Acute changes in hematocrit: their effect on flows in the great arteries of newborns

To study the effect of acute hematocrit changes on the central circulation of human neonates, pulsed Doppler echocardiography was performed to evaluate flow velocities in the main pulmonary artery (PA) and the ascending aorta (Ao) five and seven hours of age in 16 polycythemic neonates (mean hematocrit of 68.1%), and in 12 normal neonates (mean hematocrit of 57.1%). All the polycythemic neonates were asymptomatic and underwent isovolumic partial exchange transfusion between five and seven hours of age to lower their mean hematocrit to 51.3%. Flow velocity integral per min (FVI/min) (cm/min), acceleration time (AT) (ms), and the ratio of pre-ejection period to ejection time (PEP/ET) were measured on the PA and Ao flow velocity tracings. Despite the significant differences in hematocrit, no significant difference was observed in any of their flow velocity indices at five hours age between the normal and polycythemic neonates. All flow velocity indices remained unchanged between five and seven hours of age in normal neonates. In polycythemic neonates, PA FVI/min and Ao FVI/min increased significantly between five and seven hours of age, reflecting increases in flow in both great arteries, while the difference between Ao FVI/min and PA FVI/min decreased, suggesting a reduction in a left-to-right shunt via the ductus arteriosus. Moreover, PA-AT increased and PA-PEP/ET decreased significantly, suggesting a decrease in pulmonary vascular resistance. These changes caused by an acute decrease in hematocrit resembled the changes in the central circulation previously reported to occur in normal neonates during the postnatal period. In conclusion, an acute decrease in hematocrit transiently accelerates physiological changes in the central circulation during the neonatal period.     

Left-to-right shunt via the foramen ovale in the early neonatal period: evaluation by Doppler color flow mapping

Serial two-dimensional Doppler echocardiography was performed in 22 normal neonates (2-9 hours after birth). A left-to-right shunt through the foramen ovale and a shunt through the ductus arteriosus were evaluated. Interatrial shunts were observed as transseptal jets in 16 of 22 neonates on initial examination and resolved nine to 26 hours after birth in 13 neonates. In the remaining three neonates the shunts were observed more than six days and resolved by two months of age. Shunts through the ductus arteriosus were observed in all neonates examined as diastolic or continuous flows toward the transducer in the main pulmonary artery at the initial examination. The ductal flow resolved simultaneously with (3/13) or after (10/13) the disappearance of interatrial flow. With two-dimensional echocardiography, the enlarged left atrium and rightward deviation of the interatrial septum were observed in the neonates with interatrial shunts. This was confirmed by the immobile septum primum and the increased ratio of the left atrial to aortic diameters (LA/Ao ratio) on the M-mode echo. The interatrial septum became mobile and the LA/Ao ratio decreased after disappearance of the interatrial shunts. It was speculated that in neonates with large ductal shunts, large pulmonary venous flow enters into the less compliant left ventricle and raises the left ventricular end-diastolic pressure. Then, increased left atrial pressure distends the interatrial septum and causes left-to-right interatrial shunts via the stretched foramen ovale. This shunt is considered one of the physiological phenomena occurring in the early neonatal period.     

Bidirectional ductal shunts in the early neonatal period: evaluation by Doppler color flow imaging

