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.     

Assessment of left ventricular diastolic function with color Doppler flow-comparison with pulsed Doppler and radionuclide angiography

To determine the relations among color Doppler echocardiographic, pulsed Doppler echocardiographic and radionuclide angiographic fractions of left ventricular filling, 37 patients were studied using the three techniques. Favorable correlations of the filling fractions were found between color Doppler (flow area/left ventricular cavity area) and radionuclide angiography both during early diastole (r = 0.94) and atrial systole (r = 0.90). The above results were better than those obtained from pulsed Doppler (E area/Total, A area/Total) and radionuclide angiography: during early diastole (r = 0.78) and atrial systole (r = 0.76). Color Doppler can be used as a new method for assessing the pattern of left ventricular filling.     

Relationship between echocardiography, cardiac output, and abnormally contracting segments in patients with ischemic heart disease.

Twenty-four patients with proven coronary artery disease and abnormally-contracting segments were studied by both echocardiography and biplane angiographic techniques. Comparison was made between the left ventricular biplane angiographic volumes and those obtained from echocardiographic measurements which were calculated from cubed function and regression equaltion methods. The percent abnormally contracting segment (ACS) was obtained from biplane left ventricular angiography and was calculated from the diastolic and systolic anteroposterior and lateral angiocardiograms. The angiographic end-diastolic volume correlated with that calculated from the echocardiographic dimensions with an r value of 0.865 and SEE of +/- 22.64 ml. The angiographic end-systolic volume and echo end-systolic volume did not correlate as well, with an r = 0.7063. The difference in stroke volume predicted by the diastolic and systolic echocardiographic dimensions and the actual stroke volume determined by Fick technique was related to the percent abnormally contracting segment of the left ventricle (r = 0.8967). The percent ACS could be estimated from echo and Fick stroke volume measurements by the cube function and regression equations. Echo ventricular volume determinations were analyzed for the cube function method and the regression equations of Fortuin et al. and Teichholz and coworkers, with the method of Fortuin et al. producing the most sensitive relationship: % ACS = 0.32 (SVecho - SVFick) % + 8.9%. The correlation coefficient for the estimate was 0.8967 with a SEE of +/- 4.78%. In patients with coronary artery disease and abnormally contracting segments, echocardiography can provide reliable measurements of left ventricular end-diastolic volume but estimates of end-systolic volume are less accurate. If mitral regurgitation or a ventricular aneurysm can be excluded, the difference in echocardiographic and forward stroke volume by an independent method is related to the angiographic and forward stroke volume by an independent method is related to the angiographic abnormally contracting segment, and this relationship permits estimation of the size of the abnormally, contracting segment.     

Comparison of M-mode echocardiography and angiography in the evaluation of left ventricular hypertrophy

The authors analysed in a group of 82 patients with a symmetric left ventricle and a homogeneous ventricular wall thickness the reliability of M-mode echocardiography in recognizing left ventricular hypertrophy. In concentric hypertrophies, a sufficient diagnostic criterion is ventricular wall thickness. Measurement of the interventricular septum offers a better correlation with angiographic values (r = 0.609, p less than 0.001) than measurement of the posterior wall (r = 0.358, p less than 0.01); a correct diagnosis can be determined in 84%. In excentric hypertrophies, the hypertrophy must be assessed on the basis of calculating the left ventricular mass. The most accurate of echocardiographic methods proved to be the calculation according to the authors' own formula (r = 0.760, p less than 0.001), which recognizes left ventricular hypertrophy correctly in 85%. The diagnostic correctness of Teichholz' formula is 80% and of the cubic formula 74%. Fortuin's equations proved to be of no value for documenting ventricular hypertrophy. In a group of 13 patients with hypertrophic cardiomyopathy, the correlation between angiographic and echocardiographic values of the left ventricular mass was very low (r = 0.534, p = 0.05).     

Is angiographic ventriculography necessary for the assessment of ischemic patients?

