Assessment of regional wall motion abnormalities with real-time 3-dimensional echocardiography

Relationship between Preoperative Echocardiographic Parameters and the Incidence of Postoperative Complications in Patients Undergoing Clipping of Unruptured Intracranial Aneurysms: A Retrospective Cohort Study

Background and Objectives: Preoperative echocardiography is widely performed in patients undergoing major surgeries to evaluate cardiac functions and detect structural abnormalities. However, studies on the clinical usefulness of preoperative echocardiography in patients undergoing cerebral aneurysm clipping are limited. Therefore, this study aimed to investigate the correlation between preoperative echocardiographic parameters and the incidence of postoperative complications in patients undergoing clipping of unruptured intracranial aneurysms. Materials and Methods: Electronic medical records of patients who underwent clipping of an unruptured intracranial aneurysm from September 2018 to April 2020 were retrospectively reviewed. Data on baseline characteristics, laboratory variables, echocardiographic parameters, postoperative complications, and hospital stays were obtained. Univariable and multivariable logistic regression analyses were performed to identify independent variables related to the occurrence of postoperative complications and prolonged hospital stay (≥8 d). Results: Among 531 patients included in the final analysis, 27 (5.1%) had postoperative complications. In multivariable logistic regression, the total amount of crystalloids infused (1.002 (1.001-1.003), p = 0.001) and E/e' ratio (1.17 (1.01-1.35), p = 0.031) were significant independent factors associated with the occurrence of a postoperative complication. Additionally, the maximal diameter of a cerebral aneurysm (1.13 (1.02-1.25), p = 0.024), total amount of crystalloids infused (1.001 (1.000-1.002), p = 0.031), E/A ratio (0.22 (0.05-0.95), p = 0.042), and E/e' ratio (1.16 (1.04-1.31), p = 0.011) were independent factors related to prolonged hospitalization. Conclusions: Echocardiographic parameters related to diastolic function might be associated with postoperative complications in patients undergoing clipping of unruptured intracranial aneurysms.

Multimodality imaging of myocardial viability: an expert consensus document from the European Association of Cardiovascular Imaging (EACVI)

In clinical decision making, myocardial viability is defined as myocardium in acute or chronic coronary artery disease and other conditions with contractile dysfunction but maintained metabolic and electrical function, having the potential to improve dysfunction upon revascularization or other therapy. Several pathophysiological conditions may coexist to explain this phenomenon. Cardiac imaging may allow identification of myocardial viability through different principles, with the purpose of prediction of therapeutic response and selection for treatment. This expert consensus document reviews current insight into the underlying pathophysiology and available methods for assessing viability. In particular the document reviews contemporary viability imaging techniques, including stress echocardiography, single photon emission computed tomography, positron emission tomography, cardiovascular magnetic resonance, and computed tomography and provides clinical recommendations for how to standardize these methods in terms of acquisition and interpretation. Finally, it presents clinical scenarios where viability assessment is clinically useful.

Clinical implications of exercise-induced regional wall motion abnormalities in significant aortic regurgitation

BACKGROUND

Significant aortic regurgitation (AR) is sometimes accompanied by regional wall motion abnormalities (RWMA) during exercise stress echocardiography. The aim of this study was to estimate the association between RWMA after exercise and in the presence of significant AR in patients with coronary artery disease (CAD) or volume overload and to predict the eventual need for aortic valve replacement (AVR).

METHODS AND RESULTS

We retrospectively reviewed 182 patients with significant AR who underwent exercise echocardiography. In addition, we investigated patients with AR who underwent coronary angiography (CAG) or coronary computed tomography angiography (CCTA) and were diagnosed with CAD. The presence of RWMA after exercise was defined as newly developed RWMA after exercise and included all changes in wall motion. Patients were divided into two groups according to the presence of RWMA after exercise: the RWMA group (n = 42) and non-RWMA group (n = 140). In the RWMA group, 31 patients (73.8%) underwent coronary artery evaluation by CAG or CCTA. Only two patients in the RWMA group were diagnosed with current CAD and underwent percutaneous coronary intervention. Patients with RWMA were older (61.6 ± 10.8 vs 52.0 ± 13.7 years, P < .001), had more severe AR (54.8% vs 32.9%), and underwent AVR more frequently (40.5% vs 14.3%, P = .001) than patients without RWMA. METs (odds ratio [OR], 0.796; P = .019), difference between rest and postexercise left ventricular end-diastolic volume (OR, 0.967; P = .001), and the difference between pre- and postexercise left ventricular end-systolic volume (OR, 1.113; P < .001) were identified as independent factors associated with RWMA after exercise according to multivariable logistic regression analysis. The majority of wall motion changes were seen in the lateral and inferior segments, and the locations of wall motion changes were relatively consistent with the direction of the AR jet. The relationship between RWMA after exercise and time to AVR was investigated by simple linear regression (hazard ratio [HR], 3.402; P < .001). After adjusting for baseline parameters of diastolic blood pressure, left ventricular end-systolic dimension (LVESD), aorta size, deceleration time, and METs, the presence of RWMA after exercise was not predictive of time to AVR (HR, 1.106; P = .81). On the other hand, without forcible entry of RWMA after exercise, LVESD (HR, 1.119; P < .001) and METs (HR, 0.828; P = .006) independently predicted the eventual need for AVR as an outcome.

CONCLUSION

The degree of change in wall motion from rest to exercise in those with significant AR was not correlated with CAD, but was correlated with the severity of volume overload and exercise-induced preload changes, as well as the direction of the AR jet. In addition, RWMA after exercise had no role in predicting the need for AVR.

Directional Doppler in Cardiology: A 50-Year Journey

In 1968, while cardiologists were focused on cardiac structures imaged by ultrasound, Daniel Kalmanson in Paris, France, devised a new ultrasonic modality, directional continuous-wave Doppler, enabling him to record instantaneous cardiovascular blood flow velocities with recognition of their direction (relative to the transducer) in vessels. An innovative presentation of Doppler data also made velocity traces physiologically understandable. Following the noninvasive study of the arterial and venous beds, flow velocity in the right (1969) and left (1970) cardiac chambers was studied by means of a directional Doppler catheter. The curtain was then raised for the renewal of our pathophysiologic understanding of cardiac dynamics and the adoption of a new methodology. Technological evolution paved the way for clever researchers to pioneer important advances, diversifying the technique. Guided by the early principles, which are still valid in 2018, directional Doppler finally gained acceptance from the entire scientific community.

