Left ventricular volume from paired biplane two-dimensional echocardiography.

To evaluate the applicability of two-dimensional echocardiography to left ventricular volume determination, 30 consecutive patients undergoing biplane left ventricular cineangiography were studied with a wide-angle (84 degrees), phased-array, two-dimensional echocardiographic system. Two echographic projections were used to obtain paired, biplane, tomographic images of the left ventricle. We used the short-axis view (from the precordial window) as an anolog of the left anterior oblique angiogram, and the long-axis, two-chamber view (from the apex impulse window) as a right anterior oblique angiographic equivalent. A modified Simpson's rule formula was used to calculate systolic and diastolic left ventricular volumes from the biplane echogram and the biplane angiogram. These methods correlated well for ejection fraction (r = 0.87) and systolic volume (r = 0.90), but only modestly for diastolic volume (r = 0.80). These correlations are noteworthy because 65% of the patients had significant segmental wall motion abnormalities. The volumes determined from the minor-axis dimensions of M-mode echograms in 23 of the same patients correlated poorly with angiography.     

Two-dimensional echocardiographic evaluation of the size, function and shape of the left ventricle in chronic aortic regurgitation: comparison with radionuclide angiography

To evaluate the usefulness of two-dimensional echocardiography in asymptomatic or minimally symptomatic patients with significant aortic regurgitation and left ventricular enlargement, left ventricular size and function measurements obtained by a nongeometric technique, gated blood pool radionuclide angiography, were compared with measurements made by several two-dimensional echocardiographic methods in 20 patients. Left ventricular size was best assessed by an apical biplane modified Simpson's rule algorithm obtained by computer-assisted planimetry. For end-diastolic volume, r = 0.95 and standard error of the estimate = 25 ml; for end-systolic volume, r = 0.94 and standard error of the estimate = 16 ml. A newly introduced simplified two-dimensional method obviating the need for planimetry and using multiple axis measurements yielded satisfactory results, although volumes larger than 300 ml were markedly underestimated. Evaluation of volumes from a single minor axis measured directly from two-dimensional images and M-mode tracings obtained under two-dimensional echocardiographic control was inadequate for clinical use. Ejection fraction was correctly assessed by the modified Simpson's rule method as well as by the simplified two-dimensional method (r = 0.81 to 0.83, standard error of the estimate = 7%). However, when methods without planimetry were further simplified, a satisfactory correlation was no longer obtained. The M-mode approach using a corrected cube formula also provided an accurate estimation of ejection fraction, a finding that is attributed to the absence of regional wall motion abnormalities in this group of patients, the ability to locate the M-mode beam more adequately under two-dimensional control and the persistence of an ellipsoidal configuration and a circular cross section in the left ventricular chamber. The data indicate that two-dimensional echocardiography is a valuable approach to the assessment of left ventricular size and function in these patients. Moreover, this approach provides a practical and convenient way of improving M-mode evaluation of function and of determining left ventricular shape, thus permitting adequate selection of geometric algorithms for volume calculations.     

Value and limitations of transesophageal echocardiography in determination of left ventricular volumes and ejection fraction.

Several formulas exist for estimating left ventricular volumes and ejection fraction using conventional two-dimensional echocardiography from transthoracic views. Transesophageal imaging provides superior resolution of endocardial borders but employs slightly different scan planes. The estimation of left ventricular volumes by transesophageal echocardiography has not been validated in human patients. Therefore, the purpose of this study was to compare left ventricular volumes and ejection fraction derived from transesophageal short-axis and four-chamber images with similar variables obtained from ventriculography. End-diastolic and end-systolic volumes and ejection fraction were calculated using modified Simpson's rule, area-length and diameter-length models in 36 patients undergoing left ventriculography. Measurements of left ventricular length were obtained from the transesophageal four-chamber view and areas and diameters were taken from short-axis scans at the mitral valve, papillary muscle and apex levels. Data from transesophageal echocardiographic calculations were compared with end-diastolic volume (mean 172 +/- 90 ml), end-systolic volume (mean 91 +/- 74 ml) and ejection fraction (mean 52 +/- 15%) from cineventriculography using linear regression analysis. The area-length method (r = 0.88) resulted in a slightly better correlation with left ventricular end-diastolic volume than did Simpson's rule (r = 0.85) or area-length (r = 0.84) formulas. For end-systolic volume, the three models yielded similar correlations: Simpson's rule (r = 0.94), area-length (r = 0.93) and diameter-length (r = 0.95). Each of the methods resulted in significant underestimation of diastolic and systolic volumes compared with values assessed with angiography (p less than 0.003). Ejection fraction was best predicted by using the Simpson's rule formula (r = 0.85) in comparison with area-length (r = 0.80) or diameter-length (r = 0.73) formulas. Measurements of left ventricular length by transesophageal echocardiography were smaller for systole (mean 5.7 +/- 1.6 cm) and diastole (mean 7.7 +/- 1.2 cm) than values by ventriculography (mean 9.2 +/- 1.4 and 8.1 +/- 1.6 cm, respectively; p less than 0.0001), suggesting that underestimation of the ventricular length is a major factor contributing to the smaller volumes obtained by transesophageal echocardiography. In conclusion, currently existing formulas can be applied to transesophageal images for predicting left ventricular volumes and ejection fraction. However, volumes obtained by these models are significantly smaller than those obtained with angiography, possibly because of foreshortening in the transesophageal four-chamber view.     