A total of 53 patients with a provisional diagnosis of ischemic heart disease and without any clinical evidence of valvular, congenital, or primary muscle heart disease were studied by echocardiography and biplane left ventricular cineangiography. For angiographic ejection fraction analysis, a program developed in our department for use on an Apple Macintosh computer interfaced to a digitizing tablet was employed. Echocardiographic outlines of systolic and diastolic images were traced with a digitizing system on the screen and ejection fractions were calculated by a program incorporated in the echo machine. Good echo windows allowing ejection fraction calculations were present in 35 patients. There was a good correlation between angiographic and echocardiographic ejection fraction (r = 0.7, SEE = 0.09), and wall motion assessment revealed no significant discrepancies between the two image modalities. The remaining 18 patients had poor echo windows, preventing accurate echocardiographic determination of the ejection fraction. However, limited assessment of left ventricular size and wall motion was possible in all patients and allowed the identification of those who had impaired left ventricular function as judged by angiography (angiographic ejection fraction < 35%). We conclude that even in patients with poor echo windows echocardiographic assessment of left ventricular function provides clinical information similar to angiography which should not be considered mandatory for the investigation of ordinary ischemic patients.     

Assessment of left ventricular dimensions and function by echocardiography

Left ventricular dimensions and function indexes were measured in 40 patients with cardiac disease by both angiocardiographic and echocardiographic techniques. Good correlation was obtained between echocardiographic and angiographic values in 18 patients with technically excellent studies obtained by both techniques. The left ventricular echogram appears to be an effective technique for the noninvasive determination of left ventricular dimensions and volume. Echocardiographic indexes of ventricular function, including percent shortening of internal diameter, mean shortening velocity of internal diameter, ejection fraction, percent thickening of posterior wall and mean posterior wall velocity, distinguished between groups of patients with normal and abnormal left ventricular function. However, a single echocardiographic or angiographie measurement does not appear to provide selective data for the accurate functional classification of most individual patients.     

Relationships between echocardiographic findings, pulse wave velocity, and carotid atherosclerosis in type 2 diabetic patients.

The purpose of the present study was to analyze the relationships between echocardiographic findings, brachial-ankle pulse wave velocity, and carotid atherosclerosis in type 2 diabetic patients. In 70 type 2 diabetic patients without cardiovascular disease, pulse wave velocity was measured using an automatic waveform analyzer, and the carotid plaque score was obtained by carotid ultrasonography. The left ventricular wall thickness and the indexes of left ventricular diastolic function (the peak velocity of early rapid filling [E velocity], the peak velocity of atrial filling [A velocity], and the E/A ratio) were obtained by echocardiography. Brachial-ankle pulse wave velocity correlated significantly with the carotid plaque score, but the correlation was weak (r=0.37, p=0.001). The brachial-ankle pulse wave velocity demonstrated a strong correlation with the A velocity (r=0.73, p<0.001), the ratio of E to A (E/A) (r=-0.63, p<0.001), and the deceleration time of the E velocity (r=0.48, p<0.001). Stepwise regression analysis showed that the A velocity (beta coefficient=0.42, p<0.001) and ventricular septal thickness at the left ventricular outflow tract (beta coefficient=0.27, p=0.001) were independently associated with brachial-ankle pulse wave velocity. Stepwise regression analysis indicated that ventricular septal thickness at the left ventricular outflow tract (beta coefficient=0.38, p=0.001) was independently associated with the plaque score. These results indicate that left ventricular diastolic dysfunction as revealed by increased peak velocity of atrial filling reflects arterial stiffening in type 2 diabetic patients. In addition, myocardial wall thickening at the left ventricular outflow tract reflects not only arterial stiffening but also carotid atherosclerosis. Therefore, these abnormal echocardiographic findings of left ventricular diastolic dysfunction and myocardial wall thickening may be useful markers of the presence of progressive arteriosclerosis in type 2 diabetic patients.     

