Aims. Mitral valve (MV) repair is the preferred treatment for mitral regurgitation associated with organic MV prolapse (MVP). Our goals were to describe by transhoracic real-time 3D echocardiography (RT3D TTE) the pre-operative changes in mitral annulus (MA) dynamic morphology related to MVP, compared with a normal population, and to evaluate the differential long term effects induced by annuloplasty, using either an incomplete flexible band or a complete semi-rigid ring. Methods and Results. Forty-four patients (62±11yrs) with organic MVP and ejection fraction >55% were studied by RT3D TTE the day before MV repair, and 3- and 6-months after (23 patients received a complete rigid ring - CAR, 21 an incomplete flexible band - COS). An age-matched group of 20 normal subjects (57±9yrs) was studied as control. After initialization, the MA was tracked frame-by-frame in 3D, and several parameters computed. Differences in MVP vs controls, vs pre-surgery, and between rings were tested (p<.05). MVP showed enlarged MA resulting in greater area and height during the cardiac cycle, with reduced planarity compared to controls. Annuloplasty resulted in reduced MA area in both CAR and COS, with minimal area change, and planar shape (more evident in CAR than COS). Conclusions. The main factor affecting MA function after annuloplasty appears to be the undersizing of the MA dimensions, and not the choice of the ring. This methodology could represent the basis for further evaluation of implanted rings, to provide the surgeon with additional information to be used in the pre-surgical planning and ring selection.

Background. Intraoperative real-time 3D transesophageal echocardiography (3DTEE) has been shown useful in the evaluation of mitral valve (MV) apparatus, and dedicated commercial software allows its quantitative assessment. Our aims were: a) to quantify the effects induced by prolapse on MV anatomy, in presence of fibroelastic deficiency (FED) or Barlow (BL) disease; b) to assess the effect of surgery on MV apparatus; c) to investigate the potential role of 3DTEE on surgical planning. Methods. 56 patients (29 FED, 27 BL) undergoing MV repair and annuloplasty were studied immediately before and after surgery. Also, 18 age-matched patients (CTRL) with normal MV anatomy, undergoing coronary artery bypass, were used as reference. 3DTEE datasets were acquired and analyzed to quantify several MV annulus and leaflet parameters using dedicated software. Results. MV prolapse and regurgitation were associated with a markedly enlarged annulus (area: FED=12.0±3.2cm², BL=15.4±3.8cm²) and leaflets compared to CTRL (area: 7.5±2.1cm²), while annular height (CTRL=4.5±1.3mm, FED=4.0±1.3mm, BL:5.3±1.6mm) and the mitral aortic angle (CTRL=136±12°, FED=141±12°, BL=137±11°) were similar. BL patients showed greater values than FED patients. MV repair and annuloplasty led to a significant undersizing of leaflets and annular areas (FED=4.0±1.1cmcm², BL=4.9±1.3cm²), diameters, and height (FED=2.6±1.1mm, BL=3.4±1.4mm) compared to CTRL. Coaptation length remained in the normal range (CTRL=30±5mm; FED=24±6mm; BL=28±6mm). Differences between BL and FED were reduced but still present after surgery. Conclusions. Intraoperative 3DTEE allows quantitative evaluation of the MV apparatus in presence of FED or BL disease, and could be useful for immediate assessment of the surgical procedure.

Background. Severe mitral regurgitation is often associated with left atrium (LA) enlargement, which is a well-known predictor of adverse cardiovascular outcomes. However, only few data are available on the effect of mitral valve (MV) repair on LA size. The aim of this study was to evaluate, using real-time three-dimensional echocardiography (RT3DE), the changes in LA volumes after MV repair. Methods. A total of 65 patients with severe mitral regurgitation due to MV prolapse and scheduled for repair at an early stage were enrolled. Before the procedure, RT3DE was performed to assess LA volumes (maximum, preA and minimum). The same evaluation was repeated 6 months and 1 year after MV repair. Twenty normal subjects matched for age and gender were enrolled as a control group. Results. Before MV repair, patients showed significantly higher values of LA volumes (maximum=43±14 mL/m², preA=33±12 mL/m², minimum=23±11 mL/m²) as compared to controls (maximum=22±6 mL/m², preA=13±4 mL/m², minimum=8±3 mL/m²). Six months after the operation, LA volumes significantly decreased (maximum=25±8 mL/m², preA=18±8 mL/m², minimum=13±5 mL/m²), with a further reduction at 1 year follow-up (maximum=23±7 mL/m², preA=15±7 mL/m², minimum=11±5 mL/m²), resulting in values similar to controls. The extent of LA reverse remodeling was inversely correlate with age (r=-0.42) and postoperative transmitral mean pressure gradient (r=-0.32), while a positive correlation was found with the reduction in LV volume after MV repair (r=0.35).
Discussion. In patients with severe mitral regurgitation due to MV prolapse, mitral valve repair, when performed at an early stage, results in a significant LA reverse remodeling.

