from those of healthy children (13.2 ± 2.3, 8.2 ± 2.0 cm/s, 1.6 ± 0.5, 46.2 ± 8.7 ms, and 42.0 % ± 5.7 %, respectively). Only peak expiratory flow (PEF) rate from the pulmonary function tests was negatively correlated with the E′/A′ ratio of the tricuspid annulus (r = ?0.38, p = 0.01). This study showed that although the findings of clinical and conventional echocardiography were apparently normal in children with asthma, TDE showed subclinical dysfunction of the right ventricle, which is negatively correlated with PEF. These findings signify the diagnostic value of TDE in the early detection and monitoring of such deleterious effects among asthmatic patients.     

Regression of Right Ventricular Pressure in Ventricular Septal Defect in Infancy: A Longitudinal Color-Flow Doppler Echocardiographic Study

To determine the course of right ventricular pressure (RVP) in patients with isolated ventricular septal defect (VSD) and factors influencing it, unselected 148 infants were followed-up longitudinally with color-Doppler echocardiography from a median age of 1 month for 201 patient-years. The patients were divided into three groups by absolute echographic size of VSD: group I, ≤4.0 mm; group II, >4 to ≤7 mm; group III, >7 mm. Sixty percent belonged to group I. Muscular defects dominated in group I, perimembranous defects dominated in group II, and those with outlet extensions dominated in group III. Peak systolic RVP was obtained by Doppler-estimated difference between systolic brachial artery and peak gradient across the VSD. Initial RVP ranged between 15 and 95 mmHg and increased in parallel to the size of defect. According to the regression equations RVP decreased in general by 0.17 mmHg per month. This correlated significantly with the size of the defect. In group I, the rate of decrease was very fast and is best expressed by a log function of time (r=−0.67, r ²= 0.45). In groups II and III the rate of decrease was less steep and had a greater variability. RVP normalized in 100% in those of group I and in 90% of group II, at median ages of 0.17 and 0.33 years, respectively. Median Q _p:Q _s values were 1.5, 2.2, and 3.0 in groups I–III, respectively. The outcome depended on the size of VSD. Spontaneous closure was observed in 51% of group I, 10% of group II, and none of group III. The rate was higher in muscular defects. Congestive heart failure was present in 53% and 100% in groups II and III, respectively. Death rate was 2.03%, all in patients with large defects. It is concluded that the temporal course of RVP with time can be estimated fairly well by the regression equation presented in relation to the initial size of the VSD.     

Effect of Antiepilepsy Drug Therapy on Ventricular Function in Children With Epilepsy: A Tissue Doppler Imaging Study

Impaired cardiac myocardial function may contribute to the risk for sudden unexpected death of a patient with epilepsy. This study aimed to investigate the effect of antiepilepsy drugs (AEDs) on cardiac function in pediatric epileptic patients using standard and tissue Doppler imaging (TDI) echocardiography. This hospital-based, prospective cross-sectional study investigated 52 epileptic children (mean age 9.3 ± 3.1 years) treated with AEDs (duration 2.4–10.0 years) and 36 healthy children (mean age 9.5 ± 4.0 years). In the epilepsy group, standard echocardiography showed increased left ventricular (LV) end-diastolic and end-systolic diameters, an increased LV mass index, and preserved ejection fraction. The patients also exhibited increased mitral peak A-wave velocity and mitral E-wave deceleration time as well as a decreased mitral E/A ratio. The E/Em ratio was significantly higher in the epilepsy group (5.6 ± 1.2) than in the control group (5.2 ± 1.1) (p = 0.016). In the epilepsy group, TDI showed an increased isovolumetric relaxation time and myocardial performance index (MPI). It also exhibited decreased early diastolic velocity (Em) and a decreased mitral annular displacement index in these patients. There were positive correlations between the LV lateral wall MPI (r = 0.231), septal MPI (r = 0.223), and LV mass index (p < 0.05) but no correlation with the duration of AED treatment. The authors detected subclinical ventricular dysfunction associated with AEDs at a preclinical stage. They suggest that TDI can be useful for determining the short- and long-term cardiac effects of AEDs.     

