Effects of heart rate and right ventricular pressure on right coronary arterial flow and its systolic versus diastolic distribution in a variety of congenital heart diseases in children

BACKGROUND AND METHODS: In order to elucidate the underlying adjusting mechanism of human right coronary arterial (RCA) flow to increased right ventricular pressure (RVP) in children, we recorded RCA flow velocity in 24 pediatric cardiac patients at the orifice of its main trunk at the time of heart catheterization using the Doppler guidewire. RESULTS: The ratio of diastolic flow (DF)/total flow (TF), or the proportion of the DF time integral over a total of one cardiac cycle, had a negative correlation with heart rate (HR; r = -0.58, n = 11) in children with normal right ventricular systolic pressure (RVSP; RVSP < 35 mmHg). In contrast, the DF/TF ratio had a good correlation (r = 0.88, n = 24) with RVSP in all patients under study. The ratio of diastolic area (DA)/total area (TA), defined as the ratio of an area encircled by the aortic pressure curve above and the RVP curve below for diastole, over a total of one cardiac cycle, representing the overall effect of both HR and transcoronary pressure difference, also correlated well (r = 0.89, n = 24) with DF/TF. Total volume flow of the RCA also increased (r= 0.76, n = 24) with increases in RVSP, first by an increase in flow velocity through the RCA, during both systole and diastole, then by widening of the RCA lumen at very high pressures. These changes were initially more dependent on diastole with increasing RVSP because: (i) of a more marked augmentation of flow velocity in diastole compared with systole; and then (ii) of a significant decrease in flow velocity in systole at very high pressures. CONCLUSIONS: We clarify how the RCA manages to increase flow through it at different HR as a function of chronic RVP overload in pediatric cardiac patients.     

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??Abstract??Objective To investigate the correlation among plasma N-terminal pro-brain natriuretic peptide ??NT-proBNP?? and right ventricular Tei ??RVTei?? and right ventricular fractional area change ??RVFAC?? in children with pulmonary hypertension. Methods From January 2007 to November 2012??echocardiography and serological examination data of 38 patients from Samsung Seoul Hospital in Korea were retrospectively analyzed. Patients were divided into two groups ??16 cases with 30??PASP??70mmHg ??mild to moderate?? and 22 cases with PASP≥70mmHg ??severe??. Results ??1??RVFAC?? PASP and plasma concentration of NT-proBNP had a statistically significant difference??P??0.05?? between mild to moderate PAH group and severe PAH group . RVTei index had no difference between the two groups??P??0.05??. ??2??Correlation analysis??the plasma concentration of NT-proBNP had a positive correlation ??r = 0.544??P??0.05??with PASP??a negative correlation??r = -0.767??P??0.05??with RVFAC??RVFAC had a negative correlation??r = -0.711??-0.767??P??0.05?? with PASP and the plasma concentrations of NT-proBNP?? the RVTei had no correlation with the plasma concentration of NT-proBNP?? PASP or RVFAC??r = -0.041??-0.048??0.016??P??0.05??. Conclusion Whether there are correlations between the plasma concentration of NT-proBNP and RVFAC depends on the degree of PAH. This suggests that the plasma concentration of NT-proBNP and RVFAC can be used as evaluation of right ventricular function in children with pulmonary hypertension.     

室间隔完整的肺动脉闭锁合并右室依赖冠状动脉循环胎儿超声心动图特征

目的 探讨室间隔完整的肺动脉闭锁（PA/IVS）合并右室依赖冠状动脉循环（RVDCC）胎儿超声心动图特征,提高对本病的认识及诊断的准确率。方法 回顾性分析2010年9月至2013年5月于首都医科大学附属北京安贞医院儿童心血管病中心就诊,经超声心动图确诊的4例PA/IVS合并RVDCC的胎儿超声心动图特征,并与PA/IVS未合并RVDCC的胎儿和正常胎心胎儿超声心动图表现进行比较。结果 4例PA/IVS合并RVDCC胎儿中,3例引产后经尸解证实,1例出生后经超声心动图证实。与PA/IVS未合并RVDCC胎儿及正常胎心胎儿超声心动图表现比较,PA/IVS合并RVDCC胎儿超声心动图除了具有室间隔完整的肺动脉瓣膜性闭锁的一般超声影像学特征（室间隔完整、肺动脉膜性闭锁和动脉导管逆灌等）外,还具有：①右心室显著发育不良、右室壁多显著肥厚、三尖瓣口（环）径明显缩小和Z值﹤-3;②彩色多普勒血流显像显示右室心肌内冠状窦隙开放,形成右心室与冠状动脉的异常血流交通;③异常血流方向为从右心室至冠状动脉灌注为主的双期双向血流信号。结论 胎儿超声心动图可准确诊断PA/IVS合并RVDCC,一经确诊,应尽早采取相应的干预措施。     

