Echocardiographic systolic time intervals in premature infants with patent ductus arteriosus

Summary Thirty-six premature infants with respiratory distress syndrome and clinically significant patent ductus arteriosus (PDA) were studied by M-mode echocardiography before and after closure of the ductus. Before closure the ratio of left ventricular preejection period to left ventricular ejection time (LPEP/LVET) was .26±.03 (mean±SD). After closure of the ductus, LPEP/LVET was .38±.04 (mean±SD), significantly different from the value before closure but not significantly different from the value found in 21 control infants; also, a ratio < .30 was always associated with a clinically significant shunt. The combination of systolic time interval measurement with standard M-mode measurement of the left side of the heart enhanced echocardiographic detection of PDA in our series. Serial evaluation of systolic time interval measurements may provide a further index of left-to-right shunt through a PDA and be a valuable adjunct to the clinical management of these patients.Supported in part by grants from the Kentucky Heart Association.     

Echocardiographic characteristics of premature infants with patient ductus arteriosus

As part of a multicenter collaborative study, M-mode echocardiograms were obtained shortly after birth on 3,559 premature infants with birth weight less than or equal to 1,750 g. Of these infants, 1,496 did not develop a cardiac murmur or other signs of a "hemodynamically significant" patent ductus arteriosus (PDA). Echocardiographic parameters from this "normal" group were compared with results obtained from 415 infants in whom PDA was diagnosed on the basis of clinical findings alone, irrespective of the echocardiogram (PDA group). The best discrimination between the two groups, when considering a single parameter, was provided by a left atrial to aortic root ratio (LA/AO) of 1.40, a left ventricular to aortic root ratio (LV/AO) of 2.10, or a left ventricular systolic time interval ratio (LPEP/LVET) of 0.27. Multivariate analysis demonstrated that better separation between the two groups occurred when the left atrial to aortic root ratio and the left ventricular systolic time interval ratio were considered jointly. Because of a large degree of overlap of all echocardiographic variables between the normal group and the group with PDA, the echocardiogram alone was not a good indicator of PDA. However, when used in conjunction with a priori estimates of the probability of PDA (based, for example, on birth weight and degree of respiratory disease), use of echocardiographic data was found to improve the detection of hemodynamically significant patent ductus arteriosus in premature infants.     

Left ventricular thrombosis during infancy: Report of two cases

Two patients with left ventricular thrombosis diagnosed by echocardiography are presented. The first patient was a 6-week-old girl with supraventricular tachycardia. Cross-sectional echocardiography showed a rounded and mobile structure protruding from the left ventricular wall. The girl was in heart failure and had signs of peripheral embolization. After sinus rhythm had been restored the thrombus diminished gradually and the girl recovered. The second patient was a newborn boy with severe aortic stenosis and a large massive thrombus along the left side of the interventricular septum. The boy died after valvotomy, the postmortem examination confirmed the diagnosis of a large thrombus. Left ventricular thrombosis is uncommon in neonates and infants but may appear secondary to abnormal hemodynamics.     

Normal pulmonary vascular resistance and left ventricular hypertrophy in young infants with bronchopulmonary dysplasia: an echocardiographic and pathologic study

To evaluate the cardiac anatomy and functional hemodynamics in young infants with chronic lung disease, nine patients, aged 2 to 7 months, with a clinical diagnosis of bronchopulmonary dysplasia (BPD) underwent echocardiographic examination. All infants required supplemental O2 (mean FIO2 35%) to maintain adequate systemic oxygenation (Pao2 greater than 50 mm Hg). None of the infants had evidence of a patent ductus arteriosus at the time of examination. Echocardiographic measurements of left and right ventricular systolic time intervals revealed normal systolic time interval ratios suggesting pulmonary vascular resistances. However, echocardiographic evidence of left ventricular hypertrophy was found in eight of the nine infants, while right ventricular anterior wall thickness and right ventricular diastolic dimensions were not increased. Two infants died; marked left ventricular hypertrophy was noted at the time of postmortem examination while the right ventricular wall thickness was normal. The findings of left ventricular hypertrophy led to a retrospective review of autopsy material of seven patients who died with BPD over the past year. In six of seven cases examined, left ventricular posterior wall thickening was noted (range 7 to 11 mm); while the right ventricular wall thickness was normal (range 2 to 5 mm). These data suggest that (1) as assessed by echocardiography, the pulmonary vascular resistance is not significantly elevated in young infants with BPD, and (2) a hypertrophic left ventricle evolves which may assume importance in the pathogenesis of pulmonary edema in BPD, though the precise etiology remains undetermined.     