On-Line Automated Border Detection for Echocardiographic Quantification of Right Ventricular Size and Function in Children

Rapid, accurate assessment of right ventricular (RV) size is important for the management of children with congenital heart disease. The usefulness of the Acoustic Quantification system of automated border detection (ABD) and on-line quantification (AQ) for assessment of RV size was tested in 36 children. AQ data were compared to ``corrected AQ' measurements (after correction for cavity areas erroneously included in the region of interest) required for AQ. Furthermore, the influence of necessary changes to gain settings was tested in ``lateral gain control' (LGC) images obtained by removal of ABD overlays. All results were compared to conventional echocardiography (echo), and agreement with magnetic resonance imaging (MRI) RV areas was assessed. Systematic differences (±) limits of agreement with MRI (transverse plane) for conventional echo and AQ (apical four-chamber view) were as follows: end-diastolic −0.8 ± 3.8 (conventional echo) versus −1.7 ± 4.6 (AQ) cm²/m² (p < 0.001); end-systolic −1.3 ± 3.2 versus −4.9 ± 5.8 (AQ) cm²/m² (p < 0.001); fractional area change 7.8 ± 17.0% versus 26.9 ± 31.4% (AQ) (p < 0.001). Differences between conventional echo, LGC, and corrected AQ areas were not statistically significant. The best agreement between MRI and echocardiography was with conventional echo. We conclude that automated border detection of the RV can be performed successfully with the AQ system at a fixed point in the cardiac cycle. For adequate assessment of RV function manual corrections of online AQ results are still required, which results in an important reduction of the time gain of on-line quantification.     

脉冲振荡肺功能在儿童支气管哮喘中的应用

目的探讨脉冲振荡肺功能在儿童支气管哮喘(哮喘)中的临床意义。方法选取哮喘患儿60例。其中急性发作期36例(急性发作组),临床缓解期24例(临床缓解组),健康儿童20例(健康对照组)。采用Master Screen脉冲振荡肺功能仪分别检测3组肺功能情况。结果哮喘急性发作组患儿振荡频率5 Hz、20 Hz时呼吸道阻力(R5、R20)(单位:Kap.L-1.s-1)、振荡频率在5 Hz、20 Hz时呼吸道阻力之差(R5-R20)为周围呼吸道阻力、肺弹性阻力(X5)的负值、呼吸阻抗(Zrs)及共振频率(Fres)[分别为(1.28±0.31)、(0.85±0.13)、(0.43±0.23)、(-0.59±0.19)、(1.42±0.37)Kap.L-1.s-1和(25.32±3.00)Hz]均较临床缓解组[分别为(0.81±0.11)、(0.56±0.24)、(0.23±0.99)、(-0.27±0.08)、(0.86±0.11)Kap.L-1.s-1和(20.41±1.98)Hz]、健康对照组[分别为(0.63±0.03)、(0.48±0.23)、(0.27±0.11)、(-0.23±0.05)、(0.52±0.21)Kap.L-1.s-1和(14.30±0.85)Hz]高(Pa<0.001)。临床缓解组患儿R5、Zrs、Fres较健康对照组仍高(t=6.79、6.80、12.83,Pa<0.001)。而R20、R5-R20、X5差异无统计学意义(t=1.14、1.33、1.79,Pa>0.05)。结论脉冲振荡肺功能可提供哮喘发作及缓解的各项客观指标,并可作为哮喘患儿肺功能检测及治疗监测的方法。     