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

Introduction. Mitral valve (MV) repair has become the preferential treatment for mitral regurgitation (MR) associated with degenerative MV disease. Although the functional benefits of early MV repair are known, the associated alterations in left ventricular (LV) shape have not been studied. Our goal was to evaluate the serial changes in LV performance and 3D shape following MV repair, using a new analysis technique. Methods. Fifty patients (age 59±;12 years) with severe asymptomatic MR and ejection fraction (EF)>55%, undergoing MV repair, were enrolled. Transthoracic real-time 3D echocardiography (RT3DE) was performed the day before, 6 and 12 months after MV repair. An age-matched control group of 50 normal (NL) subjects was studied for comparison. Endocardial surfaces were extracted to compute 3D shape indices of sphericity (S) and conicity (C), which were compared in patients between different time points, and versus the NL group. Results. Postoperatively, LV volumes were decreased compared to pre-surgical values. EF was slightly decreased 6 months after surgery, but restored at 12 months. These changes were associated with modifications in end-diastolic LV shape: prior to surgery, compared to NL, S was augmented and C was decreased; at 6 months, these shape changes were reversed, with no further improvement at 12 months. In conclusion, patients with asymptomatic MR and preserved LV function already exhibit changes in LV shape. Early MV repair leads to near normal morphology after surgery, indicating the benefits of this procedure. Conclusions. RT3DE and novel 3D shape analysis allow detailed serial examination of the complex relationship between LV performance and shape. PubMed

Background. Despite the potential ability of left ventricular (LV) shape analysis to provide independent information complementary to ventricular size and function, in clinical practice only ejection fraction (EF) is currently assessed while LV shape is not routinely quantified. Moreover, geometric assumptions in the computation of EF from multiple two-dimensional (2-D) cut-planes by disc summation or area-length methods, introduce inaccuracies in the estimates. Also, previous approaches for the quantification of LV shape were based on geometric modeling and, as a result, proved inaccurate. Our aims were (1) to develop and test a three-dimensional (3-D) technique for direct quantification of LV shape from real-time 3-D echocardiographic (RT3DE) images without the need for geometric modeling using a new class of LV shape indices; and (2) to study the relationship between these indices and ventricular size and function in normal and abnormal ventricles. Methods. Spherical (S), ellipsoidal (E) and conical (C) shape indices were calculated using custom software for analysis of transthoracic RT3DE images on both global and regional levels and initially tested on computer simulated objects of different shapes. The feasibility of using these indices to differentiate between normal and abnormal ventricles was tested in three groups of patients: normal volunteers (NL, n=9), dilated cardiomyopathy (DCM, n=9) and coronary artery disease with apical regional wall motion abnormalities (RWMA, n=9). Computer simulation demonstrated that these shape indices are size-independent and can correctly classify the simulated objects. Results. In human ventricles, both S and C but not E correlated well with LV volumes and EF. Also, S and C changed throughout the cardiac cycle while E remained almost constant. In addition, both regional and global S and C were able to identify differences between NL and abnormal ventricles: normal ventricles were less spherical and more conical than those of patients with DCM at both end-systole and end-diastole (p<0.05) both globally and regionally. In contrast, in patients with RWMA, similar differences were noted only at end-systole, both on a global level and in the apical region. Conclusions. In this study, we demonstrated the feasibility of quantifying LV shape from transthoracic RT3DE images at both global and regional levels. Potentially, such 3-D shape analysis could be combined with conventional evaluation of LV volume and function to provide a more comprehensive assessment of left ventricular performance. PubMed

Background A reduction in tricuspid annular plane systolic excursion (TAPSE) and peak systolic velocity (PSV) of tricuspid annulus after cardiac surgery is a well-known phenomenon, even though its origin is not well established. Recently, a new three-dimensional (3D) echocardiographic software adapted for right ventricular (RV) analysis has been validated. Aims of this study were to evaluate RV function in patients with mitral valve prolapse undergoing surgical valvular repair and to compare and correlate 3D RV ejection fraction (RVEF) with TAPSE and PSV before and after surgery. Methods and results Forty patients were studied by transthoracic 2D and 3D echocardiography pre- and 3, 6, and 12 months post-surgery. TAPSE (15.5 +/- 3, 16.5 +/- 3, and 18.5 +/- 4 mm at 3, 6, and 12 months, respectively) and PSV (11.9 +/- 2, 12 +/- 2, and 12.8 +/- 3 cm/s at 3, 6, and 12 months, respectively) were significantly (P < 0.001) lower after surgery in comparison with pre-surgical values (TAPSE: 25.3 +/- 4 mm; PSV: 17.8 +/- 4 cm/s). On the contrary, pre-operative RVEF (58.4 +/- 4%) did not change after surgery (56.9 +/- 5, 59.5 +/- 5, and 58.5 +/- 5% at each step). Conclusion Despite the post-operative reduction of RV performance along the long axis suggested by TAPSE and PSV, the absence of a decrease in 3D RVEF leads to caution in the interpretation of these 2D and Doppler parameters after cardiac surgery, supporting the hypothesis of geometrical rather than functional changes in the right ventricle. PubMed

Background Mitral and aortic valves are known to be coupled via fibrous tissue connecting the two annuli. Previous studies evaluating this coupling have been limited to experimental animals using invasive techniques. The new matrix array transesophageal transducer provides high-resolution real-time 3D images of both valves simultaneously. We sought to develop and test a technique for quantitative assessment of mitral and aortic valve dynamics and coupling. Methods and results Matrix array transesophageal (Philips iE33) imaging was performed in 24 patients with normal valves who underwent clinically indicated transesophageal echocardiography. Custom software was used to detect and track the mitral and aortic annuli in 3D space throughout the cardiac cycle, allowing automated measurement of changes in mitral and aortic valve morphology. Mitral annulus surface area and aortic annulus projected area changed reciprocally over time. Mitral annulus surface area was 8.0+/-2.1 cm(2) at end-diastole and decreased to 7.7+/-2.1 cm(2) in systole, reaching its maximum (10.0+/-2.2 cm(2)) at mitral valve opening. Aortic annulus projected area was 4.1+/-1.2 cm(2) at end-diastole, then increased during isovolumic contraction reaching its maximum (4.8+/-1.3 cm(2)) in the first third of systole and its minimum (3.6+/-1.0 cm(2)) during isovolumic relaxation. The angle between the mitral and aortic annuli was maximum (136+/-13 degrees ) at end-diastole and decreased to its minimum value (129+/-11 degrees ) during systole. Conclusion This is the first study to report quantitative 3D assessment of the mitral and aortic valve dynamics from matrix array transesophageal images and describe the mitral-aortic coupling in a beating human heart. This ability may have impact on patient evaluation for valvular surgical interventions and prosthesis design. PubMed

