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.

The recent development of cardiac magnetic resonance (CMR) techniques has allowed detailed analyses of cardiac function and tissue characterization with high spatial resolution. We review characteristic CMR features in ischemic and non-ischemic cardiomyopathies (ICM and NICM), especially in terms of the location and distribution of late gadolinium enhancement (LGE). CMR in ICM shows segmental wall motion abnormalities or wall thinning in a particular coronary arterial territory, and the subendocardial or transmural LGE. LGE in NICM generally does not correspond to any particular coronary artery distribution and is located mostly in the mid-wall to subepicardial layer. The analysis of LGE distribution is valuable to differentiate NICM with diffusely impaired systolic function, including dilated cardiomyopathy, end-stage hypertrophic cardiomyopathy (HCM), cardiac sarcoidosis, and myocarditis, and those with diffuse left ventricular (LV) hypertrophy including HCM, cardiac amyloidosis and Anderson-Fabry disease. A transient low signal intensity LGE in regions of severe LV dysfunction is a particular feature of stress cardiomyopathy. In arrhythmogenic right ventricular cardiomyopathy/dysplasia, an enhancement of right ventricular (RV) wall with functional and morphological changes of RV becomes apparent. Finally, the analyses of LGE distribution have potentials to predict cardiac outcomes and response to treatments.

The HCM patients had more DE than the DCM patients, and DE volume correlated to lower global and local LV function. DE-MRI may be useful to evaluate myocardial damage in HCM patients, and to differentiate the dilated phase of HCM from DCM.

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Background-The presence of syncope in patients with aortic valve stenosis (AS) predicts a grave prognosis. However, the evaluation of AS severity has been limited to valve-specific factors such as aortic valve area and mean transaortic pressure gradient. Recently, valvuloarterial impedance (Zva) was proposed for the estimation of global left ventricular afterload. Therefore, because predictors of syncope in patients with AS have not been investigated in recent years, we assessed the effect of clinical characteristics and echocardiographic parameters, including Zva, on syncope in patients with AS. Methods and Results-We retrospectively studied 451 patients with moderate and severe AS without low left ventricular ejection fraction (<40%). Patients with syncope (n=79; 18%) had higher Zva (5.1±0.9 versus 4.4±0.9 mm Hg/mL per m 2 ; P<0.001) than those without (n=372; 82%). However, no significant differences existed in the mean transaortic pressure gradient (P=0.076) or the aortic valve area (P=0.160) between the 2 groups. In the multivariable analysis, only Zva was an independent predictor of syncope in patients with AS (odds ratio, 2.02; 95% confidence interval, 1.54-2.64; P<0.001). However, systolic blood pressure, relative wall thickness, the early transmitral flow velocity to peak early diastolic mitral annular velocity ratio, and mean transaortic pressure gradient were not identified as independent predictors. Receiver operating characteristic curve analysis identified Zva ≥4.7 mm Hg/mL per m 2 as the cutoff value associated with syncope in patients with AS. Conclusions-Our study suggests that high Zva, but not conventional parameters of AS, identifies AS patients with an increased risk of syncope. (Circ Cardiovasc Imaging. 2013;6:1024-1031.)