Evaluation of left atrial size in patients with atrial arrhythmias: comparison of standard 2D versus real time 3D echocardiography

AIM: Two-dimensional echocardiography may not correctly indicate size in nonspherical atria. The present study compares different parameters of left atrial size evaluated by standard two-dimensional echocardiography with left atrial volume measured using three-dimensional echocardiography (3DE). METHODS AND RESULTS: One hundred seventy consecutive patients with a history of atrial arrhythmias were studied by standard two-dimensional and by real time 3DE. Of these 166 (98%) recordings were of sufficient quality for interpretation by both imaging techniques. The following parameters of left atrial size were measured: parasternal long axis diameter (PLAX), apical 4-chamber short-axis diameter (4CH short axis), apical 4-chamber (4CH long axis), and 2-chamber long-axis diameters and planimetry areas. Two-dimensional-derived left atrial volumes were calculated by using both single plane (4CH area-length) and biplane area-length methods. The 2D parameters were then correlated with left atrial volume measured by 3D echocardiography. Linear regression analysis showed moderate correlation for 4-chamber planimetry area (r = 0.76, P < 0.0001) and 2D-derived volume calculations (r of 4CH single plane area-length LA volume = 0.74 and biplane area-length LA volume = 0.78, P < 0.0001). Diameters correlated less well with 3DE volume (r of PLAX = 0.67, 4CH short axis = 0.68, 4CH long axis = 0.63, P < 0.0001 respectively). CONCLUSION: The results demonstrate that measurements of dimensions using standard echocardiography are of limited accuracy to assess left atrial volume. If 3DE is not available, 4-chamber planimetry area is a valid simple parameter for evaluating left atrial size in clinical practice. Two-dimensional-derived volume by biplane area-length method was only slightly better correlated with 3DE volume than 4-chamber planimetry area.     

Left atrial volume estimation by two-dimensional echocardiography

We examined 12 patients aged six months to 76 years by echocardiography to determine left atrial volume. The results were compared with angiographic left atrial volumes calculated by the biplane Simpson's rule method. Three two-dimensional planes were used: precordial long axis, apical two-chamber, and four-chamber. Area outlines were traced using a light pen computational system providing single plane area length estimates of left atrial volume. The two apical left atrial outlines were combined, and Simpson's rule method was used to calculate left atrial volume. M-mode echocardio-grams performed on these patients were used to estimate left atrial volume. As the resuits of covariance analysis showed that there was no significant difference in the line of regression in systole and diastole, these data were pooled for subsequent comparison with angiography. The closest correlation with angiography was the biplane Simpson rule method with the echocardiographic left atrial volume (Y) = 1.0, angiographic volume (X) + 6.3 ml, r = 0.86. The single plane area length estimates also correlated well with angiography, but correction factors were required. M-mode estimates of left atrial volume could only correlate to angiography using a power function y = 3.7 X^1.80, r = 0.69. We conclude that left atrial volume can be determined by two-dimensional echocardiography and that this technique is superior to M-mode echocardiography.     

Left atrial volume determination by echocardiography

To validate echocardiographic left atrial volume measurements, 25 patients with mitral stenosis were studied before and after mitral balloon valvuloplasty. Seven normals served as controls. The modified Simpson's rule was used for echocardiographic and angiographic left atrial volume determination from two orthogonal planes. Left atrial antero-posterior diameter was measured from parasternal long axis view and supero-inferior and medio-lateral diameters from apical four-chamber view. Transthoracic echocardiographic left atrial volume correlated well, but systematically underestimated angiographic left atrial volume (y=0.4x+27, r=0.92). Monoplane transesophageal echocardiography did not improve correlation, nor the underestimation. Out of the several left atrial diameters, antero-posterior dimension showed the closest correlation with angiographic volume (r=0.91), which persisted after exclusion of patients with atria >400 ml (r=0.84). Futhermore, relative changes of antero-posterior diameter after mitral valvuloplasty were closely related to the relative changes observed in left atrial volume (r=0.82). Our results suggest that, in spite of a consistent underestimation, bidimensional, transthoracic echocardiographic and angiographic left atrial assessment correlate closely. Moreover, it is suggested that the mere antero-posterior diameter from transthoracic two-dimensional image is sufficient in clinical practice for routine follow-op of left atrial volume.     