In the current scientific literature, particular attention is dedicated to the study of the mitral valve and to comprehension of the mechanisms that lead to its normal function, as well as those that trigger possible pathological conditions. One of the adopted approaches consists of computational modelling, which allows quantitative analysis of the mechanical behaviour of the valve by means of continuum mechanics theory and numerical techniques. However, none of the currently available models realistically accounts for all of the aspects that characterize the function of the mitral valve. Here, a new computational model of the mitral valve has been developed from in vivo data, as a first step towards the development of patient-specific models for the evaluation of annuloplasty procedures. A structural finite-element model of the mitral valve has been developed to account for all of the main valvular substructures. In particular, it includes the real geometry and the movement of the annulus and papillary muscles, reconstructed from four-dimensional ultrasound data from a healthy human subject, and a realistic description of the complex mechanical properties of mitral tissues. Preliminary simulations allowed mitral valve closure to be realistically mimicked and the role of annulus and papillary muscle dynamics to be quantified. PubMed

Mitral valve (MV) repair is the preferred treatment for mitral regurgitation associated with organic MV prolapse (MVP). Our goal was to describe the dynamic changes in mitral annulus (MA) geometry after annuloplasty, using custom software for MA tracking from transthoracic real-time 3D echocardiography (RT3DE). Forty-four MVP patients were studied by RT3DE the day before MV repair (23 received a complete rigid ring - RIG, 21 an incomplete flexible one - FLEX), and 3 and 6 months after. RT3DE was also obtained in 20 normal (NL) subjects. After manual initialization, the MA was tracked frame-by-frame in the 3D space, and several parameters, concerning MA area, height and shape, were computed. As expected, MVP had an enlarged MA resulting in greater area and height during the cardiac cycle, leading to a reduced planarity compared to NL. Annuloplasty resulted in reduced area in both RIG and FLEX and in a more planar MA shape. Interestingly, at 3 and 6 months, FLEX height was greater than RIG, due to the lower planarity associated with incomplete ring design compared to the complete one. At 6 months, all values were unchanged. MA dynamic analysis from RT3DE was feasible in patients undergoing MV repair, giving new insights in the in-vivo performance of the implanted annular prosthesis. This represents a new tool for the clinical decision process and follow-up monitoring. Full Text

Mitral valve (MV) physiopathological function and the effects of surgical repair can be studied through finite element models (FEMs). However, this approach assumes idealized morphology and boundary conditions limiting the analysis to paradigmatic scenarios and precluding patient-specific surgical planning. To overcome this limitation, we integrated into a MV FEM the patient-specific information about leaflets, annulus and papillary muscles geometry and dynamics, obtained from real-time 3D echocardiography. An ad-hoc web platform was created to facilitate FEM development from remote users, and grant access to parallel computing facilities. This approach was tested simulating MV closure in three normal subjects. Modelled valvular dynamics and quantitative results were consistent with experimental findings from literature. FEMs implementation required about 6 min, while simulations required about 7.5 hours on 32 parallel CPUs. Our approach appears reliable, reproducible and reasonably fast and may constitute the basis for the development of patient-specific tools for MV surgery. Full Text

Mitral valve (MV) repair is the preferential treatment for mitral regurgitation (MR) associated with degenerative MV disease, and the functional benefits of early surgery are known. Our goal was to evaluate the changes in LV shape following MV repair, using a new method based on real-time 3D echocardiography (RT3DE). Fifty patients with severe asymptomatic MR were enrolled. Transthoracic RT3DE imaging was performed the day before, 6 and 12 months after MV repair. A group of 66 normal subjects (NL) was studied as a reference. LV 3D shape indices of sphericity (S) and conicity (C) were computed. Post-operatively, LV volumes were decreased compared to pre-surgical values. EF was slightly decreased 6 months after surgery, but restored at 12 months. Modifications in end-diastolic LV shape were found: prior to surgery, S was elevated and C was decreased compared to NL; at 6 months, these changes were reversed with no further improvement at 12 months. Early MV repair in asymptomatic patients is associated with changes in LV shape which remodels to near normal morphology. Novel 3D shape analysis based on RT3DE, allows serial examination of the complex relationship between LV performance and shape. Full Text

Combined assessment of left ventricular (LV) shape and function could provide new insights into the process of LV remodeling. Real-time 3D echocardiography (RT3DE) allows rapid and accurate semi-automated extraction of LV endocardial surfaces. Our aims were to quantify LV morphology both globally and regionally, using new ellipsoidal (E), spherical (S) and conical (C) shape indices, in a large population in order to define normal values. During systole the LV became less spherical and more conical, while E index remained unchanged. LV volume estimation was more affected by operator subjectivity than C and S indexes computation. These results constitute a reference for future comparisons with serial follow-up of patients during LV remodeling.

Finite element models are an innovative tool for the biomechanical analysis of dynamic cardiac structures, such as the mitral valve. Still, existing models are limited by a simplified description of valve morphology. We aimed at overcoming such limitation by integrating into a mitral valve structural finite element model the information about annulus and papillary muscles geometry and dynamics, obtained in humans by analysis of real time 3D echocardiographic images. The model was used to simulate valve closure from end diastole to systolic peak and to analyze the valve biomechanics. Simulated valvular dynamics and leaflets coaptation were realistic, and all gathered quantitative results were consistent with experimental findings from literature. This novel approach may lead to the development of a patient-specific modeling tool for clinical purposes. Full Text