Three-dimensional echocardiography in various types of heart disease: a comparison study of magnetic resonance imaging and 64-slice computed tomography in a real-world population

BACKGROUND

Accurate quantification of left ventricular (LV) volumes [end-diastolic volume (EDV) and end-systolic volume (ESV)] and ejection fraction (EF) is of critical importance. The development of real-time three-dimensional echocardiography (RT3DE) has shown better correlation than two-dimensional (2D) echocardiography with magnetic resonance imaging (MRI) measurements. The aim of our study was to assess the accuracy of RT3DE and 64-slice computed tomography (CT) in the evaluation of LV volumes and function using MRI as the reference standard in a real-world population with various types of heart disease with different chamber geometry.

METHODS

The study population consisted of 66 patients referred for cardiac MRI for various pathologies. All patients underwent cardiac MRI, and RT3DE and 64 slices CT were then performed on a subsequent day. The study population was then divided into 5 clinical groups depending on the underlying heart disease.

RESULTS

RT3DE volumes correlated well with MRI values (R ² values: 0.90 for EDV and 0.94 for ESV). RT3DE measurements of EF correlated well with MRI values (R ² = 0.86). RT3DE measurements resulted in slightly underestimated values of both EDV and ESV, as reflected by biases of -9.18 and -4.50 mL, respectively. Comparison of RT3DE and MRI in various types of cardiomyopathies showed no statistical difference between different LV geometrical patterns.

CONCLUSION

These results confirm that RT3DE has good accuracy in everyday clinical practice and can be of clinical utility in all types of cardiomyopathy independently of LV geometric pattern, LV diameter or wall thickness, taking into account a slight underestimation of LV volumes and EF compared to MRI.

Efficacy of a device to narrow the coronary sinus in refractory angina

BACKGROUND

Many patients with coronary artery disease who are not candidates for revascularization have refractory angina despite standard medical therapy. The balloon-expandable, stainless steel, hourglass-shaped, coronary-sinus reducing device creates a focal narrowing and increases pressure in the coronary sinus, thus redistributing blood into ischemic myocardium.

METHODS

We randomly assigned 104 patients with Canadian Cardiovascular Society (CCS) class III or IV angina (on a scale from I to IV, with higher classes indicating greater limitations on physical activity owing to angina) and myocardial ischemia, who were not candidates for revascularization, to implantation of the device (treatment group) or to a sham procedure (control group). The primary end point was the proportion of patients with an improvement of at least two CCS angina classes at 6 months.

RESULTS

A total of 35% of the patients in the treatment group (18 of 52 patients), as compared with 15% of those in the control group (8 of 52), had an improvement of at least two CCS angina classes at 6 months (P=0.02). The device was also associated with improvement of at least one CCS angina class in 71% of the patients in the treatment group (37 of 52 patients), as compared with 42% of those in the control group (22 of 52) (P=0.003). Quality of life as assessed with the use of the Seattle Angina Questionnaire was significantly improved in the treatment group, as compared with the control group (improvement on a 100-point scale, 17.6 vs. 7.6 points; P=0.03). There were no significant between-group differences in improvement in exercise time or in the mean change in the wall-motion index as assessed by means of dobutamine echocardiography. At 6 months, 1 patient in the treatment group had had a myocardial infarction; in the control group, 1 patient had died and 3 had had a myocardial infarction.

CONCLUSIONS

In this small clinical trial, implantation of the coronary-sinus reducing device was associated with significant improvement in symptoms and quality of life in patients with refractory angina who were not candidates for revascularization. (Funded by Neovasc; COSIRA ClinicalTrials.gov number, NCT01205893.).

Transcatheter treatment for refractory angina with the Coronary Sinus Reducer

AIMS

To evaluate the clinical efficacy of the coronary sinus (CS) Reducer in attenuating angina severity in patients suffering from severe refractory angina.

METHODS AND RESULTS

Patients with refractory angina, objective evidence of myocardial ischaemia and no option for revascularisation were treated with CS Reducer implantation at two medical centres. Six-month follow-up evaluation consisted of clinical assessment of angina severity. Objective assessment of ischaemia at six-month follow-up was performed in one of the two centres. Successful CS Reducer implantation was achieved in 21 of 23 eligible patients, at both centres. No device-related adverse effects were observed during the procedure or the follow-up period. Canadian Cardiovascular Society (CCS) score diminished from a mean of 3.3 at baseline to 2.0 at six months (n=20, p<0.01), exercise duration was prolonged from 3:16 to 5:16 min (min:sec; n=8, p=0.05). Thallium SPECT summed stress score and summed difference score were both reduced (n=9, 21.5±10 vs.13.2±9, p=0.01, and 11.1±6 vs. 4.7±4, p=0.007, respectively). Wall motion score index at peak dobutamine infusion was also significantly improved (n=8, 1.9±0.4 vs. 1.4±0.4, p=0.046).

CONCLUSIONS

CS Reducer implantation was safe and resulted in significant improvement of angina class. The results of the ongoing randomised sham-control trial will address the concern regarding the possible placebo effect, and hopefully further support our encouraging observations.

Clinical application of three-dimensional echocardiography

Echocardiography is one of the most valuable diagnostic tools in cardiology. Technological advances in ultrasound, computer and electronics enables three-dimensional (3-D) imaging to be a clinically viable modality which has significant impact on diagnosis, management and interventional procedures. Since the inception of 3D fully-sampled matrix transthoracic and transesophageal technology it has enabled easier acquisition, immediate on-line display, and availability of on-line analysis for the left ventricle, right ventricle and mitral valve. The use of 3D TTE has mainly focused on mitral valve disease, left and right ventricular volume and functional analysis. As structural heart disease procedures become more prevalent, 3D TEE has become a requirement for preparation of the procedure, intra-procedural guidance as well as monitoring for complications and device function. We anticipate that there will be further software development, improvement in image quality and workflow.

Initial experience using contrast enhanced real-time three-dimensional exercise stress echocardiography in a low-risk population

Although emerging data support the utility of real-time three-dimensional echocardiography (RT3DE) during dobutamine stress testing, the feasibility of performing contrast enhanced RT3DE during exercise treadmill stress has not been explored. Two-dimensional (2D) and three-dimensional (3D) acquisition were performed in 39 patients at rest and peak exercise. Contrast was used in 29 patients (74%). Reconstruction was performed manually by generating short axis cut planes at the base, mid-ventricle and apex, and automatically by generating 9 short axis slices. Three-dimensional acquisition was feasible during rest and stress regardless of the use of contrast. Time to acquire stress images was reduced using 3D (35.2±17.9 s) as compared to 2D acquisition (51.6±14.7 s; P<0.05). Using a 17-segment model, of all 663 segments, 588 resting (88.6%) and 563 stress segments (84.9%) were adequately visualized using manually reconstructed 3D data, compared with 618 resting (93.2%) and 606 stress segments (91.4%) using 2D data (P rest=0.06; P stress=0.07). We concluded that contrast enhanced RT3DE is feasible during treadmill stress echocardiography.

