Doppler echocardiographic evaluation of left-to-right shunts in congenital heart disease

Doppler echocardiography enables the possibility of determining pulmonary to systemic flow ratios in patients with left to right shunts. Volume flow is calculated as the product of mean velocity over time, as evaluated by pulsed Doppler, and the cross-sectional area through which the flow passes. Appropriate sites for measurement of velocity and cross-sectional area of flow are the ascending aorta, right ventricular outflow tract and pulmonary artery as well as the tricuspid and mitral valve orifices. Velocity is always recorded as parallel as possible to the direction of flow. Echocardiographic measurements of the area of flow are carried out at the level of the sample volume. In the presence of an atrial or ventricular septal defect, the flow in the ascending aorta normally serves as systemic flow; alternatively, mitral or tricuspid flow may be used to cross-check these values. The latter serves for calculation of systemic flow in patent ductus arteriosus. In atrial or ventricular septal defect, the pulmonary flow is normally derived in the region of the pulmonary artery; in patent ductus arteriosus, however, in the region of the ascending aorta. As an alternative, or for confirmative use, in atrial septal defect the tricuspid flow and in ventricular septal defect and patent ductus arteriosus the mitral flow, can be taken into consideration. Studies we performed in 31 patients with atrial septal defect showed a close correlation between Doppler echocardiographic measurements and data obtained by cardiac catheterization and radionuclide studies.(ABSTRACT TRUNCATED AT 250 WORDS)     

Noninvasive evaluation of left-to-right shunts by pulsed Doppler echocardiography

The systemic and pulmonary blood flows and the ratio of pulmonary to systemic flow were noninvasively evaluated by pulsed Doppler echocardiography in 25 children with left-to-right shunts. Fourteen patients had atrial septal defect and 11 had ventricular septal defect. In patients with atrial septal defect, right ventricular stroke volume was obtained from the recordings of mean velocity flow and the diameter at the level of pulmonary valve in short-axis view. The left ventricular stroke volume was evaluated from the suprasternal approach by positioning the sample volume within the ascending aorta just above the valvar leaflets. In children with ventricular septal defect, the pulmonary blood flow was determined at the level of the mitral orifice, whereas the systemic blood flow was estimated from the ascending aorta. The systemic and pulmonary blood flows and their ratio determined by pulsed Doppler echocardiography in the 25 patients examined, were compared using simple linear regression analysis with the results obtained by cardiac catheterization. The ratio of pulmonary-to-systemic flow showed an excellent correlation in patients with atrial septal defect (r = 0.82) and in those with ventricular septal defect (r = 0.79). Our study validates the accuracy of cross-sectional Doppler echocardiography, especially for minimizing some possibility of errors in the presence of left-to-right shunts by employing new approaches.     

The importance of tricuspid valve structure and function in the surgical treatment of rheumatic mitral and aortic disease.

A significant proportion of individuals with rheumatic disease have tricuspid valve involvement which may be clinically important and alter the medical or surgical approach to treatment. Therefore 50 patients with rheumatic left-sided valvular lesions who were referred for operative treatment were studied. Thirty patients had angiographically significant tricuspid regurgitation (group I) and 20 had a competent tricuspid valve (group II). Pre-operative cardiac assessment included Doppler echocardiography and contrast ventriculography. Patients with tricuspid regurgitation more commonly had mitral valve disease or combined mitral and aortic valve lesions, (P less than 0.001) and were more likely to have atrial fibrillation than those without tricuspid regurgitation (P less than 0.001). Pulmonary arterial systolic and mean right atrial pressures were higher in group I (both P less than 0.01). A close relationship was found between the angiographic and Doppler assessment of the degree of tricuspid regurgitation (P less than 0.01). Doppler-derived measurement of the right ventricular-right atrial systolic pressure difference correlated well with the systolic trans-tricuspid pressure difference measured at cardiac catheterization (y = 0.7x + 22, r = 0.67, P less than 0.001) and the pulmonary arterial systolic pressure (y = 0.8x + 27, r = 0.71, P less than 0.001). Rheumatic involvement of the tricuspid valve identified by pre-operative echocardiography was confirmed in five patients at surgery. Of the 13 patients with functional tricuspid regurgitation at operation, only two had been diagnosed as having organic disease by echocardiography. Furthermore, in all 18 cases where Doppler suggested grade 3 or 4+ tricuspid regurgitation, surgical repair or replacement of the valve was performed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rapid increase in plasma endothelin concentrations during percutaneous balloon dilatation of the mitral valve in patients with mitral stenosis.