Combined assessment of left ventricular (LV) shape and function could provide new insights into the process of LV remodeling. Real-time 3D echocardiography (RT3DE) allows rapid and accurate semi-automated extraction of LV endocardial surfaces. Our aims were to quantify LV morphology both globally, using conical (C) and spherical (S) indexes, and locally, studying the mean curvature, in a large set of normal subjects in order to define normal values and test their age-dependency. In each age group the LV became less spherical and more conical during systole. LV shape is the same among the age groups, except for young subjects in which the highest S and lowest C values were found, associated with a greater K at medial and apical inferior regions when compared to other age groups. These results constitute a reference for future comparisons with serial follow up of patients during LV remodeling. Full Text

The recently developed echocardiographic matrix array transesophageal (mTEE) transducer provides realtime 3D images of high spatial and temporal resolution that may be suitable for detailed simultaneous study of functional anatomy of the mitral and aortic valves. We developed software that detects and tracks throughout the cardiac cycle mitral and aortic annuli (MA and AoA) and tested it in 15 patients with normal valves. Following manual initialization of each annulus in 15 planes rotated around the valve's axis, the position of each annulus was tracked using a two-step 3D feature tracking algorithm based on maximum likelihood and Lucas-Kanade optical flow techniques and parameters of valve geometry were automatically measured throughout the cardiac cycle. Frame-by-frame detection and tracking of MA and AoA was possible in all patients. This approach allowed for the first time non-invasive quantitative measurements of the 3D dynamic geometry of normal MA and AoA and their coupling from mTEE data. Full Text

Purpose The importance of right ventricular (RV) function in the surgical outcome has been increasingly recognized. RV function is commonly assessed measuring tricuspid annular plane systolic excursion (TAPSE) and peak systolic velocity (PSV). However, the reduction in such indices after surgery has been related to geometrical rather than functional changes, hampering their reliability in the assessment of post surgical RV function. Our aim was to compare indices of RV function based on tissue Doppler imaging (TDI) to those obtained using new techniques, such as 3D transthoracic echocardiography (TTE) and 2D strain analysis by speckle tracking echocardiography (STE), in a group of patients before and after surgery. Methods Standard 2D TTE and TDI in the apical 4chamber view, and realtime 3D TTE were performed in 40 patients undergoing mitral valve repair the day before and 6 months after surgery. TAPSE and PSV were calculated from TDI. 2D datasets were processed offline using STE software to evaluate longitudinal and radial strains throughout the cardiac cycle. Maximum strain values, separately for the free and the septal walls, were considered. Also, based on the tracked 2D RV contours, fractional area change (FAC) was defined as the % change between the enddiastolic (ED) and endsystolic (ES) RV areas. RV ejection fraction (EF) was calculated as the % change between ED and ES volumes obtained from 3D TTE. Pre and postsurgical values for each parameter were compared (paired ttest). Results TAPSE (Pre:25±4 vs Post:17±3mm), PSV (17±4 vs 12±2 cm/s) and RV FAC (42±8 vs 38±8 %) were found decreased after surgery (p<0.01), while 3D EF maintained the presurgical values (59±7 vs 59±6%, p=0.72). STE showed different results when considering radial or longitudinal strain: both in the free (29±31 vs 21±22%, p=0.15) and septal (21±18 vs 19±12%, p=0.38) walls radial strain was preserved after surgery. Conversely, longitudinal strain was reduced (p<0.01) both in the free (26±7 vs 17±5%) and in the septal walls (20±5 vs 14±4%). Conclusions Comparison of pre and postsurgical RV function showed a globally preserved 3D EF, while different results in 2D indices were found according to the direction of RV motion: longitudinally, TAPSE, PSV and strain were reduced, while radially strain was unchanged; FAC, as a combination of radial and longitudinal properties, was slightly decreased. These findings support the hypothesis of geometrical rather than functional changes in RV function after surgery. STE could be a useful approach to relate local and space dependent changes to the global RV function.

Purpose Mitral valve (MV) repair is the preferred treatment for mitral regurgitation associated with organic MV prolapse (MVP). Our goal was to describe the dynamic changes in mitral annulus (MA) geometry following MV repair with annuloplasty, using custom software for MA tracking from transthoracic real-time 3D echocardiography (RT3DE). Methods Forty-four patients (62±11yrs) with organic MVP and ejection fraction (EF)>55% were studied by RT3DE the day before MV repair (23 received a complete rigid ring - RIG, 21 an incomplete flexible one - FLEX), and 3 and 6 months after. An age-matched group of 20 normal (NL) subjects (57±;9yrs) was studied as control. After manual initialization, the MA was tracked frame-by-frame in the 3D space, and several parameters were computed: min and max 3D surface area (A), delta area (ΔA=maxA-minA), 2D projected vs 3D surface area ratio (A2D/A3D), max longitudinal displacement (LD), mean height (H) and delta height (ΔH=maxH-minH). Differences vs pre-surgery, and in MVP vs NL values were tested (p<.05). Results As expected, MVP had an enlarged MA resulting in greater area and height during the cardiac cycle, leading to a reduced planarity compared to NL. Annuloplasty resulted in: 1) reduced area in both RIG and FLEX, with ΔA during the cardiac cycle; 2) more planar MA shape, as depicted by a reduced H and an increased A2D/A3D. Interestingly, at 3- and 6-months, FLEX height was greater than RIG, due to the lower planarity associated with incomplete ring design compared to the complete one. At 6-months, all values were found unchanged. Conclusions MA dynamic analysis from RT3DE was feasible in patients undergoing MV repair, giving new insights in the in-vivo performance of the implanted annular prosthesis. This would constitute a new useful tool for the surgeon in the clinical decision process and in follow-up monitoring.