Serial Doppler echocardiographic examinations were performed in 10 normal neonates (0.3-4.0 hrs after birth). The flow patterns through the ductus arteriosus were evaluated using Doppler color flow imaging, pulsed Doppler echocardiography and continuous-wave Doppler echocardiography. At the initial examination, flow through the ductus arteriosus was clearly visualized in all the neonates using Doppler color flow imaging. The ductal flow patterns were categorized as follows: 1. Systolic blue color (right-to-left shunt flow) and diastolic red color (left-to-right shunt flow) in four neonates (group 1). 2. Systolic blue color and diastolic mosaic colors in four neonates (group 2). 3. Continuous mosaic colors in two neonates (group 3). Using pulsed Doppler echocardiography, the systolic right-to-left ductal shunt flow in the groups 1 and 2 was triangular in shape beginning in early systole. The diastolic left-to-right shunt flow was box-like in shape beginning late in systole and lasting long in diastole in the group 1. In the group 2, the diastolic flow showed a wide spectrum (turbulent flow). In the group 3, the flow through the ductus arteriosus had a continuous wide spectrum (turbulent flow). Mosaic or turbulent ductal flow of a left-to-right ductal shunt had high velocities by continuous-wave Doppler echocardiography. Serial examinations revealed that the ductal flow pattern observed in the group 1 changed to the flow pattern observed in the group 2, and then to that of the group 3 with increasing diastolic ductal flow velocities. The estimated aorto-pulmonary pressure gradient according to the simplified Bernoulli equation (delta p = 4V2) using a maximum diastolic left-to-right ductal shunt velocity increased within 12 hrs after birth. It was concluded that bidirectional ductal shunts may be observed in most normal neonates (8/10). With increasing diastolic velocities the bidirectional ductal flows changed to the pattern of a continuous left-to-right shunt. The bidirectional ductal shunt is considered due to physiologic pulmonary hypertension of the newborn and due to less conduction time from the pulmonary valve to the pulmonary end of the ductus than from the aortic valve to the aortic end of the ductus. Analysis of the flow through the ductus provides informations about the neonatal circulatory adaptation, especially in the early neonatal period.     

The ductus arteriosus in healthy newborn infants studied by continuous Doppler guided by two-dimensional Doppler color echocardiography

To characterize the ductus arteriosus shunt after birth, 53 normal newborn infants (36-41 weeks gestation), appropriate in size for gestational age, were examined using two dimensional Doppler echocardiography directed continuous Doppler for evidence of patent ductus arteriosus. The infants were examined within six hours of birth, and every six-eight hours thereafter until ductus arteriosus shunt could no longer be detected. In 51/53 infants, an adequate examination was possible and ductus arteriosus was detected in every infant using the standard precordial approach. Using two dimensional Doppler echocardiography a yellow-orange-red jet, sometimes blue in the central area, directed at the lateral wall of the pulmonary artery was recorded; using continuous Doppler a diastolic or continuous spectral flow into the main pulmonary artery was recorded. Ductus arteriosus shunt could no longer be detected in 7 infants 12 hours after birth, in 26 infants 12-24 hours after birth, in 11 infants 24-36 hours after birth, in 5 infants 36-48 hours after birth and in 2 infants 48-60 hours after birth. A diastolic spectral Doppler flow was present in 38 infants and became continuous before duct closure in 27 infants. In 13 infants it was continuous at first examination and until the ductus arteriosus closure. Both diastolic or continuous spectral Doppler flow could present a flat waveform profile, or a protodiastolic or protosystolic peak velocity. The shunt peak velocity increased significantly with the age i.e. (1.5 +/- 0.7 m/sec mean and SD-), at first examination, vs 2.3 +/- 0.6 m/sec at last examination before ductus arteriosus closure (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Noninvasive Doppler echocardiographic evaluation of shunt flow dynamics of the ductus arteriosus

The pulsed Doppler technique was used to record the flow velocity patterns in the ductus arteriosus and the pulmonary artery in 26 patients with either isolated or complicated patent ductus arteriosus (PDA). In all patients, abnormal Doppler signals indicating left-to-right (L-R) or right-to-left shunt flow or both could be obtained at the site of the ductus arteriosus. These Doppler flow patterns determined within the ductus coincided with the direction of ductal flow seen on the contrast two-dimensional echocardiogram. No Doppler signals of shunt flow were demonstrated in any of 42 control subjects. The peak, mean, and diastolic velocities of the L-R shunt flow within the ductus were measured from the ductal flow velocity profiles. With the Doppler-derived measurements of the mean and diastolic velocities, patients with normal pulmonary arterial pressure and those with evidence of pulmonary hypertension could be correctly identified. In addition, the mean velocity of the diastolic antegrade flow portion obtained from the proximal left pulmonary artery, which was related to ductal L-R shunting, was measured in 16 patients with isolated PDA. This Doppler flow determinant showed a good linear correlation with the L-R shunt ratio determined by Fick's method (r = .88, p less than .01). Our technique permits the noninvasive evaluation of shunt flow dynamics in patients with PDA.     