OBJECTIVE--To investigate the relation between plasma concentrations of immunoreactive endothelin and haemodynamic variables before and after percutaneous transvenous balloon dilatation of the mitral valve. DESIGN--Prospective study. SETTING--National cardiovascular centre. PATIENTS--25 patients with mitral stenosis and 26 healthy volunteers. MAIN OUTCOME MEASURES--Plasma concentrations of immunoreactive endothelin were measured in the pulmonary artery, left atrium, ascending aorta, and femoral vein before and after balloon dilatation of the mitral valve. RESULTS--Peripheral venous concentrations (mean (SD)) of endothelin were higher in the patients with mitral stenosis than in the healthy volunteers (1.76 (0.51) v 1.37 (0.45) pg/ml, p < 0.05) and they correlated with the mean left atrial pressure (r = 0.74, p < 0.01). Balloon dilatation of the mitral valve reduced the mean left atrial pressure without changing the mean right atrial pressure, systemic arterial pressure, heart rate, or cardiac index. Concentrations of plasma endothelin in the femoral vein increased from 1.76 (0.51) to 3.39 (2.46) (p < 0.01), 4.82 (2.34) (p < 0.001), and 2.43 (0.52) pg/ml (p < 0.05) at 15 and 30 minutes and 24 hours after the procedure. The concentration of endothelin in the pulmonary artery also increased from 1.85 (0.85) to 4.32 (1.58) pg/ml (p < 0.01) 30 minutes after the dilatation, whereas there were no appreciable changes in endothelin concentration in the left atrium or ascending aorta. CONCLUSIONS--Plasma endothelin concentrations were higher in patients with mitral stenosis than in healthy volunteers and the increase was proportional to left atrial pressure. After balloon dilatation of the mitral valve there was an abrupt rise in endothelin in the femoral vein and pulmonary artery but no change in left atrial or aortic blood samples. These findings suggest that endothelin may be another vasoactive substance involved in congestive heart failure.     

Noninvasive measurement of left ventricular filling pressures by means of transmitral pulsed Doppler ultrasound

In 54 consecutive patients, ages 59 +/- 11 years, the transmitral diastolic flow velocity profile was derived by means of pulsed Doppler echocardiography simultaneously with right-sided heart catheterization. In 30 of them, ages 57 +/- 10 years, left-sided heart catheterization was performed at the same time. The sample volume was positioned exactly in the mitral anulus plane, bisecting the anulus. The ratio of the time-velocity integrals of the A wave (atrial contraction) and E wave (early filling) was calculated (A/E ratio of integrals). Linear regression analysis showed a highly significant linear correlation of the A/E ratio of integrals with regard to left ventricular (LV) end-diastolic pressure (r = 0.98, p less than 0.001) and pulmonary capillary wedge pressure (r = 0.98, p less than 0.001). The A/E ratio of integrals also correlated with other hemodynamic parameters, such as cardiac output (r = -0.73, p less than 0.001), cardiac index (r = -0.74, p less than 0.001) and stroke volume index (r = -0.65, p less than 0.001). For 19 additional patients, ages 55 +/- 8 years, the values of LV end-diastolic pressure and pulmonary capillary wedge pressure were calculated by means of the corresponding formulas from the first data set. The correlation between the calculated and invasively measured LV filling pressures expressed in terms of intraclass correlation coefficients shows highly significant correlations for both LV end-diastolic pressure (intraclass correlation coefficient = 0.99, p less than 0.001) and pulmonary capillary wedge pressure (intraclass correlation coefficient = 0.99, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Pulmonary venous flow dynamics before and after balloon mitral valvuloplasty as determined by transesophageal Doppler echocardiography.

