Ventricular septal defect in infancy: Detection with two dimensional echocardiography

To determine the sensitivity and specificity of two dimensional echocardiography in detecting ventricular septal defect two dimensional echocardiograms were performed on 53 infants under 1 year of age. The diagnosis of ventricular septal defect was confirmed by cardiac catheterization in 27 patients; an intact ventricular septum was confirmed by catheterization in 18 and clinically in 8. Using a 35 ° mechanical sector scanner with a 3.5 megahertz transducer, we imaged the ventricular septum in the long axis and in a four chamber view (apical or subcostal, or both). Images were recorded on videotape and reviewed independently by two observers unaware of the diagnosis. Interobserver agreement was 94 percent. Among the 27 patients with a ventricular septal defect, the lesion was correctly identified in 20 (74 percent) and was undetected in 7 (3 of whom had a defect less than 4 mm in diameter, as determined by angiography). No defect less than 4 mm in diameter was detected. Among the 26 patients with an intact septum, a defect was correctly excluded in 23 (88 percent); a false positive diagnosis was made in 3. The apical and subcostal views demonstrated the greatest number of defects (20 of 20), but also gave the highest number of false positive diagnoses (3 of 3). The long axis view was helpful when positive, but showed only 9 of 20 of the defects.In this study, two dimensional echocardiography detected approximately three fourths of ventricular septal defects large enough to warrant cardiac catheterization in the 1st year of life. False positive diagnoses were related to dropout of echoes in the membranous septum when imaged in the four chamber views.     

Reliability and reproducibility of two dimensional echocardiograph measurement of the stenotic mitral valve orifice area.

A wide angle phased array sector scanner was used to find the optimal method, the reliability and the reproducibility of measuring the mitral valve area with two dimensional echocardiography in patients with rheumatic mitral stenosis. Initial experience with 18 patients revealed that tracing the early diastolic actual black-white interface of the perceived orifice was the most reliable method for drawing the mitral valve orifice area. Good interobserver correlation was obtained when two observers used either method to calculate the mitral valve area (r = 0.93). Similarly good intrastudy reliability was obtained when any one observer applied one measurement method to different diastolic cycles within the same study (r = 0.89). The phased array two dimensional echocardiogram properly differentiated patients with critical mitral stenosis from those with non-critical mitral stenosis, but the correlation between the echocardiographically and the hemodynamically derived mitral valve areas was less good than previously reported (r = 0.83). Imaging a test object with varied known orifice sizes and excised stenotic mitral valves of known orifice size with a phased array and mechanical sector scanner failed to reveal superiority of either instrument. Further testing with a phased array instrument revealed that the perceived orifice was critically dependent on receiver gains settings for any transmitted power level. Receiver gain settings too low led to image dropout, indicating a falsely large orifice. Receiver gain settings too high led to image saturation, indicating a falsely narrowed orifice. Six additional patients with predominant mitral stenosis later underwent imaging with strict attention paid to individual receiver gain settings. Combining the data from these 6 patients with those from the initial 18 patients gave a better correlation between the echocardiographic and hemodynamic calculated mitral valve areas (r = 0.92).Accurate noninvasive measurement of the mitral valve area with two dimensional echocardiography in patients with mitral stenosis appears to depend on use of the proper echocardiographic technique to localize the true commissural edge of the valve in early diastole, the correct instrument settings and the appropriate method for drawing the perceived orifice. The noninvasive measurement of the mitral valve orifice with two dimensional echocardiography in mitral stenosis provides clinically useful data that are reliable and reproducible if these factors are taken into account.     

Two dimensional echocardiographic visualization of ventricular septal rupture after acute anterior myocardial infarction

In three consecutive cases of ventricular septal rupture after acute anterior myocardial infarction, wide angle two dimensional echocardiography readily visualized the septal defect, permitting the defect to be localized and its size estimated. In addition, negative contrast echoventriculography identified a left to right shunt at the ventricular level. The echocardiographic findings were corroborated by cardiac catheterization data in all patients, by perioperative examination in two and by postmortem findings in one patient. Postoperative echocardiographic studies afforded demonstration of the patch closing the defect.In patients with acute myocardial infarction associated with the sudden appearance of a systolic murmur, two dimensional echocardiography should be performed promptly in order to guide the diagnosis and management of these critically ill patients. In some patients with severe cardiogenic shock, in whom a favorable prognosis depends on rapid treatment, two dimensional echocardiography may allow the patient to be taken to surgery immediately without further study.     