Pulsed Doppler echocardiographic evaluation of neonatal circulatory changes.

Pulsed Doppler echocardiograms were obtained from 42 normal fullterm neonates at less than 12 hours (20 subjects), 4 days (20 subjects), and 33 days (12 subjects). The acceleration time of the flow velocity and ventricular systolic time intervals were measured on recordings obtained at the right and left ventricular outflow tract, and the patency of the ductus arteriosus was evaluated by the flow at the pulmonary end of the ductus. The flow velocity pattern of the right ventricular outflow tract changed from a triangular shape with a peak velocity in early systole in the younger age groups to a dome-like contour with a peak velocity in mid-systole; thus the ratio of mean acceleration time to right ventricular ejection time increased with age. The flow velocity pattern of the left ventricular outflow tract was triangular in all age groups, and the ratio of mean acceleration time to left ventricular ejection time showed no significant change with age. The right ventricular pre-ejection period shortened and the right ventricular ejection time lengthened with age; thus the ratio of mean right ventricular pre-ejection period to right ventricular ejection time decreased with age. The left ventricular systolic time intervals showed no significant change with age. The ductus arteriosus was patent in all subjects who were less than 12 hours old but was closed in the older neonates. Pulsed Doppler echocardiography is a valuable method of evaluating pulmonary vascular bed in the early neonatal period.     

Pulsed Doppler echocardiographic evaluation of neonatal circulatory changes

Pulsed Doppler echocardiograms were obtained from 42 normal fullterm neonates at less than 12 hours (20 subjects), 4 days (20 subjects), and 33 days (12 subjects). The acceleration time of the flow velocity and ventricular systolic time intervals were measured on recordings obtained at the right and left ventricular outflow tract, and the patency of the ductus arteriosus was evaluated by the flow at the pulmonary end of the ductus. The flow velocity pattern of the right ventricular outflow tract changed from a triangular shape with a peak velocity in early systole in the younger age groups to a dome-like contour with a peak velocity in mid-systole; thus the ratio of mean acceleration time to right ventricular ejection time increased with age. The flow velocity pattern of the left ventricular outflow tract was triangular in all age groups, and the ratio of mean acceleration time to left ventricular ejection time showed no significant change with age. The right ventricular pre-ejection period shortened and the right ventricular ejection time lengthened with age; thus the ratio of mean right ventricular pre-ejection period to right ventricular ejection time decreased with age. The left ventricular systolic time intervals showed no significant change with age. The ductus arteriosus was patent in all subjects who were less than 12 hours old but was closed in the older neonates. Pulsed Doppler echocardiography is a valuable method of evaluating pulmonary vascular bed in the early neonatal period.     

Aortic flow patterns in normal neonates with patent ductus arteriosus: evaluation by Doppler color flow imaging

Serial Doppler echocardiography was performed in 12 normal neonates (0.5-4.0 hrs after birth) to evaluate flow patterns through the ductus arteriosus, and in the aorta and brachiocephalic artery. At the initial examination, flow through the ductus arteriosus was bidirectional in eight of the 12 neonates and continuously left-to-right in the remaining four. The bidirectional ductal shunts became continuous left-to-right flows within 11-21 hrs after birth in seven of the eight neonates and resolved by 29-47 hrs after birth. In the remaining four neonates, the continuous left-to-right shunts disappeared 14-36 hrs after birth. Systolic ejection flow patterns in the aorta and brachiocephalic artery had a triangular shape with the peak velocity in early systole, followed by a minimal flow reversal in all sites examined. Diastolic flow patterns in each arterial site were as follows: 1. In the ascending aorta, there was slow and sustained diastolic forward flow, which did not change with increasing age. 2. In the brachiocephalic artery, there was a pan-diastolic flow reversal in the neonates with bidirectional ductal flow (7/8). This pattern changed to slow pan-diastolic forward flow when the ductal changed to continuous left-to-right flow or when the ductal closure was confirmed. Most (3/4) of the remaining four neonates with continuous left-to-right ductal flow exhibited pan-diastolic forward flow. Another showed a pan-diastolic flow reversal 2 hrs after birth, which changed to pan-diastolic forward flow in the second examination 6 hrs after birth. 3. In the distal aortic arch, there was a pan-diastolic forward flow in all the neonates, and the velocity decreased when a closure of the ductus was confirmed. 4. In the descending aorta, there was a pan-diastolic flow reversal in neonates with bidirectional ductal flow (7/8). This reversal changed to pan-diastolic forward flow, when the ductal flow changed to continuous left-to-right flow or when the ductal closure was confirmed. In the remaining four neonates with continuous left-to-right ductal flow, two showed a pan-diastolic flow reversal at the initial examinations 2 to 3 hrs after birth. This became a pan-diastolic forward flow at the second examinations 6 and 12 hrs after birth. In the other two, there was a pan-diastolic forward flow which did not change. This pan-diastolic flow reversal observed in the brachiocephalic artery and descending aorta was closely related to the bidirectional ductal flow.(ABSTRACT TRUNCATED AT 400 WORDS)     