Echocardiographic findings of large patent ductus arteriosus in the very low birthweight infant before and after treatment with indomethacin.

17 very low birthweight infants (mean birthweight 850 g) with large patent ductus arteriosus (PDA) were studied by echocardiography before and after treatment with indomethacin. Before treatment left heart dimensions were increased suggesting large left-to-right shunt. Echographic measurements of augmented left ventricular (LV) contraction could be attributed to increase in preload, and reduction in afterload in PDA. After indomethacin, in infants showing clinical response, left heart dimensions returned rapidly to normal and LV contraction became normal or reduced. Two infants had reduced LV contraction with persistent pulmonary oedema suggesting LV failure. In contrast, infants showing no clinical response to the drug also had no significant changes in echographic measurements. Right ventricular systolic time intervals (RPEP/RVET) did not alter after indomethacin treatment in either group, suggesting that the drug does not increase pulmonary vascular resistance.     

The critically ill premature infant with patent ductus arteriosus and pulmonary disease-an echocardiographic assessment.

The effect of left-right shunting upon left ventricular and atrial dimensions was assessed by means of 129 serial echocardiographic studies in 37 premature infants with patent ductus arterisus. The cardiac dimensions of asymptomatic premature infants and those with pulmonary disease were similar and served as control subjects. Left cardiac dimensions were enlarged in infants with significant PDA. Dimensions were greatest in surgically treated infants (post-operatively they returned rapidly to normal) in contrast with the persistent enlargement observed in some medically treated infants. Serial echocardiography was a valuable adjunct to clinical assessment of the course of PDA in premature infants with pulmonary disease.     

Value of systolic time intervals in the diagnosis of large patent ductus arteriosus in fluid-restricted and mechanically ventilated preterm infants

M-mode echocardiographic features suggesting a patent ductus arteriosus are based on two groups of indirect criteria: dilation of the left cardiac cavities and changes of systolic time intervals. The reliability of the first group of criteria has been questioned in fluid-limited, mechanically ventilated preterm infants. The sensitivity of the systolic time intervals in the same circumstances is investigated. Twenty-three patients with a large patent ductus arteriosus were selected. Review of their echocardiograms shows that the sensitivity of the various criteria (expressed as percentage of positivity) was as follows: inversion of the ratio of left ventricular preejection period to right ventricular preejection period, 91.3%; left ventricular preejection period to left ventricular ejection time over right ventricular preejection period to right ventricular ejection time less than 1,83%; left atrium dilation, 74%; shortening of left ventricular preejection period, 70%; dilation of left ventricular internal dimensions in diastole, 65%; increase in left atrium/aorta, 52%; and decrease of left ventricular preejection period to left ventricular ejection time, 48%. Three criteria involving time intervals (left ventricular preejection period to right ventricular preejection period, left ventricular preejection period, and left ventricular preejection period to left ventricular ejection time) had 100% specificity. The lowest specificity was found with criteria involving the left atrium (left atrial to aortic root ratio 75% and left atrium 63%). It is concluded that study of systolic time intervals is a reliable means of detecting preterm infants with hemodynamically significant left-to-right shunt through a patent ductus arteriosus even if the infants are mechanically ventilated and fluid restricted.     