Echocardiographic features of supracristal ventricular septal defect with prolapsed aortic valve leaflet.

Anatomically diagnostic echocardiographic features of a supracristal ventricular septal defect with prolapsed right coronary aortic leaflet are described in four children aged 2 to 10 years. Both single crystal M mode as well as 80 ° phased array sector scan techniques were used. The echographic features in the M mode scan from the aorta to the left ventricle in three of four patients included (1) the position of the ventricular septal defect as a clear space between the interrupted septal echoes below the aortic root, and (2) the prolapsed right coronary aortic leaflet as anomalous linear echoes in the right ventricular outflow tract. Angiographic, intraoperative and echocardiographic contrast studies were used to establish the diagnosis.On sector scanning using the long axis view, the supracristal ventricular septal defect was recognized as a clear space between the top of the ventricular septum and the anterior segment of the aortic root in three of four patients. The right coronary aortic leaflet was seen to prolapse into the right ventricular outflow tract through this defect, and its motion could be clearly followed during systole and diastole. It is concluded that echocardiography provides anatomic diagnosis of this lesion. Furthermore, the severity and progression of this lesion can be assessed by quantitation of the left ventricular size and performance.     

Transesophageal cross-sectional echocardiography

A transesophageal cardiac imaging system is described. This system employs hand-held mechanical sector and linear scanners each having a flexible tube and a small ultrasonic transducer contained within a small oil bag easily swallowed by adults. In the sector scanner, a small transducer in the esophagus rotates alternately and horizontal heart images are displayed. In the linear scanner, a small transducer in the esophagus moves up and down and vertical heart images are displayed. The system was evaluated in 31 adult subjects. In all subjects, stable high quality heart images were observed continuously from base to apex as the transducer was being withdrawn or advanced in the esophagus. In horizontal scans, entire heart images were observed at the level of the atrioventricular valves. In vertical scans, the bifurcation of the pulmonary artery could be observed clearly. There was little difference in the image quality among subjects.     

Observations on detecting left ventricular thrombus with two dimensional echocardiography: emphasis on avoidance of false positive diagnoses

Observations made in detecting left ventricular thrombus with two dimensional echocardiography in 25 patients are reviewed. In 20 patients thrombus was documented on angiography, surgery, postmortem examination or serial two dimensional echocardiographic findings; in the remaining five patients two dimensional echocardiographic findings of thrombus were unequivocal. In all 25 patients wall motion abnormalities ranging from hypokinesia to frank dyskinesia were present at the site of the thrombus. Twenty-three patients had an apical thrombus; two had thrombus adjacent to the inferior wall. Clear delineation of the endocardium and thrombus margin was considered essential to the correct diagnosis of thrombus. Both intracavitary motion of the thrombus margin and a layering effect were noted infrequently although they were of benefit in identifying an intracardiac mass as thrombus. In addition, serial evaluations were helpful in establishing the correct diagnosis.False positive diagnoses can be minimized if one understands certain technical limitations of this method and correctly identifies apical structures that are not thrombi. Axial and lateral resolution problems inherent with this technique can produce intracavitary echoes that may simulate thrombi. In addition, normal or pathologic structures at the apex may also simulate thrombi. These structures include the papillary muscles, muscular trabeculae, chordal structures and tangential information from normal myocardium. Varying the sector orientation or acoustic window, or both, will aid in correctly identifying these structures and distinguishing them from left ventricular thrombi.     