特发性室性期前收缩患儿心率变异性和心率减速力的研究

目的探讨不同起源特发性室性期前收缩患儿的心率变异性(HRV)与心率减速力(DC)各项指标的关联性。方法回顾性分析155例特发性室性期前收缩患儿的临床资料,按不同年龄组分为婴幼儿期(3岁),学龄前期组(3~6岁)和学龄期(~16岁),并在不同年龄组内按室性期前收缩来源部位不同,分为右室型组和左室型组;比较分析不同年龄组、不同来源期前收缩组之间HRV与DC各指标的差异。结果三个不同年龄组的DC和HRV时域分析各项参数的差异均有统计学意义(P0.05)。婴幼儿组中,右室型组和左室型组间相邻RR间期差值的均方根(RMSSD)、高频功率(HF)、低频功率(LF)/HF、DC、相邻RR间期差值50 ms的百分数(PNN50)差异均有统计学意义(P均0.05);学龄前期组中,右室型组和左室型组间的RMSSD、LF、HF、LF/HF、DC差异有统计学意义(P均0.05),学龄期组中,右室型组和左室型组间的RMSSD、HF、LF/HF、DC差异均有统计学意义(P均0.05)。结论特发性室性期前收缩患儿自主神经平衡调节受损,以迷走神经张力的降低为主;起源于优势心室(婴幼儿期及学龄前期患儿以右心室占优势,学龄期患儿左心室为优势心室)的频发室性期前收缩,增加了恶性心律失常发生的风险。     

Unique variant of Taussig-Bing heart: Double-outlet right ventricle with double ventricular septal defects and double overriding of great arteries

Summary A cyanotic, tachypneic newborn was diagnosed to have double-outlet right ventricle of the Taussig-Bing type. Cardiac failure did not respond to medical treatment or surgical palliation. Postmortem examination revealed two ventricular septal defects (VSDs), one a malalignment VSD in the membranous septum and adjacent tissue and the other in the anterosuperior part of the muscular septum. The D-malposed aortic root emerged mainly from the right ventricle, with aortic-mitral continuity. The larger posterolateral pulmonary root arose almost entirely from the right ventricle, confluent with the muscular VSD, and unrelated to the mitral valve. Its right ventricular aspect was obstructed by hypertrophied infundibulum.This unique malformation of the heart functioned as a double-outlet right ventricle of Taussig-Bing type. In addition, however, the malformation had elements of tetralogy of Fallot because of the malaligned VSD and hypertrophied conal musculature (although pulmonary flow was excessive), and also of complete transposition of the great arteries because of the arrangements of the two VSDs, which favored aortic flow from right ventricle and pulmonary blood flow from the left ventricle. Thus, a single heart presented similarities to three anatomic and functional entities.     

先天性心脏病肺动脉高压手术前后右心功能变化和治疗

目的 了解先天性心脏病左向右分流导致的重度肺动脉高压对右心功能的影响以及手术矫治后右心功能的恢复状态。方法 对室间隔缺损(室缺)合并重度肺动脉高压(全肺循环阻力增加)的40例患儿，用心导管的方法进行术前、术后5～7年右心功能、肺循环的血流动力学随访测定。结果 术前右心心搏指数、作功指数、心排指数显著高于术后；术前右房压、右室收缩压及舒张压、肺动脉压力和阻力均增高，缺损修补后右室舒张压恢复正常，收缩压的降低与肺动脉压力下降有关；大型室缺左向右分流重度肺动脉高压右心功能不全系继发性右室高排出量心力衰竭，且伴有舒张功能障碍。结论 治疗心力衰竭不宜首选正性心肌收缩药物；降低肺动脉压力、减少左向右分流、根治心内畸形是合理的选择；术后右室收缩压持续不能恢复至正常水平，提示继发性肺血管梗阻性病变存在。     