Feasibility of real-time three-dimensional stress echocardiography: pharmacological and semi-supine exercise

Background

Real time three dimensional (RT3D) echocardiography is an accurate and reproducible method for assessing left ventricular shape and function.

Aim

assess the feasibility and reproducibility of RT3D stress echocardiography (SE) (exercise and pharmacological) in the evaluation of left ventricular function compared to 2D.

Methods and results

One hundred eleven patients with known or suspected coronary artery disease underwent 2D and RT3DSE. The agreement in WMSI, EDV, ESV measurements was made off-line.

The feasibility of RT-3DSE was 67%. The inter-observer variability for WMSI by RT3D echo was higher during exercise and with suboptimal quality images (good: k = 0.88; bad: k = 0.69); and with high heart rate both for pharmacological (HR < 100 bpm, k = 0.83; HR ≥ 100 bpm, k = 0.49) and exercise SE (HR < 120 bpm, k = 0.88; HR ≥ 120 bpm, k = 0.78). The RT3D reproducibility was high for ESV volumes (0.3 ± 14 ml; CI 95%: -27 to 27 ml; p = n.s.).

Conclusions

RT3DSE is more vulnerable than 2D due to tachycardia, signal quality, patient decubitus and suboptimal resting image quality, making exercise RT3DSE less attractive than pharmacological stress.

Baseline and follow-up assessment of regional left ventricular volume using 3-Dimensional echocardiography: comparison with cardiac magnetic resonance

The assessment of regional volumes is an option for analysis of the response of LV segments to interventions such as revascularization or cell therapy. We sought to compare regional volumes from 3D-echocardiography (3DE) with cardiac magnetic resonance (CMR) over follow-up. CMR regional volumes were assessed at baseline and after one year follow-up in 30 unselected patients (28 men, 65 +/- 11 years) presenting for evaluation of cardiac function with previous infarction. 3DE images were also gathered over 4 cardiac cycles and measurements were performed off-line. CMR images were obtained using a 1.5 Tesla scanner and measured offline by method of landmarks and by centre of mass. Regional volumes were measured at end-diastole (rEDV) and end-systole (rESV) and the change in volume was compared for each over follow-up. There was good correlation between 3DE and both CMR methods at baseline and follow-up. Changes in rEDV with 3DE vs CMR(L) were comparable (0.11 +/- 3 ml vs 0.12 +/- 3 ml, p = 0.94), as was change in CMR(M) (0.26 +/- 2 ml, p = 0.69). However the change in regional volume by 3DE and CMR(L) correlated poorly (r = 0.03, p = 0.68), as did change in 3DE vs CMR(M) (r = 0.04, p = 0.65). Similarly, changes in rESV with 3DE and CMR(L) were similar (0.27 +/- 2 ml vs 0.36 +/- 2 ml, p = 0.70), as was change in CMR(M) (0.05 +/- 1 ml, p = 0.31). Again, correlations between rESV by 3DE vs CMR(L) were poor (r = 0.03, p = 0.72), as well as 3DE vs CMR(M) (r = 0.07, p = 0.40). Although global 3DE volumes compare well with CMR volumes, new developments in image quality and automated software will be needed before changes in regional volumes can be reliably followed with 3DE.

Real-time 3-dimensional echocardiographic quantification of left ventricular volumes: multicenter study for validation with magnetic resonance imaging and investigation of sources of error

OBJECTIVES

We sought to study: 1) the accuracy and reproducibility of real-time 3-dimensional echocardiographic (RT3DE) analysis of left ventricular (LV) volumes in a multicenter setting, 2) interinstitutional differences in relationship with the investigators' specific experience, and 3) potential sources of volume underestimation.

BACKGROUND

Reproducibility and accuracy of RT3DE evaluation of LV volumes has not been validated in multicenter studies, and LV volumes have been reported to be underestimated compared to cardiac magnetic resonance (CMR) standard.

METHODS

A total of 92 patients with a wide range of ejection fractions underwent CMR and RT3DE imaging at 4 different institutions. Images were analyzed to obtain LV end-systolic volume (ESV) and end-diastolic volume (EDV). Reproducibility was assessed using repeated analyses. The investigation of potential sources of error included: phantom imaging, intermodality analysis-related differences, and differences in LV boundary identification, such as inclusion of endocardial trabeculae and mitral valve plane in the LV volume.

RESULTS

The RT3DE-derived LV volumes correlated highly with CMR values (EDV: r = 0.91; ESV: r = 0.93), but were 26% and 29% lower consistently across institutions, with the magnitude of the bias being inversely related to the level of experience. The RT3DE measurements were less reproducible (4% to 13%) than CMR measurements (4% to 7%). Minimal changes in endocardial surface position (1 mm) resulted in significant differences in measured volumes (11%). Exclusion of trabeculae and mitral valve plane from the CMR reference eliminated the intermodality bias.

CONCLUSIONS

The RT3DE-derived LV volumes are underestimated in most patients because RT3DE imaging cannot differentiate between the myocardium and trabeculae. To minimize this difference, tracing the endocardium to include trabeculae in the LV cavity is recommended. With the understanding of these intermodality differences, RT3DE quantification of LV volume is a reliable tool that provides clinically useful information.

Real-time 3-dimensional echocardiography early after acute myocardial infarction: incremental value of echo-contrast for assessment of left ventricular function

BACKGROUND

Accurate and reproducible assessment of left ventricular (LV) systolic function is important in patients with acute myocardial infarction (AMI). Real-time 3-dimensional echocardiography (RT3DE) is an accurate technique, but it relies heavily on good image quality. The aim of the present study was to evaluate the incremental value of contrast-enhanced RT3DE.

METHODS

A total of 140 consecutive patients (58 +/- 11 years, 78% men) with ST-elevation AMI clinically underwent nonenhanced and contrast-enhanced RT3DE within 24 hours from AMI to evaluate global and regional LV systolic function. Endocardial border definition was graded for each of the 16 LV segments as follows: 0 = border invisible, 1 = border visualized only partially, and 2 = complete visualization of the border. Three image-quality groups (good, fair, and uninterpretable) were identified. Left ventricular volumes and ejection fraction were measured off-line. Wall motion was graded for each visible segment as follows: 1 = normal, 2 = hypokinetic, 3 = akinetic, and 4 = dyskinetic.

RESULTS

During contrast-enhanced RT3DE, as compared with nonenhanced RT3DE, the number of segments with complete visualization of the endocardial border increased from 66% to 84% (P < .001); and the number of patients with a good-quality echocardiogram increased from 59% to 94% (P < .001). Intra- and interobserver agreement for assessment of global and regional LV systolic function improved during contrast-enhanced RT3DE, as compared with nonenhanced RT3DE.