Two-dimensional echocardiographic determination of ventricular volumes in the fetal heart. Validation studies in fetal lambs

The determination of ventricular volumes in the fetal heart from two-dimensional echocardiography (2DE) may give a better estimate of fetal ventricular size than simple diameter measurements, but the accuracy of this method has not been established. In fetal lambs, we tested whether ventricular volume calculations from 2DE using a biplane Simpson's rule algorithm are accurate. Calculations of left and right ventricular end-diastolic volumes from 2DE were compared with cast volumes of these ventricles. Also, at different levels of left atrial pressure, left ventricular stroke volumes calculated from 2DE were compared with stroke volumes measured simultaneously by an electromagnetic flowmeter. There was a good correlation between volumes determined from 2DE (y axis) and from casts (x axis) for both the left (r = 0.92; y = 0.2 + 1.1x; SEE = 0.19 ml) and right ventricle (r = 0.90; y = 0.7 + 0.9x; SEE = 0.21 ml). Left ventricular stroke volumes calculated from 2DE correlated well with those measured by the electromagnetic flowmeter (r = 0.87; y = 0.2 + 0.9x; SEE = 0.27 ml). Thus, calculation of fetal ventricular volumes from 2DE images using a biplane Simpson's rule method is feasible and accurate.     

Validation of real-time three-dimensional echocardiography for quantifying left ventricular volumes in the presence of a left ventricular aneurysm: in vitro and in vivo studies

OBJECTIVES: To validate the accuracy of real-time three-dimensional echocardiography (RT3DE) for quantifying aneurysmal left ventricular (LV) volumes. BACKGROUND: Conventional two-dimensional echocardiography (2DE) has limitations when applied for quantification of LV volumes in patients with LV aneurysms. METHODS: Seven aneurysmal balloons, 15 sheep (5 with chronic LV aneurysms and 10 without LV aneurysms) during 60 different hemodynamic conditions and 29 patients (13 with chronic LV aneurysms and 16 with normal LV) underwent RT3DE and 2DE. Electromagnetic flow meters and magnetic resonance imaging (MRI) served as reference standards in the animals and in the patients, respectively. Rotated apical six-plane method with multiplanar Simpson's rule and apical biplane Simpson's rule were used to determine LV volumes by RT3DE and 2DE, respectively. RESULTS: Both RT3DE and 2DE correlated well with actual volumes for aneurysmal balloons. However, a significantly smaller mean difference (MD) was found between RT3DE and actual volumes (-7 ml for RT3DE vs. 22 ml for 2DE, p = 0.0002). Excellent correlation and agreement between RT3DE and electromagnetic flow meters for LV stroke volumes for animals with aneurysms were observed, while 2DE showed lesser correlation and agreement (r = 0.97, MD = -1.0 ml vs. r = 0.76, MD = 4.4 ml). In patients with LV aneurysms, better correlation and agreement between RT3DE and MRI for LV volumes were obtained (r = 0.99, MD = -28 ml) than between 2DE and MRI (r = 0.91, MD = -49 ml). CONCLUSIONS: For geometrically asymmetric LVs associated with ventricular aneurysms, RT3DE can accurately quantify LV volumes.     

