Masaki Izumo

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.

Mechanisms of Acute Mitral Regurgitation in Patients With Takotsubo Cardiomyopathy 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.

Echocardiographic Evaluation of Iatrogenic Atrial Septal Defect After Catheter-Based Mitral Valve Clip Insertion

The geometries and sizes of persistent iatrogenic atrial septal defects (IASDs) after transseptal puncture during catheter-based mitral valve clip insertion (MVCI) have not been detailed. In this study, 11 IASDs were investigated in 10 patients who underwent MVCI using a guide catheter (24Fr proximally and 22Fr at the atrial septum). The diameters of the long and short axes and the area at maximum and minimum during a cardiac cycle were measured after MVCI using real-time 3-dimensional (RT3D) transesophageal echocardiography (TEE). A circular shape was assumed on 2-dimensional TEE, resulting in an area calculation of π × (dimension/2)(2). The anatomic geometries of IASDs were visualized in a 3-dimensional en face view of the atrial septum. Furthermore, 1 month after MVCI, IASDs were evaluated using echocardiography. The IASDs had a variety of irregular geometries. The mean long-axis diameter was 1.0 ± 0.24 cm, the mean short-axis diameter was 0.51 ± 0.22 cm, and the mean area was 0.40 ± 0.24 cm(2) on RT3D TEE. The diameters and area changed significantly between the maximal and minimal values during the cardiac cycle. Importantly, 2-dimensional TEE underestimated the maximal diameters of IASDs (0.54 ± 0.17 vs 1.0 ± 0.24 cm by RT3D TEE, p <0.01) and the maximal areas of IASDs (0.25 ± 0.15 vs 0.40 ± 0.23 cm(2) by RT3D TEE, p <0.05). One month after MVCI, the smallest and the second smallest IASDs had closed, and the other 9 remained open. In conclusion, RT3D TEE is useful to assess the irregular geometries of IASDs created during MVCI.

Relationship between left ventricular ejection fraction and mitral annular displacement derived by speckle tracking echocardiography in patients with different heart diseases.

BACKGROUND Speckle tracking echocardiography (STE)-derived mitral annular displacement (MAD) utilizes the speckle tracking technique to measure strain vectors, which provides accurate estimates of left ventricular ejection fraction (LVEF). Here, we investigated a link between STE-derived MAD and LVEF in patients with different heart diseases and evaluated its clinical usefulness. METHODS This study included 266 outpatients and 84 controls. Of the study patients, 52 patients had ischemic heart disease (IHD), 37 patients had dilated cardiomyopathy (DCM), 34 patients had hypertrophic cardiomyopathy (HCM), 74 patients had valvular heart disease (VHD), and 69 patients had hypertensive heart disease (HHD). STE continuously tracked annular motion throughout the cardiac cycle in the apical 4- and 2-chamber views. RESULTS In all participants, the curvilinear relationship was found between STE-derived MAD and LVEF (R(2)=0.642). The strong correlation between STE-derived MAD and LVEF was also found in the patients with IHD (R(2)=0.733, p=0.001) and in those with DCM (R(2)=0.614, p=0.008). However, such a correlation was not found in the patients with HCM, VHD, or HHD. CONCLUSION The specificity in the correlation between STE-derived MAD and LVEF was found in patients with each heart disease, which should be taken into account when assessing these parameters.

Three-dimensional echocardiographic assessments of exercise-induced changes in left ventricular shape and dyssynchrony in patients with dynamic functional mitral regurgitation

AIMS Left ventricular (LV) shape and LV dyssynchrony are two cofactors associated with functional mitral regurgitation (MR) in patients with heart failure. Both can be accurately examined by real-time three-dimensional echocardiography (3DE). We examined the relationship between dynamic MR and exercise-induced changes in LV shape and synchronicity using 3DE. METHODS AND RESULTS Fifty patients with systolic LV dysfunction underwent 2D and 3D quantitative assessment of LV function, shape, and synchronicity at rest and during symptom-limited exercise test. According to the magnitude of change in MR, patients were divided into EMR group (15 patients, 30%), if the degree of MR increased during test, and NEMR group. During exercise, the changes in LV volumes and ejection fraction were similar in both groups, whereas changes in mitral valvular deformation parameters, in LV sphericity index, and in the extent of LV dyssynchrony were more pronounced in the EMR group. At rest, only the 3D sphericity index could distinguish the two groups. By stepwise multiple regression model, dynamic changes in the systolic dyssynchrony index, sphericity index, and coaptation distance were associated with dynamic MR (r(2) = 0.45, P = 0.012). CONCLUSION Dynamic MR during exercise is related to the 3D changes in LV shape and in LV synchronicity.

