Aleksandra Lange

Doppler Tissue Imaging: Myocardial Wall Motion Velocities in Normal Subjects

With a scanner modified for Doppler tissue imaging, mean myocardial velocities (MMV) across the myocardium were measured. The aim of this study was to determine the normal range of the maximum MMV in six standardized phases of the cardiac cycle. The MMV was defined as the average value of the myocardial velocity measured along each M-mode scan line throughout the thickness of the myocardium. The maximum MMV was defined as the maximum value of the MMV during the particular cardiac phase. Simultaneous gray-scale and Doppler tissue imaging M-mode images were taken of the interventricular septum and the left ventricular posterior wall from the parasternal long-axis and short-axis views in 15 normal volunteers (aged 21 to 47 years; mean 32 +/- 6 years). Each cardiac cycle was divided into six phases: atrial contraction, isovolumetric contraction, ventricular ejection, isovolumetric relaxation, rapid ventricular filling, and diastasis. Isovolumetric contraction, isovolumetric relaxation, and diastasis were subdivided into two parts a and b because of changes in the direction of the myocardial movement. For each volunteer, the mean and standard deviation of the maximum MMV were measured for each cardiac phase averaged from 12 cardiac cycles from both long-axis and short-axis views. Finally, the mean and standard deviation were taken for each cardiac phase from 180 cardiac cycles from 15 volunteers. We have found that specific cardiac phases show significant differences in the maximum MMV between the adjoining cardiac phases and significant differences also occur between the maximum MMV measured in the interventricular septum and the left ventricular posterior wall during the same cardiac phases. These normal values provide a standard against which future Doppler tissue imaging M-mode studies of abnormal left ventricular function might be compared.

Characterisation of coronary atherosclerotic morphology by spectral analysis of radiofrequency signal: in vitro intravascular ultrasound study with histological and radiological validation

Objective To determine whether spectral analysis of unprocessed radiofrequency (RF) signal offers advantages over standard videodensitometric analysis in identifying the morphology of coronary atherosclerotic plaques. Methods 97 regions of interest (ROI) were imaged at 30 MHz from postmortem, pressure perfused (80 mm Hg) coronary arteries in saline baths. RF data were digitised at 250 MHz. Two different sizes of ROI were identified from scan converted images, and relative amplitudes of different frequency components were analysed from raw data. Normalised spectra was used to calculate spectral slope (dB/MHz), y-axis intercept (dB), mean power (dB), and maximum power (dB) over a given bandwidth (17–42 MHz). RF images were constructed and compared with comparative histology derived from microscopy and radiological techniques in three dimensions. Results Mean power was similar from dense fibrotic tissue and heavy calcium, but spectral slope was steeper in heavy calcium (−0.45 (0.1)) than in dense fibrotic tissue (−0.31 (0.1)), and maximum power was higher for heavy calcium (−7.7 (2.0)) than for dense fibrotic tissue (−10.2 (3.9)). Maximum power was significantly higher in heavy calcium (−7.7 (2.0) dB) and dense fibrotic tissue (−10.2 (3.9) dB) than in microcalcification (−13.9  (3.8) dB). Y-axis intercept was higher in microcalcification (−5.8 (1.1) dB) than in moderately fibrotic tissue (−11.9  (2.0) dB). Moderate and dense fibrotic tissue were discriminated with mean power: moderate −20.2 (1.1) dB, dense −14.7 (3.7) dB; and y-axis intercept: moderate −11.9 (2.0) dB, dense −5.5  (5.4) dB. Different densities of fibrosis, loose, moderate, and dense, were discriminated with both y-axis intercept, spectral slope, and mean power. Lipid could be differentiated from other types of plaque tissue on the basis of spectral slope, lipid −0.17 (0.08). Also y-axis intercept from lipid (−17.6 (3.9)) differed significantly from moderately fibrotic tissue, dense fibrotic tissue, microcalcification, and heavy calcium. No significant differences in any of the measured parameters were seen between the results obtained from small and large ROIs. Conclusion Frequency based spectral analysis of unprocessed ultrasound signal may lead to accurate identification of atherosclerotic plaque morphology.