Percentage of shortening of the echocardiographic left ventricular dimension. Its use in determining ejection fraction and stroke volume

The percentage of shortening of the echocardiographic left ventricular dimension (% delta D) was prospectively evaluated in 42 patients without detectable asynergy during diagnostic cardiac catheterization and was found to correlate well with angiographic ejection fraction (r = 0.90). Ejection fraction was calculated as the product of % delta D X 1.7 or as % delta (D2), both formulae having similar degrees of accuracy and a better correlation with the angiographic determination than conventional formulae. Ejection fractions (angiographic and echocardiographic) of 51 percent or greater were always associated with a % delta D of 30 percent or more. In five patients the echocardiographically derived ejection fractions were normal (greater than or equal to 51 percent), while the angiographic ejection fractions were reduced; four of these patients had valvular regurgitation. End-diastolic volumes were calculated from end-diastolic echocardiographic dimensions utilizing a linear regression equation derived from correlating the end-diastolic echocardiographic dimension with the end-diastolic volume in 27 patients without valvular regurgitation (end-diastolic echocardiographic dimension ranged from 3.7 to 8.2 cm). The value for stroke volume determined as the product of calculated end-diastolic volume times ejection fraction correlated with the angiographically determined stroke volume (r = 0.88; standard error of estimate, +/- 11 ml) better than the value for stroke volume derived from conventional echocardiographic formulae.     

Ejection fraction determination without planimetry by two-dimensional echocardiography: a new method

A new method for determining ejection fraction by two-dimensional echocardiography was assessed in 60 patients undergoing angiography. In method A, the left ventricular minor axis was measured at the midventricular cavity level in end-systole and end-diastole using the apical four chamber view in the 60 patients. The left ventricular major axis was also measured from the left ventricular apex to the base of the mitral valve at end-systole and end-diastole. The ejection fraction was determined using a modified cylinder-ellipse algorithm. In method B, measurements of the left ventricular minor axis were made in 40 consecutive patients, at the upper, middle and lower thirds of the left ventricular cavity at end-systole and end-diastole of the same cardiac cycle and left ventricular major axis was measured as in method A. With use of the same algorithm, three regional ejection fractions were determined and averaged to yield the total ejection fraction. The two echocardiographic methods were compared with single plane cineangiography in all patients and with gated nuclear scanning in 14 patients. Reproducibility was assessed by interobserver comparison. Correlation was determined in all patients and then separately for those with echocardiographic wall motion abnormalities. The correlation coefficient for all patients was 0.79 (probability [p] less than 0.001) for method A and 0.90 (p less than 0.001) for method B. For patients with wall motion abnormalities, method A had a correlation coefficient of 0.38 (p less than 0.1) and method B showed much higher correlation with r = 0.82 (p less than 0.001). Corresponding values for methods A and B in patients without wall motion abnormality were 0.85 (p less than 0.001) and 0.88 (p less than 0.001), respectively. Unlike a previous study, this method directly measures fractional shortening of left ventricular major axis and ejection fraction values are not arbitrarily modified by type of wall motion abnormality. With this method, accurate measurement of ejection fraction can be made by two-dimensional echocardiography without planimetry. In the absence of echocardiographic wall motion abnormalities, a very simple method A suffices. If wall motion abnormalities are present, the regional ejection fraction method B provides excellent results.     

An evaluation of the left atrial/aortic root ratio in children with ventricular septal defect.

Echocardiograms were performed in 80 infants and children with isolated ventricular septal defect (VSD) who underwent cardiac catheterization. The pulmonary-to-systemic flow ratio (Qp/Qs) was correlated with the echocardiographic left atrial-to-aortic root diameter ratio (LA/Ao), and a relatively poor correlation (r = 0.62) was found. The end-systolic diameters of the left atrium and aorta at the level of the aortic root, obtained from lateral cineangiograms of 55 of the 80 patients, were compared with the corresponding echocardiographic dimensions. To assess the possible effect of transducer beam angulation upon the echocardiographic determinations, the angiographic measurements were made at 0 degrees position (perpendicular to the frontal plane) and at angles of 5 degrees, 10 degrees, 15 degrees and 20 degrees from zero, using the aortic root center as the point of intersection. The echocardiographic and angiographic aortic root measurements were comparable (r = 0.95), and the angiographically derived aortic diameter did not vary with different angle projections. However, the left atrial angiographic dimensions were significantly influenced by the angle of projection. We conclude that the echocardiographic LA/Ao ratio cannot reliably estimate the severity of the shunt flow in VSD.     

