Nozomi Wada

Mitral annulus flattens in ischemic mitral regurgitation: geometric differences between inferior and anterior myocardial infarction: a real-time 3-dimensional echocardiographic study.

Background—New surgical strategies to restore the saddle shape of the mitral annulus are expected to increase annuloplasty effectiveness. Preoperative and postoperative configuration of the curved annulus, however, is difficult to quantify with 2-dimensional echocardiography. We sought to investigate the geometric deformity in the mitral annulus in ischemic mitral regurgitation (MR), comparing inferior and anterior myocardial infarction (MI) with the use of a custom quantitation software system with transthoracic 3-dimensional echocardiography. Methods and Results—We performed real-time 3-dimensional echocardiography in 23 patients with ischemic MR attributable to inferior MI or anterior MI and in 10 controls. Three-dimensional data were cropped into 18 radial planes, and we manually marked the annulus in mid systole. Three-dimensional annular images were reconstructed, and annular circumferences, areas, and heights were quantified. Annulus was significantly more dilated and flattened in ischemic MR than in controls and was further deformed in anterior MI as compared with inferior MI (control: circumference 9.9±0.7 cm, area 9.6±0.5 cm2, height 5.0±0.7 mm; inferior MI: circumference 11.5±1.2 cm [P<0.01 compared with control], area 11.4±2.0 cm2 [P<0.05 compared with control], height 3.5±1.6 mm [P<0.05 compared with control]; anterior MI: circumference 14.2±2.4 cm [P<0.0001 compared with control, P<0.05 compared with inferior MI], area 13.7±2.8 cm2 ]P<0.01 compared with control, P<0.05 compared with inferior MI], height 1.7±1.5 mm [P<0.0001 compared with control, P<0.05 compared with inferior MI]). Conclusions—Mitral annulus flattens in ischemic MR. Deformity of the mitral annulus was greater in anterior MI group than in the inferior MI group.

Geometry of the proximal isovelocity surface area in mitral regurgitation by 3-dimensional color Doppler echocardiography: Difference between functional mitral regurgitation and prolapse regurgitation

BACKGROUND The geometry of the proximal isovelocity surface area (PISA) of functional mitral regurgitation (MR), which is conventionally assumed to be a hemisphere, remains to be clarified. We investigated the 3-dimensional (3D) geometry of PISA of functional MR as opposed to that of MR due to mitral valve prolapse (MVP) by real-time 3D echocardiography with color Doppler capability. METHODS Twenty-seven patients with functional MR and 27 patients with MVP were examined. The horizontal PISA length in the commissure-commissure plane and each PISA radius in 3 anteroposterior planes (medial, central, and lateral) were measured by real-time 3D echocardiography with 3D software. The effective regurgitant orifice (ERO) area was calculated with the maximum PISA radius and compared to that by 2D quantitative Doppler method. RESULTS En-face 3D color Doppler images showed an elongated and slightly curved PISA geometry along the leaflet coaptation in functional MR, whereas the geometry was rounder in MVP. The PISA horizontal length in functional MR was longer than that in MVP (2.3 +/- 0.4 vs 1.2 +/- 0.2 cm, P < .001). The PISA method with the maximum radius underestimated the ERO area by 2D quantitative Doppler method (by 24%) in functional MR, but not in MVP. CONCLUSIONS The geometry of PISA in functional MR was elongated, distinctly different from the more focal pathology of MVP, leading to underestimation of the ERO area by PISA method.

Diagnostic Value of Left Ventricular Outflow Area in Patients with Hypertrophic Cardiomyopathy: A Real-Time Three-Dimensional Echocardiographic Study

BACKGROUND Earlier studies demonstrated the ability of real-time 3-dimensional (3D) echocardiography (3DE) to measure left ventricular outflow tract (LVOT) area (A(LVOT)) in patients with hypertrophic cardiomyopathy (HCM). However, its clinical value is unknown. OBJECTIVE We sought to investigate the feasibility and accuracy of real-time 3DE-derived A(LVOT) to diagnose significant LVOT obstruction in a large number of patients with HCM. METHODS A total of 162 patients with HCM had 3DE by using a volumetric system. The smallest A(LVOT) during systole was determined by moving a 2-dimensional plane in 3D space. The pressure gradient across LVOT was assessed by continuous wave Doppler method. Provocation was performed in patients without significant LVOT obstruction (pressure gradient across LVOT < 50 mm Hg) at rest. RESULTS Twenty (12%) patients with poor image quality of 3DE were excluded; 16 (28%) patients with a volumetric system, but only 4 (4%) patients with commercial equipment (P < .001). In the remaining 142 patients, A(LVOT) inversely correlated with pressure gradient across LVOT both at rest (r = 0.82, P < .001) and after provocation (r = 0.60, P < .001). The value of A(LVOT) less than 0.85 cm(2) and less than 2.0 cm(2) predicted resting and provokable LVOT obstruction with sensitivity of 87% and 81%, and specificity of 77% and 90%, respectively. CONCLUSIONS Real-time 3DE measurement of A(LVOT) was successful in diagnosing and quantifying LVOT obstruction at rest and after provocation in a large number of patients with HCM.