Real-time bidimensional-color Doppler evaluation of patent ductus arteriosus

In order to assess the presence and severity of left-to-right shunt at ductal level, eleven patients with proven ductus arteriosus (PDA), ages 1 day to 16 years, were examined by real-time two-dimensional Doppler echocardiography. Eighteen subjects with no signs of cardiovascular disease were selected as normal controls. Normal pulmonary flow pattern was clearly visualized in the healthy subjects examined. The jet stream through the ductus was well imaged in the main pulmonary artery in patients with PDA and disappeared in two infants after pharmacologic manipulation with indomethacin. The colour-coded shunt area was related to the left-to-right shunt calculated at cardiac catheterization. Moreover, the combined use of colour-flow Doppler and continuous-wave Doppler yielded a reliable noninvasive assessment of pulmonary artery pressure.     

Non-invasive assessment of the peak pressure gradient between the aorta and pulmonary artery in patent ductus arteriosus

The validity of continuous wave Doppler ultrasound estimation of the peak pressure gradient between the aorta (Ao) and pulmonary artery (PA) in patients with patent ductus arteriosus (PDA) was evaluated. Ten patients, all without other anomalies, underwent cardiac catheterization and cine-angiography, and the peak pressure gradient between the Ao and PA (dP(C)) was measured during catheterization. In all cases the mean PA pressure was less than 35 mmHg. According to the angiographic findings, the patients were categorized as Group A, consisting of seven patients whose features of the ductus were wedge- or tube-like in configuration; Group B, consisting of two patients whose features were termed "orifice-like" stenosis including one with abrupt narrowing on the PA side of the ductus and the other with a short segmental ductus. Group C consisted of one patient who had a long curved segmental ductus. The maximum velocity of ductus flow was measured by continuous wave Doppler ultrasonography, and the estimated peak pressure gradient between the Ao and PA by Doppler (dP(D] was calculated using the simplified Bernoulli equation (dP = 4V2). In group A, dP(D) was overestimated compared to dP(C) in all patients by 19 to 51 mmHg (mean 34 mmHg). However, in group B, the difference between dP(D) and dP(C) was small, 5 mmHg and 7 mmHg, respectively. In group C, dP(D) was underestimated as opposed to dP(C). Thus, in the limited cases, the simplified Bernoulli equation could be used in estimating the peak pressure gradient between the Ao and PA. However, this equation leads to overestimation in many cases.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transcatheter treatment of "pulmonary artery hypertension" due to patent ductus arteriosus and pulmonary artery stenosis

The association between large, left-sided patent ductus arteriosus and severe, peripheral, right pulmonary artery stenosis with no other cardiac malformation is an unreported condition that might be misdiagnosed as pulmonary hypertension due to long-standing ductal shunt. A 57-year-old man with supposed hypertensive patent ductus arteriosus underwent confirmatory cardiac catheterization. At angiography, a severe pre-hilar right pulmonary artery stenosis (peak pressure gradient, 65 mmHg) was found to complicate the hemodynamic picture of a moderate-to-large patent ductus arteriosus (QP/QS, 1.7:1), by causing pulmonary hypertension (mean pressure, 65 mmHg) and left-to-right pulmonary flow imbalance. Both lesions were treated in a single procedure of right pulmonary artery stenting and patent ductus arteriosus closure, after which the pulmonary artery pressure significantly decreased (mean, 35 mmHg). In our opinion, a thorough hemodynamic evaluation followed by pulmonary angiography should be mandatory before proceeding to patent ductus arteriosus closure in the adult patient who has "hypertensive" ductus, in whom possible associated malformations can be missed due to a poor echocardiographic window.     

