Maiko Shiota

Accuracy of Right Ventricular Volumes and Function Determined by Three-Dimensional Echocardiography in Comparison with Magnetic Resonance Imaging: A Meta-Analysis Study

BACKGROUND Determining right ventricular (RV) function is challenging because of the complex anatomy of the right ventricle. Three-dimensional echocardiography (3DE) has achieved better estimation, but underestimations of volumes and ejection fraction (EF) has often been reported, and no previous study has synthesized these data. The investigators performed a meta-analysis on the bias and examined the related factors. METHODS Studies comparing RV volumes and/or EF between 3DE and magnetic resonance imaging were eligible. A meta-analysis was performed to evaluate the systematic bias. The related bias was investigated using univariate and multivariate regression analysis. RESULTS Twenty-three studies including 807 subjects revealed underestimation of RV volumes (P < .00001) and EF (P = .03). Larger volumes and EF were associated with more underestimation. Older patient age was associated with overestimation of volumes and underestimation of EF. CONCLUSIONS This meta-analysis found underestimation of RV volumes and EF by 3DE and factors affecting the bias. These data provide a more detailed basis for improving the accuracy of 3DE for further clinical application.

Comparison of Left Ventricular Outflow Geometry and Aortic Valve Area in Patients With Aortic Stenosis by 2-Dimensional Versus 3-Dimensional Echocardiography

The present study sought to elucidate the geometry of the left ventricular outflow tract (LVOT) in patients with aortic stenosis and its effect on the accuracy of the continuity equation-based aortic valve area (AVA) estimation. Real-time 3-dimensional transesophageal echocardiography (RT3D-TEE) provides high-resolution images of LVOT in patients with aortic stenosis. Thus, AVA is derived reliably with the continuity equation. Forty patients with aortic stenosis who underwent 2-dimensional transthoracic echocardiography (2D-TTE), 2-dimensional transesophageal echocardiography (2D-TEE), and RT3D-TEE were studied. In 2D-TTE and 2D-TEE, the LVOT areas were calculated as π × (LVOT dimension/2)(2). In RT3D-TEE, the LVOT areas and ellipticity ([diameter of the anteroposterior axis]/[diameter of the medial-lateral axis]) were evaluated by planimetry. The AVA is then determined using planimetry and the continuity equation method. LVOT shape was found to be elliptical (ellipticity of 0.80 ± 0.08). Accordingly, the LVOT areas measured by 2D-TTE (median 3.7 cm(2), interquartile range 3.1 to 4.1) and 2D-TEE (median 3.7 cm(2), interquartile range 3.1 to 4.0) were smaller than those by 3D-TEE (median 4.6 cm(2), interquartile range 3.9 to 5.3; p <0.05 vs both 2D-TTE and 2D-TEE). RT3D-TEE yielded a larger continuity equation-based AVA (median 1.0 cm(2), interquartile range 0.79 to 1.3, p <0.05 vs both 2D-TTE and 2D-TEE) than 2D-TTE (median 0.77 cm(2), interquartile range 0.64 to 0.94) and 2D-TEE (median 0.76 cm(2), interquartile range 0.62 to 0.95). Additionally, the continuity equation-based AVA by RT3D-TEE was consistent with the planimetry method. In conclusion, RT3D-TEE might allow more accurate evaluation of the elliptical LVOT geometry and continuity equation-based AVA in patients with aortic stenosis than 2D-TTE and 2D-TEE.

Non-circular shape of right ventricular outflow tract: a real-time 3-dimensional transesophageal echocardiography study.

