【作者】 高含；

【导师】 谢明星；

【作者基本信息】 华中科技大学 ， 超声诊断学， 2011， 硕士

【摘要】 动脉导管未闭(patent ductus arteriosus,PDA)是常见的先天性心脏病,占先心发病率的5-10%。动脉导管是连接主动脉和肺动脉的一种血管性结构,在胎儿血液循环中是必需的,出生后因胎盘前列腺素减少和遇氧而产生生理性收缩,形成功能上的关闭。若其持续开放,则成为降主动脉与肺动脉之间的异常通道。在PDA的病程初期,血液由压力高的主动脉流向压力低的肺动脉,即左向右分流,若分流量不大,肺循环阻力低于体循环,则仅有左心容量负荷的增加;若分流量很大,回流入左心的血过多,左室容量负荷过重,左房和肺静脉压上升,若此时肺循环阻力仍低于体循环,左室则因容量负荷超载而发生衰竭,而一旦肺循环阻力高于体循环,则出现肺动脉高压(Pulmonary arterial hypertension group,PAH ),导致右室压力负荷增加,影响右心功能,最终导致右心室肥厚、右心衰竭。本研究旨在应用超声斑点追踪成像技术定量分析PDA患者在未发生PAH以及已发生PAH两种情况下其右室的收缩功能及左室扭转运动特征并探讨PAH对PDA患者右室收缩功能及左室同步性运动的影响。根据肺动脉收缩压≥35mmHg(肺动脉收缩压=三尖瓣反流压差+右房压)为标准将动脉导管未闭患者35例分为合并肺动脉高压组(Pulmonary arterialhypertension, PAH组)12例和单纯的PDA组23例,应用超声斑点追踪成像技术测量右室游离壁、室间隔各节段及整体的收缩期峰值应变(Strain,S)、应变率(Strain rate,SR),并与37例正常对照组获取的上述指标进行组间比较。结果显示:①单纯PDA组患者右室游离壁各节段及整体收缩期峰值S均低于正常对照组(P <0.01);②PAH组患者右室游离壁、室间隔各节段及整体收缩期峰值S、SR均低于正常对照组及单纯PDA组(P <0.01)。根据肺动脉收缩压≥35mmHg(肺动脉收缩压=三尖瓣反流压差+右房压)为标准将动脉导管未闭患者35例分为合并肺动脉高压组(Pulmonaryarterialhypertension,PAH组)12例和单纯的PDA组23例,应用超声斑点追踪成像技术测量左室短轴观心底部及心尖部旋转角度峰值及达峰时间,计算左室扭转角度峰值及达峰时间、主动脉瓣关闭时间点扭转角度及时间,并与37例正常对照组获取的上述指标进行组间比较。结果显示:①PAH组患者左室心尖部旋转角度峰值、左室扭转角度峰值及主动脉瓣关闭时间点(AVC)的扭转角度均低于单纯PDA组和正常对照组(P<0.01),而PAH组患者左室心底部旋转角度峰值与另两组无统计学差异(P>0.05);②PAH组患者左室心底部旋转角度达峰时间早于主动脉瓣关闭时间,而心尖部旋转角度达峰时间及左室扭转角度达峰时间均迟于主动脉瓣关闭时间(P<0.01);③单纯PDA组患者与正常对照组各指标之间的差异均无统计学意义(P>0.05)。结论①超声斑点追踪成像技术可以客观评价动脉导管未闭患者的右室收缩功能,单纯动脉导管未闭患者右室收缩功能减低,合并肺动脉高压组患者右室收缩功能明显减低。②超声斑点追踪成像技术可无创地评价动脉导管未闭患者的左室扭转运动特征及左室运动的同步性。合并肺动脉高压组患者左室收缩功能受损,且左室运动不同步。更多还原

【Abstract】 Patent ductus arteriosus (PDA) is one of the most common congenital heartdiseases,accounting for 5-10% ofcongenital heart disease. The ductus arteriosus isanormalvascular structure which connects the aorta and pulmonary artery and allowsmost of the blood leaving the right ventricle to bypass the pulmonary circulation andpass into the descending aorta. Normally, functional closure of the ductus arteriosusoccursinhealthyinfantsafterbirth.Thisoccursbyabruptcontractionofthemuscularwall of the ductus arteriosus, which is associated with decresss in the production ofprostaglandin E2 (PGE2) and increases in the partial pressure of oxygen (PO2)coincident with the first breath. As many as 85% of the normal infant’s ductusarteriosus wasclosed and form the arterial ligament within two months. Cassels et aldefined true persistence of the ductus arteriosus as a patent ductus arteriosus presentin infants older than 3 months. A patent ductus arteriosus produces a left-to-rightshunt. In other words, it allows blood to go from the systemic circulation to thepulmonary circulation. Therefore, pulmonary blood flow is excessive. a largeleft-to-right shunt through a patent ductus arteriosus results in left atrial and leftventricular enlargement and even left heart failure. The pulmonary overcirculationresults in pulmonary arterial hypertensionpressure, right ventricular load resistanceIncrease,right ventricular enlargement and at last right heart failure. The aim of this research is to quantify the right ventricular systolic function and the left ventriculartwist in patients with patent ductus arteriosus byultrasound speckle tracking imaging,and to discuss the right ventricular systolic function and the left ventricularsynchronismundertheinfluenceofthepulmonaryarterialhypertensioncondition.35 patients with patent ductus arteriosus (PDA) patients were categorized intotwo groups according to pulmonary arterial systolic pressure (PASP): the pulmonaryarterial hypertension group(PAH group) and the pure PDAgroup. Right ventricularpeak systolic global and segmental strain (S), strain rate (SR) were measuredrespectively in 35 patients and 37 healthy controls by STI from the apical 4-chamberview, and compared the indexes above among the three group.Results:①Rightventricular peak systolic strain (S) of basal, mid, apical segment in free wall and theglobal S were lower in PDA group than the controls group (P<0.01), while higherthan the PAH group (P<0.01);②S and SR were significantly lower in PAH groupthanthecontrolsgroup(P<0.01).35 patients with patent ductus arteriosus (PDA) patients were divided into twogroups according to pulmonary arterial systolic pressure (PASP): the Pulmonaryarterialhypertensiongroup(PAHgroup)andthepurePDAgroup.Basalandapicalleftventricle (LV) short-axisimageswereacquiredintheallstudysubjects. Recorded andcalculatedthebasalandapicalleftventricularpeakrotation(Prot),leftventricularpeak twist (Ptw), twist at aortic valve closure (AVCtw) and time to Prot , Ptw andAVCtw respectively in 35 patients and 37 healthy controls, then compared theindexes above among the three groups. Results:①The apical left ventricular peakrotation, left ventricular peak twist and twist at aortic valve closure were lower inPAH group than pure PDA group and controls group (P<0.01);②The time to thebasal LV peak rotation was earlier than aortic valve closure (AVC) timing , while thetime to the apical LVpeak rotation and the LV peak twist (Ptw) delayed(P<0.01);③T here was no statistcs in all indexes between the pure PDAgroup and the controls(P>0.05).Conclusions:①STI may be used to objectively evaluate the right ventricular systolic function inpatients withPDA. Right ventricular systolic functionis decreasedinpatients ofPDAwithoutPAH,andobviouslydecreasedseverelyintheoneswithPAH.②STI can measure the LV rotation and twist noninvasively and evaluate the LVsynchronism in patients with PDA. Left ventricular systolic function is decreased andcausestheLVdyssynchronyinPDApatientswithPAH.更多还原