GROWTH PATTERNS OF CARDIAC STRUCTURES AND CHANGES IN SYSTOLIC TIME INTERVALS IN THE NEWBORN AND INFANT: A Longitudinal Echocardiographic Study

Abstract. Oberhänsli, I., Brandon, G., Lacourt, G. and Friedli, B. (Department of Pediatrics and Genetics, University Hospital, Geneva, Switzerland). Growth patterns of cardiac structures and changes in systolic time intervals in the newborn and infant. Acta Paediatr Scand, 69: 239, 1980.—A longitudinal study was undertaken in 21 newborns to determine cardiac growth pattern by echocardiography over the course of the first year of life. Most cardiac structures increased in size as a linear function of age and weight; however, the right ventricular end-diastolic diameter remained unchanged so that the RV/LV ratio decreased as a parabolic function of age. Left and right ventricular systolic time intervals (RVSTI, LVSTI) after birth were also studied. The ratio of left ventricular preejection period (LVPEP) to left ventricular ejection time (LVET) decreased markedly immediately after birth and subsequently remained at a constant mean value (0.30 ± 0.04) for the rest of the study period. Right ventricular systolic time interval ratios (RVPEP/RVET) decreased rapidly and significantly during the first days of life (from a mean value of 0.39 ± 0.08 in the first 24 hours to 0.28 ± 0.05 on the 6th day of life). Constant values of 0.24 ± 0.03 were found from the 3rd month of life onwards. The decrease in RVPEP/RVET in the first days of life followed a parabolic function reflecting the physiological decrease of pulmonary vascular resistance after birth.     

Impaired left ventricular diastolic function in newborn infants of mothers with pregestational or gestational diabetes with good glycemic control

THE AIM OF THE STUDY: We assessed by echocardiography the left ventricular systolic and diastolic function in newborn infants of mothers with well-controlled pregestational type 1 or gestational diabetes (IDM) in comparison to normal term neonates. SUBJECTS AND METHODS: Two-dimensional/M-mode and Doppler transmitral flow velocity measurements were performed in 18 IDM and 26 control infants of non-diabetic mothers (gestational ages 36-40 and 36-41 weeks, respectively) between days 2 and 5 after birth. In the IDM, there were nine mothers with pregestational (White class C or D) and nine mothers with gestational diabetes (White class A or A/B). Peak early and atrial filling velocity, early deceleration time, early acceleration time, early, atrial and total time velocity integrals were used to examine the left ventricular diastolic performance. We also calculated the early/atrial velocity ratio, early/atrial integral ratio and early/total integral ratio. The fractional shortening, fractional shortening area, midwall fractional shortening (mFS), left ventricular mass and indexed left ventricular mass for body surface area (BSA) and birth weight were used in assessment of left ventricular systolic performance. RESULTS: The early deceleration time was longer, resulting in higher early integral and early filling fraction (EFF) in the IDM than in the control infants (p<0.01). In the IDM, the fractional shortening was somewhat greater and the left ventricular mass/body surface area ratio was higher than in the control group (p<0.05), although the measures of systolic performance were within the normal range. There were no significant differences in the systolic or diastolic function parameters between the gestational and pregestational groups. CONCLUSION: In the infants of mothers with well-controlled pregestational or gestational diabetes, we found prolonged deceleration time of early left ventricular diastolic filling, probably reflecting an impaired left ventricular relaxation rather than compliance. The mechanism for the findings may be maternal hyperglycemia during the third trimester and subsequent fetal hyperinsulinaemia leading to neonatal cardiac hypertrophy.     