The pattern of left atrial filling was studied in 14 patients with severe mitral stenosis in sinus rhythm before and immediately after successful balloon mitral valvuloplasty by transesophageal pulsed Doppler echocardiography of the left superior pulmonary vein. Mean mitral valve orifice area increased from 0.8 +/- 0.1 to 2.2 +/- 0.3 cm2 (p less than 0.0001), and left atrial mean pressure decreased from 30 +/- 5 to 12 +/- 4 mm Hg (p less than 0.0001) after the procedure. After balloon mitral valvuloplasty, significant increases in peak systolic pulmonary velocity (35 +/- 16 to 44 +/- 10 cm/s; p less than 0.01), systolic flow velocity time integral (3.3 +/- 1.5 to 5.9 +/- 2.0 cm; p less than 0.001) and the ratio of systolic/diastolic pulmonary venous flow velocity time integrals (0.8 +/- 0.4 to 1.4 +/- 0.5; p less than 0.001) were observed. An acute increase in mitral valve orifice area caused no significant changes in peak diastolic forward flow velocity (40 +/- 7 to 41 +/- 9 cm/s; p = not significant [NS]), diastolic forward flow velocity time integral (4.3 +/- 1.7 to 4.6 +/- 1.8 cm; p = NS) and atrial flow reversal velocity (30 +/- 3 to 35 +/- 3 cm/s; p = NS) compared with at baseline. The results suggest that in patients with severe mitral stenosis and sinus rhythm, left atrial filling is biphasic with a diastolic preponderance, and successful mitral valvuloplasty is associated with an immediate increase in pulmonary venous systolic forward flow.     

Two-dimensional mitral flow velocity profiles in pig models using epicardial doppler echocardiography

Objectives. This study investigated the velocity distribution across the natural mitral valve.Background. Information about the blood velocity distribution across the mitral valve is of interest in bask fluid dynamic studies of the natural mitral valve and is needed for precise cardiac output estimatess by Doppler echocardiography.Methods. The velocity distribution across the mitral valve was measured by epicardial Doppler echocardiography in ten 90-kg anesthetised pigs. By routing the ultrasound transducer in 30 ° intervals from the apical position, we constructed two-dimensional velocity profiles across the left ventricular inflow tract from diameters from each rotation arranged around a reference point. The time-averaged mitral velocity profile was calculated to estimate the error in cardiac output calculations that may occur with pulsed Doppler ultrasound when a single sample volume is used to record the mean velocity across the mitral orifice.Results. The time-averaged diastolic cross-sectional mitral velocity profiles at the level of the mitral annulus and leaflet tips were variably skewed because of the development of a large anterior vortex in the left ventricle during the deceleration of early diastolk inflow and atrial systole. The ratio of the time-velocity integral of the center sample volume to the spatially averaged time-velocity integral was 1.13 ± 0.15 (mean ± SD) (range 0.80 to 1.32). Using regression analysis, we found a correlation between the degree of nonuniformity of the cross-sectional velocity distribution and the peak velocity of the anterior vortex (r = 0.65, p < 0.01).Conclusions. The assumption of a flat mean velocity profile across the mitral valve can introduce errors of +13 ± 15% (mean ± SD) in cardiac output measured with pulsed Doppler ultrasound when one is interrogating a single center sample volume.     

Incidence and concomitant factors of tricuspid valve insufficiency in patients with aortic and mitral valve diseases

Invasive data about the frequency and associated factors of tricuspid regurgitation in normals and in patients with aortic and mitral valve disease are still rare. Thus, right ventricular biplane angiograms (RAO/LAO projection), the mean pulmonary artery pressure and the presence of atrial fibrillation were analyzed with regard to tricuspid regurgitation in 30 normals and 165 patients with pure mitral regurgitation, mitral stenosis, aortic regurgitation, aortic stenosis, combined mitral valve disease or combined aortic valve disease. Patients with tricuspid stenosis or coronary artery disease were excluded. In 52 of the 195 patients tricuspid regurgitation was present. Tricuspid regurgitation occurred statistically more often in patients with mitral stenosis (33%), mitral regurgitation (48%) or combined mitral valve disease (68%) than in patients with aortic regurgitation (4%) or combined aortic valve disease (3%). In patients with aortic stenosis and in normals tricuspid regurgitation was not present. In patients with combined mitral valve disease, tricuspid regurgitation was more often present than in patients with pure mitral stenosis (p less than 0.002), despite comparable values of the mean pulmonary artery pressure, the right ventricular enddiastolic and endsystolic volume indexes, the right ventricular ejection fraction and the frequency of atrial fibrillation. Only in patients with pure mitral regurgitation tricuspid regurgitation was associated with an elevated mean pulmonary artery pressure (p less than 0.02). Differences in the right ventricular size and function did not occur between normals and patients with mitral or aortic valve disease. Therefore, the mean pulmonary artery pressure, atrial fibrillation and the size and function of the right ventricle are not major determinants for the occurrence of tricuspid regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of acoustic quantification and Doppler echocardiography in assessment of left ventricular diastolic variables.

