Clinical significance of incomplete tricuspid valve closure seen on two-dimensional echocardiography.

Incomplete closure of the tricuspid valve without apparent cusp disease was noted on two-dimensional echocardiography in 31 patients. This abnormality was defined as a failure of the tricuspid valve leaflet tips to reach the plane of the tricuspid valve anulus by at least 1 cm in the standard apical four chamber view at the point of maximal systolic closure. This resulted in a final systolic leaflet position deeper within the right ventricular cavity than is normally seen. The finding was present in the following diagnostic subgroups: Group A, pulmonary hypertension (11 patients); Group B, rheumatic heart disease (4 patients); Group C, dilated cardiomyopathy (9 patients) and Group D, previous myocardial infarction (7 patients). Right atrial, right ventricular and tricuspid anulus measurements were made and compared with those from a group of 67 normal subjects. The results were as follows: right atrial endsystolic area = 27.2 +/- 8.6 cm2 (normal = 13.4 +/- 2.0); right ventricular end-systolic area = 25.6 +/- 8.7 cm2 (normal = 10.9 +/- 2.9); right ventricular end-diastolic area = 31.5 +/- 9.1 cm2 (normal = 20.1 +/- 4.9) and tricuspid valve anular end-systolic dimension = 4.0 +/- 0.6 cm (normal = 2.2 +/- 0.3). The differences from the normal data were all statistically significant (p less than 0.001). Incomplete closure of the tricuspid valve, although a nonspecific diagnostic finding, is primarily associated with right-sided chamber enlargement. Tricuspid regurgitation may be present. The mechanism could be related to geometric changes in valve apparatus dynamics secondary to right-sided cardiac enlargement and tricuspid valve anular dilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of high pulse repetition frequency and continuous wave Doppler echocardiography in the assessment of high flow velocity in patients with valvular stenosis and regurgitation.

Continuous wave Doppler echocardiography has proved useful in detecting and quantitating the high velocity flow disturbances that characterize many stenotic and regurgitant valvular lesions. Pulsed Doppler echocardiography, in contrast, is limited in its ability to quantitate the high velocities that are detected. Recently, new pulsed Doppler systems have been developed that employ high pulse repetition frequencies and can theoretically measure higher flow velocities than those measured by the standard pulsed Doppler systems. To determine the ability of high pulse repetition frequency Doppler echocardiography to accurately measure high velocity flow signals in comparison with the continuous wave method, 80 patients undergoing routine echocardiographic examination for the assessment of valvular heart disease were studied using both techniques. A total of 113 high velocity flow disturbances were detected in 68 patients. In 41 instances, the maximal velocities by the two methods were within 0.5 m/s of each other. In 68 of the 113 high velocity lesions, however, the high pulse repetition frequency technique underestimated the peak velocity found with continuous wave Doppler echocardiography by more than 0.5 m/s. Comparison of the peak velocities recorded by the two methods for the total group showed no significant correlation (r = 0.04, p = NS). Comparison of the difference in peak velocities obtained by the two techniques with the maximal continuous wave velocity (n = 94, r = 0.70, slope = 0.71) suggested that the underestimation becomes greater as the peak velocity increases. Fifteen of the study patients with aortic stenosis subsequently underwent catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)

A new echocardiographic model for quantifying three-dimensional endocardial surface area.

A new technique for quantitatively mapping the three-dimensional left ventricular endocardial surface was developed, using measurements from standard cross-sectional echocardiographic images. To validate the accuracy of this echocardiographic mapping technique in an animal model, the endocardial areas of 15 excised canine ventricles were calculated using measurements made from echocardiographic studies of the hearts and compared with areas determined with latex casts of the same ventricles. Close correlation (r = 0.87, p less than 0.001) between these two measures of endocardial area provided preliminary confirmation of the accuracy of the maps. To further characterize the mapping algorithm, it was translated into computer format and used to map the surfaces of idealized hemiellipsoids. Areas measured with this mapping technique closely approximated the actual areas of idealized surfaces with a wide spectrum of shapes; maps were particularly accurate for ellipsoids with shapes similar to those of undistorted human ventricles. Also, the accuracies of area calculations were relatively insensitive to deviation from the assumed positions of the echocardiographic short-axis planes. Finally, although the accuracy of the mapping technique improved as data from more transverse planes were added, the procedure proved reliable for estimating surface areas when data from only three planes were used. These studies confirm the accuracy of the echocardiographic mapping technique, and they suggest that the resulting planar plots might be useful as templates for localizing and quantifying the overall extent of abnormal wall motion.