Purpose Right ventricular (RV) evaluation is of diagnostic and prognostic importance in cardiac diseases. Recently a new RV dedicated 3D transthoracic echocardiographic (3DTTE) software has been validated. However accuracy of 3DTTE method was analysed in limited series of normal (N) or pathological subjects. Aim of this study was to evaluate 3DTTE reference values of RV volumes and function in a large series of N. Methods We studied 245 N with a good echocardiographic window: 119 men(M) and 126 women (F), at least 15 for each of 6 age deciles from 20 to 80 years. A complete TTE exam was performed and completed with 3D apical acquisitions adapted for RV and for LV 3D evaluation. Off-line 3D RV and LV volumes were obtained through dedicated softwares, RV ejection fraction (RVEF), RV (RVSV) and LV (LVSV) stroke volumes were calculated. Results RV parameters were related to age and gender. RVSV and LVSV were compared. The table shows RV end-diastolic (RVEDV) and end-systolic (RVESV) volumes normalized for body surface area and RVEF across age deciles in the all population and with differentiation into F and M. RV volumes both for F and M were found to satisfy a normal distribution (KS test). RVEDV and RVESV significantly (2-way Anova) varied both with gender (lower in ?) and with age (decrease with ageing). RVSV and LVSV significantly correlated (r = 0.87, bias -1.5±;6.7 ml). Inter-observer variability was RVEDV 0.9±;11 (7%) and RVESV -2.9±;5 (13%). Intra-observer variability was RVEDV 0.6±2.5 (2%) and RVESV 0.7±2.2 (5.5%). Conclusions In conclusion 3D echo analysis of RV volumes and function required normal 3D echo reference ranges. Our data, obtained on 245 normal subjects, may be useful for identification of clinical abnormalities.

Purpose Finite element models (FEMs) constitute an innovative approach for the biomechanical analysis of dynamic cardiac structures, and have been previously applied to analyse mitral valve (MV) behaviour with great benefits compared to animal studies. However, existing MV FEMs, based on animal or ex-vivo measurements, include important simplifications: valve symmetry and planarity, idealized leaflets free margin profile, and no contraction. Moreover, the use of FEM is restricted to highly specialized personnel and is time consuming, both in terms of model preparation and of computational resources. Our aims were: 1) to design a realistic MV FEM by integrating quantitative information from real-time 3D echocardiographic (RT3DE) data, and simulate MV closure from end-diastole (ED) to systolic peak using a high performance processing environment (32 parallel computers); 2) to make the process of model customization to patient-specific data fast and feasible for a remote clinical user. Methods An ad-hoc virtual platform with an easy-to-use graphical user interface (GUI) accessible via world wide web was created. Using this GUI, the remote user implemented the FEM by integrating the following information obtained from RT3DE data: a) the 3D geometrical description of the MV annulus, initially defined at ED, and tracked frame-by-frame by custom software; b) the papillary muscles tips position; c) the spatial orientation and size of the opened leaflets. The FEM was completed with 39 branched chordae tendineae of three orders. To simulate MV closure, a physiological time-dependent pressure up to 120 mmHg was applied on the leaflets. At the end of the simulation, the remote user was invited by e-mail to access and retrieve the model results. Feasibility of the procedure was tested using data obtained from 4 normal volunteers. Results The total time needed for FEM implementation by the remote user was about 6 min. Using 32 parallel computers, MV closure was simulated in <8 hours (81 hours were needed if using a single computer). In the studied subjects, valve dynamics, chordae tendineae tensions, leaflets coaptation and stresses were consistent with in-vitro observations. Conclusions For each subject, a realistic MV model was obtained by integration of quantitative information extracted by RT3DE, thus overcoming most of the limitations of previous models. Remote access to high computational resources allowed obtaining FEM results within a time period reasonable for its clinical application. This approach represents the basis for the development of a patient-specific modeling tool for surgical planning.

Purpose Mitral annulus (MA) dilation is a feature of chronic regurgitation caused by leaflet prolapse. Patients undergoing mitral valve (MV) repair usually have leaflet resection combined with ring annuloplasty. Our goal was to describe the changes in dynamic geometry of the MA after insertion of a semi-rigid ring, using custom software for MA frame-by-frame tracking from transthoracic real-time 3D echo (RT3DE) datasets. Methods 10 patients with organic MV prolapse and ejection fraction (EF) >55% (2D biplane) were studied by RT3DE imaging the day before MV repair and annuloplasty with a semi-rigid ring (size 28 or 30 mm), and 3 and 6 months after surgery. Following initialization, the MA was tracked over time in 3D space, and several MA parameters were then extracted: min and max 3D surface area (A) throughout the cardiac cycle, surface area change (A%: 100*(max-min)/max), 2D projected vs 3D surface area ratio (2D/3D), max longitudinal displacement (LD), mean height (H) and height change (H%: 100*(max-min)/max) throughout the cardiac cycle. Differences vs pre-surgery values were tested (p<.05). Results MA dynamic analysis was feasible in all patients. Post-surgical MA areas were considerably reduced and consistent with nominal ring orifice area; pre-surgery pulsatility was not modified, as shown by area change. Ring implant resulted in increased MA planarity, as evidenced by both reduced MA mean height, and increased area ratio. However, an increasing trend in height change was visible, in particular after 6 months. Longitudinal displacement was reduced post-surgery. Conclusions MA dynamic analysis applied to RT3DE datasets was feasible in patients undergoing surgical repair with concomitant implanted annular prosthesis. This new technique allows gaining new insight about the in-vivo performance of the implanted annular prosthesis, offering to the surgeon a new tool for support in the clinical decision process and in follow-up monitoring.