CONCLUSIONS

Assessment of LV systolic function in AMI patients with RT3DE is frequently hampered by suboptimal echocardiographic quality. Contrast-enhanced RT3DE is of incremental value, improving the endocardial border visualization and the reproducibility of LV function assessment.

Real-time three-dimensional echocardiographic assessment of left ventricular remodeling index in patients with hypertensive heart disease and coronary artery disease

Left ventricular remodeling index (LVRI) was assessed in patients with hypertensive heart disease (HHD) and coronary artery disease (CAD) by real-time three-dimensional echocardiography (RT3DE). RT3DE data of 18 patients with HHD, 20 patients with CAD and 22 normal controls (NC) were acquired. Left ventricular end-diastolic volume (EDV) and left ventricular end-diastolic epicardial volume (EDVepi ) were detected by RT3DE and two-dimensional echocardiography Simpson biplane method (2DE). LVRI (left ventricular mass /EDV) was calculated and compared. The results showed that LVRI measurements detected by RT3DE and 2DE showed significant differences inter-groups (P<0.01). There was no significant difference in NC group (P>0.05), but significant difference in HHD and CAD intra-group (P<0.05). There was good positive correlations between LVRI detected by RT3DE and 2DE in NC and HHD groups (r=0.69, P<0.01; r=0.68, P<0.01), but no significant correlation in CAD group (r=0.30, P>0.05). It was concluded that LVRI derived from RT3DE as a new index for evaluating left ventricular remodeling can provide more superiority to LVRI derived from 2DE.

Clinical application of three-dimensional echocardiography: past, present and future

Significant advances in three-dimensional echocardiography have made this modality a powerful diagnostic tool in the cardiology clinic. It can provide accurate and reliable measurements of chamber size and function, including the quantification of left ventricular mechanical dyssynchrony to guide patient selection for cardiac resynchron-isation therapy. Furthermore, three-dimensional echocardiography offers novel views and comprehensive anatomic definition of valvular and congenital abnormalities, improving diagnosis and preoperative planning. In addition, it is extremely useful in monitoring the effectiveness of surgical or percutaneous transcatheter interventions. As its efficacy for more and more clinical applications is demonstrated, it is clear that three-dimensional echocardiography has become part of the routine clinical diagnostic armamentarium. In this article, we describe the development of three-dimensional echocardiography over the last decades, review the scientific evidence for its current clinical use and discuss potential future applications. (Neth Heart J 2009;17:18-24.).

Head to head comparison of 2D vs real time 3D dipyridamole stress echocardiography

Real-time three-dimensional (RT-3D) echocardiography has entered the clinical practice but true incremental value over standard two-dimensional echocardiography (2D) remains uncertain when applied to stress echo. The aim of the present study is to establish the additional value of RT-3D stress echo over standard 2D stress echocardiography. We evaluated 23 consecutive patients (age = 65 ± 10 years, 16 men) referred for dipyridamole stress echocardiography with Sonos 7500 (Philips Medical Systems, Palo, Alto, CA) equipped with a phased – array 1.6–2.5 MHz probe with second harmonic capability for 2D imaging and a 2–4 MHz matrix-phased array transducer producing 60 × 70 volumetric pyramidal data containing the entire left ventricle for RT-3D imaging. In all patients, images were digitally stored in 2D and 3D for baseline and peak stress with a delay between acquisitions of less than 60 seconds. Wall motion analysis was interpreted on-line for 2D and off-line for RT-3D by joint reading of two expert stress ecocardiographist. Segmental image quality was scored from 1 = excellent to 5 = uninterpretable. Interpretable images were obtained in all patients. Acquisition time for 2D images was 67 ± 21 sec vs 40 ± 22 sec for RT-3D (p = 0.5). Wall motion analysis time was 2.8 ± 0.5 min for 2D and 13 ± 7 min for 3D (p = 0.0001). Segmental image quality score was 1.4 ± 0.5 for 2D and 2.6 ± 0.7 for 3D (p = 0.0001). Positive test results was found in 5/23 patients. 2D and RT-3D were in agreement in 3 out of these 5 positive exams. Overall stress result (positive vs negative) concordance was 91% (Kappa = 0.80) between 2D and RT-3D. During dipyridamole stress echocardiography RT-3D imaging is highly feasible and shows a high concordance rate with standard 2D stress echo. 2D images take longer time to acquire and RT-3D is more time-consuming to analyze. At present, there is no clear clinical advantage justifying routine RT-3D stress echocardiography use.

Real-time three-dimensional echocardiography: an update

Real-time three-dimensional echocardiography (RT3DE) is the only on-line 3D method based on real-time volumetric scanning, as compared with other 3D imaging techniques such as computed tomography and magnetic resonance imaging, which are based on post-acquisition reconstruction and not on volumetric scanning. In recent years, several studies have revealed possible advantages of 3DE in daily clinical practice. The aim of this manuscript is to give a brief review of the development of the clinical applications of RT3DE.

Comparison of two- versus three-dimensional myocardial contrast echocardiography for assessing subendocardial perfusion abnormality after percutaneous coronary intervention in patients with acute myocardial infarction

Myocardial contrast echocardiography (MCE) visualizes myocardial perfusion abnormalities after acute myocardial infarction. However, the limited view of 2-dimensional echocardiography reduces its ability to estimate perfusion abnormalities, especially in the subendocardial region. Three-dimensional echocardiography provides images of the left ventricular endocardium directly. This study was conducted to evaluate the ability of 3-dimensional MCE to assess abnormalities of subendocardial perfusion. Intracoronary 2- and 3-dimensional MCE was performed after primary percutaneous coronary intervention in 47 patients with acute myocardial infarction. Myocardial perfusion within the risk area was evaluated as good, poor, or no reflow on 2-dimensional MCE or as good, poor, or no myocardial opacification in endocardium on 3-dimensional MCE. The 2 methods showed different distributions of perfusion patterns: good, poor, and no reflow on 2-dimensional MCE in 31 (66%), 9 (19%), and 7 (15%) patients and good, poor, and no myocardial opacification in endocardium on 3-dimensional MCE in 17 (36%), 16 (34%), and 14 (20%) patients, respectively. Although only 19 patients (61%) with good reflow on 2-dimensional MCE showed myocardial perfusion grade 3 on angiography, 16 of 17 patients (94%) with good myocardial opacification in endocardium on 3-dimensional MCE showed myocardial perfusion grade 3. Although there were no significant differences in peak creatine kinase among the 3 subsets classified by 2-dimensional MCE, peak creatine kinase showed significant differences not only among the 3 groups but also among the subsets classified by 3-dimensional MCE. Classification by 3-dimensional MCE also predicted regional wall motion after 4.6 +/- 2.7 months, with significant differences between each pair of groups, whereas there was significant overlap of these values between the group with poor reflow and other 2 groups by 2-dimensional MCE. In conclusion, 3-dimensional MCE is a feasible way to assess subendocardial perfusion and predicts infarct size and functional recovery more precisely than 2-dimensional MCE.