An echocardiographic technique for quantifying and displaying the extent of regional left ventricular dyssynergy.

A convenient noninvasive method of mapping the left ventricular endocardial surface has been developed that can be used to display regional dysfunction and calculate the total area of abnormal endocardial excursion from data obtained in two orthogonal apical and three or more short-axis cross-sectional echocardiographic images. Visually identified regions of abnormal systolic function are plotted on end-diastolic, planar endocardial surface maps, and the extent of dysfunction can be expressed either as an absolute area or as a fraction of the total endocardial surface area involved. The extent of the left ventricular surface moving abnormally, calculated with this echocardiographic mapping technique, was compared with two histochemical measures of infarct size in a series of 11 closed chest dogs with acute circumflex coronary artery occlusions. Overall extent of abnormally moving left ventricular wall correlated closely with both the fraction of the endocardial area overlying infarct (r = 0.92, p less than or equal to 0.001) and the fraction of the myocardial volume infarcted (r = 0.86, p less than or equal to 0.001). This suggests that the echocardiographic mapping technique can be used to accurately quantify the global extent of abnormal systolic function in the presence of regional wall motion abnormalities.

The natural history of regional wall motion in the acutely infarcted canine ventricle.

Two-dimensional echocardiography was employed to define the natural history of regional wall motion abnormalities in a canine model of acute experimental myocardial infarction. Serial short-axis two-dimensional echocardiograms were recorded in 11 closed chest dogs before coronary occlusion and 10, 30, 60, 180 and 360 minutes after permanent coronary ligation. Radiolabeled microsphere-derived blood flows were obtained in each study period and the histochemical (triphenyltetrazolium chloride) extent of infarction was determined at 6 hours. Previously published methods were used to quantitate field by field (every 16.7 ms) excursion of 36 evenly spaced endocardial targets. The circumferential extent of abnormal wall motion was followed sequentially using previously published definitions of abnormality: 1) systolic fractional radial change of less than 20%; 2) dyskinesia (systolic bulging) at the point in time (echocardiographic field) in which there is maximal dyskinesia; and 3) correlation with composite normal ray motion falling outside the 95% confidence limits defined in the control period. On the basis of the triphenyltetrazolium chloride staining pattern, the ventricle was divided into five zones: central infarct zone, zone with greater than 25% transmural infarction, total infarct zone, border zones and normal zone. Mean systolic fractional radial change was calculated for each zone and used as an index of the magnitude of abnormal wall motion. Regardless of the definition of abnormality employed, the circumferential extent of abnormal wall motion manifested at 10 minutes after occlusion did not significantly change, even up to 6 hours later. Similarly, 10 minutes after coronary occlusion the three infarct zones and border zones demonstrated significantly reduced systolic fractional radial change. This remained stable over the remainder of the 6 hour study period. It is concluded that once established at 10 minutes after coronary occlusion, the circumferential extent and magnitude of abnormal wall motion do not significantly change in the immediate postinfarct (6 hour) period.

Comparison of the echocardiographic and hemodynamic diagnosis of rheumatic tricuspid stenosis.

Two-dimensional echocardiography has proved to be reliable in the diagnosis of mitral, aortic and pulmonary stenosis. Its role in the diagnosis of rheumatic tricuspid stenosis is still being defined; therefore, the tricuspid valve echograms of 147 patients with rheumatic heart disease were examined. Thirty-eight of these patients also underwent hemodynamic evaluation. Tricuspid stenosis was defined echocardiographically as diastolic anterior leaflet doming, thickening and restricted excursion of the other two tricuspid leaflets and decreased separation of the leaflet tips. Using these criteria, the sensitivity and specificity of the echocardiogram in detecting tricuspid stenosis were 69 and 96%, respectively, in the group of 38 patients who had both echocardiographic and hemodynamic evaluations. However, when the smaller group of 17 patients who had simultaneous right atrial and right ventricular pressure recordings were considered separately, there was complete agreement between the echocardiographic and hemodynamic data. Thus, the two-dimensional echocardiogram is a sensitive and specific test for diagnosing rheumatic tricuspid stenosis. In addition, these data provided an opportunity to determine the prevalence of tricuspid stenosis in this group of patients with chronic rheumatic valvular disease. Tricuspid stenosis was present in 14 (9.5%) of the total group of 147 patients who had two-dimensional echocardiograms, and in 10 (26.3%) of the 38 who had both echocardiographic and hemodynamic studies. In patients with rheumatic heart disease about to undergo cardiac catheterization, an echocardiographic study should prove useful in making the diagnosis of tricuspid stenosis.