Non-invasive left ventricular volume determination by two-dimensional echocardiography.

Twenty patients undergoing routine left ventricular single-plane angiography have been investigated by an ultrasonic triggered B-scan technique to provide a two-dimensional cross-sectional image of the left ventricle in end-systole end-diastole. An area-length method has been used to establish the correlation between the angiographic and the echocardiographic assessments of left ventricular chamber volume (r equals 0.88) and ejection fraction (r equals 0.81). Differences between the two techniques are discussed, and it is concluded that in approximately 80 per cent of patients triggered B-scanning may provide a safe, non-invasive, and convenient technique for the determination of volumes and certain functional parameters, especially in patients with dilated hearts and irregular left ventricular shape, where M-scanning is known to be less reliable.     

Myocardial structure in volume-overloaded hearts before and after valve replacement

The purpose of this study was to evaluate the histological characteristics of left ventricular muscle in volume-overloaded hearts. A preoperative biopsy was obtained in 31 patients: 14 with mitral regurgitation, 14 with aortic regurgitation and 3 with mitral regurgitation and aortic regurgitation. Postoperative tissue samples were available in 15 patients. Histological findings were correlated with echocardiographic and angiographic data before (preop) and one year after (postop) operation. Myocardial cell diameter was correlated with both the end-diastolic (r = 0.77, p less than 0.01) and end-systolic (r = 0.78, p less than 0.01) dimensions of the left ventricle, but was inversely correlated with the end-diastolic wall thickness-to-radius (h/R) ratio (r = -0.71, p less than 0.01). Percent fibrosis increased proportionally to the diameter (r = 0.42, p less than 0.05). For one year after operation, echocardiographic left ventricular dimensions and angiographic left ventricular volumes were significantly reduced (p less than 0.05), but in some patients postoperative values remained greater than normal. With regard to left ventricular morphology, myocardial cell diameter and interstitial fibrosis decreased significantly after valve replacement (p less than 0.05). However, the myocardial fiber remained hypertrophied and interstitial fibrosis remained above normal after surgery. Thus, postoperative ventricular dilatation was dependent upon the degree of myocardial fiber hypertrophy and interstitial fibrosis.     

Estimation of right ventricular volume with two dimensional echocardiography

To evaluate the applicability of two dimensional echocardiography to right ventricular volume determination, a study was made of 33 consecutive patients separated into three groups (control, right ventricular volume overload and right ventricular pressure overload). Biplane two dimensional echocardiograms that were perpendicular to each other were obtained from the apical approach. The echocardiographic right ventricular volume, calculated by applying Simpson's rule, was considered to be right ventricular body volume without right ventricular outflow tract volume. The echocardiographic dimensions of the right ventricular long, short and maximal short axes were also measured in each view. These volumes and dimensions were compared with both the angiographic right ventricular body volumes calculated by applying Simpson's rule and with the values in each group. Correlation between the echocardiographic and the angiographic right ventricular body volumes (r = 0.94 at end-diastole, r = 0.84 at end-systole) was good and much better than that between echocardiographic right ventricular dimensions and angiographic right ventricular body volumes. Echocardiographic calculation of right ventricular body volume was useful in distinguishing the control group from the group with right ventricular volume overload (p < 0.005).

The correlation between the echocardiographic dimensions of the right ventricular long axis and angiographic right ventricular volumes was poor, whereas that between the echocardiographic dimensions of the right ventricular short or maximal short axis and the angiographic right ventricular volumes was fairly good. It was therefore suspected that during right ventricular enlargement, the increase in size is more extensive in the direction of the short than in the direction of the long axis. It is concluded that estimation of right ventricular volume and morphology with two dimensional echocardiography may be of value in clinical practice.     