OBJECTIVE--To assess the haemodynamic correlations of the waveforms of left ventricular area change obtained by automated boundary detection with newly developed acoustic quantification technology. DESIGN--The timing of events in the cardiac cycle was identified on the wave-form automated boundary detection and was correlated with the corresponding timing derived from pulsed wave Doppler flow velocity traces of the mitral valve and left ventricular outflow tract. The amounts of area change during the rapid filling phase and during atrial contraction were correlated with the time-velocity integrals of early and late diastolic ventricular filling obtained from Doppler tracings of the mitral inflow. SETTING--A university medical school echocardiography laboratory. SUBJECTS--16 healthy volunteers and 19 patients referred for echocardiographic studies. RESULTS--A significant correlation was found between the methods for measurement of the time from the R wave to mitral valve opening (r = 0.72, p < 0.01), isovolumic relaxation time (r = 0.62, p < 0.01), and ejection time (r = 0.54, p < 0.01). The change of total area that occurred during rapid filling and atrial filling phases measured from the acoustic waveform correlated with the time-velocity integrals of the early and late diastolic mitral valve inflow velocity derived from Doppler echocardiography (r = 0.60 and r = 0.80, respectively). CONCLUSION--The waveform of left ventricular area obtained by the automated boundary detection technique identifies the phases of the cardiac cycle and correlates with Doppler values of left ventricular diastolic function. Therefore, this new method of automated boundary detection has potential uses in the assessment of left ventricular diastolic function.     

Determination of cardiac output by Doppler echocardiography: a critical appraisal

Doppler echocardiography enables noninvasive determination of blood velocity and flow area through which quantitation of blood flow in vessels and across valvular orifices can be achieved. The stroke volume is rendered as the product of the flow area and the area beneath the velocity curve; on taking the heart rate into consideration, the cardiac output can be calculated. Essentially, this method can be used in the region of all four cardiac valves, the ascending aorta and the pulmonary artery. For calculation of the mitral and tricuspid velocity, the sample volume is positioned in the region of the tips of the leaflets or in the valve anulus. The flow area is most frequently calculated from the diameter of the valve anulus under the assumption of a circular cross-section. Additionally, in some studies, with respect to correction for area changes during diastole, separation of the leaflets in the M-mode echocardiogram has been employed. Determination of the right ventricular output is accomplished through the combination of the blood flow velocity in the pulmonary artery and the cross-sectional area of this vessel, the right ventricular outflow tract or the pulmonic anulus. To calculate flow in the ascending aorta, both pulsed and continuous-wave Doppler techniques have been employed and the diameter of the ascending aorta or the aortic root is derived echocardiographically. Comparative studies of the various methods show that measurement of flow in the region of the aortic anulus yields results somewhat superior to that of the other methods. Possible sources of error in these methods result from simplifying assumptions with respect to calculation of the area of flow, that is, equating the anatomical area with the area of flow, circular or elliptical cross-sectional models, temporal constancy of the areas as well as the velocities, that is, constant position of the sample volume, flat velocity profile and neglect of angle deviations.     