Background—The shape of right ventricular outflow tract (RVOT) has been assumed to be circular. The aim of this study was to assess RVOT morphology using 3-dimensional transesophageal echocardiography (3D TEE). Methods and Results—This prospective study included 114 patients who underwent 3D TEE. Two-dimensional (2D) TEE measured maximum and minimum RVOT diameters (RVOTD max and min) during a cardiac cycle. 3D TEE determined RVOT area (RVOTA) max and min, RVOT fractional area change, and RVOT shape index (RVOTSI; vertical/horizontal RVOTD). Cardiac output (CO) was calculated using 2D TEE, 3D TEE, and a Swan-Ganz catheter in 23 patients. All patients were classified into group 1 (RVOTSI ⩽1) or group 2 (RVOTSI >1) based on the RVOT shapes. The mean RVOTSIs were 0.84±0.21(max) and 0.82±0.20 (min). Only 17 patients (14.9%) had circular RVOT (RVOTSI: 0.95–1.05); 82 patients (71.9%) were categorized into group 1 and 32 patients (28.1%) into group 2. 2D TEE, compared with 3D TEE, underestimated RVOTA max and min (both P<0.001). CO with 3D TEE had better agreement with CO with a catheter than CO with 2D TEE (r=0.83 and 0.53, respectively). Conclusions—3D TEE revealed that RVOT geometry was not generally circular but oval with 2 different types. Because of the detailed morphological information of RVOT, 3D TEE could provide more accurate assessment of CO than 2D TEE.Background— The shape of right ventricular outflow tract (RVOT) has been assumed to be circular. The aim of this study was to assess RVOT morphology using 3-dimensional transesophageal echocardiography (3D TEE). Methods and Results— This prospective study included 114 patients who underwent 3D TEE. Two-dimensional (2D) TEE measured maximum and minimum RVOT diameters (RVOTD max and min) during a cardiac cycle. 3D TEE determined RVOT area (RVOTA) max and min, RVOT fractional area change, and RVOT shape index (RVOTSI; vertical/horizontal RVOTD). Cardiac output (CO) was calculated using 2D TEE, 3D TEE, and a Swan-Ganz catheter in 23 patients. All patients were classified into group 1 (RVOTSI ≤1) or group 2 (RVOTSI >1) based on the RVOT shapes. The mean RVOTSIs were 0.84±0.21(max) and 0.82±0.20 (min). Only 17 patients (14.9%) had circular RVOT (RVOTSI: 0.95–1.05); 82 patients (71.9%) were categorized into group 1 and 32 patients (28.1%) into group 2. 2D TEE, compared with 3D TEE, underestimated RVOTA max and min (both P <0.001). CO with 3D TEE had better agreement with CO with a catheter than CO with 2D TEE ( r =0.83 and 0.53, respectively). Conclusions— 3D TEE revealed that RVOT geometry was not generally circular but oval with 2 different types. Because of the detailed morphological information of RVOT, 3D TEE could provide more accurate assessment of CO than 2D TEE.

Determinants of Secondary Pulmonary Hypertension in Patients with Takotsubo Cardiomyopathy.

Although takotsubo cardiomyopathy (TTC) has been reported to have a favorable outcome, many complications may occur in the acute phase. Heart failure is the most common clinical complication in patients with TTC. We aimed to investigate determinants of secondary pulmonary hypertension (PH) in patients with TTC.

ASSESSMENT OF THE LEFT VENTRICULAR OUTFLOW TRACT AND AORTIC VALVE AREA IN PATIENTS WITH AORTIC STENOSIS; 2-DIMENSIONAL AND 3-DIMENSIONAL ECHOCARDIOGRAPHY

The study sought to elucidate the geometry of the left ventricular outflow tract (LVOT) in patients with aortic stenosis and its effect on the accuracy of the continuity equation (CE)-based aortic valve area estimation. Forty patients with aortic stenosis who underwent 2D transthoracic

Non-Circular Shape of Right Ventricular Outflow TractClinical Perspective: A Real-Time 3-Dimensional Transesophageal Echocardiography Study

