Usefulness of anatomic parameters derived from two-dimensional echocardiography for estimating magnitude of left to right shunt in patients with atrial septal defect

The ability of two-dimensional echocardiography (2DE) to quantitate the atrial septal defect size and left-to-right shunt magnitude was examined in 75 adult patients with simple ostium secundum atrial septal defect (ASD) with left-to-right shunts of 19-92% of systemic flow as determined by oximetry. The ASD was visualized in 71 of 75 (95%) patients utilizing subcostal 2DE, and the end-systolic atrial septal defect diameters in subcostal 2DE (ASDe) were measured. The maximal diameters of ASD measured during operation (ASDop) were obtained in 45 of these patients, who then underwent surgical ASD repair. The correlation between ASDe and ASDop was high (r = 0.91, p less than 0.001), indicating accuracy of quantitating defect size via subcostal 2DE approach. However, the correlation between the left-to-right shunt magnitude and ASDe was only fair (r = 0.76, p less than 0.01). In large ASDe the shunts varied greatly, while in small ASDe the shunts increased proportionally with increasing sizes of ASD. In addition, the ratio of left-to-right ventricular diameter (RVD/LVD) was determined. The RVD/LVD correlated relatively well with the shunt magnitudes (r = 0.83, p less than 0.001). Using the two new echocardiographic parameters of ASDe and RVD/LVD, a high percentage (85%) of patients with a large left-to-right shunt requiring surgical closure can be identified. All 43 patients with ASDe greater than 2.0 cm and RVD/LVD greater than 1.1 had a left-to-right shunt greater than 40%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Role of two-dimensional echocardiography, pulsed, continuous wave color flow Doppler techniques in the assessment of ventricular septal rupture after myocardial infarction

Two-dimensional echocardiography, pulsed and continuous wave Doppler techniques were used for the evaluation of 15 consecutive patients (9 men, 6 women; mean age 71 years, range 61 to 79) with ventricular septal rupture due to acute myocardial infarction (7 anterior, 8 posterior). Standard and modified off-axis 2-dimensional echocardiographic views from parasternal, apical and subcostal windows correctly identified this defect in 14 of the 15 patients. Pulsed Doppler echocardiography confirmed the presence of left-to-right-sided shunt by showing a high-velocity, aliased, systolic flow and a low-velocity diastolic flow in the right ventricle in 14 patients. Continuous wave Doppler echocardiography showed a high-velocity systolic and low-velocity diastolic flow signal of left-to-right shunt in 14 patients. Color flow Doppler imaging identified a left-to-right shunt in all 6 patients in whom it was performed. Doppler and 2-dimensional echocardiographic studies missed a small apical septal defect in 1 patient with anteroseptal myocardial infarction. Two-dimensional echocardiography correctly diagnosed right ventricular infarction in all 5 patients with posteroinferior infarction. Ventricular septal rupture and/or left-to-right-sided shunt was confirmed in all 15 patients by the following: surgical inspection in 11, necropsy in 3, left ventricular cineangiography in 5 and right-sided heart catheterization and oximetry data in 13 patients. Data indicate that 2-dimensional echocardiography correctly shows the precise location of septal rupture in most patients after acute myocardial infarction and allows assessment of left and right ventricular infarction and function.(ABSTRACT TRUNCATED AT 250 WORDS)     

彩色多普勒超声心动图在老年房间隔缺损封堵术中的价值

目的探讨彩色多普勒超声心动图(CDE)在老年房间隔缺损(ASD)封堵术中的价值。方法选择老年ASD患者64例,封堵术前应用二维超声心动图观察ASD位置,测量ASD大小和残余边缘,彩色多普勒血流显像观察过房间隔分流束血流信号和过心脏瓣膜反流束血流信号,连续多普勒估测肺动脉压,合并心房颤动和多发ASD经食管超声心动图检查,筛选ASD封堵术适应证。ASD封堵术中应用二维超声心动图监视封堵器位置,用彩色多普勒血流显像监视有无过房间隔残余分流。ASD封堵术后应用CDE判断疗效。结果 64例老年ASD患者实施ASD封堵术全部获得成功,ASD封堵术后CDE判断疗效满意。结论 CDE在老年ASD封堵术中有重要价值。ASD封堵术前应用二维超声心动图观察ASD位置、大小和残余边缘,连续多普勒估测肺动脉压,合并心房颤动和多发ASD行经食管超声心动图检查是筛选老年ASD封堵术适应证的关键。     