Right atrial size relates to right ventricular end-diastolic pressure in an adult population with congenital heart disease

Aim: Noninvasive markers of right ventricular (RV) diastolic dysfunction are limited by their lack of reproducibility and accuracy. We tested the hypothesis that right atrial (RA) size measured by echocardiography was correlated to invasive parameters of RV diastolic filling. Methods and Results: We studied 31 consecutive adult patients with congenital heart disease. From 2D echocardiography images, we measured maximal RA long‐axis and short‐axis lengths, area and volume. We compared each of these measures to right ventricular end‐diastolic pressure (RVEDP) and mean right atrial pressure (mRAP) measured by right heart catheterization. RA long‐axis, short‐axis, area, and volume correlated significantly with RVEDP (r = 0.78, P < 0.001; r = 0.61, P < 0.001; r = 0.79, P < 0.001; and r = 0.75, P < 0.001, respectively) and mRAP (r = 0.66, P < 0.001; r = 0.56, P = 0.002; r = 0.70, P < 0.001; r = 0.68, P < 0.001, respectively). Single cut points for each echocardiographic parameter demonstrated reasonable accuracy to rule‐in and rule‐out RVEDP ≥7 mm Hg (sensitivity = 74%, specificity = 82%, positive LR = 4.1, negative LR = 0.32 for RA long‐axis of 49 mm; sensitivity = 89%, specificity = 82%, positive LR = 4.9, negative LR = 0.12 for RA area of 14 cm²; sensitivity = 89%, specificity = 82%, positive LR = 4.9, negative LR = 0.13 for RA volume of 37 mL). Conclusion: RA size measured by echocardiography is strongly correlated to invasive parameters of RV diastolic filling and predicts high RV end‐diastolic pressure. (Echocardiography 2011;28:109‐116)     

Right ventricular volumes and ejection fraction estimated by two-dimensional echocardiography

The right ventricular volumes and ejection fraction (RVEF) obtained from two-dimensional echocardiography and from right ventricular angiography were compared in 20 patients with congenital heart disease. Single plane area-length method of apical four-chamber view was used to estimate echocardiographic right ventricular volumes and single plane right anterior oblique projection was used to calculate angiographic right ventricular volumes. The results showed that right ventricular volumes estimated by echocardiography correlated highly with that calculated by angiography, the correlation coefficients of end-diastolic volume, end-systolic volume and stroke volume were 0.983, 0.976, 0.973 respectively. Echocardiographic RVEF also correlated strongly with angiographic RVEF (r = 0.992, P less than 0.001), and there were no significant difference between the two methods (P greater than 0.05). Conclusion: two-dimensional echocardiography can be used to accurately estimate right ventricular volumes and ejection fraction.     

Left and right atrial volume by freehand three-dimensional echocardiography: in vivo validation using magnetic resonance imaging.