Background Mitral valve (MV) repair combined with annuloplasty has become the preferential treatment for MV degenerative prolapse, allowing the preservation of the valvular apparatus. Although functional benefits of early MV repair are known, the induced modifications in left ventricular (LV) morphology have never been extensively studied. Our goal was to evaluate by real-time 3D echocardiography (RT3DE) the long-term changes in LV function and shape induced by MV repair, using custom software for 3D shape analysis. Methods 50 patients (age 59±12) with MV organic prolapse and biplane ejection fraction (EF) >55% undergoing MV repair, were enrolled. Transthoracic RT3DE imaging was performed the day before, 6 and 12 months after the intervention. Also, an age-matched group of 66 normal (NL) subjects was prospectively studied for comparison. LV endocardial surfaces were extracted to compute end-diastolic (ED) and end-systolic (ES) volumes, EF, and novel LV 3D shape indices of sphericity (S) and conicity (C). Parameters from MV patients were compared at each phase of the study, and versus the NL group. Results Post-operative LV volumes were decreased compared to pre-surgery values, while EF was slightly decreased 6 months after surgery, but restored to initial values after 1 year. Functional changes accompanied modifications in ED LV shape, with permanently decreased S and increased C indices. In the MV group, index S was found higher while C smaller than in NL, even if a trend toward NL values was noted. Conclusion Early MV repair with annuloplasty resulted in progressive and long lasting changes in LV shape, accompanying the functional improvement. 3D shape analysis of RT3DE images allows early detection of LV reshaping, independent of LV function. This methodology may be useful in the quantitative evaluation of the effects of annuloplasty procedure on LV modifications.

Background Mitral valve (MV) repair combined with annuloplasty has become the preferential treatment for MV degenerative prolapse, allowing the preservation of the valvular apparatus. Although functional benefits of early MV repair are known, the induced modifications in left ventricular (LV) morphology have never been extensively studied. Our goal was to evaluate by real-time 3D echocardiography (RT3DE) the long-term changes in LV function and shape induced by MV repair, using custom software for 3D shape analysis. Methods 50 patients (age 59±12) with MV organic prolapse and biplane ejection fraction (EF) >55% undergoing MV repair, were enrolled. Transthoracic RT3DE imaging was performed the day before, 6 and 12 months after the intervention. Also, an age-matched group of 66 normal (NL) subjects was prospectively studied for comparison. LV endocardial surfaces were extracted to compute end-diastolic (ED) and end-systolic (ES) volumes, EF, and novel LV 3D shape indices of sphericity (S) and conicity (C). Parameters from MV patients were compared at each phase of the study, and versus the NL group. Results Post-operative LV volumes were decreased compared to pre-surgery values, while EF was slightly decreased 6 months after surgery, but restored to initial values after 1 year. Functional changes accompanied modifications in ED LV shape, with permanently decreased S and increased C indices. In the MV group, index S was found higher while C smaller than in NL, even if a trend toward NL values was noted. Conclusion Early MV repair with annuloplasty resulted in progressive and long lasting changes in LV shape, accompanying the functional improvement. 3D shape analysis of RT3DE images allows early detection of LV reshaping, independent of LV function. This methodology may be useful in the quantitative evaluation of the effects of annuloplasty procedure on LV modifications.

Background Assessment of left ventricular (LV) shape using real-time 3D echocardiographic (RT3DE) imaging could provide new insights into LV remodelling following surgical mitral valve (MV) repair. Our goals were: 1) to define reference values for LV shape in a large group of normal subject over a wide age range; 2) to evaluate LV shape changes over time after annuloplasty and MV repair. Methods We studied 119 normal subjects (NL, age 20-88 yrs) and 22 patients (age 54±11) with MV prolapse due to degenerative disease and ejection fraction (EF) >55% (Simpson's rule), undergoing MV repair (Carpentier Physio Ring implant). Transthoracic RT3DE imaging (Philips) was performed one day before surgery, 6 months and 1 year after. LV endocardial surfaces were semi-automatically detected (TomTec) from full-volume datasets throughout the cardiac cycle and used to calculate global LV 3D sphericity (S) and conicity (C) using custom software. Normal sphericity and conicity ranges were defined in the NL group. Results In patients prior to surgery, LV end-diastolic (ED), end-systolic (ES) volumes and EF were 144±57 ml, 57±23 ml, and 61±5%, respectively. ED sphericity was significantly increased, and both ED and ES conicity were decreased compared to NL subjects (Figure, horizontal shaded interval represents mean±2SD in NL). At 6 months post MV repair, due to decreased preload, both ED and ES LV volumes were reduced (102±27 and 46±14 ml, respectively), together with a slight reduction in EF (55±6%). However, both ED sphericity and conicity showed a trend towards normal values. After 1 year, LV volumes remained essentially unchanged (ED: 105±24 ml; ES: 44±11 ml), and EF was close to pre-surgical values (58±4%). Both ED sphericity and conicity showed further improvement compared to pre-surgery, resulting in values not different from the NL ones. Conclusion MV repair with annuloplasty resulted in progressive, persistent and long lasting changes in LV shape, which preceded the improvement in LV function. Post-surgical 3D shape analysis of RT3DE images allows early detection of LV remodelling, independent of LV function. This methodology may be useful in the quantitative evaluation of the effects of annuloplasty procedure on LV remodelling.

Background Mitral valve (MV) repair has become preferential to replacement in the overwhelming majority of patients with MV prolapse (MVP), and is usually combined with ring annuloplasty. Our goal was to study the effects on LV morphology of MV repair with insertion of rings with different geometry, using new custom software for LV 3D shape analysis applied to endocardial surfaces semi-automatically extracted from real-time 3D echocardiographic (RT3DE) images. Methods 30 patients (pts, mean age 57.7±11.8) with MVP and ejection fraction (EF) >55% (Simpson's rule), undergoing MV repair, were evaluated. Cosgrove (COS, n=15) or Carpentier Physio Ring (CPR, n=15) were implanted. RT3DE transthoracic imaging (Philips) was performed the day before the intervention, 6 months and 1 year after surgery. LV endocardial surfaces were extracted (TomTec) and used to compute global LV 3D shape indexes of sphericity (S) and conicity (C). Results As a consequence of the decreased overload, at 6 moths after MV repair a decrease in end diastolic (ED) volume and EF was found in all groups. After 1 year, EF was restored to pre-surgery values. While in CPR pts functional changes were accompanied by modifications in ED LV shape, with a reduction in S and an increase in C after 6 months and preserved at 1 year, COS pts did not show any change in LV shape. Conclusion Our results confirmed the potential utility of coupled LV shape-function 3D analysis by RT3DE in evaluating pts outcome after MV repair with annuloplasty. Different rings seemed to generate different effects on LV shape. This procedure could be utilized to gain new insight about the in-vivo performance of the implanted rings in the mid- and long-term follow up monitoring.