Noninvasive pulsed Doppler echocardiographic detection of the direction of shunt flow in patients with atrial septal defect: usefulness of the right parasternal approach

Noninvasive pulsed Doppler echocardiography combined with two-dimensional echocardiography by the right parasternal approach was performed to detect the shunt flow through the defect in 31 patients with suspected secundum atrial septal defect (ASD). A defect of the interatrial septum was seen on the two-dimensional echocardiograms of 30 of 31 patients. In all the 30 patients, Doppler signals of shunt flow could be recorded by placing the sample volume in the center of the defect on the two-dimensional echocardiogram. Neither a defect nor Doppler signal indicating shunt flow were demonstrated in any of 15 normal control subjects. Cardiac catheterization indicated significant shunt flow in all the 31 patients with suspected ASD. Doppler signals obtained from the center of the defect showed left-to-right and/or right-to-left shunt flow patterns. The direction of the shunt flow was mainly left to right, with its peak in late systole and atrial systole in 28 of 30 patients; mainly right-to-left flow was present in the remaining two patients, who had Eisenmenger's syndrome. The direction of flow as predicted by the Doppler signal was confirmed by the coincidence of direction of flow as seen on the contrast two-dimensional echocardiogram. In 22 patients for whom the measurement of the pulmonary-to-systemic flow ratio by oximetry was believed to be reasonably accurate, the ratio was fairly well correlated with Doppler-determined left-to-right shunt flow velocity (r = .71, SEE = 6.7 cm/sec).(ABSTRACT TRUNCATED AT 250 WORDS)     

Detection and evaluation of tricuspid regurgitation using a real-time, two-dimensional, color-coded, Doppler flow imaging system: comparison with contrast two-dimensional echocardiography and right ventriculography

To detect and evaluate regurgitant flow in tricuspid regurgitation (TR) with a newly developed, realtime, 2-dimensional (2-D), color-coded, Doppler flow imaging system (Doppler 2-D echo), 27 patients (18 with suspected TR and 9 normal subjects) were examined and the findings were compared with those obtained using contrast 2-D echocardiography (contrast 2-D echo) and right ventriculography. In 16 of 18 patients with suspected TR, Doppler 2-D echo easily visualized the color-coded regurgitant flow in the right atrium and estimated the severity of TR from the distance of the visible TR jet. On the basis of the QRS synchronized appearance of contrast in the inferior vena cava by the subxiphoid approach or of the negative contrast effect above the tricuspid valve just after the contrast entered the right ventricle with its subsequent back-and-forth movements across the tricuspid valve, Doppler 2-D echo was more sensitive and specific in detecting TR (100% and 100%) than contrast 2-D echo (75% and 82% in the subxiphoid view, 56% and 100% in the 4-chamber view) when the fast Fourier transformation frequency analysis was used as the standard of TR, and it was more sensitive in detecting TR (85%) than contrast 2-D echo (69% in the subxiphoid approach, 46% in the 4-chamber view) when right ventriculography was used as the standard of TR. Additionally, the severity of TR as shown by Doppler 2-D echo correlated fairly well with that shown by right ventriculography. Thus, Doppler 2-D echo is clinically useful for detecting and evaluating TR.     

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.     

Two-dimensional Doppler color flow mapping in congenital heart disease

The development of a system that images intracardiac anatomy cross-sectionally while simultaneously displaying intracardiac blood flow in realtime has the potential of increasing diagnostic capabilities in the evaluation of congenital heart lesions. This would translate into the ability to visualize intracardiac lesions not identified by standard M-mode, two dimensional (2-D), pulsed, and continuous wave Doppler modalities. A review of 1000 consecutive studies in our laboratory was performed. Doppler color flow mapping was performed in each case after complete segmental analysis by 2-D and Doppler echo. Identification of intracardiac lesions or abnormalities of blood flow by Doppler color flow mapping, not appreciated on routine 2-D/Doppler studies included ventricular septal defect (VSD) (n = 24), atrial septal defect (n = 4), mitral regurgitation (n = 13), tricuspid regurgitation after VSD closure (n = 5), tricuspid regurgitation in association with atrial septal defect (ASD) (n = 7), residual ventricular septal defect after surgery (n = 10), pulmonary insufficiency (n = 4), aortic insufficiency (n = 4), and patent Blalock-Taussig shunt (n = 2). Identification of multiple ventricular septal defects in two patients and the presence of a large left-to-right shunt across an atrial septal defect in the presence of septal aneurysm formation was also aided by Doppler color flow. Use of color flow to identify areas of maximal velocity and turbulence greatly enhanced continuous wave Doppler measurements by directing placement of the Doppler beam within the flow areas.     