Changes in mitral regurgitation and left ventricular geometry during exercise affect exercise capacity in patients with systolic heart failure.

AIMS exercise may dramatically change the extent of functional mitral regurgitation (MR) and left ventricular (LV) geometry in patients with chronic heart failure (CHF). We hypothesized that dynamic changes in MR and LV geometry would affect exercise capacity. METHODS AND RESULTS this study included 30 CHF patients with functional MR who underwent symptom-limited bicycle exercise stress echocardiography and cardiopulmonary exercise testing for quantitative assessment of MR (effective regurgitant orifice; ERO), and pulmonary artery systolic pressure (PASP). LV sphericity index was obtained from real-time three-dimensional echocardiograms. The patients were stratified into exercised-induced MR (EMR; n = 10, an increase in ERO by ≥13 mm(2)) or non-EMR (NEMR; n = 20, an increase in ERO by <13 mm(2)) group. At rest, no differences in LV volume and function, ERO, and PASP were found between the two groups. At peak exercise, PASP and sphericity index were significantly greater (all P < 0.01) in the EMR group. The EMR group revealed lower peak oxygen uptake (peak VO(2); P = 0.018) and greater minute ventilation/carbon dioxide production slope (VE/VCO(2) slope; P = 0.042) than the NEMR group. Peak VO(2) negatively correlated with changes in ERO (r = -0.628) and LV sphericity index (r = -0.437); meanwhile, VE/VCO(2) slope was well correlated with these changes (r = 0.414 and 0.364, respectively). A multivariate analysis identified that the change in ERO was the strongest predictor of peak VO(2) (P = 0.001). CONCLUSION dynamic changes in MR and LV geometry contributed to the limitation of exercise capacity in patients with CHF.

Simple exercise echocardiography using a Master's two-step test for early detection of pulmonary arterial hypertension

BACKGROUND Early detection of pulmonary arterial hypertension (PAH) is indispensable, although, echocardiography at rest alone does not provide sufficient evidence for it. Here, this study aimed to investigate the usefulness of simple exercise echocardiography using a Masters two-step test for detecting early PAH. METHODS This study included 52 connective tissue disease patients who had mild symptoms in World Health Organization functional classification 2, suspected as having early PAH, and underwent exercise echocardiography and right heart catheterization. Echocardiography was performed before and after the Masters two-step exercise test; the study patients were classified into the non-PAH (mean pulmonary arterial pressure <25 mmHg, n=37) or PAH (mean pulmonary arterial pressure ≥25 mmHg, n=15) groups. RESULTS Rest systolic pulmonary artery pressure estimated using echocardiography did not significantly differ between the two groups; however, a significant difference in post-exercise systolic pulmonary artery pressure was found (non-PAH, 58.8±10.8 mmHg; PAH, 80.2±14.3 mmHg, p<0.0001). The multiple logistic regression analysis indicated post-exercise systolic pulmonary artery pressure as an independent predictor of PAH (p=0.013). The area under the curve by post-exercise systolic pulmonary artery pressure was 0.91 for PAH. Post-exercise systolic pulmonary artery pressure ≥69.6 mmHg predicted PAH with the sensitivity of 93% and the specificity of 90%. CONCLUSIONS Simple exercise echocardiography using the Masters two-step test could detect PAH in mildly symptomatic connective tissue disease patients. The usefulness of this method should be verified for the early detection of PAH.

Peak time of acute coronary syndrome in patients with sleep disordered breathing.

BACKGROUND Recently, sleep disordered breathing (SDB) has gained attention in the field of cardiology. Until now, no study describing the relationship between acute coronary syndrome (ACS) and SDB has been carried out in Japan. METHODS Among ACS patients admitted to our hospital, 44 patients (mean age 60.6+/-13.5 years) who received a portable polysomnography to measure apnea hypopnea index (AHI) were selected for this study. The circadian pattern of ACS onset was studied in 6-h intervals. In addition, all subjects were divided into three groups according to AHI severity (AHI < 5, 5 < or = AHI < 15, and 15 < or = AHI). Then, a comparative study between peak time of ACS and AHI severity was conducted for each group. RESULTS In the AHI < 5 group, 66.0% patients suffered from ACS between 12:00 h and 18:00 h and 17.0% between 18:00 h and 24:00 h, and a total of 83.0% patients had ACS between 12:00 h and 24:00 h. In the 5 < or = AHI < 15 group, 49.9% patients had ACS between 24:00 h and 06:00 h, 16.7% patients between 06:00 h and 12:00 h. 12:00-18:00 h and 18:00-24:00 h showed no significant difference. All 22 patients in the 15 < or = AHI group suffered from ACS between 24:00 h and 12:00 h. CONCLUSION The results of this study suggest a possible relationship between SDB and the onset of ACS between midnight to morning.