不同剂量野百合碱诱导SD幼鼠右室阻力负荷性心力衰竭模型的比较

目的采用不同剂量野百合碱(monocrota line,MCT)诱导SD幼鼠右心衰竭模型,探讨适合的右心衰竭模型制作方法。方法清洁级SD雄性幼鼠125只,随机分为G0、G1、G2、G3、G4组,每组各25只SD幼鼠。G1～G4组幼鼠分别一次性腹腔注射MCT 30、40、50、60 mg/kg,诱导制作右心衰竭动物模型;G0组为对照组,给予生理盐水腹腔注射。腹腔注射后每2周1次,采用彩色多普勒超声仪测SD幼鼠右心室横径、三尖瓣反流速度、肺动脉压、射血分数(EF值)、缩短分数(FS值),共检测6周,4次;随后处死SD幼鼠,取心脏、肺组织病理切片对比观察。结果 G0组SD幼鼠无死亡,G1、G2、G3组SD幼鼠的死亡率远远低于G4组。各组SD幼鼠右心室横径逐渐增大,G1～G4组较G0组更明显(P<0.01);G0组SD幼鼠各时期的三尖瓣反流速度、肺动脉压无明显改变,而G1～G4组逐渐增高(P<0.01)。G1组SD幼鼠肺动脉仅出现轻度新生内膜病变,心脏组织病理切片无明显改变;G2组SD幼鼠肺动脉可见较明显新生内膜病变,心脏组织病理切片可见明显炎性细胞浸润;G3、G4组SD幼鼠肺组织病理切片可见中小动脉中膜明显增厚和小动脉肌化,部分肺组织远端小动脉闭塞,肺泡内可见心衰细胞,右室心肌细胞肥大伴纤维组织增生。结论 50 mg/kg MCT可成功诱导建立肺动脉高压致右心衰竭模型,其病理变化可更好模拟重度肺动脉高压致右心衰竭,且实验动物有较高的生存率。     

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目的总结法洛四联症和右室双出口合并冠状动脉畸形手术治疗经验,探讨冠状动脉畸形对右室流出道重建的影响。方法1989年4月至2004年5月治疗合并冠状动脉畸形的法洛四联症和右室双出口患儿20例,其中单支冠状动脉畸形11例,左前降支起自右冠状动脉6例,右冠状动脉肺动脉瘘2例,左右冠状动脉交通支形成蔓状血管丛1例。行姑息手术1例,根治术19例。结果根治术早期死亡1例,18例随访10个月至8年,残余漏2例,残余梗阻3例,余结果满意。结论根据畸形冠状动脉走行特点,选择手术切口,避免损伤异常冠状动脉。有些术中被迫使用异体材料或无法行根治术,影响了中远期效果,应引起足够重视。     

Left and right ventricular volume characteristics in tetralogy of Fallot and their relationship to arterial oxygen saturation and age

Left (LV) and right ventricular (RV) volume characteristics in 43 patients with tetralogy of Fallot (TOF) undergoing no prior surgical intervention, aged 3–50 months, were evaluated. The control group consisted of 45 patients with Kawasaki disease without cardiac lesions, aged 12–82 months. The TOF patients were divided into four groups: those having arterial oxygen saturation < 80% with an age at the time of study < 18 months (group 1a) or with that ≧ 18 months (group 1b), and those with arterial oxygen saturation ≧ 80% with an age < 18 months (group 2a) or with that ≧ 18 months (group 2b). The results were compared with those in control subjects. In group 1a, each of LV end-diastolic volume (EDV), LV ejection fraction (EF), RVEDV and RVEF was reduced. In group 1b, LVEDV, LVEF and RVEF were decreased. In groups 2a and 2b, RVEF alone was depressed. From these results, the severity of hypoxemia was an important risk factor for ventricular dysfunctions. No influence of age on the volume characteristics was found. The investigations suggested that patients with TOF having an arterial oxygen saturation < 80% are probably candidates for early surgical intervention.     

