A method for the morphological analysis of the regurgitant mitral valve using three dimensional echocardiography

Let there be light! The meteoric rise of cardiac imaging

Imaging plays a central role in modern cardiovascular practice. It is a field characterised by exciting technological advances that have shaped our understanding of pathology and led to major improvements in patient diagnosis and care. The UK has played a key international role in the development of this subspecialty and is the current home to many of the leading global centres in multimodality cardiovascular imaging. In this short review, we will outline some of the key contributions of the British Cardiovascular Society and its members to this rapidly evolving field and look at how this relationship may continue to shape future cardiovascular practice.

Three-Dimensional Echocardiography Assessment of Right Ventricular Volumes and Function: Technological Perspective and Clinical Application

Right ventricular (RV) function has important prognostic value in a variety of cardiovascular diseases. Due to complex anatomy and mode of contractility, conventional two-dimensional echocardiography does not provide sufficient and accurate RV function assessment. Currently, three-dimensional echocardiography (3DE) allows for an excellent and reproducible assessment of RV function owing to overcoming these limitations of traditional echocardiography. This review focused on 3DE and discussed the following points: (i) acquisition of RV dataset for 3DE images, (ii) reliability, feasibility, and reproducibility of RV volumes and function measured by 3DE with different modalities, (iii) the clinical application of 3DE for RV function quantification.

Role of modern 3D echocardiography in valvular heart disease

Three-dimensional (3D) echocardiography has been conceived as one of the most promising methods for the diagnosis of valvular heart disease, and recently has become an integral clinical tool thanks to the development of high quality real-time transesophageal echocardiography (TEE). In particular, for mitral valve diseases, this new approach has proven to be the most unique, powerful, and convincing method for understanding the complicated anatomy of the mitral valve and its dynamism. The method has been useful for surgical management, including robotic mitral valve repair. Moreover, this method has become indispensable for nonsurgical mitral procedures such as edge to edge mitral repair and transcatheter closure of paravaluvular leaks. In addition, color Doppler 3D echo has been valuable to identify the location of the regurgitant orifice and the severity of the mitral regurgitation. For aortic and tricuspid valve diseases, this method may not be quite as valuable as for the mitral valve. However, the necessity of 3D echo is recognized for certain situations even for these valves, such as for evaluating the aortic annulus for transcatheter aortic valve implantation. It is now clear that this method, especially with the continued development of real-time 3D TEE technology, will enhance the diagnosis and management of patients with these valvular heart diseases.

Comparison of real-time three-dimensional transesophageal echocardiography to two-dimensional transesophageal echocardiography for quantification of mitral valve prolapse in patients with severe mitral regurgitation

Real-time 3-dimensional (3D) transesophageal echocardiography (TEE) provides more accurate geometric information on the mitral valve (MV) than 2-dimensional (2D) TEE. The aim of this study was to quantify MV prolapse using real-time 3D TEE in patients with severe mitral regurgitation. In 102 patients with severe mitral regurgitation due to MV prolapse and/or flail, 2D TEE quantified MV prolapse, including prolapse gap and width in the commissural view. Three-dimensional TEE also determined prolapse gap and width with the use of the 3D en face view. On the basis of the locations of MV prolapse, all patients were classified into group 1 (pure middle leaflet prolapse, n = 50) or group 2 (involvement of medial and/or lateral prolapse, n = 52). Prolapse gap and prolapse width determined by 3D TEE were significantly greater than those by 2D TEE (all p values <0.001). The differences in prolapse gap and prolapse width between 2D TEE and 3D TEE were significantly greater in group 2 than group 1 (Δ gap 1.3 ± 1.4 vs 2.4 ± 1.8 mm, Δ width 2.5 ± 3.0 vs 4.4 ± 5.1 mm, all p values <0.01). The differences in prolapse gap and width between 2D TEE and 3D TEE were best correlated with 3D TEE-derived prolapse width (r = 0.41 and r = 0.74, respectively). Two-dimensional TEE underestimated the width of MV prolapse and leaflet gap compared to 3D TEE. Two-dimensional TEE could not detect the largest prolapse gap and width, because of the complicated anatomy of the MV. In conclusion, 3D TEE provided more precise quantification of MV prolapse than 2D TEE.