Differentiation Between Restrictive Cardiomyopathy and Constrictive Pericarditis by Early Diastolic Doppler Myocardial Velocity Gradient at the Posterior Wall

BACKGROUND The differential diagnosis between restrictive cardiomyopathy (RCM) and constrictive pericarditis (CP) is challenging and, despite combined information from different diagnostic tests, surgical exploration is often necessary. METHODS AND RESULTS A group of 55 subjects (mean age, 63+/-11 years; 36 men and 19 women) were enrolled in the study; 15 had RCM, 10 had CP, and 30 were age-matched, normal controls. The diagnosis of RCM was supported by a biopsy; in the CP group, the diagnosis was confirmed either surgically or at autopsy. All patients underwent a transthoracic echocardiogram that included the assessment of Doppler myocardial velocity gradient (MVG), as measured from the left ventricular posterior wall during the predetermined phases of the cardiac cycle. MVG was lower (P<0.01) in RCM patients compared with both CP patients and normal controls during ventricular ejection (2. 8+/-1.2 versus 4.4+/-1.0 and 4.7+/-0.8 s(-1), respectively) and rapid ventricular filling (1.9+/-0.8 versus 8.7+/-1.7 and 3.7+/-1.4 s(-1), respectively). Additionally, during isovolumic relaxation, MVG was positive in RCM patients and negative in both CP patients and normal controls (0.7+/-0.4 versus -1.0+/-0.6 and -0.4+/-0.3 s(-1), respectively; P<0.01). During atrial contraction, MVG was similarly low (P<0.01) in both RCM and CP patients compared with normal controls (1.6+/-1.7 and 1.7+/-1.8 versus 3.8+/-0.9 s(-1), respectively). CONCLUSIONS Doppler myocardial imaging-derived MVG, as measured from the left ventricular posterior wall in early diastole during both isovolumic relaxation and rapid ventricular filling, allows for the discrimination of RCM from CP.

Assessment of atrial septal defect morphology by transthoracic three dimensional echocardiography using standard grey scale and Doppler myocardial imaging techniques: comparison with magnetic resonance imaging and intraoperative findings

Objective To determine whether transthoracic three dimensional echocardiography is an accurate non-invasive technique for defining the morphology of atrial septal defects (ASD). Methods In 34 patients with secundum ASD, mean (SD) age 20 (17) years (14 male, 20 female), the measurements obtained from three dimensional echocardiography were compared to those obtained from magnetic resonance imaging (MRI) or surgery. Three dimensional images were constructed to simulate the ASD view as seen by a surgeon. Measured variables were: maximum and minimum vertical and horizontal ASD dimension, and distances to inferior and superior vena cava, coronary sinus, and tricuspid valve. In each patient two ultrasound techniques were used to acquire three dimensional data: standard grey scale imaging (GSI) and Doppler myocardial imaging (DMI). Results Good correlation was found in maximum ASD dimension (both horizontal and vertical) between three dimensional echocardiography and both MRI (GSI r = 0.96, SEE = 0.05 cm; DMI r = 0.97, SEE = 0.04 cm) and surgery (GSI r= 0.92, SEE = 0.06 cm; DMI r = 0.95, SEE = 0.06 cm). The systematic error was similar for both three dimensional techniques when compared to both MRI (GSI = 0.40 cm (27%); DMI = 0.38 cm (25%)) and surgery (GSI = 0.50 cm (29%); DMI = 0.37 cm (22%)). A significant difference was found in both horizontal and vertical ASD dimension changes during the cardiac cycle. This change was inversely correlated with age. These findings were consistent for both DMI and GSI technique. In children (age ⩽ 17 years), the feasibility of detecting structures and undertaking measurements was similar for both echo techniques. However, in adult ASD patients (age ⩾ 18 years) this feasibility was higher for DMI than for GSI. Conclusions Transthoracic three dimensional imaging using both GSI and DMI accurately displayed the varying morphology, dimensions, and spatial relations of ASD. However, DMI was a more effective technique than GSI in describing ASD morphology in adults.

The variation of integrated backscatter in human hearts in differing ultrasonic transthoracic views