Clinical and angiographic implications of a depressed echocardiographic ejection fraction in coronary artery disease

To evaluate the clinical and angiographic implications of a depressed echocardiographic ejection fraction (EF) in coronary artery disease, 45 patients with an echocardiographic EF < 0.50 were studied with complete cardiac catheterizations. Most of the patients had clinical evidence of a prior myocardial infarction, cardiomegaly, and/or congestive heart failure. All had coronary arteriographic evidence of multivessel disease and either reduced cardiac output, elevated left ventricular end-diastolic pressure, or both. Reduction in percentage of echocardiographic dimensional shortening closely paralleled reduction in echocardiographic EF. Forty of the 45 patients (89%) had an angiographic EF less than 0.50. There was considerable scatter of angiographic EF's with echocardiographic EF's between 0.40 and 0.50, limiting the usefulness of these latter values. However, 23 of the 24 patients (96%) with an echocardiographic EF less than 0.40 had an angiographic EF less than 0.40, and there was a linear relationship between these echocardiographic and angiographic values with a correlation coefficient (r) = 0.54 (SEE = ±0.15, p<0.05). All of the 12 patients with both reduced septal and reduced posterior wall excursion on the echocardiogram had both abnormal echocardiographic and angiographic ejection fractions, and 10 of the 12 had EF < 0.40 by both techniques. Our study suggests that coronary artery disease patients with extensive left ventricular dysfunction can be identified noninvasively, and the echocardiographic EF may be useful in deciding whether such patients may require special cardiac catheterization procedures to evaluate contractile reserve if cardiac surgery is being considered.     

Comparison of contrast angiography and two-dimensional echocardiography for the evaluation of left ventricular regional wall motion abnormalities after acute myocardial infarction

Regional left ventricular wall motion abnormalities were assessed using 2-dimensional echocardiography and contrast ventriculography within 12 hours of the onset of chest pain in 20 patients with acute myocardial infarction (AMI); 10 patients had anterior infarctions and 10 had inferior. End-diastolic and end-systolic sinus beats from right anterior oblique contrast ventriculograms were analyzed using the center-line chord technique with both a standard overlap method of chord assignment and a nonoverlap method. Echocardiograms were obtained in parasternal long- and short-axis and apical 2- and 4-chamber views and analyzed using a 16-segment scoring system to derive anterior and infero-posterolateral wall motion indexes using both overlap (10 segments for anterior, 8 inferior) as well as nonoverlap (9 segments anterior, 7 inferior) methods of segment assignment. There was a significant inverse correlation between the standard (nonoverlap) echocardiographic analysis and the standard (overlap) angiographic analysis for infarct regions (y = -0.43 X +1.11, r = -0.59, p less than 0.05). Fifteen of 18 patients with angiographic infarct regional score less than or equal to -1 standard deviation/chord had an echocardiographic index greater than or equal to 1.5, while 15 of 16 patients with echocardiographic regional infarct index greater than or equal to 1.5 had an angiographic score less than or equal to -1 standard deviation/chord. Correlation between the 2 methods for noninfarct territories was poor (r = -0.34) because the angiographic method assesses hyperkinesis while the echocardiographic method does not.(ABSTRACT TRUNCATED AT 250 WORDS)     

Limitations of comparing left ventricular volumes by two dimensional echocardiography,myocardial markers and cineangiography

Measurement of left ventricular volume at end-diastole or end-systole with both two dimensional echocardiography and either Cineangiography or radionuclide scans, not recorded simultaneously, has shown large echocardiographic underestimation of volumes even in normal ventricles. In this study fluoroscopic and two dimensional echocardiographic recordings were obtained in 18 patients with abnormal wall motion and previously implanted myocardial markers. The echocardiographic values for volume and those derived from myocardial markers correlated well (r = 0.87), and there were no statistically significant differences in values obtained with the two methods at end-diastole or end-systole. The ejection fractions obtained with two dimensional echocardiography (mean ± standard deviation 46 ± 7 percent) and with fluoroscopic recording of the markers (41 ± 9 npercent) did not differ statistically.These results were compared with those in another 18 patients (nine with abnormal wall motion) having two dimensional echocardiography within 24 hours of a 30 ° right anterior oblique contrast left ventriculogram. Again, two dimensional echocardiographic ventricular volume correlated well with the angiographic volume (r = 0.85), although echocardiographic end-diastolic volume was consistently 20 percent less than angiographic end-diastolic volume (p < 0.01). Ejection fraction obtained with echocardiography (47 ± 8 percent) was less than that obtained with angiography (60 ± 7 percent) (p < 0.001). Interobserver variability in calculating volume with echocardiography was 4 percent.Probable reasons for the lack of severe underestimation of volume with echocardiography even in very abnormal ventricles, relative to that demonstrated in prior reports, include improvements in ultrasonic beam width, tracing method, transducer position and scan plane orientation within the ventricle. In addition, the possible effects of angiographic dye in the ventricular trabeculae are discussed and the effect of simultaneous studies by two different methods are compared.     