Real-time three-dimensional transesophageal echocardiography for assessment of mitral valve functional anatomy in patients with prolapse-related regurgitation

The aim of the study was to evaluate the additional diagnostic value of real-time 3-dimensional transesophageal echocardiography (RT3D-TEE) for surgically recognized mitral valve (MV) prolapse anatomy compared to 2-dimensional transthoracic echocardiography (2D-TTE), 2D-transesophageal echocardiography (2D-TEE), and real-time 3D-transthoracic echocardiography (RT3D-TTE). We preoperatively analyzed 222 consecutive patients undergoing repair for prolapse-related mitral regurgitation using RT3D-TEE, 2D-TEE, RT3D-TTE, and 2D-TTE. Multiplanar reconstruction was added to volume-rendered RT3D-TEE for quantitative prolapse recognition. The echocardiographic data were compared to the surgical findings. Per-patient analysis of RT3D-TEE identified prolapse in 204 patients more accurately (92%) than 2D-TEE (78%), RT3D-TTE (80%), and 2D-TTE (54%). Even among those 60 patients with complex prolapse (>1 segment localization or commissural lesions), RT3D-TEE correctly identified 58 (96.5%) compared to 42 (70%), 31 (52%), and 21 (35%) detected by 2D-TEE, RT3D-TTE, and 2D-TTE (p < 0.0001). Multiplanar reconstruction enabled RT3D-TEE to differentiate dominant (≥5-mm displacement) and secondary (2 to <5-mm displacement) prolapsed segments in agreement with surgically recognized dominant lesions (100%), but with a low predictive value (34%) for secondary lesions. In addition, owing to the identification of clefts and subclefts (indentations of MV tissue that extended ≥50% or <50% of the total leaflet height, respectively), RT3D-TEE accurately characterized the MV anatomy, including that which deviated from the standard nomenclature. In conclusion, RT3D-TEE provided more accurate mapping of MV prolapse than 2D imaging and RT3D-TTE, adding quantitative recognition of dominant and secondary lesions and MV anatomy details.

Pre-operative transthoracic real-time three-dimensional echocardiography in patients undergoing mitral valve repair: accuracy in cases with simple vs. complex prolapse lesions

AIMS

The aim of this study, undertaken in patients who underwent mitral valve (MV) repair surgery, was to evaluate the accuracy of pre-operative three-dimensional (3D) transthoracic echocardiography (TTE) in the evaluation of MV pathology in cases with simple or complex lesions.

METHODS AND RESULTS

Two hundred consecutive patients with severe mitral regurgitation due to degenerative MV prolapse underwent a complete 3DTTE the day before surgery. Three-dimensional TTE data were compared with MV surgical inspection. Three-dimensional echocardiography was feasible in a relatively short time (5 ± 3 min) with good (67%) and optimal (21%) imaging quality in the majority of cases. Three-dimensional TTE allowed an accurate identification (95% accuracy) of all MV lesions. Seventy-three (36.5%) patients had simple lesions at 3DTTE and 71 of them (97.2%) underwent a simple surgical procedure; 127 (63.5%) had complex lesions at 3DTTE and, in these cases, surgeons performed either simple procedures (48%) or complex procedures (47.2%) or valve replacement in 4.7% (after a first attempt for repair).

CONCLUSION

Three-dimensional TTE is feasible, not time-consuming, and accurate in identifying cases with simple vs. complex MV lesions.

Intraoperative application of geometric three-dimensional mitral valve assessment package: a feasibility study

OBJECTIVE

To study the feasibility of using 3-dimensional (3D) echocardiography in the operating room for mitral valve repair or replacement surgery. To perform geometric analysis of the mitral valve before and after repair.

DESIGN

Prospective observational study.

SETTING

Academic, tertiary care hospital.

PARTICIPANTS

Consecutive patients scheduled for mitral valve surgery.

INTERVENTIONS

Intraoperative reconstruction of 3D images of the mitral valve.

RESULTS

One hundred and two patients had 3D analysis of their mitral valve. Successful image reconstruction was performed in 93 patients-8 patients had arrhythmias or a dilated mitral valve annulus resulting in significant artifacts. Time from acquisition to reconstruction and analysis was less than 5 minutes. Surgeon identification of mitral valve anatomy was 100% accurate.

CONCLUSIONS

The study confirms the feasibility of performing intraoperative 3D reconstruction of the mitral valve. This data can be used for confirmation and communication of 2-dimensional data to the surgeons by obtaining a surgical view of the mitral valve. The incorporation of color-flow Doppler into these 3D images helps in identification of the commissural or perivalvular location of regurgitant orifice. With improvements in the processing power of the current generation of echocardiography equipment, it is possible to quickly acquire, reconstruct, and manipulate images to help with timely diagnosis and surgical planning.

Accuracy of real-time 3-dimensional echocardiography in the assessment of mitral prolapse. Is transesophageal echocardiography still mandatory?

BACKGROUND

Segmental analysis in mitral prolapse is important to decide the chances of valvular repair. Multiplane transesophageal echocardiography (TEE) is the only echocardiographic tool validated for this aim hitherto. The aim of the study was to assess if segmental analysis can be performed with transthoracic real-time 3-dimensional (3D) echocardiography as accurately as with TEE, hence representing a valid alternative to TEE.