Evaluation of secondary tricuspid regurgitation by intraoperative epicardial pulsed Doppler echocardiography

Since 1985, we have evaluated secondary tricuspid regurgitation associated with acquired mitral valve disease in patients undergoing open mitral surgery by intraoperative epicardial two-dimensional and pulsed Doppler echocardiography. We found intraoperative pulsed Doppler echocardiography to be a sensitive, safe technique allowing surgeons to evaluate the severity of tricuspid regurgitation intraoperatively, even in critically ill patients who cannot afford preoperative cardiac catheterization. To assess the severity of tricuspid regurgitation intraoperatively, the transducer was placed directly on the right atrium. The ultrasound beam was transmitted into the right atrium at right angles to the tricuspid valve orifice to record intraoperative four-chamber two-dimensional echocardiograms, which were used to detect the sites of eight sample volumes, one in the right ventricle and seven in the right atrium, for pulsed Doppler echocardiography. The pulsed Doppler signals were recorded in each sample volume before and after cardiac procedures. The pansystolic abnormal signals lasting from tricuspid valve closure to the subsequent opening and consisting of components moving away from the tricuspid valve were interpreted as tricuspid regurgitant flows. Without operative correction of the tricuspid valve, secondary tricuspid regurgitation can resolve following mitral valve surgery alone. However, to our knowledge, there are no published reports of objective findings of intraoperative changes of secondary tricuspid regurgitation. Here we present the unique intraoperative pulsed Doppler echocardiographic features of tricuspid regurgitation before and after cardiac procedures. A 30-year-old woman with preoperative diagnosis of aortic regurgitation, mitral stenosis and severe tricuspid regurgitation underwent aortic and mitral valve replacement. The intraoperative pulsed Doppler echocardiograms recorded after pericardiotomy and before cannulation of the heart showed tricuspid regurgitant flow signal in all of the seven sample volumes in the right atrium, which was interpreted as severe tricuspid regurgitation. After surgical procedures, no regurgitant flow from the tricuspid orifice to the right atrium was detected in the eight sample volumes. This suggested that preoperative secondary tricuspid regurgitation improves without operative procedures for the tricuspid valve. All intraoperative echocardiographic procedures were performed within 5 min, and no arrhythmias or other complications related to this technique were noted. Epicardial pulsed Doppler echocardiography is helpful in assessing tricuspid valve function of patients undergoing mitral valve surgery bef     

Prospective study comparing different echocardiographic measurements of pulmonary capillary wedge pressure in patients with organic heart disease other than mitral stenosis

In 25 patients with cardiac disease, but free of left ventricular inflow obstruction, the electrocardiogram and M-mode echocardiogram of the aortic root, left atrium and both the mitral and the aortic valves were obtained simultaneously with the pulmonary artery wedge pressure (PAWP) during right heart catheterization. The echocardiographic measurements of the left atrial size, PR-AC interval, left atrial emptying index and the ratio between the electrocardiographic Q wave to mitral valve closure (Q-MVC) and between aortic valve closure to the mitral E point (AVC-E) were correlated to the pulmonary artery wedge pressure by means of linear regression analysis. A formula in which PAWP = 36.6 (Q-MVC/AVC-E)-- 2 was prospectively used to study the measured pressure in the current group of patients. The pulmonary artery wedge pressure derived from these latter measurements correlated well with the invasive measurement of this pressure (r = 0.91). The pulmonary artery wedge pressure calculated by echocardiography differed from the pulmonary artery wedge pressure measured by catheterization by 3 mm Hg or less in 19 of the 25 patients, by 4 mm Hg or less in 22 patients and by 6 mm Hg or less in 24 patients. Although the correlation between the (Q-MVC/AVC-E) ratio and measured pulmonary artery wedge pressure was highly significant (r = 0.91, probability [p] less than 0.001, n = 25), the left atrial emptying index, PR-AC and left atrial size revealed poor correlation coefficients (r = 0.45, r = 0.45 and r = 0.56 [p less than 0.05]), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

The clinical spectrum of tricuspid regurgitation detected by pulsed Doppler echocardiography