Systolic and diastolic function in children with chronic renal failure

BACKGROUND: Cardiovascular complications are the most frequent cause of death in patients with end-stage renal failure (ESRF). We aimed to investigate systolic and diastolic functions in children with ESRF. METHODS: Thirty-nine children with ESRF (17 on continuous ambulatory peritoneal dialysis (CAPD), eight on hemodialysis and 14 on predialysis) were examined to assess systolic and diastolic functions by echocardiography and ultrasound Doppler. Left ventricular systolic and diastolic functions were measured both in patients and age-matched healthy controls (n = 20) and the indices of cardiac performance were compared. RESULTS: Increased left ventricular mass index (LVMI) and decreased volume/mass ratio with normal systolic left ventricular function was found in patients, as compared with controls. Left ventricular diastolic dysfunction was observed in dialysis patients. In most of these patients, left ventricular isovolumic relaxation time was prolonged, except in CAPD patients. The peak of late diastolic flow (A) velocities were increased with a reduction of the early diastolic flow velocity (E)--the E/A ratio. The E velocities were unchanged in all patients as compared with controls. Our data indicated an abnormality of myocardial relaxation in patients with ESRF. We found no relationship between E/A ratio and LVMI. Among three groups of patients, the LVMI and diastolic abnormalities were highest in the hemodialysis group indicative of poor control of hypervolemia and hypertension. CONCLUSIONS: The technique of CAPD has some advantages as a renal replacement therapy for preserving cardiac functions as compared with hemodialysis. However, it must be remembered that patients with hemodialysis have features that effects cardiac status, such as higher volume load and higher afterload (hypertension).     

A blinded comparison of clinical and echocardiographic evaluation of the preterm infant for patent ductus arteriosus

The accuracy of the characteristic physical signs of a patent ductus arteriosus (PDA), that is, a systolic murmur, increased volume of pulses and increased praecordial activity, in diagnosing a haemodynamically significant PDA in ventilated premature infants was prospectively evaluated. Fifty-five ventilated preterm infants (birthweight >1500g) had daily echocardiographic and clinical evaluation for a PDA for the first 7 days of life. The examiners were blinded to each other's findings. Probability analysis was performed for the accuracy of each clinical sign in detecting a haemodynamically significant PDA as defined by echocardiographic criteria. Clinical signs were poor at detecting a significant PDA in the first 4 days of life. On day 1, none of the 10 infants with a significant PDA had a murmur. By day 4, clinical signs were better at detecting a significant PDA, but specificity remained poor with many false positive signs. Six infants had murmurs with a closed duct. The development of echocardiographic haemodynamic significance preceded the development of physical signs by a mean of 1.8 days. Significant ductal shunts often occurred silently, but the development of a murmur often marked an increase in the velocity of the flow through the duct rather than an increase in the size of a shunt. This study confirms that echocardiography is required for the reliable early diagnosis of a PDA in ventilated preterm infants.     

Noninvasive cardiac evaluation of young patient with cystic fibrosis

Cardiac involvement was evaluated by echocardiography in 26 young cystic fibrosis patients. The mean age was 48.4 months (range 3 months to 15 years). The findings were compared with 26 age- and sex-matched children without a history of cardiopulmonary complaints. All patients had normal values of left ventricular ejection fraction and fractional shortening. Interventricular septal and posterior left ventricular wall thicknesses were similar to control group but right ventricular free wall thickness was found greater than in the control group. Abnormal septal motion was documented in six patients. Right ventricular pre-ejection period to ventricular ejection time ratio was found over the upper limit of normal in two patients and there was a negative correlation with clinical Shwachman scores (r: -0.55). Left ventricular pre-ejection period to ventricular ejection time ratio was found over the upper limit of normal in five patients. For both mitral and tricuspid valves, the mean ratios of peak velocity during passive filling (E) phase of diastole to peak velocity during atrial contraction (A) phase were found significantly lower than in the control group (p < 0.05). Early diastolic peak velocity was similar to that in the control group but late atrial peak velocity was higher in the patient group (p < 0.05). Isovolumic relaxation time was found the same as in the control group. We conclude that cardiac changes in diastolic and systolic functions begin at very young ages in cystic fibrosis patients.     

