Wang Xin-fang

Echocardiographic study of Marfan’s syndrome

SummaryBased on an echocardiographic study of a series of 52 patients with Marian’s syndrome, we found that the echocardiographic characteristic of Marfan’s syndrome was marked dilatation of aortic root with or without mitral valve prolapse. 48 cases (92.3%) in this series were found to have aortic root enlargement, 11 of which were associated with mitral valve prolapse. This finding suggested that marked dilatation of aortic root should be an important diagnostic picture of Marfan’s syndrome. Echocardiogram enhanced significantly the detection rate of cardiovascular defects, so it is helpful in observation of outstanding family tendency toward involvement of different organ-systems in different families in Marfan’s syndrome.

Left coronary artery fistula identified by color doppler flow imaging

SummaryCoronary artery fistula (CAF) is an abnormal communication between a coronary artery and a cardiac chamber, great vessel, or other vascular structures. The presence of the fistula is usually identified by angiography. In this paper, the diagnosis of left coronary artery-right ventricle fistula was made by color Doppler before angiography? and it was confirmed by surgery. Color Doppler flow imaging is a non-invasive method which can reveal the proximal dilatation, the course and the draining site of CAF.

Determination of most appropriate Nyquist velocity for applying hemispherical flow convergence equation to calculate flow rate using the transorifice pressure gradient: digital computer analysis of Doppler color flow convergence region.

SummaryNyquist velocity and transorifice pressure gradient dramatically influence color aliasing shape and accuracy of simple hemispherical flow convergence equation for calculation of flow rate. The present in vitro study was performed to determine whether the value of Nyquist velocity, at which the shape of proximal isovelocity surface is best fit for a given shape assumption in different orifice size, and the flow rate may be a determinable and orifice size independent function of clinically measurable peak velocity or transorifice pressure gradient. Steady flow was driven through circular discrete orifices with diameter of 3. 8 mm, 5.5 mm and 10 mm and flow rate ranging from 2.88 L/min to 8.2 8 L/min. For every flow rate, Doppler color encoded M-mode images through the center of flow convergence region were transferred into the microcomputer in their original digital format. The continuous wave Doppler traces of maximal velocity through the orifice were performed for the calculation of pressure gradient. Direct numerical spatial velocity measure using color pixel intensity was obtained from the transferred color encoded M-mode images with computer software. The shape of isovelocity surface was determined by the ratio of calculated flow rate with hemispherical flow convergence equation to the actual flow rate. Both the flow rate and orifice size influence the position of the velocity profile curve. The shape of isovelocity surface is not constant and changes with the velocities used for the calculation of flow rates for a given flow rate and orifice size or pressure gradient and also changes with the flow rate or transorifice pressure gradients for a constant Nyquist velocity and orifice size. It was found that for a given ratio of calculated flow rate to actual flow rate (0. 7 and 1) the velocities used for the calculation of flow rate with hemispherical flow convergence equation were correlated well with the pressure gradient for a given orifice size and the differences in velocities among different orifice sizes adjusted for the covariance pressure gradients were not statistically significant (P = 0.794 for ratio = 0.7 andP = 0.81 for ratio = l). Our present study provides an orifice size independent quantitative method with which to select the most suitable Nyquist velocity for applying simple hemispherical flow convergence equation according to clinically measurable pressure gradients ranging from 5.32 kPa to 26.60 kPa, and offers a correcting factor for the hemispherical flow convergence equation when pressure gradient is less than 5.32 kPa.

Visualization of patent foramen ovale by biplanar transesophageal echocardiography

SummaryIt is difficult for conventional transthoracic echocardiography (TTE), by which precise and accurate images of interatrial septum (IAS) can not be acquired, to diagnose patent foramen ovale (PFO) clearly. To evaluate the diagnostic value of biplanar transesophageal echocardiography (TEE) for PFO, TTE and biplanar TEE were performed simultaneously in 270 patients. It was found that in 7 patients patent foramen ovale was detected only through longitudinal planes of biplanar TEE. IAS, which consists of primitive septum and membrane of fossa ovalis, can be directly visualized by two-dimensional images of TEE; in patients with PFO, a dull color flow, which shunts from the right atria to the left atria through the gap between primitive septum and fossa ovalis, can be detected by color Doppler flow images. Furthermore, some right-to-left shunting microbubbles through the valve of patent fossa ovalis can be discovered by cardiac acoustic contrast echocardiography. In conclusion, biplanar TEE combined with color Doppler image and cardiac acoustic contrast facilitates a definite diagnosis of patent foramen ovale as the excellent anatomic images of IAS can be obtained from multiple views under this kind of performance.