Volume stitching in three-dimensional echocardiography: distortion analysis and extension to real time

Three-dimensional (3D) echocardiography is challenging due to limitation of the data acquisition rate caused by the speed of sound. ECG-gated stitching of data from several cardiac cycles is a possible technique to achieve higher resolution. The aim of this work is two-fold: it is, firstly, to provide a method for real-time presentation of stitched echocardiographic images acquired over several cardiac cycles and, secondly, to demonstrate that the geometrical distortion of the images is decreased when stitching is applied to 3D ultrasonic data of the left ventricle (LV). We present a volume stitching algorithm that merges data from N consecutive heart cycles into an assembled data volume. The assembly is performed in real time, making immediate volume rendering of the full volume possible. In-vivo images acquired with this technique are presented. Through simulations with a kinematic model of the LV wall, geometrical distortion and volume estimation errors due to long image capture time was quantified for 3D recordings of the LV. Curves showing the variation throughout the cardiac cycle of the maximal geometrical distortion in the LV walls are presented, as well as curves showing the volume estimates compared with the true LV volume of the model. We conclude that real-time display of stitched 3D ultrasound data is feasible and that it is an adequate technique for increasing the volume acquisition rate at a given spatial resolution. Furthermore, the geometrical distortion decreases substantially for data with higher volume rate and, for a full scan of the LV, stitching over at least four cycles is recommended.

Real-time Three-Dimensional Echocardiography in Stress Testing: Bi- and Triplane Imaging for Enhanced Image Acquisition

Real-time three-dimensional echocardiography with its methodological advantage of rapid scanning of the complete left ventricle may be the optimal modality to overcome some limitations of conventional two-dimensional stress echocardiography. Matrix array transducers allow bi- or triplane scanning or full-volume three-dimensional acquisition. Both techniques have been shown to significantly reduce scanning time without losing sensitivity and test accuracy, although here the emphasis is on bi- and triplane imaging. Several advantages of real-time three-dimensional stress testing during acquisition but also in the analysis and interpretation of echo data have been demonstrated over the last few years.

Interactive volume rendering of real-time three-dimensional ultrasound images

Real-time, three-dimensional (RT3D) ultrasound allows video frame rate volumetric imaging. The ability to acquire full three-dimensional (3-D) image data in real-time is particularly helpful for applications such as cardiac imaging, which require visualization of complex and dynamic 3-D anatomy. Volume rendering provides a method for intuitive graphical display of the 3-D image data, but capturing the RT3D echo data and performing the necessary processing to generate a volumetric image in real time poses a significant technical challenge. We present a data capture and rendering implementation that uses off-the-shelf components to real-time volume render RT3D ultrasound images. Our approach allowed live, interactive volume rendering of RT3D ultrasound scans.

Quantitative Real-time 3-Dimensional Stress Echocardiography: A Preliminary Investigation of Feasibility and Effectiveness

BACKGROUND

Use of rapidly emerging real-time 3-dimensional (3D) echocardiography promises to improve the diagnostic accuracy of stress echocardiography (SE). However, widespread acceptance of 3D-SE, based on real-time 3D echocardiography, is hampered in part by lack of efficient, accurate, and objective analysis tools.

METHODS

We propose novel algorithms for interactive visualization, registration (alignment), and quantitative analysis of prestress and poststress real-time 3D echocardiography to facilitate an objective diagnosis. In a preliminary evaluation, two experts independently performed wall-motion analysis in 15 patients with known/suspected coronary artery disease, using the novel quantitative 3D-SE methods.

RESULTS

Compared with previously reported values for conventional 2-dimensional SE, improved interexpert agreement (kappa = 0.85) was observed for segment-wise classification of normal/abnormal wall motion using the novel 3D-SE methods. Overall, 6 of 6 patients with abnormal myocardial segments were correctly identified by both experts with 3D-SE, compared with 4 of 6 with conventional 2-dimensional SE.

CONCLUSION

Initial results are promising and indicate the feasibility and potential of our proposed quantitative 3D-SE methodologies for improving diagnosis of wall-motion abnormalities.

Real-time Three-dimensional Color Doppler Echocardiography Overcomes the Inaccuracies of Spectral Doppler for Stroke Volume Calculation

Real-time 3-dimensional echocardiography is increasingly used in clinical cardiology. Studies have been shown that this technique can be accurately used to assess both cardiac mass and chamber volumes. We review the work showing that real-time 3-dimensional Doppler echocardiography can be used to accurately calculate intracardiac flow volumes that can potentially be used to assess cardiac function, intracardiac shunt, and valve regurgitation.

Volumetric analysis of regional left ventricular function with real-time three-dimensional echocardiography: validation by magnetic resonance and clinical utility testing

BACKGROUND

Quantitative information on regional left ventricular volumes from real-time three-dimensional echocardiographic (RT3DE) images has significant clinical potential but needs validation.

AIM

To validate these measurements against cardiac magnetic resonance (CMR) and test the feasibility of automated detection of regional wall motion (RWM) abnormalities from RT3DE data.

METHODS

RT3DE (Philips) and CMR (Siemens) images were obtained from 31 patients and analysed by using prototype software to semiautomatically calculate indices of regional left ventricular function, which were compared between RT3DE and CMR (linear regression, Bland-Altman). Additionally, CMR images were reviewed by an expert, whose RWM grades were used as a reference for automated classification of segments as normal or abnormal from RT3DE and from CMR images. For each modality, normal regional ejection fraction (REF) values were obtained from 15 patients with normal wall motion. In the remaining 16 patients, REFs were compared with thresholds that were derived from patients with normal wall motion and optimised using receiver operating characteristic analysis.

RESULTS

RT3DE measurements resulted in good agreement with CMR. Regional indices calculated in patients with normal wall motion varied between segments, but overall were similar between modalities. In patients with abnormal wall motion, RWM was graded as abnormal in 74% segments. CMR and RT3DE thresholds were similar (16-segment average 55 (10)% and 56 (7)%, respectively). Automated interpretation resulted in good agreement with expert interpretation, similar for CMR and RT3DE (sensitivity 0.85, 0.84; specificity 0.81, 0.78; accuracy 0.84, 0.84, respectively).

CONCLUSION

Analysis of RT3DE data provides accurate quantification of regional left ventricular function and allows semiautomated detection of RWM abnormalities, which is as accurate as the same algorithm applied to CMR images.