Quantitation of left-to-right shunts in secundum atrial septal defect by two-dimensional contrast echocardiography with use of Albunex

Our data indicate that 2-dimensional contrast echocardiography with use of Albunex is a safe, non-invasive, and feasible method for quantitating left-to-right shunts in patients with secundum ASD.     

Ventricular septal rupture after myocardial infarction: Diagnosis by two-dimensional and pulsed doppler echocardiography

Rupture of the ventricular septum in the acute phase of myocardial infarction (MI) requires prompt recognition for correct management. The 2-dimensional and pulsed Doppler echocardiographic findings are reported from 11 patients with ventricular septal (VS) rupture. VS rupture was confirmed by cardiac catheterization in 9 patients, surgery in 4 patients and necropsy examination in 3 patients. Two-dimensional echocardiography (echo) directly visualized the rupture in 7 patients and assessed the size and location of an associated aneurysm in 10. In all patients, M-mode pulsed Doppler echo allowed detection of the left-to-right shunting due to VS rupture, but failed to indicate the rupture site. M-mode pulsed Doppler echo was reliable for detecting VS rupture after MI. Conversely, 2-dimensional echo was less effective in the direct visualization of the rupture, but provided anatomic and functional information that was useful in medical and surgical management. Thus, the techniques are complementary and should be used in combination for the assessment of VS rupture in acute MI.     

Partial atrioventricular septal defect assessed by real-time three-dimensional echocardiography: a case report

A 48-year-old woman was admitted with a heart murmur and increased difficulty in breathing. Two-dimensional echocardiography revealed a defect in the lower part of the atrial septum [(primum atrial septal defect (ASD)] and a pouch at the interventricular septum. Color Doppler echocardiography detected grade 3/4 mitral regurgitation. Real-time three-dimensional echocardiography (RT-3DE) revealed a cleft in the anterior leaflet of the mitral valve toward the tricuspid valve, and the ASD located near the atrioventricular valves with 14mm in minor axis. Color Doppler three-dimensional echocardiography disclosed left-to-right ASD shunt toward the atrial posterior wall. No shunt through the pouch at the membranous part, left ventricular outflow obstruction, or partial anomalous pulmonary venous connection was observed. RT-3DE is quite useful to describe complicated congenital heart disease.     

Diagnosis and quantitative evaluation of secundum-type atrial septal defect by transesophageal Doppler echocardiography

Transesophageal echocardiography (horizontal sector scan) was performed in 11 patients with secundum atrial septal defect (ASD). In all 11 patients, transesophageal echocardiography presented the definite visualization of the defect and a clear laminar shunt flow that showed its 2 peaks in late systole and late diastole. We estimated the size of ASD and a shunt volume across the defect by using transesophageal echocardiography. The defect size determined by transesophageal echocardiography was correlated with the surgical measurement (horizontal width, r = 0.92, p less than 0.001; vertical length, r = 0.85, p less than 0.01). A significant high correlation was shown between the shunt volume measured by transesophageal echocardiography and that by Fick's method (r = 0.87, p less than 0.01). There was no significant correlation between the pulmonary to systemic flow volume (ratio) and the mean shunt flow velocity across ASD, although a high linear correlation was observed between the pulmonary to systemic flow ratio and the defect size in horizontal direction (r = 0.82, p less than 0.01). Transesophageal echocardiography used for diagnosis and quantitative evaluation of ASD could be performed easily and satisfactorily within 10 minutes. Thus, transesophageal echocardiography is a useful method in evaluation of the defect size and the shunt flow volume of ASD. The mean shunt flow velocity was not a reliable index for estimating the shunt flow volume. The defect size might be a valuable determinant of left-to-right shunt volume in ASD.     