Tissue acoustic properties of fresh left ventricular thrombi and visualization by two dimensional echocardiography: Experimental observations

Although two dimensional echocardiography can detect left ventricular thrombi In certain cardiovascular disease states, there Is theoretical concern that the acoustic Impedance properties of recently formed fresh thrombi may not allow their echocardiographic visualization. If such were the case, false negative studies might occur even with technically adequate echocardiographic examinations. To determine if the tissue acoustic properties of acute thrombi allow their visualization and differentiation from surrounding intracavitary blood and adjacent myocardium with two dimensional echocardiography, an in vivo canine model of acute left ventricular thrombus was studied. In 10 dogs left ventricular thrombus was induced using coronary ligation and subendocardial injection of a sclerosing agent, sodium rlclnoleate. Acoustically distinct left ventricular thrombi were imaged by two dimensional echocardiography within hours (mean ± standard deviation 121 ± 40 minutes, range 45 to 180), and the thrombi could easily be differentiated from surrounding blood and adjacent myocardium. Thrombi with a maximal dimension as small as 0.6 cm at autopsy were highly reflective and could be imaged with echocardiography. Histologic examination of the thrombi showed characteristic features of early thrombosis. In six dogs, echocardiographic imaging revealed two acoustically distinct areas of thrombi. Gross and microscopic examination of the thrombi in these animals confirmed two distinct types of thrombus with differing histologie features.Although technical aspects of the echocardiographic examination or certain biologic features of thrombi such as thrombus size may limit the detection of thrombi by echocardiography in certain situations, our data indicate that the tissue acoustic properties of recently formed thrombi are not a primary limitation to their echocardiographic detection. These findings support the use of two dimensional echocardiography in the investigation of the natural history, prevention and therapy of left ventricular thrombus in patients during the early course of acute myocardial Infarction.     

Two dimensional echocardiographic evaluation of mustard operation for d-transposition of the great arteries

Two dimensional sector scan echocardiography was used to evaluate the morphologic characteristics of the surgically revised atria in 17 patients with d-transposition of the great arteries who had undergone the Mustard operation. Echocardiographic imaging of the atria was obtained from various planar projections. Dimensional measurements of various segments of the systemic and pulmonary venous atria were obtained in each patient. Correlative hemodynamic, angiographic, postmortem and echocardiographic data showed that seven patients (Group I) had no structural abnormalities of the atria. These 7 patients served as controls for 10 other patients with structural abnormalities of the surgically created atria. One patient (Group II) showed stenosis of the junction of the superior vena cava and systemic venous atrium compared with findings in the control group. Three patients (Group III) had significantly reduced echocardiographic dimensions of the junction of the anterior and posterior segments of the pulmonary venous atrium. Six patients (Group IV) had increased echocardiographic dimensions of all components of the pulmonary venous atrium due to tricuspid regurgitation. These data show that qualitative and quantitative two dimensional sector echocardiography can reliably detect structural abnormalities of the surgically revised atria after the Mustard operation.     

Comparison of three dimensional echocardiographic findings with anatomical specimens of various congenitally malformed hearts.

OBJECTIVE--To compare the reconstructions obtained by three dimensional echocardiography with the anatomical specimens used to generate the echocardiograms. DESIGN--The heart specimens were immersed in a water bath and imaged with a 5 MHz echocardiographic transducer mounted into a scan frame which allowed the transducer to travel a total distance of 4.4 cm in steps of 0.25 mm. The transducer records a tomographic slice at each incremental level thus producing 176 parallel slices of the heart to form the dataset. Reconstruction of the anatomical structures of the heart in a three dimensional format is achieved by means of different grey scales. MATERIALS--72 specimens of either normal or various congenitally malformed hearts. RESULTS--Good quality echocardiographic pictures were obtained, permitting three dimensional reconstructions in each heart. The cardiac chambers and valves could be displayed in a three dimensional format which accurately displayed the internal anatomy of the specimens. No artefacts, such as spurious septal defects, were produced in specimens with intact septums. The atrioventricular valvar leaflets, however, appeared thicker in the images than they were in the specimens. CONCLUSIONS--Three dimensional echocardiography accurately displays the anatomy of normal and congenitally malformed hearts.     

Three‐Dimensional Echocardiographic Assessment of Patent Foramen Ovale in Platypnea‐Orthodeoxia

Platypnea‐orthodeoxia is an uncommon syndrome characterized by positional dyspnea and hypoxia when upright that improves with lying down. We present a 75‐year‐old man with platypnea‐orthodeoxia in the setting of a patent foramen ovale (PFO) and a 2.1 cm highly mobile atrial septal aneurysm with 2 cm bowing. Prior reports have established the use of three‐dimensional echocardiography to facilitate percutaneous closure of PFO and atrial septal defect, but its use in patients with platypnea‐orthodeoxia is unclear. We document three‐dimensional echocardiographic images that accurately estimated PFO defect size and confirmed placement of the occluder device.     