INTRODUCTION: Measurement of left and right atrial size is important for the management of arrhythmias, valvular and congenital heart disease. We have demonstrated that freehand three-dimensional (3D) echocardiography is more accurate and reproducible than two-dimensional (2D) echocardiography for measurement of left ventricular mass and volume. However, no prior study has validated the accuracy of freehand 3D for the determination of left or right atrial volume. METHODS: End-systolic (maximum) left and right atrial volumes were determined in 21 volunteer patients and normal subjects by one, two, and freehand 3D transthoracic echocardiography and compared to volumes obtained by gradient recalled magnetic resonance imaging. Three-dimensional echocardiographic determination of atrial volume was obtained using an acoustic spatial locator, a line-of-intersection display, and a surface reconstruction algorithm. Two-dimensional echocardiographic atrial volumes were obtained from apical biplane images of the left atrium and an apical single plane image of the right atrium using a summation of disks method. One-dimensional (ID) estimates of left atrial volume were determined by cubing the M-mode ID antero-posterior dimension obtained on the parasternal long axis view. RESULTS: An excellent correlation was Obtained between freedhand 3D echocardiography and magnetic resonce imaging (MRI) for the left atrium (r = 0.90, SEE=9.6 ml) and for the right atrium (r = 0.91, SEE = 8.8 ml) with a small bias (left atrium 5.25 ml, right atrium 12.06 ml) and narrow limits of agreement (left atrium 22.14 ml, right atrium 25.54 ml). Two-dimensional echocardiography correlated less well (left atrium r = 0.87, SEE = 10.23 ml, right atrium r = 0.79, SEE = 19.74 ml), and had a higher bias (left atrium 14.46 ml, right atrium 8.99 ml) and larger limits of agreement (left atrium 24.37 ml, right atrium 41.16 ml). One-dimensional estimates of left atrial volume correlated poorly with magnetic resonance determined left atrial volume (r = 0.80, SEE = 6.61 ml) and had unacceptably high bias (45.09 ml) and limits of agreement (35.52 ml). Interobserver variability was lowest for 3D echocardiography (left atrium 7.2 ml, 11%, right atrium 8.7 ml, 16%). CONCLUSIONS: Freehand 3D echocardiography using the line of intersection display for guidance of image positioning and a polyhedral surface reconstruction algorithm is a valid, accurate, reproducible method for determining left and right atrial volume in humans that is comparable to magnetic resonance imaging and is superior to current ID and 2D echocardiographic techniques.     

Best method in clinical practice and in research studies to determine left atrial size.

Although the anteroposterior dimension of the left atrium is universally used in clinical practice and research, we hypothesized that it may be an inaccurate surrogate for volume because its use is based on the unlikely assumption that there is a constant relation among atrial dimensions. The following measurements of the left atrium were made at end ventricular systole: (1) M-mode-derived anteroposterior linear dimension from the parasternal long-axis view; (2) digitized planimetry of the left atrial (LA) cavity from the apical 4-chamber view; and (3) digitized planimetry of the LA cavity from the apical 2-chamber view. The following volume calculations were obtained from these digital measurements: (1) volume derived from the M-mode dimension assuming a spherical shape; (2) volume derived from the single plane area-length of apical 4-chamber view, which assumes that LA geometry can be generalized from a single 2-dimensional plane; and (3) volume derived from the biplane method of discs. The correlation coefficient between the M-mode and biplane methods of determining LA volume was r = 0.76. The mean difference (+/-2 SDs) between these methods is -25 +/- 33 ml. The correlation coefficient between the single plane apical 4-chamber and biplane methods of determining LA volume is r = 0.97. The mean difference (+/-2 SDs) between these methods was -5.0 +/- 12 ml, indicating good agreement. The M-mode measure of the left atrium is an inaccurate representation of its size. Two-dimensional-derived LA volumes provide a more accurate measure of the true size of the left atrium and are more sensitive to changes in LA size. When an echocardiographic measure of LA size is made either in an individual patient or as a variable in a research study, the M-mode measure should be avoided.     