Background—The shape of right ventricular outflow tract (RVOT) has been assumed to be circular. The aim of this study was to assess RVOT morphology using 3-dimensional transesophageal echocardiography (3D TEE). Methods and Results—This prospective study included 114 patients who underwent 3D TEE. Two-dimensional (2D) TEE measured maximum and minimum RVOT diameters (RVOTD max and min) during a cardiac cycle. 3D TEE determined RVOT area (RVOTA) max and min, RVOT fractional area change, and RVOT shape index (RVOTSI; vertical/horizontal RVOTD). Cardiac output (CO) was calculated using 2D TEE, 3D TEE, and a Swan-Ganz catheter in 23 patients. All patients were classified into group 1 (RVOTSI ⩽1) or group 2 (RVOTSI >1) based on the RVOT shapes. The mean RVOTSIs were 0.84±0.21(max) and 0.82±0.20 (min). Only 17 patients (14.9%) had circular RVOT (RVOTSI: 0.95–1.05); 82 patients (71.9%) were categorized into group 1 and 32 patients (28.1%) into group 2. 2D TEE, compared with 3D TEE, underestimated RVOTA max and min (both P<0.001). CO with 3D TEE had better agreement with CO with a catheter than CO with 2D TEE (r=0.83 and 0.53, respectively). Conclusions—3D TEE revealed that RVOT geometry was not generally circular but oval with 2 different types. Because of the detailed morphological information of RVOT, 3D TEE could provide more accurate assessment of CO than 2D TEE.Background— The shape of right ventricular outflow tract (RVOT) has been assumed to be circular. The aim of this study was to assess RVOT morphology using 3-dimensional transesophageal echocardiography (3D TEE). Methods and Results— This prospective study included 114 patients who underwent 3D TEE. Two-dimensional (2D) TEE measured maximum and minimum RVOT diameters (RVOTD max and min) during a cardiac cycle. 3D TEE determined RVOT area (RVOTA) max and min, RVOT fractional area change, and RVOT shape index (RVOTSI; vertical/horizontal RVOTD). Cardiac output (CO) was calculated using 2D TEE, 3D TEE, and a Swan-Ganz catheter in 23 patients. All patients were classified into group 1 (RVOTSI ≤1) or group 2 (RVOTSI >1) based on the RVOT shapes. The mean RVOTSIs were 0.84±0.21(max) and 0.82±0.20 (min). Only 17 patients (14.9%) had circular RVOT (RVOTSI: 0.95–1.05); 82 patients (71.9%) were categorized into group 1 and 32 patients (28.1%) into group 2. 2D TEE, compared with 3D TEE, underestimated RVOTA max and min (both P <0.001). CO with 3D TEE had better agreement with CO with a catheter than CO with 2D TEE ( r =0.83 and 0.53, respectively). Conclusions— 3D TEE revealed that RVOT geometry was not generally circular but oval with 2 different types. Because of the detailed morphological information of RVOT, 3D TEE could provide more accurate assessment of CO than 2D TEE.

Non-Circular Shape of Right Ventricular Outflow Tract: A Real-Time Three-Dimensional Transesophageal Echocardiography Study