Role of Biplane and Biplane Echocardiographically Guided 3-Dimensional Echocardiography During Dobutamine Stress Echocardiography

Image acquisition time and wall-motion score of conventional 2-dimensional (2D) dobutamine stress echocardiography (DSE) were compared with those of biplane and 3-dimensional (3D) DSE in 50 patients (age 67 +/- 13 years) with regular rhythms during clinically indicated DSE. Commercially available systems were used for the study. We used a conventional transducer for 2D and a matrix-array transducer (x4 or x3-1) for two biplane (60- and 120-degree) images and one 3D full-volume image. Image quality was scored as 1 = good; 2 = adequate; and 3 = inadequate. Segmental wall-motion scores for each method were analyzed in blinded fashion. Acquisition times of biplane (9.3 +/- 2.8 seconds) and biplane-guided 3D (additional 2.6 +/- 1.0 seconds) echocardiography were significantly shorter than those of conventional 2D DSE (60.0 +/- 26.7 seconds) (P < .001). Image quality was adequate or good in 94% for biplane and 96% for 3D echocardiography. Agreement of segmental wall-motion score was present in 87.6% of segments for 2D versus biplane and 85.9% for 2D versus 3D at baseline and in 88.0% for 2D versus biplane and 87.4% for 2D versus 3D at peak stress. Acquisition of biplane or biplane-guided 3D volumetric data during DSE with use of a new matrix-array transducer was feasible and shortened image acquisition time without affecting the diagnostic yield compared with conventional 2D imaging.

Quantitative assessment of left ventricular size and function: side-by-side comparison of real-time three-dimensional echocardiography and computed tomography with magnetic resonance reference

BACKGROUND

Cardiac CT (CCT) and real-time 3D echocardiography (RT3DE) are being used increasingly in clinical cardiology. CCT offers superb spatial and contrast resolution, resulting in excellent endocardial definition. RT3DE has the advantages of low cost, portability, and live 3D imaging without offline reconstruction. We sought to compare both CCT and RT3DE measurements of left ventricular size and function with the standard reference technique, cardiac MR (CMR).

METHODS AND RESULTS

In 31 patients, RT3DE data sets (Philips 7500) and long-axis CMR (Siemens, 1.5 T) and CCT (Toshiba, 16-slice MDCT) images were obtained on the same day without beta-blockers. All images were analyzed to obtain end-systolic and end-diastolic volumes and ejection fractions using the same rotational analysis to eliminate possible analysis-related differences. Intertechnique agreement was tested through linear regression and Bland-Altman analyses. Repeated measurements were performed to determine intraobserver and interobserver variability. Both CCT and RT3DE measurements resulted in high correlation (r2 > 0.85) compared with CMR. However, CCT significantly overestimated end-diastolic and end-systolic volumes (26 and 19 mL; P < 0.05), resulting in a small but significant bias in ejection fraction (-2.8%). RT3DE underestimated end-diastolic and end-systolic volumes only slightly (5 and 6 mL), with no significant bias in EF (0.3%; P = 0.68). The limits of agreement with CMR were comparable for the 2 techniques. The variability in the CCT measurements was roughly half of that in either RT3DE or CMR values.

CONCLUSIONS

CCT provides highly reproducible measurements of left ventricular volumes, which are significantly larger than CMR values. RT3DE measurements compared more favorably with the CMR reference, albeit with higher variability.

Quantification of Regional Left Ventricular Wall Motion from Real-time 3-Dimensional Echocardiography in Patients with Poor Acoustic Windows: Effects of Contrast Enhancement Tested Against Cardiac Magnetic Resonance

OBJECTIVE

Regional left ventricular function can be assessed by real-time 3-dimensional echocardiography (RT3DE) in patients with good image quality. Our goals were to: (1) test the feasibility of RT3DE quantification of regional wall motion (RWM) in patients with poor acoustic windows who require contrast for endocardial visualization; and (2) validate these measurements against cardiac magnetic resonance (CMR) reference.

METHODS

RT3DE datasets and CMR images were obtained in 24 patients. In 16 of 24 patients with suboptimal endocardial definition, RT3DE imaging was repeated with intravenous contrast and triggering at end systole and end diastole. RT3DE datasets were analyzed using custom software designed to semiautomatically detect and segment the endocardial surface and calculate RWM values. CMR images were analyzed using commercial software to obtain reference values for RWM.

RESULTS

In 8 of 24 patients with good endocardial definition, RT3DE values of RWM correlated well with CMR (r = 0.73) with a small bias (-1.0 mm). In the remaining 16 patients, analysis of nonenhanced RT3DE datasets yielded lower correlation with CMR (r = 0.61) and a slightly greater bias (-1.5 mm). The agreement with CMR improved significantly (r = 0.76, bias -1.1 mm) with contrast enhancement.

CONCLUSIONS

The agreement between RT3DE and CMR values of RWM is directly related to RT3DE image quality. In patients with poor acoustic windows, dual-triggered contrast enhancement improves the accuracy of RWM quantification to a level similar to that noted in patients with good images without contrast.

Volumetric Quantification of Global and Regional Left Ventricular Function From Real-Time Three-Dimensional Echocardiographic Images

Background— Real-time 3D echocardiographic (RT3DE) data sets contain dynamic volumetric information on cardiac function. However, quantification of left ventricular (LV) function from 3D echocardiographic data is performed on cut-planes extracted from the 3D data sets and thus does not fully exploit the volumetric information. Accordingly, we developed a volumetric analysis technique aimed at quantification of global and regional LV function.

Methods and Results— RT3DE images obtained in 30 patients (Philips 7500) were analyzed by use of custom software based on the level-set approach for semiautomated detection of LV endocardial surface throughout the cardiac cycle, from which global and regional LV volume (LVV)–time and wall motion (WM)–time curves were obtained. The study design included 3 protocols. In protocol 1, time curves obtained in 16 patients were compared point-by-point with MRI data (linear regression and Bland-Altman analyses). Global LVV correlated highly with MRI ( r =0.98; y =0.99 x +2.3) with minimal bias (1.4 mL) and narrow limits of agreement (±20 mL). WM correlated highly only in basal and midventricular segments ( r =0.88; y =0.85 x +0.7). In protocol 2, we tested the ability of this technique to differentiate populations with known differences in LV function by studying 9 patients with dilated cardiomyopathy and 9 normal subjects. All calculated indices of global and regional systolic and diastolic LV function were significantly different between the groups. In protocol 3, we tested the feasibility of automated detection of regional WM abnormalities in 11 patients. In each segment, abnormality was detected when regional shortening fraction was below a threshold obtained in normal subjects. The automated detection agreed with expert interpretation of 2D WM in 86% of segments.

