Evaluation Of Cardiac Structure And Cardiac Function Changes In The Preterm Neonates By Echocardiography

Objective 1.To study heart structure,lumen diameter and ventricular wall thickness in preterm neonates of different gestational age by echocardiographic.2.To study heart function in preterm neonates by echocardiography and its new technology.3.To evaluate preterm neonatal cardiac structure and function noninvasiveby echocardiograph as to provide theoretical basis for clinical diagnosis and treatment. Methods 120 cases of premature infants included in the study were divided into 3 groups according to gestational age, less than 29+6 weeks, 30 weeks to 33+6 weeks, 34 weeks to 36 weeks, were defined as the 1 group, 2 group, 3 group. 2 days after birth in preterm infants, using VIVIDI color Doppler ultrasound examination,keeping premature infants in a quiet state and supine,obtaining serial echocardiographic views, excluding congenital heart disease, patent ductus arteriosus(diameter>2mm) and arrhythmia, then had the following measurement.Using the two-dimensional echocardiography,at the R wave peak, namely end-diastolic measuring RVDd, IVSd, LVDd, LVPWd, AOD,at the T wave terminal,namely the end systolic,measuring LADs, an LVDs.Took the parasternal short axis view and measured the MAP at the end systolic;Took subxyphoid four chamber view and measured the RVAW at the end diastolic. At the standard parasternal long axis view, measured LVEF and LVFS,then took the the standard apical four chamber view and measured TAPSE 、MAPSE respectively at the lateral tricuspid valve ring plane and the lateral mitral valve ring plane by M type echocardiography. Took the the standard apical four chamber view, placed sampling line respectively at the mitral, tricuspid valve leaf tips, get the blood flow velocity spectrum of tricuspid valve and mitral valve by pulse wave Doppler,then measured the TV-E,TV-A, TV-E/A, the MV-E, MV-A, MV-E/A using the software of the ultrasound.In the the standard apical four chamber view,measured the S’, E’,A’,E’/A’of at the lateral tricuspid valve ring plane and the lateral mitral valve ring plane,Use of myocardial velocity curve showed by PW-TDI, according to Tei index =(IVCT + IVRT)/ET and calculated the left performance. Combining the PW and PW-TDI measurements results,calculated TV-E/E’,MV-E/E’. To reduce the error,every index above was an average of three cardiac cycle. All the data was measured by the one people to reduce the error between the different people.Results1. The LVDd, an LVDs, LAD, LVPWd, AOD, RVDd, RVAW, MAP and IVSd index measured by two-dimensional echocardiography in different gestational age groups was statistically difference(p < 0.05).2.LVEF, LVFS, TAPSE, MAPSE measured by M type echocardiography between the three groups were statistically significant(p < 0.05). ITASPE of 29 + 6 weeks or less, 30 ~ 33+6 weeks, 34 ~ 36+6 weeks group was respectively(0.52±0.05),(0.67±0.03),(0.75±0.02)cm, and MASPE was respectively(0.40±0.02),(0.44±0.01),(0.48±0.01) cm. In the same gestational age group TAPSE were greater than MAPSE. 3.TV-E, TV-A, TV-E/A indexes of the right heart diastolic functionhad no statistical difference between three groups.MV-E, MV-A, MV-E/A indexes of the left heart diastolic function had no statistical difference between 1 and 2 group(P<0.05), Difference of 1 group, 2 group compared with 3 group was statistically significant(P<0.05). MV-E/A ratio were greater than 1, TV-E/A ratio less than 1.These indexes were measured by PW.4.MV-S’, MV-E’, MV-A’, TV-E’,TV-A’, TV-S’ of cardiac function indexes measured by PW-TDI had statistics difference between the three groups(P<0.05); For MV-E/E’,MV-E’/A’,TV-E/E’,TV-E’/A’,there were no statistically significant difference between 1 and 2 group(P>0.05), but difference of 1 group, 2 group compared with 3 group was statistically significant(P<0.05).In 1 group, 2 group and 3 group,MV-E/E’ was respectively(10.65±2.56),(10.53±2.86),(8.17±2.27), TV-E/E’ was(9.19±2.15),(8.11±2.00),(7.08±2.40) respectively. LVTei index,RVTei index calculated by PW-TDI related measurements was no statistical difference between three groups(P > 0.05), but the three groups of Tei index have difference between left and right ventricular(P < 0.05), LVTei index greater than RVTei index.Conclusion1.Preterm neonatal heart chamber size, ventricular wall thickness and large blood vessel diameter indexes measured by two-dimensional echocardiography,increases with the increase of gestational age, has a good correlation with gestational age, weight and body surface area.2. The LVEF, LVFS, TAPSE, MAPSE, MV-S’, TV-S’ indexes results shows that eft ventricular systolic function gradually improve along with the increase of gestational age;MV-E’, MV-A’, TV-E’,TV-A’ indexes shows that left and right ventricular diastolic function gradually improves along with the increase of gestational age. MV-E/A ratio were greater than 1, TV-E/A ratio is less than 1, RVTei index, LVTei index, E, A, E/A and TV-E/E’, MV-E/E’ ratio of mitral valve and tricuspid valve in different gestational age groups have no obvious trend.3.In preterm neonates, TAPSE, MAPSE, MV-E’, MV-A’, TV-E’,TV-A’ indexes shows that right ventricular systolic and diastolic function is better than in the left ventricle.