Value of color Doppler estimation of regurgitant volume in patients with chronic aortic insufficiency

We studied 16 patients with chronic aortic insufficiency to compare a method for measuring regurgitant volume with color Doppler flow mapping to stroke count ratio determined by radionuclide ventriculography and to ventricular volumes assessed by two-dimensional echocardiography. A real-time color flow map of the left ventricular was obtained from an apical two- and five-chamber view and the maximal mosaic pattern of diastolic turbulent flow was planimetered as a reflection of the maximal regurgitant volume using biplane Simpson's rule. The maximal Doppler regurgitant volume evaluated by color Doppler flow mapping correlated with the stroke count ratio measured by scintigraphy (r = 0.86, SEE = 11 cc). There were significant relationships between maximal regurgitant volume measured by color Doppler and echocardiographic left ventricular end-diastolic volume (r = 0.88), left ventricular end-systolic volume (r = 0.77), and left ventricular mass (r = 0.71). Patients with larger regurgitant volumes tended to have a larger left ventricular end-diastolic volume-to-mass ratio (r = 0.56). Thus maximal aortic regurgitant volume can be estimated noninvasively with color Doppler flow mapping. The measurement appears to relate to left ventricular morphologic changes occurring in this condition and it may prove to be useful in assessing patients with chronic aortic insufficiency and in determining their long-term management.     

Left ventricular mass and volume/mass ratio determined by two-dimensional echocardiography in normal adults

This study prospectively defined the range of left ventricular mass and volume/mass ratio determined by two-dimensional echocardiography in 84 normal adults. A modified Simpson's rule algorithm was used to calculate ventricular volumes from orthogonal two and four chamber apical views. An algorithm based on a model of the left ventricle as a truncated ellipsoid was used to calculate ventricular mass. Like left ventricular volumes, left ventricular mass values were larger in normal men than in women (mean 148 versus 108 g, p less than 0.001) and remained larger after correction for body surface area. Volume/mass ratios, however, were constant at end-diastole (0.80) and end-systole (0.26). The influence of age and heart rate on all variables in this normal group was minimal, and no correction for these variables was necessary. The definition of normal mass, volume and volume/mass ratios by two-dimensional echocardiography will facilitate the noninvasive, quantitative diagnosis of left ventricular hypertrophy and help clarify the relation between hypertrophy and systolic wall stress.     

Assessment of left ventricular ejection fraction and volumes by real-time, two-dimensional echocardiography. A comparison of cineangiographic and radionuclide techniques.

Five different algorithms for determining left ventricular (LV) ejection fraction (EF) and volumes from two-dimensional echocardiographic examination (TDE) were compared with standard methods for obtaining EF and volume from x-ray cineangiography (cine) and EF from radionuclide ventriculography (RVG) in 35 patients. Although all methods correlated positively, the degree of correlation varied with the algorithm used. For EF determination, TDE algorithms (especially those using multiple planes of section) were superior to unidimensional algorithms commonly used with M-mode echocardiography. The best algorithm (modified Simpson's rule) correlated well enough with cine EF (r = 0.78; SEE 0.097) and RVG EF (r = 0.75; SEE 0.087) to make clinically useful estimates. TDE volumes also correlated meaningfully with cine end-diastolic and end-systole volumes (r = 084; n = 70) but were associated with a large standard error of the estimate (43 ml) and offered less advantage over unidimensional volume estimates. Quantitative application of TDE appears to be a useful noninvasive method of evaluating LVEF, but is not as useful for estimating LV volumes.     

Two-dimensional echocardiographic estimation of right ventricular ejection fraction in patients with coronary artery disease

Two-dimensional echocardiographic determination of right ventricular ejection fraction was compared with right ventricular ejection fraction obtained by first pass radionuclide angiography in 39 patients with coronary artery disease. Apical four chamber and two chamber right ventricular views were obtained in 34 (87%) of the 39 patients, while a subcostal four chamber view was obtained in 31 patients (80%). Right ventricular ejection fraction by two-dimensional echocardiography was calculated by the biplane area-length and Simpson's rule methods using two paired orthogonal views and utilizing a computerized light-pen method for tracing the right ventricular endocardium. A good correlation (r = 0.74 to 0.78) was found between radionuclide angiographic and two-dimensional echocardiographic right ventricular ejection fraction for each method used. Patients with acute inferior myocardial infarction had the lowest right ventricular ejection fraction by radionuclide angiography and two-dimensional echocardiography (p less than 0.05 compared with patients with right coronary artery obstruction and no infarction). There were no differences in right ventricular ejection fraction between patients with acute and old inferior myocardial infarction by both techniques. No correlation was found between left and right ventricular ejection fraction by radionuclide angiography (r = 0.16). It is concluded that 1) right ventricular ejection fraction by two-dimensional echocardiography correlates well with radionuclide angiographic measurements and can reliably evaluate right ventricular function in coronary artery disease, 2) patients with inferior myocardial infarction have reduced right ventricular ejection fraction, and 3) changes in left ventricular ejection fraction do not directly influence right ventricular function.     