Background Assessment of left ventricular (LV) shape in addition to function could provide new insights into the process of LV remodelling. Real-time 3D echocardiography (RT3DE) allows rapid semi-automated generation of LV endocardial surfaces, which could provide the basis for 3D shape analysis, free of geometric assumptions. Our aim was to quantify LV 3D shape from RT3DE-derived dynamic endocardial surfaces in a large group of normal subjects over a wide range of ages in order to define normal values and test their age-dependency. Methods Transthoracic RT3DE datasets (iE33, Philips) were acquired in 147 normal subjects (age 3-88 yrs). Endocardial LV surfaces were semi-automatically detected (Tomtec) and used to compute: 1) novel 3D shape indexes of sphericity (S) and conicity (C), both global and regional, by helical sampling of the LV surface and comparing the resulting signal with that obtained from a sphere or a cone having the same aspect ratio of the LV; 2) regional mean curvature (K) in each of the 17 LV surface segments, estimated from normal and tangent vectors. End-diastolic (ED) and end-systolic (ES) values were computed for each age decade and compared by ANOVA. Results In each age group, C and S values were different between ED and ES. The highest values in S (ED: 0.64+/-0.05; ES: 0.59+/-0.05) and the lowest values in C (ED: 0.79+/-0.3; ES: 0.82+/-0.03) were found in subjects age<20 yrs, with significant difference from the 40-49 yrs group where the lowest S (ED: 0.61+/-0.03; ES: 0.55+/-0.04) and the highest C (ED: 0.81+/-0.02; ES: 0.84+/-0.02) were noted. In each age group, in all 17 segments, K was larger at ES than ED. For age<20 yrs, a greater K at LV base and in the inferior segment of mid and apical LV was found at ED, compared to other age groups. Conclusions 3D LV shape analysis of RT3DE images may provide useful information on LV morphology and help better understand its relation with LV function. In younger subjects, LV is more spherical and less conical than in older subjects, in particular at mid and apical LV, with larger K in basal segments. These results constitute a reference for future comparisons with serial follow up of patients during LV remodelling.

Background Mitral and aortic valves are known to be coupled via fibrous tissue connecting the two annuli. Previous studies evaluating this coupling have been limited to experimental animals using invasive techniques. We hypothesized that the new matrix array transesophageal (MTEE) transducer could provide high resolution real-time 3D images of the mitral and aortic valves simultaneously, suitable for quantitative assessment of their dynamics and coupling. Methods MTEE imaging was performed in 24 patients with normal valves (Philips iE33) undergoing clinically indicated TEE. Custom software was developed to manually initialize the mitral and aortic annuli (MA, AoA) in 3D space, and then automatically track their motion frame-by-frame (fig A). The following parameters were measured in 3D space throughout the cardiac cycle: MA surface area, AoA projected area and the angle between MA and AoA. In addition, aortic inter-commissural distances were automatically measured at end-diastole (ED), together with commissural heights and coaptation point heights with respect to AoA basal plane (fig B). Results MA surface area and AoA projected area changed reciprocally over time (figs C-D). MA surface area was 8.0±;2.1 cm2 at ED and decreased to 7.7±2.1 cm2 in systole, reaching its maximum (10.0±2.2 cm2) at mitral valve opening. AoA projected area was 4.1±1.2 cm2 at ED, then increased during isovolumic contraction (IVC) reaching its maximum (4.8±1.3 cm2) in the first third of systole and its minimum (3.6 ± 1.0 cm2) during isovolumic relaxation (IVR). MA-AoA angle was maximal (137±14°) at ED and decreased to its minimum value (123±11°) in systole. Aortic inter-commissural distances were 19.4±3.1, 20.1±3.2 and 19.1±3.2 mm respectively for non-coronary, left and right cusps. The height of the commissure between the non-coronary and left cusps (7.9±2.1 mm) was significantly smaller than that between the left and right cusps (8.8±2.2 mm) and between the right and non-coronary (9.1±2.1 mm) cusps. Coaptation point height was 6.3±2.6 mm at ED. Conclusion MTEE imaging allows quantitative 3D assessment of the mitral and aortic valve dynamics and coupling in a beating human heart. This ability may have impact on patient evaluation for valvular surgical interventions and prosthesis design.