Idiopathic infantile arterial calcification: Roentgen diagnosis of a rare cause of coronary artery occlusion

Infantile arterial calcification is a rare disorder of unknown etiology which is usually generalized and leads to death from coronary artery occlusion. The involved arteries show calcification of the internal elastic lamina and marked intimal proliferation. Vascular calcifications were demonstrated radiographically in 9 previously recorded cases. Three new patients are reported who presented with congestive heart failure. The visualization of faint vascular calcifications in the extra-thoracic soft tissues presented an opportunity to establish the diagnosis radiologically.Presented at the Annual Meeting of the Society for Pediatric Radiology, Washington, D. C. — October 1972.     

Reactivity of skin blood flow and heart rate to external thermal stimulation in anencephaly

Oscillations of skin blood flow and heart rate can be synchronised using external rhythmic thermal stimulation in healthy adults and infants. We examined the effect of thermal stimulation on the cutaneous circulation and heart rate of an anencephalic neonate using cutaneous laser Doppler flowmetry and ECG monitoring. The results suggest that synchronisation of SBF and HR to thermal stimulation can also be induced in an anencephalic newborn.     

Ventricle works as a converting organ of atrial blood flow: Physiological significance of mean ventricular pressure

The roles and characteristics of the ventricle were examined using mean ventricular pressure (MVP) in ventricular-vascular assocation. One hundred and two patients with congenital heart diseases who had undergone cardiac catheterization were studied. They were divided into five groups: Group 1, atrial septal defect without pulmonary hypertension (PH); Group 2, ventricular septal defect (VSD) without PH; Group 3, VSD with PH; Group 4, pulmonary valvular stenosis; and Group 5 as a control group. Then, we examined the relationships between mean pulmonary artery pressure (MPAP) and mean right ventricular pressure (MRVP), and also between mean systemic arterial pressure (MSAP) and mean left ventricular pressure (MLVP) among the five groups. Furthermore, we defined new indicators to express the ease of blood flow through each ventricle. They were referred to as a conductance of the right ventricle (CD_R) and a conductance of the left ventricle (CD_L), respectively. Then they were compared among the five groups. The values of MPAP/MRVP and MSAP/MLVP were kept constant to be about 1.3 and 1.7, respectively. Furthermore, CD_R was different betweeen each group according to the property of the pulmonary vascular bed, whereas CD_L took almost the same value among the five groups. The ventricle works as a converter of atrial blood flow so that it can achieve efficient blood transport.     

超声心动图评价心力衰竭患儿左、右心舒张功能

目的　探讨充血性心力衰竭（ＣＨＦ）患儿左、右心舒张功能及其相互关系。方法　对５１ 例ＣＨＦ患儿和６０ 例正常对照儿童用多普勒超声心动图测量左、右室充盈参数。结果　与正常对照组比较,ＣＨＦ组患儿左、右室充盈参数均显示舒张受损,且左、右室充盈参数呈良好相关。结论　ＣＨＦ组患儿均存在左、右心舒张功能障碍,且程度类型相似     

Effects of red cell transfusion on pulmonary blood flow and right ventricular systolic time intervals in neonates

Blood transfusion increases blood volume and blood viscosity of the neonate. Since both volume expansion and increase in blood viscosity may be associated with increased pulmonary artery pressure, we studied effects of transfusion (10 ml of red blood cells per kilogramme of body weight) on right ventricular output and right systolic time intervals by means of pulsed-Doppler echocardiography in 38 preterm infants with a mean (SD) gestational age of 28 (5) weeks (range 25–34), birth weight 1060 (395) g (range 480–1910), actual body weight 1875 (450) g (range 820–2790) and postnatal age of 44 (23) days (range 17–105). After transfusion, packed cell volume and haemoglobin increased significantly from 0.26 (0.044) to 0.38 (0.046), and from 8.2 (1.6) g/l to 12.8 (1.9), respectively. Blood viscosity increased from 1.78 (0.3) mPa to 2.68 (0.4) by 33%. Right ventricular output decreased significantly from 320 (57) ml/kg/min to 290 (70) due to decrease in heart rate by 7%. Blood pressure and right ventricular stroke volume did not change. There was a significant increase in pulmonary red cell transport (right ventricular output times packed cell volume) of 21%. Right ventricular pre-ejection period (RPEP), right time peak velocity (RTPV), right ventricular ejection time (RVET), and ratios of RTPV/RVET_(c), RPEP:RVET did not change after transfusion. Conclusion These results suggest that neither pulmonary artery pressure nor right ventricular function changed as a result of transfusion in spite of rising blood volume and blood viscosity. Received: 19 October 1996 / Accepted: 23 December 1996     