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.     

Diastolic Left-to-Right Shunting in Uncomplicated Ventricular Septal Defect

The systolic left-to-right shunt in patients with uncomplicated ventricular septal defect is associated with a classic loud murmur, and is well described. The additional diastolic left-to-right shunt, always silent, is less well recognized. Left-to-right diastolic shunt flow is directly related to the defect size, to the diastolic pressure gradient between the left and right ventricle, and to the duration of diastole. The purpose of this study was to evaluate by Doppler echocardiography the duration, magnitude, and flow velocity characteristics of the diastolic left-to-right shunt. There were 30 adult patients with uncomplicated ventricular septal defects studied by color, pulsed, and continuous wave Doppler echocardiography. In each patient, the uncomplicated ventricular septal defect was visualized by two-dimensional echocardiography and/or Doppler echocardiography, and the systolic and diastolic left-to-right shunt flow was identified by Doppler echocardiography. Accurate Doppler flow velocity peaks twice, in beginning and again at end diastole. The mean diastolic flow velocity was 0.5–1.5 msec (average 0.83 ± .22 msec). This flow velocity was markedly lower than the mean systolic shunt flow velocity (2.4–5.3 msec, average 3.8 ± .7 msec). The Doppler flow velocity integral was 0.17–0.64 m (average 0.36 ± 0.14), markedly smaller than the systolic flow velocity integral (0.8–1.8 m, average 1.3 ± 0.3). The diastolic left-to-right shunt flow was 12–41% (average 21 ± 8) of total (systolic and diastolic) shunt flow. In conclusion: Diastolic left-to-right shunts can be identified in all patients with uncomplicated ventricular septal defects, and analyzed in the majority of patients. A significant degree of the left to right shunting in uncomplicated ventricular septal defects occur during diastole.     

Transesophageal color Doppler flow mapping of iatrogenic left-to-right interatrial shunting after percutaneous transluminal mitral valvotomy

Characteristics of transesophageal color Doppler flow mapping of iatrogenic left-to-right interatrial shunts were assessed in 58 patients, 1 to 994 days after percutaneous transluminal mitral valvotomy. Transesophageal color Doppler flow mapping detected 22 cases of interatrial shunt whereas transthoracic two-dimensional echocardiography visualized only five interatrial septal defects. Five types of color Doppler flow patterns of interatrial shunts were found: type 1, a bluish jet passing through the interatrial septum into the right atrium with a small bluish proximal flow in the left atrium (50%); type 2, a bluish jet passing through the interatrial septum into the right atrium without a proximal flow (13.6%); type 3, a predominant bluish proximal flow in the left atrium passing through the interatrial septum with minimal flow entering into the right atrium (18.2%); type 4, an "en face" bluish jet in the right atrium (4.5%); and type 5, a "wall jet" with proximal flow adhering to and entering into the interatrial septum (13.6%). Oximetry demonstrated increased pulmonary-to-systemic flow ratio (range 1.07 to 3.32) in 11 patients (50%), which was significantly correlated with the maximal jet area derived from color Doppler flow mapping (r = 0.80, P = 0.001). Thus, transesophageal color Doppler flow mapping is useful in detection of left-to-right interatrial shunts after percutaneous transluminal mitral valvotomy, and recognition of the variable types of color flow mapping may further help identify these atypical interatrial shunts.     

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.     

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.     

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).     

Combined contrast echocardiographic and radionuclide diagnosis of atrial septal defect: Accuracy of the technique and analysis of erroneous diagnoses

The utility of combined peripheral vein contrast 2-dimensional echocardiography (2-D echo) and radionuclide shunt detection was evaluated in 25 patients with suspected atrial septal defect (ASD) in whom the diagnosis was confirmed at cardiac catheterization: 14 patients had ASD and 11 had no intracardiac shunt. Contrast 2-D echo correctly diagnosed 13 of 14 patients with ASD, but there were 2 false-positive diagnoses in the 11 patients without ASD. Radionuclide shunt studies correctly identified all 14 patients with ASD, but yielded 5 false-positives results among the 11 without ASD. After altering the radionuclide processing technique, there were only 2 of 11 false-positive shunt studies, and the correlation of radionuclide shunt magnitude with cardiac catheterization improved (r = 0.49, p < 0.025 to r = 0.75, p < 0.001). Thus, the improved processing method improved both the qualitative and quantitative accuracy of radionuclide shunt detection. The combination of contrast 2-D echo and radionuclide shunt detection led to a proper diagnostic and therapeutic decision in 24 of 25 patients. Therefore, these combined modalities are clinically useful in the evaluation of patients with suspected ASD.     