The comparative utilities of real-time cross-sectional echocardiographic imaging systems for the diagnosis of complex congenital heart disease

This study was designed to compare imaging characteristics and diagnostic criteria for cross-sectional echocardiography in 55 children (aged six months to 19 years) with documented forms of complex congenital heart disease who were studied using two different echocardiographic imaging systems: (1) a real-time multiple crystal, cross-sectional echocardiographic system and (2) a mechanical sector scanner. Examiners were blind to diagnosis, and images were graded with regards to visualization of great vessel orientation and atrioventricular valve morphology. Cardiac lesions included single ventricle (five children); “corrected” transposition (eight children); d-transposition (three children); Ebstein's malformation (four children); endocardial cushion defect (eight children); and various other malformations (27 children). The multiple-crystal system allowed a larger area of the heart to be visualized at any given time and resulted in a more rapid demonstration of the contour and positional relationships of atrioventricular valves and great arteries. The mechanical sector-scanner visualized a smaller area of the heart at any given time but provided high-resolution images that were particularly useful in analyzing the shape of great arteries and the insertion of the atrioventricular valves. New criteria were developed during the course of the study for analysis of the morphology of the atrioventricular valves based on the appearance of the atrioventricular valve orifice in the transverse plane and the relation of the atrioventricular valve to the atrioventricular septum as visualized with the mechanical sector scanner. The two echocardiographic systems provided complimentary information. The images obtained rapidly with the multiple-crystal system were valuable indicators of areas for further study with the sector scanner. Both systems were powerful tools for the noninvasive evaluation of complex congenital heart disease.     

Three dimensional reconstruction of the left ventricle from multiple cross sectional echocardiograms. Value for measuring left ventricular volume

The accuracy of a system for reconstructing a three dimensional image of the left ventricle from randomly recorded multiple short axis images was tested by comparing the calculated left ventricular volume with the directly measured left ventricular volume in 11 excised porcine hearts. The system comprised a real time phased array sector scanner, a transducer locating system, and a computer system for digitising outlines of the left ventricle, displaying the reconstruction image, and calculating the left ventricular volume. The reconstructed image was similar to the real image and the calculated left ventricular volume showed a high correlation with the directly measured left ventricular volume. This method was accurate in vitro and is expected to be available for clinical measurement of left ventricular volume.     

Active vegetations can be differentiated from chronic vegetations by visual inspection of standardized two-dimensional echocardiograms

The ability to differentiate active from chronic valvular vegetations (VEGs) by digital image processing and by visual observation was evaluated in 18 patients with a clinical diagnosis of infective endocarditis (IE). Two-dimensional echocardiographic (2-DE) examinations were performed on all patients at diagnosis and after a mean period of 52 days. Two comparable images (active and chronic) from the same patient and in the same phase of the cardiac cycle were digitized, magnified, and displayed on a high resolution monitor. The mean pixel intensity (MPI) was 72+/-14 in the active stage and 143 +/-23 in the chronic stage (P<0.0001). The VEG size was 0.64+/- 0.15 cm(2) in the active stage and decreased to 0.46+/-0.17 cm(2) in the chronic stage (P<0.001). Two experienced echocardiographers, who were blinded to the age of the VEGs, identified each echocardiographic image as active or chronic based on visual observation of density of the VEGs. The VEGs were correctly identified as active or chronic in 17 out of the 18 patients. In summary, although digital image processing of 2-DE may be useful, the density of VEGs assessed by visual inspection will help differentiate between active and chronic VEGs of IE. The standardization procedure at the time of the initial study and use of identical gain settings in subsequent studies are key factors in making this distinction.     

Three dimensional reconstruction of the left ventricle from multiple cross sectional echocardiograms. Value for measuring left ventricular volume.