Comparison of left and right atrial volume by echocardiography versus cardiac magnetic resonance imaging using the area-length method

Increased atrial volumes predict adverse cardiovascular events. Accordingly, accurate measurement of atrial size has become increasingly important in clinical practice. The area-length method is commonly used to estimate the volume. Disagreements between atrial volumes using echocardiography and other imaging modalities have been found. It is unclear whether this has resulted from differences in the measurement method or discrepancies among imaging modalities. We compared the right atrial (RA) and left atrial (LA) volume estimates using the area-length method for transthoracic echocardiography and cardiovascular magnetic resonance (CMR) imaging. Patients undergoing echocardiography and CMR imaging within 1 month were identified retrospectively. For both modalities, the RA and LA long-axis dimension and area were measured using standard 2- and 4-chamber views, and the volume was calculated using the area-length method for both atria. The echocardiographic and CMR values were compared using the Bland-Altman method. A total of 85 patients and 18 controls were included in the present study. The atrial volumes estimated using the area-length method were significantly smaller when measured using echocardiography than when measured using CMR imaging (LA volume 35 ± 20 vs 49 ± 30 ml/m2, p <0.001, and RA volume 32 ± 23 vs 43 ± 29 ml/m2, p = 0.012). The mean difference (CMR imaging minus echocardiography) was 14 ± 14 ml/m2 for the LA and 10 ± 16 ml/m2 for the RA volume. Similar results were found in the healthy controls. No significant intra- or interobserver variability was found within each modality. In conclusion, echocardiography consistently underestimated the atrial volumes compared to CMR imaging using the area-length method.     

New echocardiographic and angiographic methods for right atrial volume determination: In vitro validation and in vivo results

Until now, right atrial (RA) volume calculation by means of two-dimensional echocardiography (2-DE) has only been attempted in a single plane: the apical four-chamber view. Our study reports a new method for RA volume calculation using two intersecting 2-DE views. For this purpose, silicone rubber casts of 19 human necropsy hearts were obtained and thin-walled natural rubber moulds of the RA casts were prepared. Totally filled with and immersed in water, the moulds could be visualized in the apical four-chamber view and an additional 2-DE plane, the latter corresponding to the subcostal view in vivo. In this view the vertical extension of RA could be estimated. Areas and lengths of RA were determined in the respective planes, and RA volume was calculated by applying the formula, area x length, to two intersecting planes. Finally, volume of the silicone casts was determined angiocardiographically (Angio) using a biplane method (30° RAO, 40° LAO-40° hepatoclavicular). The true RA volume was 106±23 ml (mean±1SD) as determined by water displacement. Using Angio an excellent correlation was found: the calculated volume amounted to 106±23ml; the difference was 5.5±4.8ml (n.s.); Angio vol=0.93 true vol+ 7.77; r=0.95; SEE= 7,4 ml. Volume determination from the apical four-chamber view of 2-DE using a monoplane disk method resulted in a mean volume of 62±17 ml. The mean difference to the true RA volume was 44±16 ml (p < 0.001). When volume calculations were made using the biplane method, a value of 105±22 ml resulted. The mean difference to true volumes was 7.4±4.8 ml: y=0.84x + 15.88; r=0.91; SEE=9.4 ml.In an in vivo study endsystolic RA volumes were calculated in a normal adult population (n=40) from the same intersecting planes as in vitro. A normal value of 38±6 ml/m² was found. In vivo validation using Angio showed a slightly higher normal value of 43=7 ml/m². Thus, 2-DE is highly accurate in determinating RA volume. In the in vitro as well as in the in vivo study the results of monoplane calculations are clearly inferior to a method which also takes account of the vertical extension of RA.     

Two-dimensional echocardiographic assessment of left atrial size in children

The ability of 2-dimensional echocardiography (2-D echo) to estimate end-systolic left atrial (LA) size and volume was assessed in 140 infants and children. These subjects were divided into 2 groups. Group A included 91 patients with normal LA volume and Group B included 49 patients with LA volume overload. Five echocardiographic views (left parasternal long-axis, left parasternal short-axis, apical 4-chamber, apical 2-chamber and subcostal 4-chamber) were used. From these views, the LA long-axis and minor-axis lengths were measured and the area was planimetered. These echocardiographically derived measurements were compared with angiographically calculated LA volume. Although all echocardiographic measurements correlated well with angiographic LA volume measurements, the echocardiographic area tracked better than length measurements. Echo LA volume was calculated using 5 single-plane and 3 biplane area-length methods. LA volume calculated from either single- or biplane methods correlated well with angiographically determined LA volume. The degree of correlation depended on the method used. Echocardiographic area and estimated LA volume measured from the parasternal long-axis and apical 2-chamber views best separated patients with LA volume overload from normal. Two-dimensional echo using these views accurately segregated all patients with a LA volume >180% of normal and 15 of 21 patients (71%) with an LA volume between 138% and 179% of normal. Thus, 2-D echo is useful in the evaluation of LA size and volume in Infants and children.     