Background Mitral valve (MV) repair has become preferential to replacement in the overwhelming majority of patients with MV prolapse, and recent studies and guidelines have underlined the importance of early surgical intervention to preserve long term left ventricular (LV) function. However, few data have explored the complex relationship between LV function vs shape before and after MV repair, mainly because of the unavailability of reliable methods for true 3D LV morphological analysis. Accordingly, the aims of this study were: (1) to develop a technique for the quantification of LV 3D shape from real-time 3D echocardiographic (RT3DE) derived dynamic LV endocardial surfaces; (2) to investigate the effects of MV repair on LV morphology and function. Methods 40 patients (mean age, 57.6±;14.7 years) with MV prolapse and ejection fraction (EF) >55% measured by biplane Simpson's rule, scheduled for MV repair, were studied. Transthoracic RT3DE imaging (iE33, Philips) was performed the day before the intervention and 6 months later. Dynamic LV endocardial surfaces were extracted using commercial software (LV Analysis, TomTec) and used to compute end-diastolic (ED) and end-systolic (ES) volumes, EF, and new 3D shape indexes of sphericity (S), conicity (C) and ellipsoidality (E). This was performed after deriving from the LV surface a 1D signal by helical sampling, and comparing it with that obtained from a sphere, a cone or an ellipsoid, respectively, having the same aspect ratio of the LV. Results Six months after MV repair, patients showed an expected reduction in EF and LV ED volume, due to the decreased overload. This was accompanied by changes in ED LV shape, with a reduction in sphericity and a corresponding increase in conicity, while both ES volume and shape indexes were not affected. The ellipsoidal index remained unchanged, in agreeement with the fact that, independently of LV function and volumes, the LV morphology can be always described by an ellipsoidal shape. Conclusion MV repair led, in the mid-term outcome, to significant changes in ED LV morphology and EF. Our results confirmed the relationship between LV function and shape, and the potential clinical utility of coupled 3D LV shape-function analysis. This methodology could be useful to follow patients during LV remodelling.

Background Mitral annulus dilation is a feature of chronic mitral regurgitation caused by leaflet prolapse. Patients undergoing mitral valve repair usually have leaflet resection combined with ring annuloplasty. Our goal was to compare the dynamic geometry of the mitral annulus after insertion of different rings using new custom software for mitral annulus frame-by-frame tracking on 3D ultrasound datasets. Methods Transthoracic real-time 3D echocardiography (RT3DE, Philips) was performed in 15 normals (NL) and 20 pts with mitral regurgitation, before and 3 months after mitral valve repair and implant with Cosgrove (COS, N=10) or Carpentier Physio ring (CAR, N=10). Our software tracked the mitral annulus over time in 3D space and computed end-diastolic (ED) and maximal mitral annulus surface area, mitral annulus surface area change (100*(Max area-ED)/ED), maximal mitral annulus longitudinal displacement (LD), peak-systolic (S') and early diastolic (E') mitral annulus velocities. Results Mitral annulus dynamic analysis was feasible in all patients. Prior to surgery and compared with NL, all pts with mitral regurgitation had larger mitral annulus surface area throughout the cardiac cycle, reduced area change and decreased E'. Post-annuloplasty, all pts showed decreased mitral annulus size with reduced area change. In particular, CAR pts showed less ring pulsatility, due to higher rigidity associated with ring shape. On the contrary, a sub-physiological change in annulus dimensions throughout the cardiac cycle was preserved in the COS pts, due to the not complete annular ring morphology. Conclusion Dynamic analysis of the mitral annulus applied to RT3DE datasets is feasible in patients undergoing surgical repair with concomitant implanted annular prosthesis. This new technique allowed to evaluate in-vivo the changes induced by the intervention in 3D mitral annulus geometry and dynamics. In particular, the proposed procedure could be utilized to gain new insight about the in-vivo performance of the implanted annular prosthesis, offering to the surgeon a new tool for support in the clinical decision process and in follow up monitoring.

Background Although the aortic and mitral valves are coupled by fibrous aorto-mitral continuity, their synchronous dynamic behavior has not been studied in 3D in humans. We hypothesized that the new matrix array transesophageal (MTEE) transducer would allow simultaneous volumetric imaging of both valves suitable for quantitative measurements. Methods MTEE imaging was performed in 15 patients with normal valves (Phillips, iE33) undergoing clinically indicated TEE. Custom software was used to manually initialize the mitral and aortic annuli (MA, AoA) in 3D space, automatically track them frame by frame (fig A). The following parameters were measured in 3D throughout the cardiac cycle: MA surface area, AoA projected area and the angle between MA and AoA. Results MA surface area and AoA projected area changed reciprocally over time (fig B). MA surface area was 8.0±;2.0 cm2 at ED, decreasing to 7.6±;2.0 cm2 in systole and reaching its maximum (9.2±;2.0 cm2) at mitral valve opening. AoA projected area was 4.4±;1.2 cm2 at ED, then increased reaching its maximum (4.9±;1.3 cm2) during the first third of systole and its minimum (3.8±;1.0 cm2) at isovolumic contraction. MA-AoA angle was maximal (137±;14°) at ED and decreased to its minimum value (123±;11°) in systole. Conclusion MTEE imaging allows quantitative 3D assessment of the mitral and aortic valve dynamics in a beating human heart. This methodology will allow investigation of the impact of valvular surgical interventions on the mitral-aortic coupling.

Background Dynamic changes in mitral annular (MA) geometry throughout the cardiac cycle in patients with flail mitral valves and severe mitral regurgitation (MR) have never been described. Recently, transesophageal real-time 3D echocardiographic imaging has become feasible with the development of the new matrix array TEE (mTEE) probe. Our aim was to quantify the dynamic changes in mitral annular geometry and leaflet tenting in patients with flail mitral valves and severe MR. Method 20 patients were studied, including 11 patients undergoing routine TEE evaluation for flail mitral valves and 9 aged-matched patients with normal mitral valves. Wide-angled, ECG-gated full-voolume acquisitions of the left ventricle were performed using the mTEE probe (iE33, Philips). Images were analyzed using custom software designed for semi-automatic tracking of MA geometry and quantification of its motion throughout the cardiac cycle. Results In all patients, 3D imaging and analysis were successful (Figure). Patients with flail mitral valves had a significantly larger MA surface area at end diastole but preserved MA longitudinal displacement and velocity (Table; FMV - flail mitral valve). Conclusions Real-time 3D visualization of the mitral valve using the new mTEE probe is feasible. Characterization of the MA 3D morphology and dynamics from real-time 3D TEE images may aid in surgical planning in patients with flail mitral valves.