METHODS

Forty-one consecutive patients diagnosed with mitral prolapse underwent TEE and a complete 3D echocardiography study, including parasternal and apical real-time; apical full-volume; and 3D color full-volume. Investigators performing TEE were blinded to the 3D results.

RESULTS

Three-dimensional echocardiogram was feasible in 40 to 41 patients (97.7%). Ages ranged from 15 to 92 years, and all possible anatomical patterns of prolapse were represented. Thirty-seven patients (90.2%) had mitral regurgitation of any degree. The level of agreement was k = 0.93 (P < or = .0001), sensitivity of 96.7%, specificity of 96.7%, likelihood ratio for a positive result of 29.0%, and likelihood ratio for a negative result of 0.03%. Four false positives were found, corresponding to scallops A2 (1), A3 (2), and P3 (1). Four false negatives were found, corresponding to scallops A1 (2) and P1 (2). Sensitivity and specificity in the scallop P2 were 100%.

CONCLUSION

Segmental analysis in mitral prolapse can be performed with transthoracic real-time 3D echocardiography as accurately as with TEE. False negatives tend to appear around the anterolateral commissure, whereas false positives tend to appear around the posteromedial commissure. Highest accuracy was reached in central scallops.

Accuracy of real-time 3D echocardiography in the evaluation of functional anatomy of mitral regurgitation

OBJECTIVE

To evaluate the feasibility of mitral valve (MV) reconstruction protocol by real-time 3D echocardiography (RT3DE) in the assessment mitral regurgitant (MR) lesions, and to determine the accuracy of RT3DE compared with transthoracic (TTE) and transesophageal (TEE) echocardiographies using surgical findings as gold standard.

PATIENTS AND METHODS

Sixty-three consecutive patients (mean age 61.7+/-12.5 years, 35 men and 28 women) with severe organic MR were enrolled. Data were acquired in zoom and in full-volume modes from apical and/or parasternal windows. A volume rendered en-face view of MV and five serial longitudinal cut planes were reconstructed to visualize all segments of both leaflets.

RESULTS

The feasibility of RT3D reconstruction was 94%. Compared with surgical diagnosis, the accuracy of RT3D was 91% for aetiology, 92% for mechanisms, 94% for prolapse, 88% for flail and 94% for defect location. Diagnostic accuracy was significant higher for RT3D than TTE for all end points except for flail lesion and similar to TEE but inferior to this for flail lesion. The accuracy, sensitivity and specificity were higher in patients with good-excellent than those with poor image quality regarding aetiology, mechanisms and defect location (all p=0.0001).

CONCLUSIONS

RT3D imaging of MV is feasible and accurate in defining aetiology, mechanism and defect location in patients with MR and has incremental diagnostic value if TTE is inconclusive and similar diagnostic value of TEE except for flail lesion. RT3D, at least in patients with good acoustic window, may obviate the need for subsequent TEE and/or can be considered a complementary technique to study MV in patients with MR.

Three-Dimensional Echo for the Assessment of Valvular Heart Disease

Three-dimensional echocardiography (3DE) is a valuable tool to be used in addition to and not instead of two-dimensional echocardiography by providing complementary information and improved quantitative accuracy and reproducibility compared with two-dimensional techniques. 3DE has the potential to become the standard echocardiographic examination procedure for the assessment of valvular disease. This article describes applications of 3DE.

Head-to-head comparison of two- and three-dimensional transthoracic and transesophageal echocardiography in the localization of mitral valve prolapse

OBJECTIVES

The aim of this study, undertaken in patients who underwent mitral valve (MV) repair surgery, was to evaluate the feasibility and accuracy of 3-dimensional (3D) transthoracic (TTE) and transesophageal (TEE) echocardiography in the evaluation of MV pathology.

BACKGROUND

A pre-operative assessment of MV anatomy is essential to surgical design in patients undergoing MV repair. Although 2-dimensional (2D) echocardiography provides precise information regarding MV anatomy, 3D TTE and 3D TEE could increase the understanding of MV apparatus and individual scallop identification.

METHODS

One-hundred-twelve consecutive patients with severe mitral regurgitation due to MV prolapse underwent a complete 2D and 3D TTE the day before surgery and a complete 2D and 3D TEE in the operating room. Echocardiographic data obtained by the different techniques were compared with surgical inspection.

RESULTS

Three-dimensional techniques were feasible in a relatively short time (3D TTE: 7 +/- 4 min; 3D TEE: 8 +/- 3 min), with good (3D TTE 55%; 3D TEE 35%) and optimal (3D TTE 21%; 3D TEE 45%) imaging quality in the majority of cases. Three-dimensional TEE allowed more accurate identification (95.6% accuracy) of all MV lesions in comparison with other techniques. Three-dimensional TTE and 2D TEE had similar accuracies (90% and 87%, respectively), whereas the accuracy of 2D TTE (77%) was significantly lower.