Patency of the ductus arteriosus in normal neonates: two-dimensional echocardiography versus Doppler assessment

Two-dimensional echocardiography using a high resolution, 7.5 ,Jsz transduce was compared with Doppler echocardiography for the assessment of patency of the ductus arteriosus in normal newborn infants. Twenty-eight neonates were studied between 1 and 10 hours (mean 5.5) after birth and both examinations were possible in 27 (96%). Doppler echocardiography under two-dimensional direction indicated ductal patency in all 27 neonates. Doppler sampling in the pulmonary end of the ductus rather than the main pulmonary artery was more sensitive for detecting patency. When two-dimensional echocardiography only was used to predict patency, there was 85% sensitivity. Two-dimensional echocardiography showed no evidence of ductus arteriosus narrowing ion four neonates studied shortly after birth. In 18, the pulmonary portion of the ductus arteriosus appeared narrowed and in 8 of these, the narrowing extended toward the mid-portion of the ductus. In five others, there was only mid-ductus arteriosus narrowing. It is concluded that high resolution two-dimensional echocardiography can be used to assess ductus arteriosus morphology, but is limited in predicting ductal patency near the time of normal physiologic closure. Combined two-dimensional and Doppler echocardiography is a highly sensitive technique for detection of ductal patency when sampling is performed in the pulmonary end of the ductus arteriosus.     

Interatrial shunt flow profiles in newborn infants: a colour flow and pulsed Doppler echocardiographic study

Interatrial shunt flow profiles in 36 normal term infants were examined serially by colour flow and pulsed Doppler echocardiographic techniques from within an hour of birth to four or five days after birth. Shunt flow across the foramen ovale was detected in 33 normal infants (92%) within an hour of birth (mean 40 minutes). The occurrence of interatrial shunting decreased with age, but a shunt signal was still detected in 17 infants (47%) on the fourth or fifth day of life, by then the ductus arteriosus had already closed in all the normal infants. The direction of interatrial shunt flow was predominantly left-to-right, but in 64% there was a coexistent small right-to-left shunt in diastole within an hour of birth; by four to five days it was found in 19%. In the six patients with persistent fetal circulation the direction of the interatrial shunt flow was predominantly right-to-left with biphasic peaks in diastole and systole at the early stage of the disease, and the period of right-to-left shunt flow during each cardiac cycle was significantly longer than that in normal infants examined within 1 hour of birth. In all patients the ductus closed before the foramen ovale. At the time of ductal closure in all patients with persistent fetal circulation right-to-left shunt flow was seen during diastole and its period was still prolonged. These findings suggest that interatrial shunting, predominantly left-to-right, is common in normal newborn infants. Evaluation of the characteristics of the interatrial shunt by Doppler echocardiography may be useful for predicting the progress of or improvement in neonates with persistent fetal circulation.     

Accuracy of electrical impedance cardiography for measuring cardiac output in children with congenital heart defects