Echocardiographic Evaluation of Patients with Primary Pulmonary Hypertension Before and After Atrial Septostomy

Objectives: To characterize the early changes in right ventricular [right ventricle (RV)] geometry and function, as assessed by two-dimensional (2-D) and Doppler echocardiography, after balloon-dilation atrial septostomy (BDAS) in patients with severe primary pulmonary hypertension (PPH). Background. Survival in PPH is to a great extent dependent on the functional status of the RV. BDAS recently has been shown to improve functional class and hemodynamics in patients with PPH nonresponsive to conventional vasodilator treatment. Methods: Ten patients with severe PPH who underwent BDAS were studied with transthoracic and transesophageal 2-D and Doppler echocardiography. RV dimensions were measured in the apical four-chamber view. Continuous-wave Doppler echocardiography was used to obtain peak velocity of tricuspid regurgitation. Transesophageal echocardiography (TEE) primarily was used for the follow-up of the atrial septal defects (ASDs). Results: In the early post-BDAS studies, right atrial and ventricular dimensions significantly decreased in all patients (P < 0.05). Global right ventricular wall motion (RVWM) also improved. RV percent change in area after septostomy inversely correlated with the changes in RV systolic area (r =–0.75; P < 0.05) and also with the baseline (preprocedure) values of RV percent change in area (r =–0.77; P < 0.05). Neither RV wall thickness nor the degree of tricuspid regurgitation were modified significantly after the procedure. Conclusions: BDAS in the setting of severe PPH results in moderate and salutary changes in geometry and function of the RV as assessed by 2-D echocardiography. These changes mainly appear to be the result of the decompression effect of atrial septostomy.     

A new echocardiographic procedure for calculation of the accurate volume of the right atrium

The right atrial (RA) volume can be determined angiographically from two perpendicular projections. Up to now volume calculations by means of two-dimensional echocardiography (2-DE) have only been attempted in a single plane, the apical four-chamber view. Our study reports a new method for RA volume calculation using two intersecting cross-sectional echocardiographic views. For this purpose silicone rubber casts of 20 human necropsy hearts were obtained and thin walled natural rubber moulds of the RA casts were prepared. Totally filled with and immersed in water, the mouls could be visualized in the apical four-chamber view and an additional echocardiographic plane, the latter corresponding to the subcostal view in vivo. In this view the vertical extension of RA could be estimated. Areas and length of RA were determined in the respective planes and RA volume was calculated by applying the formula: - Area X Length - to two intersecting planes. Finally, the latex moulds were filled with diluted contrast agent and the volume was determined angiographically using a biplane disc method. Real volume of RA was 112 +/- 23 ml (mean +/- 1 SD). Angiographically, an overestimation resulted: the calculated volume amounted to 119 +/- 24 ml, the mean difference was 7 +/- 2 ml (p less than 0.001). The regression equation was y = 1.04 X + 2.34, r = 0.995, SEE = 2.3 ml. Volume determination from the apical four-chamber view using a monoplane disc method resulted in a mean volume of 62 +/- 17 ml. The mean difference to the real RA volume was 50 +/- 17 ml, p less than 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)     