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。     

Increasing incidence of ventricular septal defects caused by improved detection rate

Meberg A, Otterstad JE, Frøland G, Sørland S, Nitter-Hauge S. Increasing incidence of ventricular septal defects caused by improved detection rate. Acta Pzdiatr 1994;83:653–7. Stockholm. ISSN 0803–5253
In a population-based study in childrcn born alive during the 10-year period from 1982 to 1991 ( n = 22 810), ventricular septal defects (VSDs) were diagnosed in 127 cases, an incidence of 5.6 per 1000. The incidence was significantly higher in the cohort of children born during the 6-year period from 1986 to 1991 than among those born in the preceding 4-year period, 1982–1985 (6.5 and 4.0 per 1000 respectively; p < 0.05). The increase was caused entirely by an increased detection rate of small defects in the muscular part of the interventricular septum after introducing echocardiography as a standard method for investigating suspect congenital heart defects in the neonatal period. This also explained entirely an increase in the total incidence of congenital hcart defects to 10.6 per 1000 in the last period from 8.4 per 1000 in the first, although this increase was not significant ( p > 0.05). Morc children born in 1986–1991 had spontaneous closure of their VSDs (75.5%) than those born in 1982–1985 (51.5%) ( p<0.05 ). In 69.3% of patients the VSDs closed during the first year of life. For the cohort born in 1986–1991, 84.6% of the defects located in the muscular part of the septum closed spontaneously. Small defects in the muscular part of the interventricular septum with spontaneous closure in early life may represent the tail of a normal developmental process, and not defects in the sense of malformations.     

室间隔缺损远离大动脉开口的右室双出口外科治疗与适应证选择

目的回顾室间隔缺损（VSD）远离2个大动脉开口的右室双出口（double—outlet right ventricle,DORV）的病理解剖特点、手术方法选择和治疗结果,对手术适应证和方法提出优化意见。方法1984年4月至2005年4月共有37例VSD远离2个大动脉开口的DORV患儿接受外科手术,年龄5个月～12岁,根据不同手术方法将病人分3组比较,其中心室内隧道修补术（intraventricular tunnel repair,IVR）组15例,Rastalli手术组10例,Fontan手术组12例。对限制性VSD,同时扩大VSD直径。结果手术住院死亡10例,死亡率27．0％（10／37例）,其中1999年4月后死亡2例,死亡率10．5％（2／19）。IVR的手术死亡率（46．7％,7／15例）明显高于Rastalli组（20％,2／10例）和Fontan组（8．3％,1／12例）。结论三尖瓣与肺动脉之问距离是否大于主动脉瓣口直径是区别选择IVR手术和Rastalli手术的主要依据。共同房室瓣、三尖瓣附属组织跨越或嵌入到VSD和主动脉之间的区域、两个心室发育不平衡是我们选择改良Fontan的主要适应证。     

小儿致心律失常性右室心肌病诊断及治疗分析

目的：总结小儿致心律失常性右室心肌病的诊断及治疗体会。方法：14例致心律失常性右室心肌病患儿,男7例,女7例,年龄3~14岁,予心电学、心脏超声、CT、磁共振等检查。分别予胺碘酮+普萘洛尔、索他洛尔治疗,其中2例药物治疗无效者予以导管射频消融治疗。6例心功能减退明显者予以强心、利尿及扩血管治疗。结果：14例均有频发室性早搏,8例见室性心动过速发作。10例检出Epsilon波。14例患儿均有右室扩大及右室射血分数减低。5例行CT检查及5例行磁共振检查患儿均可见到右室扩张、右室室壁变薄。经治疗7例未再出现室性早搏及室性心动过速,4例室性早搏及室性心运过速发作减少。2例予以射频消融治疗的患儿随诊3月未发现室性早搏及室性心动过速发作。心功能不全患儿经药物治疗病情改善。结论：致心律失常性右室心肌病临床表现多样,需综合心电学、心脏超声等多项检查才能临床确诊。药物治疗只对部分病例有效,射频消融治疗有望在室性心律失常治疗中发挥作用。［中国当代儿科杂志,2010,12（3）：165-168］