Local dysfunction and asymmetrical deformation of mitral annular geometry in ischemic mitral regurgitation: a novel computerized 3D echocardiographic analysis.

OBJECTIVE: Most studies of the pathogenesis of functional mitral regurgitation (MR) have focused on alterations in ventricular function and geometry. We used a novel 3D echocardiographic method to assess abnormalities in mitral annular (MA) geometry and motion in patients with ischemic MR (IMR) and compared these data to those obtained from normal subjects and from patients with MR caused by dilated cardiomyopathy (DMR). METHODS: Real time 3D echo was performed in 12 normal subjects, 25 with IMR, and 14 with DMR. Eight points along the saddle-shaped MA were identified using our software at systole and diastole. From these eight points, four annular diameters at each cardiac phase were determined. Annular motion was assessed by measuring local displacement (LD) of a given point between systole and diastole. RESULTS: Annular motion was different between groups: IMR had smaller LD in posterior MA segments than did normals (2.6 +/- 1.1 vs 4.8 +/- 1.9 mm, P < 0.01), while DMR had globally reduced LD. In IMR systolic MA dilatation was striking in the anterior-posterior (diameter; IMR vs controls, 28.3 +/- 3.5 vs 22.5 +/- 2.2 mm, P< 0.05) and anterolateral-posteromedial (31.7 +/- 3.5 vs 25.1 +/- 2.2 mm, P < 0.05) directions; in IMR, systolic MA diameters in these two directions correlated with MR severity(P = 0.02). MA dilatation occurred globally in DMR. CONCLUSION: This novel 3D echo method demonstrated that MA motion and dilatation were asymmetric in IMR and symmetric in DMR. These differences in MA geometry and motion may aid in the development of distinct new therapies for IMR and DMR.

Echocardiographic insights into atrial and ventricular mechanisms of functional tricuspid regurgitation.

BACKGROUND: The etiology of functional tricuspid regurgitation (TR) is thought to be annular dilatation and tethering of tricuspid valve (TV) leaflets. However, mechanisms of leaflet tethering are incompletely understood. The purpose of this study was therefore to investigate the relationships between TV annular dilatation and leaflet tethering with the severity of functional TR and to investigate factors that influence these TV deformations. METHODS: Two hundred forty-five patients with functional TR had 2-dimensional echocardiography. Echocardiographic investigations focused on the ventricles and on the TV. Ventricular measurements included left ventricular (LV) volume, right ventricular (RV) area, and RV spherical index. Valvular measurements included systolic TV annular dimension and apical displacement (tethering height), as well as severity of TR (vena contracta width). RESULTS: Tethering height (r2 = 0.25) was related to the severity of TR (P < .001). The RV and right atrium areas influenced both annular dimension and tethering height. However, LV ejection fraction and RV spherical index affected tethering height but not annular dimension. CONCLUSIONS: Tethering of TV leaflets, a determinant of functional TR, is associated with changes in right-sided cavity size as well as RV sphericity and LV function, emphasizing the impact of changes in ventricular geometry and function on the severity of functional TR.

Determinants of ischemic mitral regurgitation in patients with chronic anterior wall myocardial infarction: a real time three-dimensional echocardiography study.

OBJECTIVE: We sought to elucidate the geometric determinants of ischemic mitral regurgitation (IMR) in patients with chronic anterior myocardial infarction (MI). MATERIALS AND METHODS: In 16 patients with anterior MI only (Group A) and 18 patients with both anterior and inferoposterior MI (Group B), three parallel equidistant anteroposterior (AP) planes (medial, central, lateral) perpendicular to the mitral valvular commissure-commissure plane were generated. The systolic tenting area of the mitral valve (MVTa) and the angles between the annular plane and leaflets (anterior, Aalpha; posterior, Palpha) on the AP planes were measured. The left ventricular end-systolic and end-diastolic volumes, and end-diastolic and end-systolic mitral annular area (MAAs) were obtained. RESULT: The regurgitant orifice area (ROA) was significantly smaller in Group A than Group B (0.08 +/- 0.09 vs 0.20 +/- 0.18 cm(2), P < 0.05). In the total of 34 patients, the medial MVTa (P < 0.001), MAAs (P < 0.05) and the spherical index (P < 0.05) were three independent determinants of ROA while the left ventricular volumes were not. MAAs was the only independent determinant of ROA in Group A, while the medial MVTa was in Group B. Palpha (P < 0.05) and MVTa (P = 0.06) tended to be larger in the medial than the lateral side in Group B, while no differences were found in Group A. CONCLUSION: The geometry of the mitral valve apparatus was more important than the left ventricular volumes in determining the severity of IMR in patients with anterior MI. The posteromedial side tenting could play a critical role in causing significant IMR when the inferoposterior MI coexists with anterior MI.

Echocardiographic predictors of successful versus unsuccessful mitral valve repair in ischemic mitral regurgitation.

Mitral valve (MV) annuloplasty is the standard surgical technique for the management of ischemic mitral regurgitation (MR). However, < or = 1/3 of patients develop recurrent MR after annuloplasty. Therefore, we sought to identify the preoperative echocardiographic parameters that predict annuloplasty failure in patients with ischemic MR. Intraoperative transesophageal echocardiograms from 365 patients who underwent MV repair for ischemic MR were reviewed. Of the 365 patients, 297 (81%) had satisfactory outcomes with < 2+ MR, and 68 (19%) had recurrent MR (> or = 2+) during a mean follow-up of 269 days. The mitral annular parameters, including mitral annular diameter, tethering height, and tethering area of the mitral leaflets, were determined in 3 different echocardiographic views. On multiple logistic stepwise regression analysis, a higher mitral annular diameter, higher tethering area, and higher MR severity were identified as independent predictors for failure of MV repair (p < 0.0001). In conclusion, these results demonstrated that preoperative echocardiographic findings can be used to identify patients with ischemic MR at increased risk of repair failure. These echocardiographic measurements should be used to guide the cardiologist and cardiac surgeon in the choice of MV repair versus replacement in patients with ischemic MR.

Tricuspid valve tethering predicts residual tricuspid regurgitation after tricuspid annuloplasty.

BACKGROUND: Tricuspid valve (TV) annuloplasty is recommended for functional tricuspid regurgitation (TR), which is caused by TV annulus dilatation and tethering of the leaflets. However, the impact of TV deformations on the outcome of TV annuloplasty remains unknown. The goal of this study was to investigate the relationship between preoperative TV deformation and residual TR after TV annuloplasty. METHODS AND RESULTS: Two hundred sixteen patients with functional TR had 2D echocardiography before and after TV annuloplasty. Right ventricular fractional area change and left ventricular ejection fraction were determined with the apical views. Minimal TV annulus diameter was determined by frame-by-frame analysis. The distance of TV tethering was measured from the annulus plane to the coaptation point and tethering area by tracing the leaflets from the annulus plane. TR severity was determined by the ratio of the maximal jet area to the corresponding right atrial area. The severity of residual TR was associated with age, right and left ventricular dysfunction, tethering distance and area, and severity of preoperative TR (all P<0.05). TV annular dimension was not associated with outcome of TV annuloplasty. Multivariate analysis revealed that age, tethering distance, and severity of preoperative TR (all P<0.001) were independent parameters predicting residual TR. The sensitivity and specificity in predicting residual TR after surgery were 86% and 80% for tethering distances >0.76 cm and 82% and 84% for tethering areas >1.63 cm2, respectively. CONCLUSIONS: Severe TV tethering predicted residual TR after TV annuloplasty, whereas preoperative TV annular dimension was not associated with outcome of TV annuloplasty.