Background—The shape of right ventricular outflow tract (RVOT) has been assumed to be circular. The aim of this study was to assess RVOT morphology using 3-dimensional transesophageal echocardiography (3D TEE). Methods and Results—This prospective study included 114 patients who underwent 3D TEE. Two-dimensional (2D) TEE measured maximum and minimum RVOT diameters (RVOTD max and min) during a cardiac cycle. 3D TEE determined RVOT area (RVOTA) max and min, RVOT fractional area change, and RVOT shape index (RVOTSI; vertical/horizontal RVOTD). Cardiac output (CO) was calculated using 2D TEE, 3D TEE, and a Swan-Ganz catheter in 23 patients. All patients were classified into group 1 (RVOTSI ⩽1) or group 2 (RVOTSI >1) based on the RVOT shapes. The mean RVOTSIs were 0.84±0.21(max) and 0.82±0.20 (min). Only 17 patients (14.9%) had circular RVOT (RVOTSI: 0.95–1.05); 82 patients (71.9%) were categorized into group 1 and 32 patients (28.1%) into group 2. 2D TEE, compared with 3D TEE, underestimated RVOTA max and min (both P<0.001). CO with 3D TEE had better agreement with CO with a catheter than CO with 2D TEE (r=0.83 and 0.53, respectively). Conclusions—3D TEE revealed that RVOT geometry was not generally circular but oval with 2 different types. Because of the detailed morphological information of RVOT, 3D TEE could provide more accurate assessment of CO than 2D TEE.Background— The shape of right ventricular outflow tract (RVOT) has been assumed to be circular. The aim of this study was to assess RVOT morphology using 3-dimensional transesophageal echocardiography (3D TEE). Methods and Results— This prospective study included 114 patients who underwent 3D TEE. Two-dimensional (2D) TEE measured maximum and minimum RVOT diameters (RVOTD max and min) during a cardiac cycle. 3D TEE determined RVOT area (RVOTA) max and min, RVOT fractional area change, and RVOT shape index (RVOTSI; vertical/horizontal RVOTD). Cardiac output (CO) was calculated using 2D TEE, 3D TEE, and a Swan-Ganz catheter in 23 patients. All patients were classified into group 1 (RVOTSI ≤1) or group 2 (RVOTSI >1) based on the RVOT shapes. The mean RVOTSIs were 0.84±0.21(max) and 0.82±0.20 (min). Only 17 patients (14.9%) had circular RVOT (RVOTSI: 0.95–1.05); 82 patients (71.9%) were categorized into group 1 and 32 patients (28.1%) into group 2. 2D TEE, compared with 3D TEE, underestimated RVOTA max and min (both P <0.001). CO with 3D TEE had better agreement with CO with a catheter than CO with 2D TEE ( r =0.83 and 0.53, respectively). Conclusions— 3D TEE revealed that RVOT geometry was not generally circular but oval with 2 different types. Because of the detailed morphological information of RVOT, 3D TEE could provide more accurate assessment of CO than 2D TEE.

Non-Circular Shape of Right Ventricular Outflow TractClinical Perspective

Background—The shape of right ventricular outflow tract (RVOT) has been assumed to be circular. The aim of this study was to assess RVOT morphology using 3-dimensional transesophageal echocardiography (3D TEE). Methods and Results—This prospective study included 114 patients who underwent 3D TEE. Two-dimensional (2D) TEE measured maximum and minimum RVOT diameters (RVOTD max and min) during a cardiac cycle. 3D TEE determined RVOT area (RVOTA) max and min, RVOT fractional area change, and RVOT shape index (RVOTSI; vertical/horizontal RVOTD). Cardiac output (CO) was calculated using 2D TEE, 3D TEE, and a Swan-Ganz catheter in 23 patients. All patients were classified into group 1 (RVOTSI ⩽1) or group 2 (RVOTSI >1) based on the RVOT shapes. The mean RVOTSIs were 0.84±0.21(max) and 0.82±0.20 (min). Only 17 patients (14.9%) had circular RVOT (RVOTSI: 0.95–1.05); 82 patients (71.9%) were categorized into group 1 and 32 patients (28.1%) into group 2. 2D TEE, compared with 3D TEE, underestimated RVOTA max and min (both P<0.001). CO with 3D TEE had better agreement with CO with a catheter than CO with 2D TEE (r=0.83 and 0.53, respectively). Conclusions—3D TEE revealed that RVOT geometry was not generally circular but oval with 2 different types. Because of the detailed morphological information of RVOT, 3D TEE could provide more accurate assessment of CO than 2D TEE.Background— The shape of right ventricular outflow tract (RVOT) has been assumed to be circular. The aim of this study was to assess RVOT morphology using 3-dimensional transesophageal echocardiography (3D TEE). Methods and Results— This prospective study included 114 patients who underwent 3D TEE. Two-dimensional (2D) TEE measured maximum and minimum RVOT diameters (RVOTD max and min) during a cardiac cycle. 3D TEE determined RVOT area (RVOTA) max and min, RVOT fractional area change, and RVOT shape index (RVOTSI; vertical/horizontal RVOTD). Cardiac output (CO) was calculated using 2D TEE, 3D TEE, and a Swan-Ganz catheter in 23 patients. All patients were classified into group 1 (RVOTSI ≤1) or group 2 (RVOTSI >1) based on the RVOT shapes. The mean RVOTSIs were 0.84±0.21(max) and 0.82±0.20 (min). Only 17 patients (14.9%) had circular RVOT (RVOTSI: 0.95–1.05); 82 patients (71.9%) were categorized into group 1 and 32 patients (28.1%) into group 2. 2D TEE, compared with 3D TEE, underestimated RVOTA max and min (both P <0.001). CO with 3D TEE had better agreement with CO with a catheter than CO with 2D TEE ( r =0.83 and 0.53, respectively). Conclusions— 3D TEE revealed that RVOT geometry was not generally circular but oval with 2 different types. Because of the detailed morphological information of RVOT, 3D TEE could provide more accurate assessment of CO than 2D TEE.