组织多普勒评价轻症病毒性心肌炎患儿左心室舒张功能

目的比较脉冲多普勒与组织多普勒对轻症病毒性心肌炎(VM)患儿左室舒张功能检测的价值。方法应用组织多普勒测量轻症VM患儿60例二尖瓣环侧壁处舒张早期和晚期运动峰值速度(Ea、Aa),计算Ea/Aa值;应用脉冲多普勒测量其二尖瓣口血流E、A峰流速(E、A)和E/A;并与40例正常儿童对照。结果组织多普勒显示患病组Ea峰值流速减低、Aa峰值流速增高、Ea/Aa值减低;脉冲多普勒显示E峰峰值流速减低、A峰峰值流速增高、E/A值减低。患病组28例Ea/Aa<1(47%),10例E/A<1(17%),组织多普勒评价轻症VM患儿左室舒张功能(u=3.53 P<0.01)。结论VM患儿早期即可出现左室舒张功能减退,组织多普勒评价左室舒张功能较脉冲多普勒更敏感、准确。     

Three-Dimensional Echocardiographic Measurement of Left Ventricular Stroke Volume in Children: Comparison with Doppler Method

Three-dimensional echocardiography (3DE) allows calculation of ventricular volumes without geometric assumption on the ventricular shape. Our aim was to apply 3DE in a normal pediatric population and to compare the left ventricular stroke volume measurements to the Doppler method. Twenty-four normal patients (median age 7 years) underwent Doppler echocardiography and 3DE for left ventricular stroke volume calculation. The left ventricular stroke volume by Doppler method was calculated as the product of the aortic Doppler flow mean velocity and the area of the aortic annulus. The 3DE method was performed using a transthoracic rotational probe (TomTec) and left ventricular volumes were calculated using the Simpson's rule. The mean time for 3DE acquisition was 90 seconds without any sedation. 3DE correlated well with the Doppler method for left ventricular stroke volume measurements (y= 0.8x− 0.2, r= 0.94). The mean difference between the average values of left ventricular stroke volume obtained by Doppler method and 3DE was 5 ± 4 ml. Intraobserver and interobserver variabilities in the left ventricular stroke volume measurement by 3DE were 2.6% and 4.4%. In conclusion, 3DE compared to the Doppler method is an accurate, noninvasive, and reproducible method to measure the left ventricular stroke volume in normal children.     

Echocardiographic Evaluation of Ventricular Function in Children With Pulmonary Hypertension

Although described in adults, it remains unclear whether ventricular dysfunction exists in pediatric patients with pulmonary hypertension (PHN). The goal of this study was to identify differences in echocardiographic indices of ventricular function among pediatric PHN patients. From 2009 to 2011, pediatric PHN patients with normal intracardiac anatomy and age-matched controls (1:3 ratio) were enrolled in this retrospective case–control study. Diagnosis of PHN was based on tricuspid regurgitation velocity or septal position estimating right-ventricular (RV) pressure >50 % systemic. Measures of RV and left ventricular systolic and diastolic function, including tissue Doppler imaging (TDI) of the mitral annulus (MA) and tricuspid annulus (TA), were compared. Enrollees included 25 PHN patients and 75 age-matched controls (mean age 7.5 years [range 1 day to 19 years]). Parameters of RV systolic and diastolic function were worse in PHN patients. Compared with controls, PHN patients had significantly decreased tricuspid valve inflow ratio, decreased TA TDI early diastolic velocities, decreased systolic velocities, increased tricuspid E/E’ ratio (all p < 0.01) and increased myocardial performance index. In an age-stratified analysis, TDI measures in PHN patients <1 year of age were similar to controls, whereas differences in TA TDI velocities and MA TDI velocities were noted in patients ≥1 year of age. Abnormalities in Doppler echocardiographic indices of ventricular systolic and diastolic function were identified in pediatric PHN patients and were more prominent with older age. These indices are promising for serial noninvasive monitoring of disease severity, but further correlation with catheterization-derived measures is needed.     