It has been shown previously that in normal subjects the interventricular septum imaged in the long-axis view (LAX) and the left ventricular posterior wall imaged in both the LAX and the short-axis view (SAX) exhibit cyclic variation of integrated backscatter (IB) throughout the cardiac cycle, with maximum values occurring at end diastole (ED) and minimum at end systole (ES). The ability to demonstrate this cyclic variation within these myocardial regions in only two ultrasonic views has limited the potential clinical utility of an IB imaging system. To determine whether clinically useful information on the variation of IB is available from different myocardial regions in different ultrasonic views, we measured ED to ES variation of IB from the parasternal and apical views in normal subjects with a radiofrequency acquisition technique. Two independent clinical observers analyzed ED to ES variation of IB from 14 normal volunteers (mean age 32 +/- 6 years; range 21 to 45 years) in reconstructed two-dimensional ultrasonic images obtained from the parasternal LAX and SAX and apical two-chamber (2C) and four-chamber (4C) views. ED to ES variation of IB was measured from manually traced regions of interest (ROI) within the myocardium. These ROIs were chosen interactively and were located within the midposterior wall and the midanteroseptum in LAX views; within the midposterior wall, midanteroseptum, midseptum, and midlateral wall in SAX views; within the midseptum and the midlateral wall in 4C views; and within the midinferior wall and the midanterior wall 2C views. In all analyzed ROIs within the parasternal and apical views, ED to ES variation of IB was found. We have shown that the maximum magnitude of IB was at ES within the midseptum and in 10 out of 14 volunteers in the midanteroseptum measured from SAX views, the midanterior wall from 2C views, and the midlateral wall from 4C views. The rest of the ROIs analyzed exhibited the maximum value of IB cyclic variation at ED. We have confirmed that the ED to ES variation of IB is present not only when measured from the two standard parasternal views but also from the two apical views in all analyzed myocardial walls, and the minimum of this cyclic variation was not always coincident with ES nor the maximum with ED.

The effect of long-term training on age-related left ventricular changes by Doppler myocardial velocity gradient

Myocardial velocity gradient (MVG) derived from Doppler myocardial imaging and standard echocardiographic parameters were used to investigate whether age-related left ventricular (LV) functional and/or structural changes are different in long-term training athletes than in those leading a sedentary life style. Eighty-nine athletes (64 men, mean age 38 years, range 18 to 64) and 105 age-matched sedentary normal subjects were enrolled into the study. The MVG was analyzed in all patients throughout the cardiac cycle, and peak values were measured in systole and in diastole during both rapid ventricular filling and atrial contraction. No differences were found in LV systolic and late diastolic function between athletes and sedentary normal subjects. However, athletes had higher peak E waves in early diastole (73 +/- 10 cm/s vs 68 +/- 10 cm/s, p <0.001) and rapid ventricular filling MVG (10.2 +/- 1.5 s(-1) vs 7.2 +/- 2.8 s(-1), p <0.001) than sedentary normal subjects, suggesting a better early relaxation pattern. From LV diastolic indexes, the rapid ventricular filling MVG age-related decrease was less pronounced in athletes than in sedentary normal subjects (r = -0.39 vs r = -0.91; p <0.01). All other diastolic variables, including transmitral Doppler inflow, had a similar degree of age-related changes in both study groups. Thus, athletes, compared with those leading a sedentary lifestyle, have higher early diastolic performance, which is less affected by the physiologic aging process. It would appear that MVG derived from Doppler myocardial imaging may play an important role in the assessment of LV functional and/or structural changes.

Quantification of mitral regurgitation orifice area by 3-dimensional echocardiography: comparison with effective regurgitant orifice area by PISA method and proximal regurgitant jet diameter

BACKGROUND The evaluation of mitral regurgitation (MR) by 3-dimensional (3D) echo has generally been performed by reconstruction of Doppler regurgitant jets but there are little data on measuring anatomic regurgitant orifice area (AROA) directly from 3D mitral valve (MV) reconstructions. METHODS AND RESULTS Transoesophageal echo (TOE) 3D images were acquired from 38 unselected patients (age 59+/-11 years, ten in atrial fibrillation) with various degrees of MR. In all patients MV was reconstructed en face from the left atrium (LA) and the left ventricle (LV). AROA was measured by planimetry from 3D pictures and compared to the effective regurgitant orifice area (EROA) by proximal isovelocity surface area and proximal MR jet width from 2D echo. AROA was measured in 95% of patients from LA, 89% from LV and in 84% from both LA and LV. Good correlation was found between EROA and AROA measured from both LA (r=0.97, P<0.0001) and LV (r=0.87, P<0.0001). The mean difference between LA-AROA and EROA was -3.01+/-6.12 mm(2) and -7.18+/-13.84 mm(2) for LV-AROA (P<0.01, respectively). An acceptable correlation was found between the proximal MR jet width and AROA from LA (r=0.71, P<0.0001) and LV perspective (r=0.68, P<0.0001). AROA>or=25 mm(2) differentiated mild MR (graded 1-2) from moderately severe (graded 3-4) with 80-90% accuracy. CONCLUSIONS 3D TOE provides important quantitative information on both the mechanism and the severity of MR in an unselected group of patients. AROA enables quantification of MR with excellent agreement with the accepted clinical method of proximal flow convergence.