The clinical diagnosis of tricuspid regurgitation (TR) is often difficult. Two-dimensional pulsed Doppler echocardiography offers a sensitive and specific method for detecting and semi-quantitating tricuspid regurgitation. The clinical, radiographic, radionuclide, echocardiographic, and when available, the right cardiac catheterization findings were evaluated in 36 patients with a diagnosis of tricuspid regurgitation by pulsed Doppler. Ten healthy subjects served as controls. The underlying cardiac cause was rheumatic heart disease in 7 (20%), ischemic heart disease in 12 (33%), dilated cardiomyopathy in 5 (14%), hypertensive heart disease in 2 (5%), aortic valve stenosis and/or regurgitation in 3 (8%), mitral valve prolapse with mitral regurgitation in 1 (3%), and congenital heart disease in 6 (17%). Seven patients (19%) had a temporary or permanent transvenous right ventricular pacing wire. A systolic murmur was heard in 29 patients (81%) with 16 (46%) having an elevated jugular venous pressure. Tricuspid regurgitation was clinically suspected in only 2 patients (6%). Isolated tricuspid regurgitation was uncommon, seen in 6 patients (17%), and usually secondary to congenital heart disease, ischemic heart disease, with the use of a transvenous pacing wire and following mitral valve replacement. Right cardiac catheterization was performed in 10 patients, of which 7 demonstrated elevated right atrial and pulmonary artery pressure. Pulsed Doppler echocardiography offers a practical and accurate method of detecting and evaluating the severity of tricuspid regurgitation. Tricuspid regurgitation is generally a functional disorder, and frequently occurs in association with left sided valvular heart disease, cardiomyopathy or congenital heart disease.     

Calculation of the pulmonary to systemic flow ratio using echo-Doppler in septal defects--correlation with oximetry

OBJECTIVE: 1. local validation of a protocol of measurement of pulmonary to systemic flow ratio (QP/QS) by echo-Doppler in children with septal defects; 2. to assess continuous wave Doppler efficacy mainly in those patients where peak pulmonary flow velocity was beyond the Nyquist limit of pulsed Doppler. DESIGN: To correlate QP/QS ratio determined by echo-Doppler with that obtained by cardiac catheterization (oximetric method) performed within 48 hours, in children with isolated septal defects. MATERIAL AND METHODS: The QP/QS ratio was evaluated by pulsed and or continuous wave echo-Doppler in 50 children who were submitted within 48 hours to cardiac catheterization. All children had an intracardiac shunt (12 atrial septal defects--ASD; 26 ventricular septal defects--VSD and 12 atrio ventricular septal defects--AVDS). Identical measurements were performed in a group of 20 children without cardiac malformation--control group. To test inter-observer variability, all the measurement in 31 patients were repeated by a second observer. Pulmonary and aortic flow was calculated as: Q = A x V x ET x CF where, A is the valvular orifice area (cm2), V the mean flow velocity (cm/sec), ET the ejection time (sec) and CF the cardiac frequency (cycles/min). The Doppler beam-flow direction angle in the pulmonary (P) artery and ascending aorta (Ao) was less than 20 degrees. Results were correlated with those obtained by catheterization (oximetric method). RESULTS: We obtained a fairly good correlation with both pulsed wave Doppler (n = 43; r = 0.88; p less than 0.001; y = 0.84x + 0.40) and continuous wave Doppler (n = 50; r = 0.91; p less than 0.001; y = 0.86x + 0.35) or with pulsed wave Doppler in the P artery and continuous wave Doppler in the Ao (n = 43; r = 0.92; p less than 0.001; y = 0.86x + 0.27). In the control group, QP/QS ratio was evaluated by echo-Doppler: pulsed wave Doppler at 1.05 +/- 0.15 (mean +/- DS); continuous wave Doppler at 1.05 +/- 0.12 and, pulsed wave Doppler in the P artery and continuous wave Doppler in the Ao at 1.03 +/- 0.12. There was no significant difference in all three groups to the normal range of 1.00 (p less than 0.01). Inter-observer variability was less than 5.5% (p less than 0.001). CONCLUSION: Pulsed and/or continuous wave echo-Doppler measurements are a reliable noninvasive method in evaluating QP/QS ratio in children with isolated septal defects.     

Relation of Still's murmur, small aortic diameter and high aortic velocity

The origin of Still's innocent murmur, first described in 1909, is obscure. Seventy normal children and young adults, 29 with Still's murmur and 41 with no murmur, were studied. Pulsed Doppler and 2-dimensional echocardiography were used to evaluate possible causes, including tricuspid regurgitation, left ventricular bands, ascending and descending aortic and pulmonary velocities, ascending aortic diameter, and magnitude of spectral widths. Mean ascending aortic diameter relative to body surface area was significantly smaller for the group with Still's murmur (p less than 0.001). Since cardiac output was similar for the 2 groups, the average peak ascending velocity (133 cm/s) and average peak descending aortic velocity (118 cm/s) were significantly higher in the innocent murmur group as compared to similar respective means in the control group without the murmur (107 and 104 cm/s, respectively) (p less than 0.001 and p less than 0.01, respectively). No significant differences were found when the 2 groups were compared with respect to mean peak pulmonary artery velocity adjusted for body size, spectral widths in the ascending and descending aorta and in the pulmonary artery, and the presence of tricuspid regurgitation or ventricular bands. These observations suggest that the origin of Still's murmur is related to a small ascending aortic diameter with concomitant high aortic blood flow velocity.     