The accuracy of a system for reconstructing a three dimensional image of the left ventricle from randomly recorded multiple short axis images was tested by comparing the calculated left ventricular volume with the directly measured left ventricular volume in 11 excised porcine hearts. The system comprised a real time phased array sector scanner, a transducer locating system, and a computer system for digitising outlines of the left ventricle, displaying the reconstruction image, and calculating the left ventricular volume. The reconstructed image was similar to the real image and the calculated left ventricular volume showed a high correlation with the directly measured left ventricular volume. This method was accurate in vitro and is expected to be available for clinical measurement of left ventricular volume.     

Evaluation of blood flow velocity in the ascending aorta and main pulmonary artery of normal subjects by Doppler echocardiography

Blood flow velocity measurements were made in the ascending aorta and proximal main pulmonary artery of 20 adult normal subjects (12 men and eight women, age range 21 to 46 years) with the use of a commercial prototype ultrasound instrument combining a spectrum analyzer-based, pulsed Doppler velocimeter with a two-dimensional sector scanner. The sector scanner was used to produce two-dimensional images of the main pulmonary artery so that the Doppler sample volume could be placed parallel to the flow stream. A 2.25 MHz right-angle M-mode ultrasound transducer was positioned in the suprasternal notch and was used to measure blood flow velocity in the ascending aorta. There were significant differences (p < 0.001) between the ascending aorta and main pulmonary artery (PA) in the following blood flow parameters: peak flow velocity (aorta = 92 cm/sec, PA = 63 cm/sec), average acceleration (aorta = 940 cm/sec², PA = 396 cm/sec²), acceleration time (aorta = 98 msec, PA = 159 msec), deceleration time (aorta - 197 msec, PA = 172 msec), average deceleration (aorta = 473 cm/sec², PA = 356 cm/sec²), and ejection time (aorta = 294 msec, PA = 331 msec). These data indicate that despite a four to five times higher arterial resistance in the systemic circuit compared to the pulmonary circuit, blood is accelerated two to three times more rapidly in the ascending aorta than in the main pulmonary artery. Also, the peak flow velocity is higher in the aorta and is achieved earlier in systole than in the pulmonary artery. In addition to providing insight into the normal physiology of flow in the great arteries, these Doppler measurements in normal subjects should provide a quantitative data base for evaluating flow velocity patterns in patients with known or suspected cardiac disorders under a variety of physiologic conditions.     

Analysis of myocardial texture in two-dimensional echocardiographic images

To evaluate tissue changes, we studied myocardial texture using two-dimensional echocardiographic images. We investigated 19 normal subjects, 28 patients with left ventricular hypertrophy, and 12 patients with old anteroseptal myocardial infarction of longer than one year duration. Using 2.5, 3.5, and 5.0 MHz transducers, two-dimensional echocardiograms in the parasternal long-axis view were obtained, and the textures of the interventricular septal images were classified in three types; type I, with a nearly uniformly speckled or echolucent appearances; type II, with multiple, discrete, small (2 to 4 mm) highly refractile echoes; type III, with larger highly refractile echoes (greater than 4 mm) appearing as a cluster of broad patches or band-like echoes. Normal subjects belonged to the type I texture, while many with left ventricular hypertrophy belonged to the type II category. Type III was often observed in patients with old anteroseptal infarction. Using a transducer of higher frequency, there tended to be a shift from type II to I or type III to II. In phantom experiments using carbolandam granules instead of the myocardium, the echocardiographic texture became rough when the phantom was farther from the transducer or the transducer was of low frequency. We suggest that the texture in two-dimensional images may reflect myocardial tissue changes, when other factors including the apparatus and technique remain stable.     

Problems and pitfalls in the performance and interpretation of color Doppler flow imaging: observations based on the influences of technical and physiological factors on the color Doppler examination of mitral regurgitation

Color Doppler flow imaging has become an integral part of the echocardiographic examination. By providing real-time, two-dimensional spatial maps of normal and abnormal cardiac blood flows, this technique provides important information that may be used to guide patient management. The acquisition and display of color Doppler flow information may be influenced by technical factors, by the physiological condition of the patient, by abnormalities of cardiac morphology, and, on occasion, by artifact. In this article, the results of a study performed to evaluate the influence of technical factors on the color Doppler assessment of mitral regurgitation are reported. Mitral regurgitation jet area size changed significantly with variation in the control settings for color gain, color process, color map, color image resolution, and sector width. A review of those factors that influence the performance and interpretation of the color Doppler flow examination is provided and their significance discussed.     