Estimation of left ventricular volume from apical orthogonal 2-D echocardiograma

In 42 consecutive patients undergoing biplane left ventricularcine-angiography, left ventricular volumes were first determinedultrasonically using a phased array transducer. To this end,two orthogonal apical long axis views were recorded one illustratingall four chambers, the other being the ‘RA O equivalent’view. Left ventricular volumes wer estimated by applying thearea-length method to both two-dimensional echocardiograms andcine-angiograms, consistently including in the former the leftventricular outflow tract of the ‘RAO equivalent’view. The echocardiographic approach employed was shown to yield goodpredictions of the angiographic results. For the end-diastolicvolume the correlation is characterized by r=0.98 and SEE 21ml or 9.7% of the angiographic mean and for the end-systolicvolume by r=0.97 and SEE 17 ml or 18.1% of the mean. The correlationfor the ejection fraction showed an r value of 0.87 and a SEEof 5.4%. Equally good correlations were obtained in the subgroupwith wall motion disorders for which the r values of the end-diastolicand end-systolic volumes were both 0.98 and that of the ejectionfraction was 0.89     

Combined hemodynamic-ultrasonic method for studying left ventricular wall stress: comparison with angiography.

Calculation of left ventricular wall stress in man has traditionally required angiographic and left ventricular pressure measurement, making study of interventions difficult. We have developed a combined hemodynamic-ultrasonic technique for measuring left ventricular meridional wass stress (sigma m) throughout the cardiac cycle. Simultaneous measurements of left ventricular pressure, ultrasonically determined wall thickness (h[echo]), and minor axis (D[echol]) were made during cardiac catheterization in nine subjects, three with chronic left ventricular pressure overload, four with left ventricular volume overload and two with normal left ventricular function. Within 30 minutes, left ventricular cineangiography was performed in each subject and angiographic wall thickness (h[angio]) and minor axis (D[angio]) were measured. Comparison of values for each subject throughout the cardiac cycle (average 18 data points/cycle) yielded close correlation: For D(echo) versus D(angio), r values ranged from 0.82 to 0.98 whereas for h(echo) versus h(angio), r values ranged from 0.56 to 0.98 for the nine subjects. Meridional wall stress was calculated after the method of Sandler and Dodge as PRi2/h(2Ri + h), where Ri equals the inner wall radius, calculated as D/2 for both ultrasonic and angiographic methods. Agreement between ultrasonic and angiographic methods was excellent in each subject, with close superimposition of the stress-time plots constructed by the different techniques. In summary, a new method for measurement of left ventricular wall stress has been developed and validated by comparison with an angiographic reference standard. This method has potential advantages, including the ability to study meridional wall stress continuously and to assess its response to serial interventions.     

Left ventricular volume determined echocardiographically by assuming a constant left ventricular epicardial long-axis/short-axis dimension ratio throughout the cardiac cycle.