Conclusions— Volumetric analysis of RT3DE data is clinically feasible and allows fast, semiautomated, dynamic measurement of LVV and automated detection of regional WM abnormalities.

Left ventricular wall motion analysis using real-time three-dimensional ultrasound

This study tested the ability of real-time 3-D (RT 3-D) echocardiography to detect and delineate regions of abnormal contraction (akinesia or dyskinesia) in a canine model of regional myocardial injury and to develop methods to simplify injury assessments. Closed chest RT 3-D scans were obtained and regional left ventricular (LV) contractile function was assessed in nine animals at baseline and after myocardial cryoinjury with a 1-cm cryoprobe. Evaluation of contractile function was based on radial shortening of LV chamber cross-sections at multiple levels. Radial length changes were analyzed using color-coded circumferential maps of the LV. Seven sets of motion maps demonstrated new areas of poorly contracting myocardium in the cryoinjured region relative to baseline. Two sets of data were excluded due to insufficient LV visualization. Motion maps derived from RT 3-D echo have the ability to detect and localize regions of abnormal LV wall motion.

Myocardial endothelin-1 release and indices of inflammation during angioplasty for acute myocardial infarction and stable coronary artery disease

BACKGROUND

Elevations in endothelin-1 (ET-1) and inflammatory cytokines may impair myocardial reperfusion through the induction of microvascular constriction or obstruction; however, the generation of these factors close to the site of lesion rupture is unknown.

METHODS AND RESULTS

Coronary sinus (CS) and aortic blood was sampled during angioplasty for acute myocardial infarction (AMI) or stable angina to assess the local release of ET-1, interleukin-1beta, interleukin-6, tumor necrosis factor-alpha and C-reactive protein following atherosclerotic plaque rupture. Transthoracic echocardiography documented left ventricular function in AMI. ET-1 levels were higher in CS than in aortic blood in AMI (3.0 +/- 0.3 pmol/L vs 2.6 +/- 0.3 pmol/L, P =.04), but not in stable angina (1.7 +/- 0.2 pmol/L vs 1.5 +/- 0.3 pmol/L, P = NS). CS ET-1 levels were also higher in AMI than in stable angina (3.0 +/- 0.3 pmol/L vs 1.7 +/- 0.2 pmol/L, P =.002), and correlated with left ventricular dysfunction (R(2) = 0.51, P =.02). In contrast, C-reactive protein levels were higher in CS than in aortic blood only in stable angina (2.3 +/- 0.4 mg/L vs 1.8 +/- 0.3 mg/L, P =.01). Similarly, CS tumor necrosis factor-alpha was higher in stable angina than in AMI (6.0 +/- 1.4 pg/mL vs 2.5 +/- 0.9 pg/mL, P =.02).

CONCLUSIONS

Local myocardial release of ET-1 is highest in AMI, where it relates to the extent of myocardial dysfunction. Although local inflammation is a component of stable coronary artery disease, it does not appear acutely enhanced in AMI.

Real-Time Three-Dimensional Echocardiography Using a Novel Matrix Array Transducer

Three-dimensional echocardiography has multiple advantages over two-dimensional echocardiography, such as accurate left ventricular quantification and improved spatial relationships. However, clinical use of three-dimensional echocardiography has been impeded by tedious and time-consuming methods for data acquisition and post-processing. A newly developed matrix array probe, which allows real-time three-dimensional imaging with instantaneous on-line volume-rendered reconstruction, direct manipulation of thresholding, and cut planes on the ultrasound unit may overcome the aforementioned limitations. This report will review current methods of three-dimensional data acquisition, emphasizing the real-time methods and clinical applications of the new matrix array probe.

Relation of local platelet glycoprotein IIb/IIIa independent activation during coronary angioplasty in acute myocardial infarction to recovery of left ventricular function

We assessed glycoprotein (GP) IIb/IIIa independent platelet activation in coronary sinus and peripheral blood from patients who underwent angioplasty for acute myocardial infarction and stable angina. Despite complete blockade of the activated GP IIb/IIIa receptor with abciximab in patients with acute myocardial infarction, unsuppressed local GP IIb/IIIa independent activation was associated with a lack of recovery of left ventricular function.

Evaluation of mitral valve prolapse using newly developed real-time three-dimensional echocardiographic system with real-time volume rendering

The development of a real-time three-dimensional (RT3D) image acquisition system and direct digital links between ultrasound equipment and the data processing computer facilitate improved 3D image reconstruction. However, at present time, it is hard to promptly display 3D images and is also ineffective for a practical use. The objective of this study was to assess the feasibility of a new transthoracic RT3D echocardiographic system for evaluation of mitral valve prolapse. Eighteen patients with mitral valve prolapse diagnosed by transthoracic two-dimensional (2D) echocardiography and M-mode were examined through this technique (11 male, mean age 42 +/- 17 years). Since visualization of mitral valve from apical four-chamber view was better than that of the parasternal approach, only apical approach was used for mitral valve evaluation. This system is capable of acquiring volumetric data from mechanical scanning of the phased-array transducer (3.5 MHz) as well as displaying the volume rendered images of the structure without storing the image data and reconstruction of the object. The prolapse of leaflet could be seen in 14/ 18 (77%) of patients with mitral valve prolapse based on conventional echocardiography. The newly developed transthoracic RT 3D ultrasound system without a reconstruction process seemed to be a useful noninvasive tool for diagnosis of mitral valve prolapse and detection of prolapsed leaflet or scallop, which is very important for deciding on a reliable surgical technique.

Partial cut-off of the left ventricle: determinants and effects on volume parameters assessed by real-time 3-D echocardiography

A total of 44 patients with coronary artery disease underwent real-time three-dimensional (3-D) echocardiography for end systolic (ES) and end diastolic (ED) left ventricular (LV) volumetric analysis to assess the effect of partial cut-off of the left ventricular (LV) apex on volumetric analysis by apical transthoracic echocardiography. Patients with LV cut-off were assigned to either group 1 (ejection fraction, (EF) < 49%) or group 2 (EF > or = 49%). Patients were additionally classified as group A if they had anterior or apical wall motion abnormalities (WMA) or group B if they had only inferoposterior or lateral WMA. Partial LV cut-offs were found in 22 subjects (50%). The estimated end diastolic cut-off volumes were as follows: 8.6 +/- 3.2 mL (group 1), 4.3 +/- 2.4 mL (group 2), 9.1 +/- 3.3 mL (group A) and 1.4 +/- 0.8 mL (group B). In group 1, more patients with LV volume cut-off were found than in group 2: chi(2) = 4.52, p < 0.05; and in group A more than in group B: chi(2) = 8.08, p < 0.01. In all, partial LV cut-off led to underestimation of LV volumes: 5.9 +/- 4.7 ml (ED) vs. 2.1 +/- 1.3 ml (ES), p <0.02. In conclusion, LV cut-offs can potentially alter the accuracy of echocardiographic volumetric analysis, particularly in anterior or apical WMA.