超声心动图对正常胎儿心腔大小及血流相关参数的分析

目的:分析不同孕周正常胎儿心腔大小及血流相关参数,为胎儿超声心动图检查提供参考。方法: 根据不同孕周将1182例正常胎儿分为5组,经腹超声检测不同孕周正常胎儿各房室腔及大血管内径、各瓣口峰值血流速度,并进行统计分析。结果: 右房室腔大于左房室腔（均P<005）。肺动脉内径大于主动脉内径（P<005）。三尖瓣峰值血流速度大于二尖瓣峰值血流速度（P<005）,二、三尖瓣E峰均小于A峰（均P<005）。主动脉瓣峰值血流速度大于肺动脉瓣峰值血流速度（P<005）。结论: 超声心动图可评价正常胎儿心腔大小及血流相关参数,对识别及诊断心血管异常具有重要意义。     

Noninvasive estimation of pulmonary artery diastolic pressure in patients with tricuspid regurgitation by Doppler echocardiography.

OBJECTIVES: The purpose of this study was to determine whether Doppler echocardiographic assessment of right ventricular pressure at the time of pulmonary valve opening could predict pulmonary artery diastolic pressure. BACKGROUND: Doppler echocardiography has been used to estimate right ventricular systolic pressure noninvasively. Because right ventricular and pulmonary artery diastolic pressure are equal at the time of pulmonary valve opening, Doppler echocardiographic estimation of right ventricular pressure at this point might provide an estimate of pulmonary artery diastolic pressure. METHODS: We studied 31 patients who underwent right heart catheterization and had tricuspid regurgitation. Pulmonary flow velocity was recorded by pulsed wave Doppler echocardiography, and tricuspid regurgitant velocity was recorded by continuous wave Doppler echocardiography. The time of pulmonary valve opening was determined as the onset of systolic flow in the pulmonary artery. Tricuspid velocity at the time of pulmonary valve opening was measured by superimposing the interval between the onset of the QRS complex on the ECG and the onset of pulmonary flow on the tricuspid regurgitant envelope. The tricuspid gradient at this instant was calculated from the measured tricuspid velocity using the Bernoulli equation. This gradient was compared to the pulmonary artery diastolic pressure obtained by right heart catheterization. MEASUREMENTS AND RESULTS: The pressure gradient between the right atrium and right ventricle obtained at the time of pulmonary valve opening ranged from 9 to 31 mm Hg (mean, 19+/-5) and correlated closely with invasively measured pulmonary artery diastolic pressure (range, 9 to 36 mm Hg; mean, 21+/-7 mm Hg; r = 0.92; SEE, 1.9 mm Hg). CONCLUSION: Doppler echocardiographic measurement of right ventricular pressure at the time of pulmonary valve opening is a reliable noninvasive method for estimating pulmonary diastolic pressure.     

Can echocardiographic evaluation of cardiopulmonary hemodynamics decrease right heart catheterizations in end-stage heart failure patients awaiting transplantation?