This study determined whether noninvasive electrical impedance cardiography accurately measures systemic blood flow (cardiac output) in children with congenital heart defects. A total of 37 patients ranging in age from 2 to 171 months underwent complete right- and left-sided heart catheterizations that included simultaneous Fick and impedance measurement of cardiac output. Based on the diagnosis, 4 groups were formed consisting of a control group (n = 11) with no shunts, a group with intracardiac left-to-right shunting and an atrial septal defect (n = 7), another with a ventricular septal defect (n = 12) and an extracardiac left-to-right shunting with patent ductus arteriosus group (n = 7). Impedance values for systemic blood flow were compared with systemic and pulmonary blood flow obtained by the direct Fick method with measured oxygen consumption. The difference between impedance and Fick systemic blood flow was less than or equal to 5% in each of the 4 groups. The highest correlation between impedance and Fick systemic blood flow was with the atrial septal defect group (r = 0.89) and lowest with the ventricular septal defect and control (r = 0.69) groups. Fick pulmonary blood flow was significantly greater than impedance or Fick systemic flow in all 3 shunt groups. Impedance cardiography accurately measured systemic blood flow in children without shunts or valvular insufficiency. Likewise, systemic blood flow was accurately measured by impedance in the presence of intracardiac left-to-right shunts (atrial and ventricular septal defects) and extracardiac left-to-right shunts (patent ductus arteriosus).(ABSTRACT TRUNCATED AT 250 WORDS)     

Pulsed Doppler flow characteristics of ductus arteriosus in infants with associated congenital anomalies of the heart or great arteries

Pulsed Doppler echocardiography (PDE) from the suprasternal approach was used to assess flow characteristics of ductus arteriosus (DA) in 145 infants (aged 1 day to 6 months) with major congenital heart disease. Direct ductal Doppler interrogation was possible in 138 patients and serial studies before and after medical treatment were performed in 28 infants. According to pulmonary artery pressure and associated heart lesions, 3 ductal shunting patterns were identified. An isolated left-to-right shunt, observed in isolated DA or in right ventricular outflow tract obstruction, was characterized by a continuous flow with a peak velocity in late systole. An isolated right-to-left shunt, observed in persistent fetal circulation and aortic arch abnormalities, was characterized by a continuous flow with a peak velocity in early systole. In patients with a bidirectional ductal shunt, the right-to-left shunt always occurred in systole and the left-to-right shunt began in late systole and extended into diastole. A systolic right-to-left shunt always corresponded to the presence of significant pulmonary hypertension. Ductal flow changes could be documented after prostaglandin E1 therapy in patients with ductus-dependent heart disease or after tolazoline therapy in patients with persistent fetal circulation. Thus, PDE with direct ductal Doppler interrogation is an important complement to the echocardiographic evaluation of DA. It is a safe noninvasive approach to ductal shunt and permits convenient evaluation of the effects of drugs on pulmonary artery resistance (tolazoline) and ductal patency (prostaglandin E1).     

Interatrial shunt flow profiles in newborn infants: a colour flow and pulsed Doppler echocardiographic study.

Interatrial shunt flow profiles in 36 normal term infants were examined serially by colour flow and pulsed Doppler echocardiographic techniques from within an hour of birth to four or five days after birth. Shunt flow across the foramen ovale was detected in 33 normal infants (92%) within an hour of birth (mean 40 minutes). The occurrence of interatrial shunting decreased with age, but a shunt signal was still detected in 17 infants (47%) on the fourth or fifth day of life, by then the ductus arteriosus had already closed in all the normal infants. The direction of interatrial shunt flow was predominantly left-to-right, but in 64% there was a coexistent small right-to-left shunt in diastole within an hour of birth; by four to five days it was found in 19%. In the six patients with persistent fetal circulation the direction of the interatrial shunt flow was predominantly right-to-left with biphasic peaks in diastole and systole at the early stage of the disease, and the period of right-to-left shunt flow during each cardiac cycle was significantly longer than that in normal infants examined within 1 hour of birth. In all patients the ductus closed before the foramen ovale. At the time of ductal closure in all patients with persistent fetal circulation right-to-left shunt flow was seen during diastole and its period was still prolonged. These findings suggest that interatrial shunting, predominantly left-to-right, is common in normal newborn infants. Evaluation of the characteristics of the interatrial shunt by Doppler echocardiography may be useful for predicting the progress of or improvement in neonates with persistent fetal circulation.     