Left ventricular opacification at rest and during stress

Although echocardiography is the most widely used cardiac imaging modality in the world, it is often limited by poor endocardial border definition. The development of contrast agents that opacify the cardiac chambers after intravenous injection now makes it possible to acquire high-quality images, even in technically difficult cases. Several studies have now shown that contrast echocardiography improves assessment of global and regional wall motion, enhances observer agreement, and salvages technically difficult studies. In addition, contrast echocardiography is valuable in specific settings, such as the intensive care unit or emergency department, where high-quality images are often most difficult to acquire. Finally, obstacles to the penetration of contrast echocardiography into routine clinical practice (such as cost/reimbursement, logistics, and education) are discussed.

Four-dimensional reconstruction of the left ventricle using a fast rotating classical phased array scan head: preliminary results

The evaluation of left ventricular function by noninvasive methods is still a major problem in cardiology. Two-dimensional echocardiography requires mental reconstruction of the heart by the physician and is always based on approximation of heart shapes and volumes. Three-dimensional echocardiography is promising but has rhythmic and function constraints because of the acquisition during many cardiac cycles. This article reports a study carried out to validate a new 4-dimensional echocardiography method. With the use of a classical phased-array sensor with a fast rotating motorized motion and a standard ultrasound system, many slices at different angulations are obtained in a single cardiac cycle. After manual endocardial delineation and computation, a representation of the left ventricle (beating heart) and a volume quantification are obtained at each instant of the cardiac cycle. This method has been tested on 11 healthy volunteers and the results are in agreement with those obtained with standard 2-dimensional echocardiography. Because of its simplicity of operation and short time acquisition, this new imaging modality is highly valuable in left ventricle evaluation, even if further studies on pathologic hearts need to be performed.

Real-time three-dimensional ultrasound methods for shape analysis and visualization

Real-time three-dimensional (RT3D) ultrasound is a relatively new imaging modality that uses a special ultrasound transducer consisting of a matrix array of elements. The array electronically steers an ultrasound beam to interrogate a 3D volume of tissue. The real-time nature of RT3D ultrasound differentiates it from reconstructed 3D ultrasound, in which a conventional ultrasound transducer is moved mechanically through the third dimension. RT3D ultrasound is considerably faster than reconstructed 3D ultrasound, making it suitable for capturing continuous rapid motion such as that of the beating heart. Although RT3D ultrasound has not yet found widespread clinical use, these scanners are presently employed in more than 20 locations worldwide, primarily for cardiac research. The author helped develop the RT3D ultrasound technology as well as specialized analysis and visualization methods for the resulting data. In developing such methods, it has been necessary to consider the physical and mathematical processes by which the ultrasound data are collected. Difficulties arise because of high noise, variation in contrast and intensity between scans, ultrasound's nonrectilinear coordinate system, and the anisotropic nature of the echoes themselves. This article reviews these specific difficulties and provides solutions that are applicable to generalized analysis and visualization of RT3D ultrasound data. Some of the methods presented can also be applied to other imaging modalities with nonrectilinear coordinates.

Improved 3-D-echocardiographic endocardial border delineation using the contrast agent FS069 (Optison) transesophageal studies in a porcine model

3-D echocardiography has the potential for quantitative assessment of regional wall motion. However, the 3-D procedures used to date do not provide the same spatial and temporal resolution as 2-D echocardiography, which results in problems with border delineation of the endocardium. There are, as yet, few studies testing if the use of contrast agent can improve endocardial definition in the 3-D data set. FS069 (Optison) was used for the first time for this purpose in the present study. A total of 12 mechanically-ventilated pigs were examined by transesophageal 3-D echocardiography, 1. using fundamental imaging and 2. following left-atrial injection of FS069 (Optison). The left ventricle was analyzed using an 18-segment model. Score with the value 0 (not visible), 1 (moderately visible) and 2 (well defined) were used to rate endocardial definition. All segments were assessed both end-diastolic and end-systolic. Various LV regions were examined by grouping segments (anterior/lateral/inferior and basal/mid-ventricular/apical). Using the contrast agent, the proportion of nonvisible segments fell diastolic from 40 (18.5%) to 15 (6.9%), and systolic from 26 (12.0%) to 11 (5.1%). The proportion of well defined segments increased diastolic from 62 (28.7%) to 108 (50%) and systolic from 73 (33.8%) to 123 (56.9%). The mean visibility score increased diastolic from 1.10 +/- 0.68 to 1.43 +/- 0.62 (p < 0.001), systolic from 1.22 +/- 0.64 to 1.52 +/- 0.59 (p < 0.001). The benefit was greatest in regions where the visibility score was lowest without contrast: in the area of the lateral wall and systolic near the apex. In conclusion, the use of FS069 (Optison) results in significantly better endocardial delineation in the 3-D data set. This could be important in future for the 3-D echocardiographic assessment of regional wall motion.

Three-dimensional echocardiography: historical development and current applications

Three-dimensional (3D) echocardiography facilitates spatial recognition of intracardiac structures, potentially enhancing diagnostic confidence of conventional echocardiography. The accuracy of 3D images has been validated in vitro and in vivo. In vitro, a detail 1.0 mm in dimension and 2 details separated by 1.0 mm can be identified from a volume-rendered 3D image. In vitro 3D volume measurements are underestimated by approximately 4.0 mL. In vivo, left ventricular volume measurements correlate highly with both cineventriculography (limits of agreement +/-18 mL for end diastole and +/-10 mL for end systole) and magnetic resonance imaging, including measurements for patients with functionally single ventricles. Studies on congenital heart lesions have shown good accuracy and good reproducibility of dynamic "surgical" reconstructions of septal defects, aortoseptal continuity, atrioventricular junction, and both left and right ventricular outflow tract morphology. Transthoracic 3D echocardiography was shown feasible in 81% to 96% of patients with congenital heart defects and provided additional information to that available from conventional echocardiography in 36% of patients, mainly in more detailed description of mitral valve morphology, aortoseptal continuity, and atrial septum. In patients with mitral valve insufficiency, 3D echocardiography was shown to be accurate in the quantification of the dynamic mechanism of mitral regurgitation and in the assessment of mitral commissures in patients with mitral stenosis. This includes not only valve tissue reconstruction but also color flow intracardiac jets. Three-dimensional reconstructions of the aortic valve were achieved in 77% of patients, with an accuracy of 90%. In conclusion, the role of 3D echocardiography, which continues to evolve, shows promise in the assessment of congenital and acquired heart disease.