Color Doppler echocardiography, two-dimensional echocardiography and signs in diagnosis of aortic regurgitation

SummaryTo assess the diagnostic significance of color Doppler and two-dimensional echocardiography and signs in aortic regurgitation (AR), we studied 48 patients with AR confirmed by color Doppler. On color Doppler, an abnormal diastolic flow originating from the aortic valve was visualized in the left ventricular outflow tract in the 48 cases. The maximal regurgitant jet area was 0.8–23.3 cm2. On two-dimensional echocardiography, the appearance of cardiac chamber and valves did not offer a clue to the existence of AR in 12 patients (25 %). On physical examination, diastolic murmur was inaudible in 18 of 45 patients. Peripheral signs of AR were not found in 20 of 45 patients. In slight AR, signs were usually not detected. From the above we are led to conclude that of the patients with AR confirmed by color Doppler echocardiography, only 75 % could be detected by two-dimensional echocardiography and about 55 % diagnosed by physical examination.To assess the diagnostic significance of color Doppler and two-dimensional echocardiography and signs in aortic regurgitation (AR), we studied 48 patients with AR confirmed by color Doppler. On color Doppler, an abnormal diastolic flow originating from the aortic valve was visualized in the left ventricular outflow tract in the 48 cases. The maximal regurgitant jet area was 0.8-23.3 cm2. On two-dimensional echocardiography, the appearance of cardiac chamber and valves did not offer a clue to the existence of AR in 12 patients (25%). On physical examination, diastolic murmur was inaudible in 18 of 45 patients. Peripheral signs of AR were not found in 20 of 45 patients. In slight AR, signs were usually not detected. From the above we are led to conclude that of the patients with AR confirmed by color Doppler echocardiography, only 75% could be detected by two-dimensional echocardiography and about 55% diagnosed by physical examination.

Effect of left ventricular outflow on flow convergence region on the left septal surface in ventricular septal defect.

SummaryThe corrected shunt flow rate (Fc) and corrected defect orifice area (Ac) were calculated by modified equation F = 2πR2 × (NL-Vlvot × Sinθ) in 23 patients with single membranous ventricular septal defect, in order to correct the effect of left ventricular outflow on flow convergence region on the left septal surface. The results indicated that Fc was closely correlated with Qp — Q5 and Qp/Qs measured by pulsed wave Doppler (r = 0. 95 andr = 0. 81 respectively,P <0. 001). And the correlation between Ac and the diameter of defect (Dd) measured directly in two-dimensional views was better than that between uncorrected defect orifice area (A) and the Dd(r = 0. 98 and 0. 69, respectively,P <0. 001). The shunt flow rate calculated by ideal equation F = 2πR2 × NL overestimated the actu al shunt flow rate in ventricular septal defect, especially in membranous type. Our study concluded that Fc can be used for a more accurate evaluation of the shunt seventy of ventricular septal defect.

Clinical Application of Three-dimensional Transesophageal Echocardiography in the Diagnosis of Atrial Septal Defect

SummaryThis paper reports the use of three-dimensional (3-D) transesophageal echocardiography (TEE) in the diagnosis of atrial septal defect. The results displayed that the interatrial septum had integrity in normal persons. The size, shape and position of atrial septal defects could he showed clearly and the type of the defects could be identified. The reconstructed imaging of interatrial septum on 3-D TEE was clear and stereoscopic. The technique is helpful in defining spatial location and extent of atrial septal defects.

Assessment of right coronary artery fistula by multiplane transesophageal echocardiography

SummaryCoronary artery fistula (CAF) is a relatively uncommon cardiovascular disease. It is an abnormal communication between a coronary artery and a cardiac chamber, great vessels, or other vascular structures. Most are congenital. Multiplane transesophageal echocardiography (multiplane TEE, MTEE) can reveal the proximal dilation, the course and the drainage site of CAF. Presented in this paper was a report of right coronary artery-left ventricle fistula, for the first time, right coronary-left ventricle fistula diagnosed by MTEE and confirmed by angiography.

Study on Three Dimensional Reconstruction of Transesophageal Echocardiographic Images

SummaryUsing biplane transesophageal echocardiography and the concept of three dimensional transthoracic echocardiography, we performed three dimensional reconstruction of transesophageal images of various clinicopathologic cases, including atrial septal defect, mitral stenosis, mitral valve prolapse and pulmonary stenosis. The hardware equipments and image processing flow chart of three dimensional reconstruction of transesophageal echocardiographic images are described. Our present study indicates that three dimensional reconstruction of transesophageal echocardiographic images could display multi-regional three dimensional structures of heart and great vessels, including superior vena cava, ascending aorta, right ventricular outflow tract, pulmonary artery and left heart, with clear, visual and stereoscopic imaging. The regional structures could be displayed at different levels of stereo-anatomic-secr tions and in different orientations of rotating stereo-images, which could provide accurate three dimensional anatomical information for cardiac stereo-morphological study and definition of spatial location and size of cardiac abnormalities.

Biplane transesophageal echocardiography: Imaging sections and anatomic segments

SummaryIn order to recognize correctly the images of transesophageal echocardiography (TEE), in 410 subjects TEE was performed with uniplane or biplane transducer, and in 7 corpses the cardiac anatomic segments were observed, at various levels and in different directions. 9 transverse and 6 longitudinal views were compared with the corresponding cardiac anatomic segments. Based on this study, the authors reported the levels of segments, insertion depth, anatomic structure identification, image characteristics and clinical application of TEE, and the advantages of biplane TEE are discussed.