Determination of left ventricular volumes by Simpson''s rule in infants and children with congenital heart disease.

Regression equations were developed from left ventricular casts of known volumes to calculate left ventricular volumes from biplane cineangiography obtained in non-standard views. Volumes were calculated by Simpson's rule from casts of postmortem specimens from patients with congenital heart disease. The casts were divided into two groups: those that came from patients with abnormal right ventricular haemodynamic function (group 1, n = 11) and those that came from patients in which it was normal (group 2, n = 9). Biplane cinegrams were taken in conventional (anteroposterior/lateral, right anterior oblique/left anterior oblique) and non-conventional (long axis oblique, hepatoclavicular, and sitting up) projections. The true volume of each cast was determined from its weight and specific gravity. Correlations between measured and true volumes (r = 0.96 to 0.99) were excellent in all projections, although each projection overestimated the true volumes (slope = 0.72 to 0.94). The regression equations obtained from conventional views were significantly different from those from the non-conventional views; however, the regression slopes in group 1 were not different from those in group 2 in any view. Regression equations obtained by Simpson's rule do not seem to be affected by the haemodynamic state of the right ventricle. Different regression equations are required to measure left ventricular volumes from non-conventional angiograms.     

Determination of left ventricular volumes by Simpson's rule in infants and children with congenital heart disease

Regression equations were developed from left ventricular casts of known volumes to calculate left ventricular volumes from biplane cineangiography obtained in non-standard views. Volumes were calculated by Simpson's rule from casts of postmortem specimens from patients with congenital heart disease. The casts were divided into two groups: those that came from patients with abnormal right ventricular haemodynamic function (group 1, n = 11) and those that came from patients in which it was normal (group 2, n = 9). Biplane cinegrams were taken in conventional (anteroposterior/lateral, right anterior oblique/left anterior oblique) and non-conventional (long axis oblique, hepatoclavicular, and sitting up) projections. The true volume of each cast was determined from its weight and specific gravity. Correlations between measured and true volumes (r = 0.96 to 0.99) were excellent in all projections, although each projection overestimated the true volumes (slope = 0.72 to 0.94). The regression equations obtained from conventional views were significantly different from those from the non-conventional views; however, the regression slopes in group 1 were not different from those in group 2 in any view. Regression equations obtained by Simpson's rule do not seem to be affected by the haemodynamic state of the right ventricle. Different regression equations are required to measure left ventricular volumes from non-conventional angiograms.     

A comparison of mathematical models for estimating right ventricular volumes in animals and man

Volume of 19 right ventricular canine casts and 11 right ventricular human casts were obtained by water displacement and compared to three different mathematical models for estimating right ventricular volumes by biplane cineangiography. In the canine studies, significant linear correlation coefficients were obtained using the longest measured length method (r = 0.92), the triangular modification of Simpson's rule (r = 0.93), and the elliptical modification of Simpson's rule (r = 0.93). The human studies resulted in similar significant correlation coefficients of 0.96, 0.97, and 0.97, respectively. Although the highest correlation with the lowest standard error of estimate was obtained using the triangular model, all three mathematical models produced volume estimations that feel within acceptabe biological limits of accuracy.     

Two-dimensional echocardiographic evaluation of right ventricular ejection fraction: comparison between three different methods

Twelve patients with chronic cor pulmonale due to chronic obstructive pulmonary disease have been examined with 2D echocardiography, performing four-chamber view by apical and subcostal approaches, and the right ventricular outflow tract view by the subcostal approach. These views have permitted evaluation of right ventricular volumes, and hence right ventricular ejection fraction, by the use of three different geometrical formulae: the biplane area-length method, Simpson's rule and the pyramidal method. The ejection fraction values obtained from each method have been compared to those obtained by equilibrium radionuclide angiocardiography. Four-chamber apical and subcostal views were satisfactorily recorded in 10 of the 12 patients (83.3%), and right ventricular outflow tract view in 8 patients (66.6%). No significant statistical differences have been found between measurements obtained from the three different echocardiographic examinations performed on each subject by the same operator, so demonstrating a satisfactory reproducibility of the technique. The highest correlation coefficient for ejection fraction was shown by Simpson's rule (r = 0.96, p less than 0.001), with a very narrow confidence intervals, while the r values for the biplane area-length method was 0.63 (p less than 0.05) and for the pyramidal method 0.50 (not statistically significant), with increasingly wider confidence intervals. The statistically significant difference between the three correlation coefficients demonstrates the higher accuracy of Simpson's rule for the determination of right ventricular ejection fraction.     