Mechanisms of Acute Mitral Regurgitation in Patients With Takotsubo CardiomyopathyClinical Perspective

Background—Recent studies have suggested acute mitral regurgitation (MR) as a potentially serious complication of takotsubo cardiomyopathy (TTC); however, the mechanism of acute MR in TTC remains unclear. The aim of this study was to elucidate the mechanisms of acute MR in patients with TTC. Methods and Results—Echocardiography was used to assess the mitral valve and left ventricular outflow tract (LVOT) pressure gradient in 47 patients with TTC confirmed by coronary angiography and left ventriculography. Mitral valve assessment included coaptation distance, tenting area at mid systole in the long-axis view, and systolic anterior motion of the mitral valve (SAM). Of the study patients, 12 (25.5%) had significant (moderate or severe) acute MR. In patients with acute MR versus those without acute MR, we found lower ejection fraction (31.3±6.2% versus 41.5±10.6%, P=0.001) and higher systolic pulmonary artery pressure (49.3±7.4 versus 35.5±8.9 mm Hg, P<0.001). Moreover, 6 of the 12 patients with acute MR had SAM, with peak LVOT pressure gradient >20 mm Hg (average peak LVOT pressure gradient, 81.3±35.8 mm Hg). The remaining 6 patients with acute MR revealed significantly greater mitral valve coaptation distance (10.9±1.6 versus 7.8±1.4 mm, P<0.001) and tenting area (2.1±0.4 versus 0.95±0.25 cm2, P<0.001) than those without acute MR. A multivariate analysis revealed that SAM and tenting area were independent predictors of acute MR in patients with TTC (all P<0.001). Conclusions—SAM and tethering of the mitral valve are independent mechanisms with differing pathophysiology that can lead to acute MR in patients with TTC.

Mechanisms of Acute Mitral Regurgitation in Patients With Takotsubo CardiomyopathyClinical Perspective: An Echocardiographic Study

Background—Recent studies have suggested acute mitral regurgitation (MR) as a potentially serious complication of takotsubo cardiomyopathy (TTC); however, the mechanism of acute MR in TTC remains unclear. The aim of this study was to elucidate the mechanisms of acute MR in patients with TTC. Methods and Results—Echocardiography was used to assess the mitral valve and left ventricular outflow tract (LVOT) pressure gradient in 47 patients with TTC confirmed by coronary angiography and left ventriculography. Mitral valve assessment included coaptation distance, tenting area at mid systole in the long-axis view, and systolic anterior motion of the mitral valve (SAM). Of the study patients, 12 (25.5%) had significant (moderate or severe) acute MR. In patients with acute MR versus those without acute MR, we found lower ejection fraction (31.3±6.2% versus 41.5±10.6%, P=0.001) and higher systolic pulmonary artery pressure (49.3±7.4 versus 35.5±8.9 mm Hg, P<0.001). Moreover, 6 of the 12 patients with acute MR had SAM, with peak LVOT pressure gradient >20 mm Hg (average peak LVOT pressure gradient, 81.3±35.8 mm Hg). The remaining 6 patients with acute MR revealed significantly greater mitral valve coaptation distance (10.9±1.6 versus 7.8±1.4 mm, P<0.001) and tenting area (2.1±0.4 versus 0.95±0.25 cm2, P<0.001) than those without acute MR. A multivariate analysis revealed that SAM and tenting area were independent predictors of acute MR in patients with TTC (all P<0.001). Conclusions—SAM and tethering of the mitral valve are independent mechanisms with differing pathophysiology that can lead to acute MR in patients with TTC.