Echocardiographic assessment of early circulatory status in preterm infants with suspected intrauterine infection

OBJECTIVE: To assess early circulatory status in very low birthweight (VLBW) infants with suspected intrauterine infections. PATIENTS: Thirteen VLBW infants who were diagnosed with prenatal infections because of raised serum IgM at birth (infectious group), and 39 infants matched for gestational age and birth weight (control group). METHODS: Echocardiographic assessments were performed consecutively from birth to day 28 in all VLBW infants. Left ventricular output (LVO) and left ventricular stroke volume (LVSV) were measured using Doppler echocardiography. Pulsed Doppler assessment of pulmonary artery pressure (PAP) was performed using the corrected ratio of the pulmonary artery acceleration time to the right ventricular ejection time (AT/RVET(c)). Blood flow in the superior mesenteric artery (SMA) was also evaluated by Doppler ultrasound. RESULTS: Mean LVO and LVSV were both significantly higher in the infectious group than in the control group at 12 hours (LVO; 188 v 154 ml/kg/min) and 72 hours (LVO; 216 v 173 ml/kg/min) of life. Pulsed Doppler assessment of PAP showed that mean AT/RVET(c) values were significantly lower in the infectious group than in the control group at 48 hours, 96 hours, day 14, and day 28. In the analysis of SMA flow velocities, both peak systolic velocities and time averaged velocities had decreased significantly in the infectious group compared with the control group at 24 hours, 36 hours, 96 hours, and day 28. CONCLUSIONS: VLBW infants with suspected prenatal infection showed a unique circulation status, namely high cardiac output, latency of high PAP, and low organ flow.     

LEFT VENTRICULAR SYSTOLIC TIME INTERVALS IN PRETERM INFANTS WITH PATENT DUCTUS ARTERIOSUS

ABSTRACT. Left ventricular systolic time intervals were recorded by a non-invasive technique, from the axillary artery, in 13 preterm infants with patent ductus arteriosus. At the onset of clinical symptoms, consistent with a large left-to right ductal shunt, the preejection intervals were shorter than in a control group of nine preterm infants without a patent ductus. The most pronounced difference was found in the shortening of the isovolumic contraction time, 10.7 msec in the ductus group compared with 22.4 msec in the control group. Ductal closure normalized the isovolumic contraction time to 22.1 msec. The very short preejection intervals, associated with a large ductal shunt, are suggested to reflect a combination of reduced aortic diastolic pressure and increased left ventricular filling pressure. In spite of increased volume load to the left ventricle there were no detectable changes in the systolic time intervals indicating impaired left ventricular function. The left ventricle seems to be competent to handle increased volume load in the presence of reduced afterload in preterm infants with symptomatic left-to right ductal shunts.     

Cardiac effects of a single course of antenatal betamethasone in preterm infants

AIM: To show the effects of a single course of antenatal betamethasone on cardiac measurements and systolic functions in premature newborn infants. METHODS: Seventy six newborn infants with a gestational age of 25-33 weeks were included in the study. They were first classified according to their gestational age: 25-29 weeks (n = 28) and 30-33 weeks (n = 48). They were then reclassified as betamethasone positive (mother received one course of betamethasone) or betamethasone negative (mother did not receive any antenatal glucocorticoid treatment). Cross sectional M mode echocardiographic scans were performed during the first three postnatal days and at the end of the first and third weeks. Left interventricular septum (IVS), left ventricular posterior wall (LVPW), left ventricular end diastolic (LVED), and left ventricular end systolic (LVES) dimensions, aortic root (AO), and left atrial diameters (LAs) were measured. The IVS to LVPW ratio was calculated to identify asymmetrical septal hypertrophy. RESULTS: In neither group was any statistically significant difference noted in IVS, LVED, LVES, LVPW, LA, and AO measurements during the three cardiac ultrasonography scans. Systolic function, as assessed by fractional shortening, was not significantly different in infants who received betamethasone antenatally, in either age group. There was no difference in the IVS/LVPW ratios between those who received antenatal steroid and those who did not for the 25-29 week and 30-33 week groups during these three consecutive scans. CONCLUSION: One course of antenatal betamethasone did not affect the cardiac wall thicknesses and systolic function in premature infants.     