中老年心房间隔缺损患者经导管封堵术后心功能变化

目的　探讨 40岁以上心房间隔缺损患者用导管封堵术治疗后的心功能变化。方法　采用封堵术治疗 2 1例40岁以上心房间隔缺损患者 ,并于术后 6个月进行随访 ,观察心脏彩超和心电图所得结果与术前比较。结果　心房间隔缺损封堵术后 6个月 ,心脏彩色多谱勒超声提示心脏收缩末期右房最大容积和右室舒张末期容积显著降低 ;左室舒张末期容积、射血分数和左室短轴缩短率显著提高 ;心电图提示PR间期和QRS宽度明显缩短。结论　40岁以上心房间隔缺损患者行心房间隔封堵术能够降低右心室的容量负荷 ,提高左心室的收缩功能 ,改善心房和心室的电传导     

Relationship between left atrial appendage function and plasma concentration of atrial natriuretic peptide.

BACKGROUND: It has been reported that the most intensely granuled cardiocytes secreting atrial natriuretic peptide (ANP) are located in the atrial appendages. AIMS: To evaluate the mechanisms of ANP release in congestive heart failure. METHODS AND RESULTS: The relationship between ANP and left atrial appendage (LAA) function was evaluated in 36 patients who underwent both transoesophageal echocardiography and cardiac catheterization. ANP level correlated positively with mean pulmonary capillary wedge pressure (mPCWP; r=0.75, P<0.0001), whereas it showed no significant correlation with the mean right atrial pressure. mPCWP correlated positively with the maximal LAA area (LAAa; r=0.79, P<0.0001) and negatively with the LAA ejection fraction during atrial contraction (LAA-EF; r=-0.61, P<0.0001) and peak late diastolic LAA emptying flow velocity (LAAF; r=-0.69, P<0.0001). ANP level correlated negatively with the LAA-EF (r=-0.56, P<0.001) and with LAAF (r=-0.61, P<0.0001). ANP level correlated more closely with the LAAa (r=0.79, P<0.0001) than with maximal LA volume (r=0.34, P<0.05). Multiple stepwise regression analysis selected LAAa as the only factor independently related to the plasma concentration of ANP (ANP=-22.4+28.6 LAAa, r=0.79, P<0.0001). CONCLUSIONS: We conclude that the factor most predictive for ANP in patients with left-sided cardiac dysfunction is distension of the LAA wall rather than elevation in the LA pressure or distension of the body of LA. This is consistent with the known distribution of ANP-secreting cardiocytes.     

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

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

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.     

New digital measurement methods for left ventricular volume using real-time three-dimensional echocardiography: comparison with electromagnetic flow method and magnetic resonance imaging.

AIM: The aim of this study was to investigate the feasibility and accuracy of using symmetrically rotated apical long axis planes for the determination of left ventricular (LV) volumes with real-time three-dimensional echocardiography (3DE). METHODS AND RESULTS: Real-time 3DE was performed in six sheep during 24 haemodynamic conditions with electromagnetic flow measurements (EM), and in 29 patients with magnetic resonance imaging measurements (MRI). LV volumes were calculated by Simpson's rule with five 3DE methods (i.e. apical biplane, four-plane, six-plane, nine-plane (in which the angle between each long axis plane was 90 degrees, 45 degrees, 30 degrees or 20 degrees, respectively) and standard short axis views (SAX)). Real-time 3DE correlated well with EM for LV stroke volumes in animals (r=0.68-0.95) and with MRI for absolute volumes in patients (r-values=0.93-0.98). However, agreement between MRI and apical nine-plane, six-plane, and SAX methods in patients was better than those with apical four-plane and bi-plane methods (mean difference = -15, -18, -13, vs. -31 and -48 ml for end-diastolic volume, respectively, P<0.05). CONCLUSION: Apically rotated measurement methods of real-time 3DE correlated well with reference standards for calculating LV volumes. Balancing accuracy and required time for these LV volume measurements, the apical six-plane method is recommended for clinical use.     