Candidacy for heart transplantation is influenced by the severity of pulmonary hypertension. In this study, invasive hemodynamics from right-sided cardiac catheterization were compared with values obtained by validated equations from Doppler 2-dimensional transthoracic echocardiography. This prospective study was conducted in 40 patients with end-stage heart failure evaluated for heart transplantation or ventricular assist device implantation. Transthoracic echocardiography and right-sided cardiac catheterization were performed within 4 hours. From continuous-wave Doppler of the tricuspid regurgitation jet, pulmonary artery systolic pressure was calculated as the peak gradient across the tricuspid valve plus right atrial pressure estimated from inferior vena cava filling. Mean pulmonary artery pressure was calculated as (0.61 × pulmonary artery systolic pressure) + 2. Pulmonary vascular resistance (PVR) was calculated as (tricuspid regurgitation velocity/right ventricular outflow tract time-velocity integral × 10) + 0.16. Pulmonary capillary wedge pressure was calculated as 1.91 + (1.24 × E/E'). Pearson's correlation and Bland-Altman analysis of mean differences between echocardiographic and right-sided cardiac catheterization measurements were statistically significant for all hemodynamic parameters (pulmonary artery systolic pressure: r = 0.82, p < 0.05, mean difference 3.1 mm Hg, 95% confidence interval [CI] -0.2 to 6.3; mean pulmonary artery pressure: r = 0.80, p < 0.05, mean difference 2.5 mm Hg, 95% CI 0.3 to 4.6; PVR: r = 0.52, p < 0.05, mean difference 0.8 Wood units, 95% CI 0.3 to 1.4; pulmonary capillary wedge pressure: r = 0.65, p < 0.05, mean difference 2.2 mm Hg, 95% CI 0.1 to 4.3). Compared with right-sided cardiac catheterization, PVR by Doppler echocardiography identified all patients with PVR > 4 Wood units (n = 4), 73% of patients with PVR <2 Wood units (n = 8), and 52% of patients with PVR from 2 to 4 Wood units (n = 10). In conclusion, echocardiographic estimation of cardiopulmonary hemodynamics is reliable in patients with end-stage cardiomyopathy. The noninvasive assessment of hemodynamics by echocardiography may be able to decrease the number of serial right-sided cardiac catheterizations in selected patients awaiting heart transplantation. However, in patients with borderline PVR, right-sided cardiac catheterization is indicated to assess eligibility for transplantation.     

Balloon atrial septostomy using echocardiographic monitoring

Six patients with d-transposition of the great arteries and 1 patient with tricuspid atresia were diagnosed echocardiographically. Balloon atrial septostomy (BAS) was performed successfully in all cases with the aid of two-dimensional echocardiography. Echocardiography may be superior to fluoroscopy during BAS because it permits easy detection of spontaneous passage of the inflated catheter into the left ventricle spontaneously through the mitral valve (like a left atrial myxoma). With the visualization of related cardiac structures during BAS, obstruction of the IVC with the balloon was also prevented. Using this method, bedside application of BAS is possible.     

Straddling mitral valve with hypoplastic right ventricle, crisscross atrioventricular relations, double outlet right ventricle and dextrocardia: morphologic, diagnostic and surgical considerations

The clinical, surgical and morphologic findings in five cases of a rare form of straddling mitral valve are presented. Three patients were diagnosed by two-dimensional echocardiography, cardiac catheterization and angiocardiography and two had diagnostic confirmation at autopsy. All five cases shared a distinctive and consistent combination of anomalies: 1) dextrocardia; 2) visceroatrial situs solitus, concordant ventricular D-loop and double outlet right ventricle with the aorta positioned to the left of and anterior to the pulmonary artery; 3) hypoplasia of right ventricular inflow (sinus) with tricuspid valve stenosis or hypoplasia; 4) large right ventricular infundibulum (outflow); 5) malalignment conoventricular septal defect; 6) straddling mitral valve with chordal attachments to the left ventricle and right ventricular infundibulum; 7) severe subpulmonary stenosis with well developed pulmonary arteries; and 8) superoinferior ventricles with crisscross atrioventricular (AV) relations. The degree of malalignment between the atrial and ventricular septa was studied quantitatively by measuring the AV septal angle projected on the frontal plane. The AV septal angle in the two postmortem cases was 150 degrees, reflecting marked malalignment of the ventricles relative to the atria. This AV malalignment appears to play an important role in the morphogenesis of straddling mitral valve. As judged by a companion study of seven postmortem cases, the more common form of straddling mitral valve with a hypertrophied and enlarged right ventricular sinus had less severe ventricular malposition than did the five rare study cases with hypoplastic right ventricular sinus. A competent mitral valve, low pulmonary vascular resistance and low left ventricular end-diastolic pressure were found at cardiac catheterization in the three living patients who underwent a modified Fontan procedure and are doing well 2.2 to 5.8 years postoperatively.