Left ventricular systolic time intervals in preterm infants with patent ductus arteriosus

Left ventricular systolic time intervals were recorded by a non-invasive technique, from the axillary artery, in 13 preterm infants with patent ductus arteriosus. At the onset of clinical symptoms, consistent with a large left-to right ductal shunt, the preejection intervals were shorter than in a control group of nine preterm infants without a patent ductus. The most pronounced difference was found in the shortening of the isovolumic contraction time, 10.7 msec in the ductus group compared with 22.4 msec in the control group. Ductal closure normalized the isovolumic contraction time to 22.1 msec. The very short preejection intervals, associated with a large ductal shunt, are suggested to reflect a combination of reduced aortic diastolic pressure and increased left ventricular filling pressure. In spite of increased volume load to the left ventricle there were no detectable changes in the systolic time intervals indicating impaired left ventricular function. The left ventricle seems to be competent to handle increased volume load in the presence of reduced afterload in preterm infants with symptomatic left-to right ductal shunts.     

Cardiovascular function before and after iron therapy by echocardiography in patients with iron deficiency anemia

BACKGROUND: The aim of the study was to estimate the left ventricular contractility using the ratio of left ventricular end-systolic wall stress to left ventricular end-systolic volume index in patients with iron deficiency anemia, for which there are no previous reports. METHODS: Cardiovascular functions were evaluated using echocardiography and pulsed Doppler echocardiography in 30 children aged 3-14 years (hemoglobin 4.9-8.5 g/dL), before, during and after iron therapy. We also studied 38 healthy children as a control group. RESULTS: The left ventricular preload was significantly higher and the left ventricular afterload was lower in the patients with anemia before iron therapy. The ratio of left ventricular end-systolic wall stress to left ventricular volume, an index of systolic function that is independent of preload and afterload, was significantly lower in the patients with anemia before iron therapy (before iron therapy 2.13 +/- 0.44, after therapy 3.52 +/- 0.76, healthy controls 3.42 +/- 0.70). Left ventricular early diastolic filling was significantly higher in the patients with anemia before iron therapy. The cardiac index was also significantly higher before therapy because of the increases in preload, heart rate and early diastolic filling, as well as the decrease of afterload. There were no significant differences in the indices of cardiovascular function between anemic patients after iron therapy compared with control subjects. CONCLUSIONS: The ratio of left ventricular end-systolic wall stress to the left ventricular volume index and the cardiac index suggested that a hemoglobin concentration < or = 6 g/dL was associated with left ventricular dysfunction and circulatory congestion.     

动脉导管未闭患儿介入治疗前后血浆N末端脑利钠肽水平及心功能变化

目的应用心脏超声技术及检测血浆N末端脑利钠肽（NT-proBNP）水平,探讨经皮动脉导管未闭（PDA）封堵术对心功能影响。方法PDA患儿55例,术前按照小儿心衰改良Ross标准分为无心衰组31例,轻度心衰组14例,中重度心衰组10例（重度心衰1例）。选择年龄、体质量相匹配健康儿童15例作为健康对照组。应用酶联免疫吸附法测定血浆NT-proBNP水平。同时测定左室舒张末期容量指数（LVEDVI）、左室收缩末期容量指数（LVESVI）、左室射血分数（LVEF）、左室缩短分数（LVFS）等反映心室功能及负荷的超声心动图指标。结果1.PDA患儿术前LVEDVI、LVESVI均显著高于健康对照组（Pa〈0.01）,且各组间随着心功能严重程度增加而显著升高（P〈0.01）。2.术前血浆NT-proBNP水平随着心功能严重程度增加而升高,中重度心衰组高于轻度心衰组（P〈0.01）,轻度心衰组高于无心衰组（P〈0.01）,无心衰组与健康对照组比较无统计学差异（P〉0.05）。3.PDA患儿术后3个月血浆NT-proBNP水平、LVEDVI、LVESVI均较术前显著降低（Pa〈0.01）,接近健康对照组水平（P〉0.05）。4.血浆NT-proBNP水平与LVESVI（r=0.653P〈0.01）、LVEDVI（r=0.741P〈0.01）呈正相关,而与LVEF、LVFS等无显著相关性（P〉0.05）。结论PDA堵闭术后3个月在临床症状和反映左室功能超声指标明显改善同时,术前高血流动力学负荷对心室细胞影响也逐渐恢复。     