Two-dimensional echocardiographic methods for assessment of left atrial volume

Left atrial (LA) size is an important predictor of cardiovascular events. Various methods of LA volume assessment exist, but their differences have not been defined. This prospective study included 631 patients (331 men; mean age of 68 +/- 14 years) without a history of atrial arrhythmias, stroke, valvular heart disease, pacemaker implantation, or congenital heart disease. All underwent echocardiography with comprehensive diastolic function assessment and LA volume measurement by 3 commonly used methods: biplane area-length, biplane Simpson's method, and the prolate-ellipsoid method. Mean LA volumes were 39 +/- 14 ml/m2 by the area-length method, 38 +/- 13 ml/m2 by the Simpson's method, and 32 +/- 14 ml/m2 by the prolate-ellipsoid method. In 92% of patients, the prolate measurement was smaller than the 2 biplane methods. Pairwise correlations (r) were 0.98 for area-length versus Simpson's, 0.85 for prolate versus area-length, and 0.86 for prolate versus Simpson's (all p values <0.001). For distinguishing normal (n = 62) from pseudonormal diastolic function (n = 240) using receiver-operating curve analysis, areas under the curves were 0.76, 0.78, and 0.75 for the area-length, Simpson's, and prolate methods, respectively (all p values <0.001, no significant intermethod differences). In conclusion, our findings suggest that there are systematic differences among existing LA volume methods. Biplane area-length and Simpson's methods compare closely, whereas the prolate-ellipsoid method generally yields smaller volumes.     

Clinical Determinations of Volumes of Normal and Aneurysmatic Left Ventricles by Three-Dimensional Transesophageal Echocardiography

Biplane methods of determining left ventricular volumes are inaccurate in the presence of aneurysmal distortions. Multiplane transesophageal echocardiography, which provides multiple, unobstructed cross-sectional views of the heart from a single, stable position, has the potential for more accurate determinations of volumes of irregular cavity forms than the biplane methods. The aim of the study was to determine the feasibility of three-dimensional measurements of ventricular volumes in patients with normal and aneurysmatic left ventricles by using multiplane transesophageal echocardiography. With the echotransducer in the mid-esophageal (transesophageal) position, nine echo cross-sectional images of the left ventricle in approximately 20 degrees angular increments were obtained from each of 29 patients with coronary artery disease who had undergone biplane ventriculography during diagnostic cardiac catheterization. In 17 of these 29 patients, echo cross-sectional images of the left ventricle with the echotransducer in transgastric position were also obtained. End-diastolic volume, end-systolic volume, and ejection fraction were determined from multiplane transesophageal echocardiographic images and biplane ventriculographic images by the disc-summation method and compared with each other. In another ten patients with indwelling pulmonary artery catheters, stroke volumes calculated from multiplane transesophageal echocardiographic images were compared with those derived from thermodilution cardiac output measurements. Correlations between biplane ventriculographic and multiplane transesophageal echocardiographic measurements were higher in the ten patients with normal ventricular shape [for end-diastolic volumes, r = 0.91, SEE = 19 ml; for end-systolic volumes, r = 0.98, SEE = 9.3 ml; for ejection fractions (EFs), r = 0.91, SEE = 5.4%] than in the 19 patients with ventricular aneurysms (for end-diastolic volumes, r = 0.61, SEE = 31.5 ml; for end-systolic volumes, r = 0.66, SEE = 32.5 ml; for EFs, r = 0.79, SEE = 8%). Correlations between echocardiographic volumes from the transesophageal and transgastric transducer positions were high independent of left ventricular geometry (for end-diastolic volumes, r = 0.84, SEE = 13.1 ml; for end-systolic volumes, r = 0.98, SEE = 9.6 ml; for EFs, r = 0.97, SEE = 3.4%). In 12 observations (4 normal and 8 aneurysmal) from the ten patients with indwelling pulmonary artery catheters, correlation between stroke volumes determined from thermodilution cardiac output measurements and those derived from multiplane transesophageal echocardiographic images was high (r = 0.91, SEE = 6 ml). The results indicate that three-dimensional measurements of volumes of irregular and distorted left ventricles are feasible with multiplane transesophageal echocardiography. This method may be more accurate than biplane methods, especially in the presence of left ventricular aneurysms.     