Noninvasive tissue characterization: diagnosis of lipomatous hypertrophy of the atrial septum by nuclear magnetic resonance imaging.

An atrial septal mass was identified by echocardiogram in a patient with multiple subcutaneous lipomas. In order to differentiate the benign condition of lipomatous hypertrophy from myxoma, thrombus and other tumors, nuclear magnetic resonance and computed tomographic imaging were performed. Both techniques identified the adipose nature of the tissue noninvasively, consistent with the diagnosis of lipomatous hypertrophy. Pathologically demonstrated lipomatous hypertrophy in a postmortem heart was similarly characterized by nuclear magnetic resonance imaging.

Prevalence of aortic valve prolapse with bicuspid aortic valve and its relation to aortic regurgitation: a cross-sectional echocardiographic study.

Although aortic valve prolapse (AVP) has been suggested as a cause of aortic regurgitation (AR) in patients with bicuspid aortic valves, neither the frequency of AVP nor its relation to AR in this setting has been defined. To assess these relations, 64 patients with bicuspid aortic valves diagnosed by 2-dimensional echocardiography and 20 normal subjects, similarly distributed according to age and sex, were studied. The presence and degree of AVP were defined using 3 quantitative terms: aortic valve prolapse distance (AVPD), area (AVPA) and volume (AVPV). Each was corrected (c) for patient size with reference to the diameter of the aorta at the level of insertion of the valve cusps. In normal subjects, the AVPDc averaged 0.09 +/- 0.06 (range 0 to 0.16) and the AVPAc averaged 0.08 +/- 0.06 cm (range 0 to 0.15). In patients with bicuspid aortic valves, the AVPDc averaged 0.26 +/- 0.10 (range 0.11 to 0.59, p = 0.00005 vs normal subjects), whereas the AVPAc averaged 0.35 +/- 0.17 cm (range 0.05 to 0.90, p = 0.00005 vs normal subjects). When the AVPDc criteria were used, 81% of the bicuspid valves were abnormal; when the AVPAc criteria were used, 87% were abnormal. The degree of prolapse defined by the AVPVc, which considers both cusp area and degree of apical displacement, was significantly greater for patients with bicuspid aortic valve with clinical AR than for those without (p = 0.008). However, because of the overlap between groups, there was no point at which this measure uniquely separated patients with and without AR.(ABSTRACT TRUNCATED AT 250 WORDS)

Hydrodynamic compression of the right atrium: a new echocardiographic sign of cardiac tamponade.

The relationship of right atrial inversion, a previously undescribed cross-sectional echocardiographic sign, to the presence of cardiac tamponade was examined. We studied 127 patients with moderate or large pericardial effusions. Cardiac tamponade was present in 19 and absent in 104. Four patients with equivocal tamponade were excluded from analysis. Right atrial inversion was present in 19 of 19 patients with cardiac tamponade and 19 of 104 without cardiac tamponade (sensitivity, 100%; specificity, 82%; predictive value, 50%). The degree of inversion as quantitated by the area-corrected curvature did not improve the ability to discriminate between patients with and without cardiac tamponade. However, consideration of the duration of inversion by the right atrial inversion time index (duration of inversion/cardiac cycle length) and an empirically derived cut-off of 0.34 did improve the specificity and predictive value (100% and 100%, respectively) without a significant loss of sensitivity (94%). We conclude that right atrial inversion, particularly if prolonged, is a useful echocardiographic marker of cardiac tamponade that may be of particular diagnostic value when the clinical picture is unclear.

Congenital aneurysms of the left atrium: recognition by cross-sectional echocardiography.

The two-dimensional echocardiographic features of three patients with congenital aneurysms of the left atrium are described. The aneurysm arose from the left atrial appendage in two patients and from the posterior left atrial wall in one. The aneurysms were characterized by their origin from an otherwise normal left atrium, a well-defined neck, their position within the pericardial space, and distortion of the left ventricular free wall by the aneurysmal body. The differentiation of these structures from other abnormalities of the left atrium are also discussed. Two-dimensional echocardiography is a safe and reliable method for diagnosing congenital aneurysm of the left atrium, and such studies should be considered in any patient with an otherwise unexplained abnormality on the chest radiograph.

Correlation between echocardiographic endocardial surface mapping of abnormal wall motion and pathologic infarct size in autopsied hearts.