Assessment of right ventricular function using two-dimensional echocardiography

With the use of two-dimensional echocardiography (2DE), we analyzed apical and subcostal four-chamber views for evaluation of right ventricular (RV) function in 30 individuals as compared to RV ejection fraction (RVEF) obtained by radionuclide angiography. In addition to previously reported parameters of changes in areas and chords, a new simple measurement of tricuspid annular excursion was correlated with RVEF. A close correlation was noted between tricuspid annular plane systolic excursion (TAPSE) and RVEF (r = 0.92). The RV end-diastolic area (RVEDA) and percentage of systolic change in area in the apical four-chamber view also showed close correlation with RVEF (r = -0.76 and 0.81); however, the entire RV endocardium could only be traced in about half of our patients. The end-diastolic transverse chord length and the percentage of systolic change in chord length in the apical view showed a poor correlation with RVEF. The correlation between RVEF and both areas and chords measured in the subcostal view was poor. It is concluded that the measurement of TAPSE offers a simple echocardiographic parameter which reflects RVEF. This measurement is not dependent on either geometric assumptions or traceable endocardial edges. When the endocardial outlines could be traced, the apical four-chamber view was superior to the subcostal view in assessment of RV function.     

Determination of left atrial area and volume by cross-sectional echocardiography in healthy infants and children

Part 1 of the study measured the end-systolic and end-diastolic left atrial (LA) areas and volumes in 30 children through sector echocardiography, and compared these values with those obtained with biplane angiocardiography. A strong correlation exists between the LA area in the frontal plane as determined by apical (r greater than 0.91) and subcostal (r greater than 0.98) echocardiography on the one hand and by angiocardiography on the other. However, there is a slight underestimation of the LA area by the apical 4-chamber view. LA volume as determined by subcostal sector echocardiography in the frontal and sagittal plane also correlated well with LA volume calculated with biplane angiocardiography (r greater than 0.97). Part 2 of the study determined LA areas and volumes in 74 healthy newborns and infants by echocardiography and related them to body weight and body surface area, thus obtaining normal values for this age group. The relation of the LA area and volume measurements in newborns and infants to body weight or surface area was best described by a linear function. The mean of the percentage of systolic-diastolic area diminution was 53 +/- 6% for the apical 4-chamber view and 50 +/- 4% for the subcostal 4-chamber view. LA ejection fraction determined by the subcostal biplane volume measurements was 62 +/- 7% (mean +/- standard deviation). These values were independent of body weight or surface area.     

Atrial volume in a normal adult population by two-dimensional echocardiography

Left atrial (LA) and right atrial (RA) volumes were calculated from two-dimensional echocardiography (2D echo) in 54 normal volunteers, of whom 23 were nonathletic men and 25 nonathletic women; 6 additional men had a history of athletic training. Ages ranged from 20 to 66 years (average nonathletic group, 38 years; athletic men, 28 years). The LA volume was measured by single-plane area-length algorithm from apical 2-chamber (2CH) and 4-chamber (4CH) views and from their combination by means of Simpson's rule. The RA volume was analyzed only in the 4CH view. Mean LA volume was larger for men than women; for nonathletic men, 46 +/- 14 ml for 2CH view and 38 +/- 10 ml for both the 4CH view and for Simpson's rule combination of the apical views. For women it was 36 +/- 11 ml for the 2CH view, 34 +/- 12 ml for the 4CH view, and 32 +/- 10 ml by Simpson's rule. Right atrial volume was 39 +/- 12 ml in nonathletic men and 27 +/- 7 ml in women. In the six athletic men, LA volume and volume index, but not RA volume and volume index, were significantly larger than in nonathletes. These findings in this small sample suggest that caution should be exercised in interpreting atrial enlargement in athletes. There were no significant correlations between atrial volumes and age, although individuals over 65 years with normal hearts were not represented. In evaluating LA volume in a given patient, it is advisable to use specific values for each apical view and algorithm and to correct for either sex or body surface area (BSA) but not for both. In the RA it is necessary to correct for both sex and BSA.