Transthoracic three-dimensional echocardiography in the preoperative assessment of atrioventricular septal defect morphology

A prospective study of 3-dimensional (3-D) transthoracic echocardiographic definition of atrioventricular septal defect (AVSD) morphology and its dynamic changes during the cardiac cycle was performed. The information obtained from 2-D and 3-D transthoracic echocardiography (TTE) was compared with intraoperative findings in an unselected group of 15 patients with AVSD (median age 22 months). In all study patients, 3-D reconstructions provided anatomic views of the atrioventricular valve(s) en face from either atrial or ventricular perspectives that allowed comprehensive assessment of dynamic valve morphology and the mechanism of valve reflux. Left-sided valve function was correctly assessed by 2-D TTE in 11 of 15 patients (73%) and in 14 of 15 (93%) by 3-D TTE. In 6 of 15 patients (40%), the severity of right-sided valve reflux was described precisely by 2-D TTE and in 12 of 15 patients (80%) by 3-D TTE. Additionally, 3-D TTE supplemented the diagnostic information to that available from 2-D TTE on atrial and ventricular septal defects. Although primum atrial septal defects were depicted by 2-D and 3-D TTE in all 15 patients, the description of defect size was more precise by the 3-D TTE (80% vs. 100%, respectively). The presence of secundum atrial septal defect was correctly diagnosed by both TTE techniques in 10 of 15 patients. Disagreement regarding the size of the defect was present only in 2 of 10 patients by 2-D TTE. In another 2 patients, 3-D TTE described multiple defect fenestrations that were missed by 2-D TTE. Thus, the agreement score was 73% for 2-D and 100% for 3-D echo. The agreement for the presence and sizing of ventricular septal defects was 67% for 2-D and 93% for 3-D echo. We conclude that 3-D TTE provided accurate anatomic reconstructions of the common atrioventricular junction and that the use of dynamic 3-D TTE enhanced the anatomic diagnostic capability of standard 2-D TTE. Medica, Inc.

Diagnostic value of transesophageal echocardiography in the assessment of congenitally corrected transposition of the great arteries in adult patients

This study was designed to evaluate the relative diagnostic values of transthoracic (TTE) and transesophageal (TEE) echocardiography in the assessment of congenitally corrected transposition of the great arteries in adult patients. Twelve patients (mean age 29 years, range 21 to 39 years) with congenitally corrected transposition of the great arteries underwent both TTE and TEE examinations to assess this complex cardiac lesion. Of the 12 patients evaluated, situs solitus and inversus were present in 8 and in 4 patients, respectively. TTE correctly identified atrial situs in only 10 patients, whereas TEE, directly evaluating the morphologic features of either appendage, correctly determined situs in every patient. In all 11 patients with intact inlet ventricular septum, the spatial relationship between the septal leaflets of atrioventricular valves was correctly evaluated by both techniques. However, the chordal attachments of both valves were clearly elucidated by TEE in all patients, whereas TTE could obtain images of these in only three patients. TTE was able to evaluate the discordant connection between the right ventricle and the anterior vessel (aorta) in 10 patients, whereas the connection between the left ventricle and the posterior vessel was clearly shown only in 7 patients. Transesophageal longitudinal planes better elucidated these two discordances in all patients irrespective of the position of the heart in the chest and atrial situs. Four patients had an associated ventricular septal defect (inlet defect in one, perimembranous in two, and muscular in one); the inlet defect was unrestrictive and could be easily detected by either imaging technique, whereas the membranous was detected by TTE and by the horizontal transesophageal planes; the muscular defect was recognized only by TTE. Three patients had an associated pulmonary stenosis; Doppler transthoracic echocardiography showed a left outflow peak gradient of 100 mm Hg in two patients and of 80 mm Hg in one but failed to adequately assess the morphologic features of the stenosis, whose features were clearly visualized by transesophageal longitudinal planes in all patients. In conclusion, in our experience TEE is superior to transthoracic imaging in studying congenitally corrected transposition of the great arteries in adult patients; the horizontal plane is best suited to the evaluation of atrial situs and the atrioventricular junction, whereas the longitudinal plane is most valuable in the study of the morphologic features of the ventriculoarterial connections. These findings should be equally applicable to multiplane transesophageal studies.

Effect of Catheter Device Closure of Atrial Septal Defect on Diastolic Mitral Annular Motion

Atrial septal defect closure with the Amplatzer septal occluder has a negative effect on diastolic mitral annulus motion in terms of decreasing longitudinal septal annular motion and changing the relation between the annulus motion and mitral inflow.