Real-time Doppler color flow mapping for detection of patent ductus arteriosus

In this study, ultrasound Doppler color flow mapping systems were utilized to examine flow in the pulmonary artery in 31 premature and term infants (aged 4 hours to 9 months) with patent ductus arteriosus accompanying respiratory distress syndrome, as an isolated lesion, or with patent ductus in association with other cyanotic or acyanotic congenital heart disorders. The flow mapping patterns were compared with those of a control population of 15 infants who did not have patent ductus arteriosus. In unconstricted ductus arteriosus, the flow from the aorta into the pulmonary artery was detected in late systole and early diastole and was distributed along the superior leftward lateral wall of the main pulmonary artery from the origin of the left pulmonary artery back in a proximal direction toward the pulmonary valve. In constricted patent ductus arteriosus, or especially in a ductus in association with cyanotic heart disease, the position of the ductal shunt in the pulmonary artery was more variable, often directed centrally or medially. Waveform spectral Doppler sampling could be performed in specific positions guided by the Doppler flow map to verify the phasic characteristics of the ductal shunt on spectral and audio outputs. Shunts through a very small patent ductus arteriosus were routinely detected in this group of infants, and right to left ductal shunts could also be verified by the Doppler flow mapping technique. This study suggests substantial promise for real-time two-dimensional Doppler echocardiographic flow mapping for evaluation of patent ductus arteriosus in infants.     

Trans-femoral ductus Botalli occlusion in patients over 60 years of age]

A persistent ductus arteriosus was occluded with an ivalon-plug introduced through the femoral artery in 14 patients over 60 years old (61 to 70 years). Two patients had previous surgery. The maximum left-to-right shunt was 53%, the maximum pulmonary artery pressure 54/24 mm Hg. In all patients ductus occlusion was successful and permanent. Bleeding at the puncture site in two patients could be stopped by manual compression. During a follow-up period of up to 5 years there were no instances of recanalization.     

Endoluminal closure of ductus arteriosus. A cooperative study

Thirty-two patients from 3 Pediatric Cardiological Centres underwent attempted endoluminal transcatheter closure of a patent ductus arteriosus. The patients' age ranged from 8 months to 67 years, but there were only 2 adults (18 and 67 years) in this series. All patients had a murmur which was continuous in 28 cases and systolic in 4 cases. Nine patients had left ventricular hypertrophy on the electrocardiogram and radiological cardiomegaly. Closure of the patent ductus was attempted by Rashkind's technique using a double umbrella of 12 mm diameter for ductus less than 4 mm diameter (26 cases), and an umbrella of 17 mm diameter when the ductus was wider (6 cases). The immediate results judged by retrograde aortography showed total occlusion in 12 patients and incomplete closure in 17 others with persistence of a minimal left-to-right shunt. In 3 cases, embolisation of the umbrella into the left pulmonary artery (2 cases) or right pulmonary artery (1 case), required thoracotomy to extract the umbrella and at the same time section-suture of the ductus arteriosus. Color Doppler echocardiographic follow-up showed the disappearance of the residual shunt in seven children.     

Doppler echocardiographic observations of pulmonary and transvalvular velocity changes after birth and during the early neonatal period

To evaluate the qualitative and quantitative changes in Doppler velocities in the normal fetus and newborn, 61 echo Doppler studies were performed in 18 neonates, nine of whom were also studied as fetuses. Four studies were inadequate in fetuses (one pulmonary artery, two mitral, and one tricuspid) and some post natal studies were inadequate due to inability to separate atrioventricular valve E and A velocity component waveforms (one tricuspid, three mitral). Heart rates for fetuses and newborns more than 24 hours of age and less than 24 hours of age were similar. Pulmonary artery diastolic velocities consistent with patent ductus arteriosus were present in 11 of 12 examinations at less than 6 hours of age, in 5 of 13 examined at 6 to 24 hours of age, and in 2 of 27 examined after 24 hours of age. Pulmonary artery times to peak velocity were similar in fetuses, m = 46, SD = 3 msec, and in neonates less than 6 hours of age, m = 51, SD = 13 msec, but lengthened significantly, p less than 0.05, at 6 to 24 hours (m = 69, SD = 14 msec). These changes are probably due to the dramatic changes in pulmonary vascular pressure that occur after birth. Data from 6 to 24 hours and greater than 24 hours (m = 78, SD = 13 msec) were similar. Significant differences existed for transmitral valve E/A ratios, which increased from m = 0.85 in utero to m = 1.17 (p less than 0.05) after birth, with no significant change thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)