Prognostic value of paradoxical low-gradient severe aortic stenosis in Japan: Japanese Multicenter Aortic Stenosis Study, Retrospective (JUST-R) Registry.

BACKGROUND Whether the prognosis of paradoxical low-gradient severe aortic stenosis (PLG-SAS), especially due to paradoxical low-flow low-gradient SAS (PLFLG-SAS), is malignant in any specific ethnicity, including Japanese, remains unclear. METHODS We retrospectively enrolled 385 consecutive Japanese patients (age, 76±8 years; 148 men) with moderate AS [MAS: 0.6≤indexed aortic valve area (iAVA)<0.85cm(2)/m(2)] or SAS (iAVA <0.6cm(2)/m(2)) with preserved left ventricular ejection fraction (≥50%). SAS patients were divided into PLG-SAS and high-gradient (HG)-SAS according to the transvalvular mean gradient (40mmHg). PLG-SAS was categorized into 2 groups: normal-flow (NF) LG-SAS [stroke volume index (SVi) ≥35mL/m(2)] and PLFLG-SAS (SVi <35mL/m(2)). Endpoints were all-cause death and major adverse cardio-cerebrovascular events (MACE). RESULTS During a median follow-up of 15 months, 31 patients died and 48 suffered MACE. All-cause death and MACE rates in PLG-SAS and PLFLG-SAS were significantly lower than those in HG-SAS and similar to those in MAS. On multivariate analysis, neither PLG-SAS nor PLFLG-SAS were independent determinants for all-cause death compared with MAS [MAS as reference, PLG-SAS: hazard ratio (HR) 0.47, p=0.32; PLFLG-SAS: HR 0.01, p=0.20; HG-SAS: HR 3.37, 95% confidence interval 1.24-9.74, p=0.02]. CONCLUSIONS In Japanese patients, the prognoses of PLG-SAS and PLFLG-SAS were better than that of HG-SAS and similar to that of MAS, being better than that in Western populations.

Comparison of Two-Dimensional Versus Real-Time Three-Dimensional Transesophageal Echocardiography for Evaluation of Patent Foramen Ovale Morphology

The aim of this study was to elucidate patent foramen ovale (PFO) morphology and the change of PFO size using real-time 3-dimensional (3D) transesophageal echocardiography (TEE). PFO is a 3D structure, and its shape changes during the cardiac cycle. Therefore, it may be difficult to estimate accurate PFO morphology using 2-dimensional (2D) TEE. The study included 50 patients with PFO who underwent 2D and 3D TEE. PFO heights (PHs) at entrance, mid, and exit were measured by 2D and 3D TEE. Systolic and diastolic areas were also measured by 3D TEE. PH by 3D TEE was larger than that by 2D TEE (entrance 0.32 ± 0.18 vs 0.21 ± 0.15 cm, p <0.001; mid 0.25 ± 0.14 vs 0.15 ± 0.11 cm, p <0.001; exit 0.19 ± 0.11 vs 0.11 ± 0.08 cm, p <0.001). Systolic area was greater than diastolic area at each location (entrance 0.19 ± 0.17 vs 0.11 ± 0.11 cm(2), p = 0.001; mid 0.13 ± 0.11 vs 0.08 ± 0.06 cm(2), p = 0.001; exit 0.09 ± 0.09 vs 0.06 ± 0.05 cm(2), p = 0.01). Additionally, entrance area was greater than exit area in systole and diastole (systole 0.19 ± 0.17 vs 0.09 ± 0.09 cm(2), p <0.001; diastole 0.11 ± 0.11 vs 0.06 ± 0.05 cm(2), p = 0.001). There were good correlations between PH by 3D TEE and PFO area (entrance r = 0.68, mid r = 0.71, exit r = 0.78) but weak correlations between PH by 2D TEE and PFO area (entrance r = 0.62, mid r = 0.50, exit r = 0.51). In conclusion, real-time 3D TEE could provide detailed and unique information on PFO morphology.