| 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. |
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