Bronchial Asthma in Singapore Children

The incidence of bronchial asthma admissions to Singapor's major Paediatric Units has increased over the years. The diagnosis of asthma was usually simple but patients with atypical presentations required the demonstration of bronchial lability to confirm the diagnosis. National statistics revealed a small but constant number of deaths from asthma in childhood. Underestimation of severity and delay in treatment were important contributing factors to deaths from asthma.     

哮喘控制问卷在支气管哮喘患儿中的应用

目的对哮喘控制问卷(ACQ)和改良哮喘控制问卷(不计肺功能,简称ACQ6)在儿童哮喘控制评估中应用的可行性进行探讨。方法选取青岛大学医学院附属医院哮喘专家门诊确诊的哮喘患儿102例,进行肺功能测试,包括一秒钟用力呼气量占预计值百分比(FEV1%)和最大呼吸流量占预计值百分比(PEF%),并进行ACQ调查;同时根据2006《哮喘管理和预防的全球策略》的哮喘控制分级标准,对哮喘患儿进行病情界定并分为控制组、部分控制组及未控制组。对3组患儿ACQ和ACQ6得分进行比较;并以FEV1%和PEF%为分组依据,比较ACQ6得分在不同FEV1%、PEF%组间的差异,分析ACQ6得分与FEV1%和PEF%的趋同性和一致性;分别对ACQ得分、ACQ6得分、FEV1%、PEF%与专家哮喘控制评估结果进行相关性分析,以检验其相关密切程度。结果 3组哮喘患儿的ACQ和ACQ6得分比较差异有统计学意义(F=171.52、117.14,Pa<0.01);ACQ6得分在不同FEV1%、PEF%水平间差异均有统计学意义(F=69.53、76.20,Pa<0.01);ACQ6与FEV1%的Spearman相关系数为-0.818,与PEF%的Spearman相关系数为-0.862,ACQ6与PEF%的相关性较FEV1%的相关性高;ACQ得分、ACQ6得分、FEV1%及PEF%与专家评估结果的Spearman相关系数分别为0.931、0.915、-0.878和-0.882,与专家评估结果关系的密切相关程度从高到低依次为ACQ>ACQ6>PEF%>FEV1%。结论 ACQ和ACQ6对不同哮喘控制水平的患儿具有良好的鉴别能力。ACQ完全可应用于儿童哮喘控制水平的评估;在缺乏肺功能设备的基层医院,ACQ6值得推广应用。     

Quantitation of the Global Right Ventricular Function in Children with Normal Heart and Congenital Heart Disease: A Right Ventricular Myocardial Performance Index

Although the assessment of right ventricular (RV) function is important in the clinical management of children with congenital heart disease, available imaging techniques have been limited because of the complex geometry of the right ventricle. A new Doppler index combining systolic and diastolic time intervals (the Tei index) has been reported to be useful for the assessment of global RV function in adults. However, normal values in children, age-related changes, and the clinical utility of the Tei index with regard to congenital heart disease have not been demonstrated. The purpose of this study was to prospectively assess RV function in children with normal heart and congenital heart disease using the Tei index. The subjects included 150 healthy children and 43 patients with congenital heart disease (35 patients with atrial septal defects and 8 patients who had had a Senning operation). The index was defined as the sum of isovolumetric contraction time and isovolumetric relaxation time divided by ejection time and was measured from conventional RV outflow and inflow Doppler velocity profiles. The Tei index was not affected by age in healthy children (0.24 ± 0.04). There was a significant difference in index rating between patients who had had a Senning operation (0.58 ± 0.09) and healthy children (p < 0.01), but there was no significant difference between children with atrial septal defect (0.25 ± 0.13) and healthy children. The Tei index is a feasible approach to use when assessing global RV function in children with congential heart disease.     