Atrioventricular valve abnormalities in infancy: two-dimensional echocardiographic and angiocardiographic comparison

The results of two-dimensional echocardiography and biplane angiocardiography from 47 infants with congenital atrioventricular (AV) valve abnormalities were compared. Eleven patients had atresia of the right AV valve, 10 had atresia of the left AV valve, 4 had hypoplasia of the right AV valve and 5 had hypoplasia of the left AV valve. Twelve patients had endocardial cushion defect, three had single ventricle and two had straddling of the left AV valve. There was agreement between the two techniques as to the number of AV valves present in each patient. The echocardiographic estimate of valve anular diameter was below normal in seven of the eight patients thought to have a hypoplastic anulus by angiocardiography. In 10 of the 12 patients with endocardial cushion defect, there was agreement between the two techniques as to the presence or absence of atrial and ventricular septal defect. The chordal attachments of straddling valves were better visualized by echocardiography; flow patterns and effective orifice size were better demonstrated by angiocardiography. The subcostal four chamber echocardiographic views and cranially angulated oblique angiocardiographic views were comparable and provided the best images for determination of the size and number of AV valves and their relation to the atrial and ventricular septa.     

In vitro measurement accuracy of three-dimensional ultrasound

OBJECTIVES: We sought to validate distance and volume measurements in three-dimensional (3-D) ultrasound images. BACKGROUND: Even with the latest equipment, it is not known how accurate 3-D echocardiographic measurements are. METHODS: Six models were imaged in ethanol solution and two within a tissue phantom using a mechanical rotation device rotating in 1 degrees intervals and a real-time 3-D scanner. Distance and volume measurements (n = 60) were performed in two-dimensional (2-D) and 3-D images using TomTec and InViVo software. RESULTS: Distance measurements had a mean total error between 1.12% and 2.31% for Acuson (2.5 MHZ, 3 MHZ, and 4 MHZ) and Hewlett Parkard (HP) fusion frequencies h and m, HP fusion harmonic B in the axial, and between 3.5% and 4.9% in the lateral dimension. HP Harmonic A and B, Volumetrics (2.5 MHZ), and HP fusion Harmonic A exhibited significantly higher differences to reality with a mean difference between 5.1% and 8.9% in the axial and between 6.2% and 7.9% in the lateral direction. Axial 2-D measurements were not different from real dimensions except Volumetrics model 1. In the lateral axis, all imaging modalities were different from reality except the fusion harmonic modus B. Using the HP fusion frequency h and HP fusion Harmonic B-mode, volume measurements in 3-D images significantly underestimated reality, while Acuson's fundamental frequency 3.5 MHZ was not different from real volumes. CONCLUSION: Three-dimensional visualization using different ultrasound settings results in different accuracy.     

Two-dimensional echocardiographic determination of aortic and pulmonary artery sizes from infancy to adulthood in normal subjects

The aorta, right pulmonary artery and pulmonary trunk were measured from the 2-dimensional echocardiogram (2?D echo) of 110 normal subjects aged 1 day to 18 years. The vessel diameters were measured from the parasternal short-axis view, the suprasternal long-axis view and the suprasternal short-axis view. Measurements were made at end-systole and at end-diastole and in both an axial and lateral direction where possible. When analyzed with respect to body surface area (BSA), the echocardiographic measurements were linearly related to the square root of the BSA, and there was inequality of variance around the relation. To establish a range of normal values for each vessel dimension, a weighted regression analysis was used to produce estimates of the regression line and a set of tolerance intervals. The systolic vessel dimension was larger than the diastolic vessel dimension and the measurement of a vessel in an axial direction was larger than the measurement of the same vessel in a lateral direction. In general, when a vessel was measured in several views, the largest diameter was obtained using the view that imaged the vessel in cross section. These data on normal values for the echocardiographic measurement of the aorta and pulmonary arteries at different BSAs should be useful for identifying patients with abnormalities in arterial size and for the serial assessment of arterial size in children who have undergone surgical or medical therapy.