Comparison of two- and three-dimensional echocardiography with cineventriculography for measurement of left ventricular volume in patients

Objectives. We compared two- and three-dimensional echocardiopaphy with cineventriculography for measurement of left ventricular volume in patients.Background. Three-dimensional echocardiography has been shown to be highly accurate and superior to two-dimensional echocardiography in measuring left ventricular volume in vitro. However, there has been little comparison of the two methods in patients.Methods. Two- and three-dimensional echocardiography were performed in 35 patients (mean age 48 years) 1 to 3 h before left ventricular cineventriculography. Three-dimensional echocardiography used an acoustic spatial locator to register image position. Volume was computed using a polyhedral surface reconstruction algorithm based on multiple nonparallel, unevenly spaced short-axis cross sections. Two-dimensional echocardiography used the apical biplane summation of disks method. Single-plane cineventriculographic volumes were calculated using the summation of disks algorithm. The methods were compared by linear regression and a limits of agreement analysis. For the latter, systematic error was assessed by the mean of the deferences (cineventriculography minus echocardiography), and the limits of agreement were defined as ±2 SD from the mean difference.Results. Three-dimensional echocardiographic volumes demonstrated excellent correlation (end-diastole r = 0.97; end-systole r = 0.98) with cineventriculography. Standard errors of the estimate were approximately half those of two-dimensional echocardiography (end-diastole ±11.0 ml vs. ±21.5 ml; end-systole ±10.2 ml vs. ±17.0 ml). By limits of agreement analysis the end-diastolic mean diferences for two- and three-dimensional echocardiography were 21.1 and 12.9 ml, respectively. The limits of agreement (±2 SD) were ±54.0 and ±24.8 ml, respectively. For end-systole, comparable improvement was obtained by three-dimensional echocardiography. Results for ejection fraction by the two methods were similar.Conclusions. Three-dimensional echocardiography correlates highly with cineventriculography for estimation of ventricular volumes in patients and has approximately half the variability of two-dimensional echocardiography for these measurements. On the basis of this study, three-dimensional echocardiography is the preferred echocardiographic technique for measurement of ventricular volume. Three-dimensional echocardiography is equivalent to two-dimensional echocardiography for measuring ejection fraction.     

Cross sectional echocardiographic assessment of left ventricular volume and ejection fraction in patients with tetralogy of Fallot. Comparison with biplane angiographic measurements.

To evaluate the usefulness and accuracy of calculating left ventricular volume and ejection fraction from cross sectional echocardiograms in patients with tetralogy of Fallot, 28 patients were studied within 24 hours of cineangiography. Indexed end diastolic and end systolic volumes were calculated from three different paired echocardiographic projections: (a) the two and four chamber views from the apical impulse window, (b) the parasternal long axis view and the subxiphoid long axis view, and (c) the four chamber view and short axis precordial views at mitral and papillary muscle level. Volumes were calculated in five different ways using three different algorithms (area length, Simpson's rule, the Parisi formula). The results were compared with data obtained from biplane angiograms using Graham's formula. The correlation varied with the algorithm used: the best results were obtained with the area length method using the parasternal long axis view and the sub-xiphoid view. The correlation was less accurate for the ejection fraction. The second best correlation was obtained with the area length method using the two and four chamber apical views; the other correlations were less satisfactory. Thus these results show that left ventricular volumes can be accurately assessed by cross sectional echocardiography in children with tetralogy of Fallot and that the ejection fraction can be satisfactorily estimated. The results depend on careful gain setting and precise demonstration of the left ventricular endocardium, which is best seen in the sub-xiphoid and long axis views.     