Doppler-derived preoperative mitral regurgitation volume predicts postoperative left ventricular dysfunction after mitral valve repair

BACKGROUND Unexpected postoperative left ventricular (LV) dysfunction after valve repair for mitral regurgitation (MR) occurs in some patients with normal preoperative LV function. Identification of factors that predispose to such LV dysfunction would enhance our understanding of the indications and outcomes of surgery. METHODS We retrospectively analyzed pre- and postoperative (median fourth day) echocardiograms of 174 patients undergoing valve repair for pure and isolated MR. Preoperative MR volume was quantified by the quantitative Doppler and/or proximal isovelocity surface area method. RESULTS There was an incremental predictive value of MR quantification over the current recommendations (global chi(2) from 48.14 to 81.57, P < .001; Hosmer-Lemeshow test, P = .98), for postoperative LV dysfunction, defined as ejection fraction <50%. The independent predictors were MR volume and LV end-systolic dimension (P < .001 and P = .01, respectively). Sixty-nine patients underwent surgery before development of the current surgical criteria, namely, symptoms, atrial fibrillation, preoperative LV dysfunction, or pulmonary hypertension. Of these, MR volume was the only independent significant predictor (P < .001) of unexpected postoperative LV dysfunction that developed in 14 patients (20%). Unexpected LV dysfunction could be predicted with sensitivity of 86% (95% CI 67%-100%) and specificity of 89% (95% CI 81%-97%), using the optimal cutoff of 80 mL for MR volume. CONCLUSIONS Doppler-derived preoperative MR volume is a powerful predictor of unexpected postoperative LV dysfunction. Prompt mitral valve repair may be beneficial for patients with high likelihood of successful repair and MR volume >/=80 mL.

Different Determinants of Residual Tricuspid Regurgitation after Tricuspid Annuloplasty: Comparison of Atrial Septal Defect and Mitral Valve Prolapse

We analyzed 20 patients with atrial septal defect (ASD) who underwent tricuspid valve (TV) annuloplasty and ASD closure, 21 patients with mitral valve prolapse (MVP) who underwent mitral valve (MV) and TV annuloplasty, and 20 healthy controls. Severity of tricuspid regurgitation (TR) was assessed by maximal TR jet area/RA area (%TR) using echocardiography before and early after surgery. Before surgery, 2 groups of patients showed significantly greater RA area, TV annulus diameter, RV systolic pressure, and %TR than controls. %TR was significantly decreased after surgery, whereas residual TR was shown in 19% of the MVP group and 25% of the ASD group. Preoperative TV tethering height and %TR were significantly associated with postoperative %TR in the MVP group, whereas preoperative RV fractional area change, RV spherical index, and RV systolic pressure were significantly associated with postoperative %TR in the ASD group. Risk stratification after TV annuloplasty should take the structural abnormality into consideration.

Diagnosis of Myocardial Viability by Fluorodeoxyglucose Distribution at the Border Zone of a Low Uptake Region

Purpose In cardiac 2-[F-18]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) examination, interpretation of myocardial viability in the low uptake region (LUR) has been difficult without additional perfusion imaging. We evaluated distribution patterns of FDG at the border zone of the LUR in the cardiac FDG-PET and established a novel parameter for diagnosing myocardial viability and for discriminating the LUR of normal variants. Materials and Methods Cardiac FDG-PET was performed in patients with a myocardial ischemic event (n = 22) and in healthy volunteers (n = 22). Whether the myocardium was not a viable myocardium (not-VM) or an ischemic but viable myocardium (isch-VM) was defined by an echocardiogram under a low dose of dobutamine infusion as the gold standard. FDG images were displayed as gray scaled-bulls eye mappings. FDG-plot profiles for LUR (= true ischemic region in the patients or normal variant region in healthy subjects) were calculated. Maximal values of FDG change at the LUR border zone (a steepness index; Smax scale/pixel) were compared among not-VM, isch-VM, and normal myocardium. Results Smax was significantly higher for n-VM compared to those with isch-VM or normal myocardium (ANOVA). A cut-off value of 0.30 in Smax demonstrated 100% sensitivity and 83% specificity for diagnosing n-VM and isch-VM. Smax less than 0.23 discriminated LUR in normal myocardium from the LUR in patients with both n-VM and isch-VM with a 94% sensitivity and a 93% specificity. Conclusion Smax of the LUR in cardiac FDG-PET is a simple and useful parameter to diagnose n-VM and isch-VM, as well as to discriminate thr LUR of normal variants.