Evaluation of pulmonary and systemic blood flow by 2-dimensional Doppler echocardiography using fast fourier transform spectral analysis

This study was designed to assess the accuracy and problems of noninvasively measuring right and left cardiac output by range-gated pulsed Doppler echocardiography. Sixteen children with cardiac disease, aged 3 months to 17 years, served as the subjects; 2-dimensional range-gated pulsed Doppler echocardiographic data were unobtainable in 2 children, leaving 14 for study. Diagnoses included shunt lesions, valvular abnormalities, coarctation, repaired defects, and Kawasaki's disease. The equipment for this study included a 2-dimensional echocardiographic Doppler sample volume locator. The Doppler frequency shift was analyzed by fast Fourier transform. Twenty 2-dimensional range-gated pulsed Doppler echocardiographic measurements (10 pulmonary and 10 aortic) were made simultaneously with indicator dilution outputs or angiographic outputs. In 4 subjects, 2-dimensional range-gated pulsed Doppler echocardiographic aortic outputs were not possible. For this study, vessel diameter was determined by both echocardiography and angiography, Doppler intercept angle by 2-dimensional echocardiography, and velocity by 2-dimensional range-gated pulsed Doppler echocardiography. Comparison of cardiac output measurements obtained by invasive methods and by 2-dimensional range-gated pulsed Doppler echocardiography (angiographic vessel measurement) showed a correlation of +0.94 (standard error of the estimate [SEE] = 0.53) with a slope of y = 0.83 × + 0.61, indicating that the slope and line of identity were almost equal and the offset from 0 was small. For 2-dimensional range-gated pulsed Doppler echocardiography (echocardiographic vessel measurement), the correlation was +0.94 for aortic flow but only +0.72 for pulmonary flow. Problems encountered in some patients included turbulence, which made velocity measurements unreliable, difficulty in obtaining aortic flow by Doppler echocardiography due to transducer configuration, and measurement of pulmonary diameter by echocardiography. The results indicate that 2-dimensional range-gated pulsed Doppler echocardiographic outputs are accurate under conditions of nonturbulent or minimally turbulent flow and adequate imaging, but only when vessel diameter can be accurately measured.     

Ultrasonographic evaluation of pulmonary to systemic flow ratio. Personal experience

Usefulness of a noninvasive, ultrasound method for pulmonary to systemic flow ration evaluation (one of the basic parameters characterizing hemodynamic disorders in cardiac defects with a left-to-right intracardiac shunt) was assessed. For that reason 153 systemic and pulmonary flows examinations of 116 patients were performed. 4 of them due to unsatisfactory quality were excluded from the further analysis. 112 remainings were divided into three groups: I. The control group without an intracardiac shunt. II. The group with a left-to-right intracardiac shunt. III. Before and after defect repair. ASD or VSD were proved or excluded basing on 2-DE. Blood flows were simultaneously with 2cDE detected using pulsed, continuous and color doppler methods. Pulmonary and systemic flow volumes were calculated by means of a combined echocardiographic and doppler method. Those volumes ratio is equal to the parameter in question. In 12 cases due to disturbed flow in mai pulmonary artery, pulmonary blood flow was measured on the mitral valve (in 11 cases) or on the right ventricular outflow tract level (in 1 patient). Systemic blood flow volume was always measured on the aortic valve level. High concordance of noninvasive calculations of pulmonary and systemic blood flow volumes was stated with differences between them not exceeded more than 20% and with correlation ratio r = 0.94. Increased pulmonary flow and pulmonary to systemic flow ratio were stated in patients with intracardiac shunt. That ratio became normal after surgical correction. There were studied changes in pulmonary and systemic flow volumes before and after a defect closure. Obtained results proved usefulness of noninvasive, ultrasound assessment of pulmonary to systemic flow ratio in a left-to-right intracardiac shunt. Some potentially encountered difficulties of the method, when its applied, was also discussed.