We previously developed a cross-sectional echocardiographic technique for quantitatively mapping the endocardial surface of the left ventricle and on which regions of abnormal wall motion can be superimposed in their correct spatial distribution. This endocardial mapping technique (EMT) provides a measure of the left ventricular endocardial surface area (ESA in cm2), the area of abnormal wall motion (AWM in cm2), and the overall percent dysfunction (%AWM) as a measure of the functional "infarct size." To test this approach, we compared the EMT measurements with the actual endocardial surface area (in cm2) and pathologic infarct size (both percent infarct by volume and percent endocardial surface overlying infarct) measured at later autopsy in 20 adults (14 men, six women) ranging in age from 47 to 76 years (mean 64 +/- 9.6 years). The median interval from echocardiographic study to death was 19 days (range 1 to 269 days). Patients were divided into two groups based on the age of their infarcts at the time of death: (1) recent (infarct age less than 14 days; mean age 5.3 +/- 4.6 days) and (2) old (infarct age greater than 6 months; mean age 3.6 +/- 3 years). When the left ventricular endocardial surface area at autopsy was compared with the EMT-derived ESA, a close correlation was found (EMT area = 1.17 X autopsy area + 20.4; r = .94, p = .0001), with the systematic difference in the measurements accounted for by systolic arrest, loss of distending pressure, and specimen shrinkage. The echocardiographic measure of infarct size (%AWM) correlated well with the autopsy percent infarction by volume (%AWM = 1.1 X infarct volume + 5.5; r = .82, p = .0001). Similarly, a good correlation was found for the percent abnormal wall motion and the autopsy percent endocardial surface area overlying infarction (%AWM = 0.89 X infarct area - 0.9; r = .89, p = .0001). When the data were examined in relation to the age of the myocardial infarct, the echocardiographic %AWM appeared to overestimate the autopsy infarct size (by percent infarct volume) in the recent infarct group (n = 6), and underestimate the extent in the old infarct group (n = 13). The findings suggest that the EMT will provide a useful quantitative measure of left ventricular endocardial surface area and the extent of ischemic/infarct-related dysfunction.

Echocardiographic measurement of right ventricular volume.

The volume of the right ventricle can be determined angiographically from its projections in two mutually perpendicular planes. Echocardiographic techniques for measuring right ventricular volume, however, have been more difficult and less successful. In this study, a method was developed for calculating right ventricular volume from two intersecting cross-sectional echocardiographic views: the apical four-chamber and subcostal right ventricular outflow tract views. First, the areas and lengths of casts of 12 human right ventricles obtained at autopsy were directly measured in the chosen views. Actual cast volumes correlated best with a formula giving volume as 2/3 times the area in one view times the long axis in the other view. The degree of correlation was similarly high for calculations involving the area derived from either view and the length of the roughly orthogonal section. This relationship for right ventricular volume was then confirmed with two-dimensional echocardiographic images of hollow latex molds made from the casts (r = .95, p less than .0001). The significance of these findings is discussed in relation to angiographic results and models of the right ventricle.

A comparison of quantitative echocardiographic methods for delineating infarct-induced abnormal wall motion.

Current echocardiographic methods for quantitating abnormal regional left ventricular wall motion rely primarily on changes in endocardial excusion from end-diastole to end-systole. Recent studies demonstrating important spatial and temporal heterogeneity in wall motion within ischemic regions, however, raise questions about the validity of this approach. To determine the optimal method for defining abnormal left ventricular wall motion, we used a canine preparation of acute experimental infarction to examine four quantitative methods of wall motion analysis. The circumferential extent of abnormal wall motion assessed by each method was compared with the circumferential extent of infarction (defined by triphenyltetrazolium chloride staining) and the circumferential extent of reduced transmural blood flow (determined by radiolabeled microsphere techniques) 6 hr after acute coronary occlusion. The following methods of quantitating abnormal wall motion were examined: (1) determination of end-diastolic to end-systolic endocardial excursion (less than 0.20 end-diastolic radius), (2) determination of the extent of maximal dyskinesis (systolic bulging), and (3) and (4) two derived correlation methods that consider the entire course of systolic radial motion by correlating the observed echocardiographic field-by-field (every 16.7 msec) motion of each of 36 evenly spaced endocardial targets with the course of normal motion established from pooled normal data. Results obtained with the correlation methods showed a better correlation with the triphenyltetrazolium chloride-defined circumferential extent of infarction (r = .87 and r = .78) than did determinations of reduced end-diastolic to end-systolic endocardial excursion (r = .35) or the extent of maximal dyskinesis (r = .37). Similarly, the best correlation with the extent of reduced flow was obtained with one of the correlation methods (r = .80). We conclude that correlation methods that "integrate" endocardial motion over the entire systolic contraction sequence provide better definition of ischemic left ventricular dysfunction than do methods that consider motion at only single points in time.