EFFECT OF EARLY AND LATE CORD CLAMPING ON THE SYSTOLIC TIME INTERVALS OF THE NEWBORN INFANT

Abstract. The effect of early and late cord clamping on the left ventricular performance of the newborn infant was assessed by measuring the systolic time intervals from the indirect carotid pulse tracings and simultaneous phonocardiogram and electrocardiogram. The study was performed in 13 normal, full-term infants sequentially at 20–105 min, 6-6½ hrs, and 24–27 hrs of age. The umbilical cords were clamped early in 7 (E.C.) and clamped late in 6 infants (L.C.). The ratio of the pre-ejection period (PEP) to the left ventricular ejection time (LVET) was found to be significantly higher in the L.C. infants (mean±S.E., 0.400±0.18, 0.433±0.018, 0.410±0.021) compared with those of the E.C. (0.334±0.010, 0.347±0.009, 0.361±0.007) with p values of <0.01, <0.005 and <0.05, respectively in the three examination periods. This higher PEP/LVET ratios in the L.C. infants were mainly attributable to a prolongation of the PEP. It is suggested that late cord clamping, by allowing a sizable placental transfusion, appeared to affect adversely the left ventricular performance of the neonate. Furthermore, it is suggested that in evaluating systolic time intervals of the neonate during the first days of life, the volumic state or status of placental transfusion should be taken into consideration as a determinant.     

生后早期床旁心脏超声预测极低出生体重儿动脉导管持续开放的研究(英文翻译)

目的 探讨出生早期床旁心脏超声预测极低出生体重儿（very low birth weight infant,VLBWI）动脉导管持续开放的价值。 方法 回顾性选取2020年3月至2021年6月收治的51例VLBWI为研究对象,入院时日龄≤3 d并且住院时间≥14 d。根据出生14 d及28 d动脉导管未闭（patent ductus arteriosus,PDA）直径大小分为3组：大PDA组（PDA直径≥2 mm）、小PDA组（PDA直径<2 mm）和PDA关闭组（PDA直径=0 mm）,比较3组间生后72 h的心脏超声参数。采用受试者工作特征（receiver operating characteristic,ROC）曲线评估生后72 h心脏超声参数预测生后14 d和28 d动脉导管持续开放（PDA直径≥2 mm）的价值。 结果 生后14 d时,大PDA组有17例,小PDA组11例,PDA关闭组23例;生后28 d时,大PDA组有14例,小PDA组9例,PDA关闭组26例。3组患儿间胎龄、出生体重、肺泡表面活性物质应用及低血压发生率的比较差异有统计学意义（P<0.05）。生后72 h的PDA直径、左肺动脉舒张末期流速、左心室输出量、左心室输出量/上腔静脉血流与生后14 d及28 d时动脉导管持续开放有关（P<0.05）;左心房/主动脉根部直径与生后28 d时动脉导管持续开放有关（P<0.05）。ROC曲线结果显示,生后72 h PDA直径预测生后14 d及28 d动脉导管持续开放的曲线下面积最大,分别为0.841和0.927;其次是左肺动脉舒张末期流速,其曲线下面积分别为0.793和0.833。 结论 生后72 h的床旁心脏超声指标,尤其是PDA直径及左肺动脉舒张末期流速,可预测VLBWI生后14 d和28 d动脉导管持续开放,为后续PDA早期目标性治疗策略的实施提供依据。