OBJECTIVES. The purpose of this study was to develop and test a simplified echocardiographic method to calculate left ventricular volume. BACKGROUND. This method was based on the assumption that the ratio of the left ventricular epicardial long-axis dimension to the epicardial short-axis dimension was constant throughout the cardiac cycle. With use of this constant ratio, the method developed to calculate left ventricular volume at a given point in the cardiac cycle required the left ventricular endocardial long-axis dimension to be measured at only one point in the cardiac cycle. METHODS. Studies were performed in 13 normal dogs, 8 normal puppies, 9 normal pigs, 12 dogs with aortic stenosis, 13 dogs with acute mitral regurgitation, 12 dogs with chronic mitral regurgitation, 7 dogs that had undergone mitral valve replacement and 6 pigs that had had chronic supraventricular tachycardia. Animals with aortic stenosis developed left ventricular pressure overload hypertrophy with a 60% increase in left ventricular mass; chronic mitral regurgitation caused left ventricular volume overload hypertrophy with a 46% increase in left ventricular volume; supraventricular tachycardia caused a dilated cardiomyopathy with a 55% decrease in left ventricular ejection fraction. RESULTS. The left ventricular epicardial long-axis/short-axis dimension ratio remained constant throughout the cardiac cycle in each animal group. End-diastolic and end-systolic volumes calculated with the simplified echocardiographic method correlated closely with angiographically measured volumes; for end-diastolic volume, echocardiographic end-diastolic volume = 1.0 (angiographic end-diastolic volume) -1.8 ml, r = 0.96; for end-systolic volume, echocardiographic end-systolic volume = 0.98 (angiographic end-systolic volume) -0.7 ml, r = 0.95. CONCLUSIONS. Thus the left ventricular epicardial long-axis/short-axis dimension ratio was constant throughout the cardiac cycle in a variety of animal species and age groups and in the presence of cardiac diseases that significantly altered left ventricular geometry and function. The simplified echocardiographic method examined provided an accurate determination of left ventricular volumes.     

Echocardiographic assessment of systolic and diastolic left ventricular function using an automatic boundary detection system Correlation with established invasive and non invasive parameters

Systolic and diastolic left ventricular function was assessed using an echocardiographic automatic boundary detection system (ABD) in 50 unselected patients undergoing left cardiac catheterisation. Automatic boundary detection system derived parameters (fractional area change [FAC], peak positive rate of area change [+dA/dt] and peak negative rate of area change [–dA/dt]) were compared with invasively (left ventricular angiography and pressures) and non invasively (Doppler mitral filling velocities and isovolumic relaxation time) acquired conventional indices of ventricular function. Adequate detection of endocardial boundaries and subsequent measurements using the ABD system were achieved in 40/50 (80%) patients in the short axis parasternal view, in 41/50 (82%) in the apical four chamber view and in 34/50 (68%) in both views. For the whole group of patients the FAC (maximal left ventricular diastolic area — minimal left ventricular systolic area/maximal left ventricular diastolic area) estimated in the short axis view correlated with the angiographic ejection fraction (EF) measured in the right oblique projection (r=0.51, p<0.001). There was only a weak correlation of the FAC estimated in the apical four chamber view with the EF (r= 0.36, p<0.01). The mean FAC (mean value of the FAC in the short axis and apical four chamber views) correlated reasonably with the EF (r=0.62, p<0.0001). There was no correlation between ABD derived parameters and left ventricular end diastolic pressure (LVEDP) in these patients.In a subgroup of patients with normal coronary arteries and left ventricular function (n = 17), although there was no correlation between EF and FAC, there was a strong positive correlation between FAC (apical four chamber and mean) and LVEDP (r=0.77, p<0.01 and r=0.87, p<0.01 respectively). No correlation was found in these patients between EF and LVEDP. In a further subgroup of patients with angiographically abnormal left ventricular function (EF<45%), there was a positive correlation between FAC (short axis, apical four chamber and mean) and EF (r=0.52, p<0.05, r=0.83, p<0.0001 and r=0.80, p<0.001 respectively) and a negative correlation between FAC (short axis and mean) and LVEDP (r=–0.52, p<0.05 and r=–0.60, p<0.01 respectively). There was also a negative correlation between LVEDP and EF in the same subgroup of patients (r=–0.65, p<0.01).None of the ABD derived parameters correlated with non invasively acquired indices of diastolic ventricular function (peak early left ventricular diastolic filling blood velocity [Emax], peak late diastolic velocity [Amax], E/A ratio and isovolumic relaxation time [IVRT], but there was a consistent positive correlation between –dP/dt and + dA/dt estimated in the four chamber view (r=0.5, p<0.01, all patients).Therefore, although ABD derived parameters cannot be used in an interchangeable way with ejection fraction, they do provide a rapid, bedside method for the assessment of left ventricular function. FAC and dA/dt do appear to reflect left ventricular performance both in patients with normal ventricles and in patients with impaired left ventricular function.