Early two-dimensional echocardiographic measurement of left ventricular ejection fraction in acute myocardial infarction

Left ventricular volume and ejection fraction were measured by 2-dimensional echocardiography from 2 orthogonal apical long axis views in 90 patients admitted with acute transmural myocardial infarction. Results were correlated with worst Killip class during hospital stay, enzymatic infarct size (peak CK-MB) and mortality. We used two algorithms, a biplane area-length algorithm and a modification of Simpson's rule. Both algorithms yielded essentially the same results: there were statistically significant trends towards higher end-diastolic and end-systolic volumes and lower ejection fraction with higher Killip -class. Ejection fraction was lower (P less than 0.01) in the 6 patients dying from cardiogenic shock (28.0 +/- 7.8% v. 46.6 +/- 10.1% in survivors with the area--length algorithm; 28.1 +/- 6.2% v. 48.1 +/- 10.2% with modified Simpson's rule). In 5 patients dying from other causes ejection fraction was 46.0 +/- 14.9% with the area-length method or 46.2 +/- 14.5% with Simpson's rule (not different from survivors). Correlation with peak CK-MB was only modest, though statistically significant: the regression equation was: y = -0. 39x + 54 (r = -0.35; P less than 0.01) with the area-length method; and y = -0. 41x + 55 (r = -0.37; P less than 0.01) with Simpson's rule. Left ventricular ejection fraction measured at the bedside in patients with acute myocardial infarction, can provide useful clinical information. Patients likely to develop shock can be identified shortly after admission.     

Volume measurement of the left ventricle in children with congenital heart defects: 3-dimensional echocardiography versus angiocardiography

BACKGROUND: Volume measurement of the left ventricle is currently done by 2-dimensional echocardiography or angiocardiography. However, for the calculation of volumes by these methods, geometrical assumptions must be made. For a precise ventricular volumetry, independent of mathematical assumptions, imaging techniques as the 3-dimensional echocardiography (3D-echo) are required, which permit the imaging of the real ventricular shape. The aim of the study was therefore to detect, whether 3D-echocardiography is suitable for left ventricular volumetry in children with congenital heart disease and whether the 3D-echocadiographically measured volumes correlate sufficiently well with angiocardiographically measured left ventricular volumes. METHODS: 102 children with congenital heart disease were investigated. For angiocardiographic left ventricular volume measurement Simpson's rule was used. Results were corrected with Lange's correction factors. The 3D-echo data sets were registered with a rotating transthoracic transducer. Ventricular volumes were calculated after manual planimetry by summation of the volumes of the single slices. RESULTS: The left ventricular volume could be calculated by 3D-echo in 83% of patients of all ages. In comparison to angiocardiography, the measured volumes were 0.6 +/- 3. 3 ml (0.9 +/- 25.8%) or 7.1 +/- 28.4 ml (7.4 +/- 12.1%) smaller during systole or diastole, respectively. The correlation coefficients r(2) were 0.89 for systolic and 0.93 for diastolic measurements after logarithmic transformation. Pressure or volume overload did not influence significantly the difference between the two methods. CONCLUSION: Transthoracic 3D-echocardiography with a rotating transmitter is feasible for volumetry of the left ventricle in most children. The volumes measured by 3D-echo were significantly smaller than those calculated from the angiocardiography by Simpson's rule. The measurements were not influenced by the kind of load of the ventricle. The correlation between the two methods is good.     

Cross sectional echocardiographic assessment of left ventricular volume and ejection fraction in patients with tetralogy of Fallot. Comparison with biplane angiographic measurements

To evaluate the usefulness and accuracy of calculating left ventricular volume and ejection fraction from cross sectional echocardiograms in patients with tetralogy of Fallot, 28 patients were studied within 24 hours of cineangiography. Indexed end diastolic and end systolic volumes were calculated from three different paired echocardiographic projections: (a) the two and four chamber views from the apical impulse window, (b) the parasternal long axis view and the subxiphoid long axis view, and (c) the four chamber view and short axis precordial views at mitral and papillary muscle level. Volumes were calculated in five different ways using three different algorithms (area length, Simpson's rule, the Parisi formula). The results were compared with data obtained from biplane angiograms using Graham's formula. The correlation varied with the algorithm used: the best results were obtained with the area length method using the parasternal long axis view and the sub-xiphoid view. The correlation was less accurate for the ejection fraction. The second best correlation was obtained with the area length method using the two and four chamber apical views; the other correlations were less satisfactory. Thus these results show that left ventricular volumes can be accurately assessed by cross sectional echocardiography in children with tetralogy of Fallot and that the ejection fraction can be satisfactorily estimated. The results depend on careful gain setting and precise demonstration of the left ventricular endocardium, which is best seen in the sub-xiphoid and long axis views.