Effects of Transdermal Nitroglycerin in Children with Congestive Heart Failure: A Doppler Echocardiographic Study

The aim of this study was to evaluate by Doppler echocardiography whether administration of transdermal nitroglycerin (NTG) to children with congestive heart failure could modify mitral flow velocity profile with redistribution of left ventricular filling to late diastole, suggesting preload reduction of the left ventricle. Twelve children with congestive heart failure, aged from 6 months to 6 years (2.83 ± 2.24 years; mean ± SD), were recruited. Patients were randomly allocated either a NTG patch (study group; n= 6) or a placebo patch (control group; n= 6) in a double-blind procedure. The NTG patch was a 10-cm² patch releasing 5 mg of NTG per day. NTG patches were adjusted to a dose of 1 cm²/kg/day (0.5 mg/kg/day). Peak velocity and time–velocity integral (TVI) of E and A waves of transmitral flow, the ratio of the velocities of the A wave and E wave, and the ratio of the TVI of the A wave to the TVI of the E wave were measured. Doppler measurements were determined before treatment (H0) and 4 hours (H4) and 23 hours (H23) after the patch application. Relative changes of these parameters were not significantly different between these two groups. In the NTG group, mean NTG plasma concentration was 1.08 ± 0.47 μg Liter⁻¹ at H4 (n= 5) and 1.18 ± 0.81 μg Liter⁻¹ at H23 (n= 5). No patient had a NTG plasma concentration greater than 2 μg Liter⁻¹ either at H3 or at H24. These data suggest that 1 cm²/kg transdermal doses of NTG may have a limited bioavailability or a higher clearance and minimal hemodynamic effects in children with congestive heart failure already receiving other medications, implying that higher doses should be used.     

Assessment of Atrial Electromechanical Delay Using Tissue Doppler Echocardiography in Children with Asthma

Right ventricular (RV) dysfunction, pulmonary hypertension, atrial enlargement, and cor pulmonale may be associated with asthma. These pathological conditions may disturb the electrophysiological properties of the right atrium. This study investigated the atrial electromechanical delay and P-wave dispersion (PWD) in patients with asthma. Thirty-four children aged 8–16 years who were being followed up for asthma constituted the patient group, and 34 age- and body mass index-matched patients constituted the control group. Both groups underwent RV tissue Doppler measurements, intra-right atrial conduction time (IRCT-echo) determination, intra-left atrial conduction time (ILCT-echo) determination, inter-atrial conduction time (IACT-echo) determination, and PWD measurement. The IRCT-echo (14.38 ± 5.46 and 8.20 ± 3.90 ms; p < 0.001) and IACT-echo (28.97 ± 6.58 and 22.79 ± 6.28 ms; p < 0.001) were higher in patients with asthma than in the control group. The PWD (44.58 ± 17.51 and 38.11 ± 13.50 ms; p = 0.09), maximum P-wave duration (87.94 ± 18.20 and 82.44 ± 16.36 ms, p = 0.19), minimum P-wave duration (43.58 ± 9.95 and 44.79 ± 9.13 ms; p = 0.60), and ILCT-echo (15.88 ± 5.40 and 14.58 ± 4.94 ms; p = 0.30) were similar between the two groups. The IRCT-echo was positively correlated with the isovolumetric relaxation time of the lateral tricuspid annulus (r = 0.60; p < 0.001) and with the myocardial performance index of the lateral tricuspid annulus (r = 0.59; p < 0.001) in patients with asthma. The IRCT-echo and IACT-echo were higher in patients with asthma than in the control group. The deterioration of the electrophysiological properties of the right atrium may result in a risk of atrial fibrillation in patients with asthma.     

支气管哮喘儿童的心理行为评价

目的分析支气管哮喘儿童的心理行为。方法采用儿童行为量表（CBCL）分别对支气管哮喘和健康儿童各100名进行问卷调查，并计算总分和行为因子，用SPSS12．0统计软件进行对比分析。结果哮喘儿童行为问题发生率显著高于健康儿童组，两组比较有显著差异（P〈0．05）；哮喘与同性别健康儿童的行为问题因子比较有显著差异（P〈0．05）。结论支气管哮喘儿童易发生心理行为异常。