CONCLUSIONS

Three-dimensional TTE and TEE are feasible and useful methods in identifying the location of MV prolapse. They were superior in the description of pathology in comparison with the corresponding 2D techniques and should be regarded as an important adjunct to standard 2D examinations in decisions regarding MV repair.

Comparison of three-dimensional imaging to transesophageal echocardiography for preoperative evaluation in mitral valve prolapse

Transesophageal echocardiography (TEE) is not optimally suited for recognizing which valve segments are involved in type II mitral valve dysfunction. This study was conducted to compare the diagnostic value of TEE and 3-dimensional image reconstruction (3DIR) in the assessment of Carpentier type II mitral valve lesions. In 74 patients (mean age 59+/-13 years) with mitral regurgitation due to type II valve dysfunction, TEE and 3DIR were performed and analyzed by 2 experts before surgical repair. Leaflet scallops and commissures were displayed in short-axis en face and long-axis views. Echocardiographic results were surgically validated. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated, broken down by valve segments and Barlow's disease. Interobserver variability was also determined. Compared with TEE, 3DIR was superior with respect to sensitivity, positive and negative predictive values, and accuracy, although not always significantly (p<0.05). Specificity was higher for P2 lesions. The clearest advantage of 3DIR over TEE was higher sensitivity in commissural and bileaflet defects (p<0.05). Interobserver agreement on 3DIR was stronger than on TEE results (kappa values 0.52 vs 0.82, p<0.0001). There were 16 disagreements (23%) on TEE but only 5 (7%) on 3DIR readings. In conclusion, the more complex the lesion, the more valuable 3DIR is compared with TEE. Before repair, 3DIR is beneficial for the evaluation and classification of the specific pathology in type II mitral valve dysfunction.

Functional mitral regurgitation in heart failure

Mitral regurgitation commonly occurs in patients with heart failure. Systolic dysfunction is the hallmark of dilated cardiomyopathy. Mitral functional regurgitation is mitral incompetence in the absence of intrinsic lesions of the mitral valve apparatus. Echocardiography can make a major contribution to the diagnosis of cardiomyopathies. A more careful anatomic and hemodynamic evaluation of mitral regurgitation mechanisms is possible with spectral Doppler, color Doppler, three-dimensional echocardiography and transesophageal echocardiography. Functional mitral regurgitation is due to the incomplete closure of mitral leaflets and is based on alterations of mitral annulus, left ventricular dimensions, function and geometry, left atrial dimensions and function. Knowledge of the mechanisms of mitral regurgitation helps us to gain an insight into therapeutic interventions that modify the mechanistic factors. Medical therapy reduces the tethering forces and also augments transmitral pressure; surgical approaches can modify geometric relationships in the left ventricular chamber and resynchronization therapy can improve co-ordinated timing of mechanical activation of papillary muscles.

[Update in cardiac imaging techniques. Echocardiography and magnetic resonance imaging]

This article is a review of the main developments in cardiac imaging techniques reported in publications during 2005. Recent advances in digital technology have led to steadily increasing reliance on imaging techniques in the management of cardiovascular disease. We discuss advances in two techniques that fall under the remit of the echocardiography working group: echocardiography and magnetic resonance imaging.

Impact of three-dimensional echocardiography in valvular heart disease

PURPOSE OF REVIEW

Recent advances in the field of three-dimensional (3D) echocardiography have allowed improved visualization of cardiac structures. These advances have also provided valuable insights into cardiac function. The purpose of this review is to describe the recent developments in 3D echocardiography in assessing valvular heart disease.

RECENT FINDINGS

Application of 3D echocardiography to valvular heart disease has improved with advances made in both the hardware and software components of 3D ultrasound systems. The most significant advancement has been the development of a matrix transducer that is capable of rapid real-time 3D acquisition and rendering. There have been many studies evaluating 3D echocardiographic assessment of mitral valve disease, aortic valve disease, as well as congenital heart disease using both real-time 3D transthoracic echocardiography (TTE) as well as off-line reconstructed 3D images from transesophageal echocardiography (TEE) using post image processing. More recent studies have combined the structural 3D information with color Doppler 3D imaging, providing qualitative functional information.

SUMMARY

Developments in the field of 3D ultrasound imaging have allowed better qualitative assessment of valvular structures. The addition of color flow Doppler to the 3D imaging has provided improved visualization of regurgitant lesions and holds great promise for improved quantitative assessment of such lesions. The ongoing miniaturization of transducers and improvements in hardware and software components of ultrasound systems will certainly enhance both the ease of image acquisition as well as image quality, which should result in more precise quantitation of valvular dysfunction. However, clinical benefits of 3D echocardiography are yet to be demonstrated in properly conducted clinical trials, which are needed for wider acceptance of this technique.