Maki Nagaya
Gifu University
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Publication
Featured researches published by Maki Nagaya.
Journal of Cardiology | 2013
Maki Nagaya; Masanori Kawasaki; Ryuhei Tanaka; Noriyuki Onishi; Noriaki Sato; Koji Ono; Takatomo Watanabe; Shingo Minatoguchi; Hirotaka Miwa; Yoshiaki Goto; Takeshi Hirose; Masazumi Arai; Toshiyuki Noda; Sachiro Watanabe; Shinya Minatoguchi
BACKGROUND The aim of this study was to validate the accuracy of three-dimensional (3D) speckle tracking echocardiography (STE) and two-dimensional (2D)-STE for the assessment of left atrial (LA) volume and function by comparison with 3D-computed tomography (CT) performed on the same day as STE. METHODS LA phasic volume and emptying function (EF) were measured in 28 patients with paroxysmal atrial fibrillation undergoing catheter ablation (62±11 years old) using both 3D-STE and 2D-STE during sinus rhythm. LA phasic volume and function measured by 3D-STE and 2D-STE were validated using 3D-CT as a gold standard. RESULTS The intraobserver correlation coefficient and variability in maximum LA volume assessed by 3D-STE were 0.99 and 1.4±6.0%, respectively. The interobserver correlation coefficient and variability in maximum LA volume assessed by 3D-STE were 0.99 and 0.2±4.5%, respectively. There were strong correlations between LA phasic volume measured by 3D-CT and those measured by 3D-STE (r=0.98, p<0.001). There were correlations between LA phasic function measured by 3D-CT and those measured by 3D-STE (r=0.85-0.88, p<0.001). There was a better agreement between 3D-CT and 3D-STE in the assessment of LA phasic volumes and function than between 3D-CT and 2D-STE in apical 2- and 4-chamber view. CONCLUSIONS 3D-STE allows more accurate measurement of LA volume and function than 2D-STE and has high reproducibility.
Journal of Cardiology | 2012
Makoto Iwama; Masanori Kawasaki; Ryuhei Tanaka; Koji Ono; Takatomo Watanabe; Takeshi Hirose; Maki Nagaya; Toshiyuki Noda; Sachiro Watanabe; Shinya Minatoguchi
BACKGROUND Left atrial appendage (LAA) thrombus increases the risk of thromboembolism in atrial fibrillation (AF), and LAA contractile function like emptying fraction (EF) should have physiological importance in thrombus formation. The aim of this study was to validate a velocity vector imaging (VVI) method for quantification of the LAA function and to elucidate echocardiographic parameters that are related to the presence of LAA thrombus in patients with nonvalvular AF. METHODS We measured left atrial (LA) dimension and LAEF by VVI using transthoracic echocardiography, and LAA emptying velocity, spontaneous echo contrast (SEC), and LAAEF by VVI using transesophageal echocardiography (TEE) in 142 consecutive patients with nonvalvular AF. The patients were divided into two groups according to the presence (n=38) or absence (n=104) of LAA thrombus. RESULTS There was a good correlation between the VVI method and manual-tracing method for LAAEF and LAEF of patients with AF (r=0.97, r=0.96, respectively, p<0.001). LAAEF in AF with thrombus was significantly reduced compared with AF without thrombus (16.9±3.1% and 29.0±9.7%, p<0.001). In multivariate logistic regression analysis, LAAEF, SEC, and prior stroke were independent determinants of LAA thrombus. Using 20% of LAAEF as a cutoff value, the sensitivity was 92% and specificity was 88% for LAA thrombus. CONCLUSION The VVI method was reliable in the measurement of LAAEF and LAEF compared with the manual-tracing method. LAAEF assessed by the VVI method using TEE was related to the presence of LAA thrombus.
Hypertension Research | 2015
Maki Saeki; Noriaki Sato; Masanori Kawasaki; Ryuhei Tanaka; Maki Nagaya; Takatomo Watanabe; Koji Ono; Toshiyuki Noda; Michael R. Zile; Shinya Minatoguchi
We recently developed novel software to measure phasic strain rate (SR) using automated one-beat real-time three-dimensional speckle tracking echocardiography (3D-STE) with high volume rates. We tested the hypothesis that left ventricular (LV) systolic function and relaxation analyzed by SR with the novel 3D-STE in hypertension (HTN) with hypertrophy may be impaired in the endocardium before there is LV systolic dysfunction. We measured LV longitudinal, radial and circumferential SR in patients with HTN (n=80, 69±7 years) and age-matched normotensive controls (n= 60, 69±10 years) using 3D-STE. HTN patients were divided into four groups according to LV geometry: normal, concentric remodeling, concentric hypertrophy and eccentric hypertrophy. We measured SR during systole as an index of systolic function, SR during isovolumic relaxation (IVR) as an index of relaxation and E/e’ as an index of filling pressure. Endocardial SR during systole in HTN with concentric and eccentric hypertrophy decreased compared with that in controls despite no reduction in ejection fraction or epicardial SR. Endocardial radial SR during IVR decreased even in normal geometry, and it was further reduced in concentric remodeling and hypertrophy despite no reduction in epicardial SR. LV phasic SR assessed by 3D-STE with high volume rates is a useful index to detect early decreases in LV systolic function and to predict subclinical LV layer dysfunction in patients with HTN.
Journal of the American College of Cardiology | 2014
Ryota Watanabe; Masanori Kawasaki; Michael R. Zile; Ryuhei Tanaka; Maki Nagaya; Helene Houle; Hirotaka Miwa; Takashi Yoshizane; Takashi Kato; Takatomo Watanabe; Koji Ono; Masazumi Arai; Toshiyuki Noda; Sachiro Watanabe; Shinya Minatoguchi
Left ventricular (LV) systolic properties in hypertension (HTN) may be impaired by pressure overload, resulting in heart failure (HF) with reduced ejection fraction (EF). Using tissue Doppler and 2-dimensional speckle tracking echocardiography (2D-STE), LV myocardial strain rate (SR) was reported as
Journal of the American College of Cardiology | 2012
Makoto Iwama; Ryuhei Tanaka; Noriyuki Onishi; Maki Nagaya; Shingo Minatoguchi; Shintaro Abe; Reiko Matsuoka; Yoshiaki Goto; Tomoko Fujii; Tai Kojima; Takeshi Hirose; Koji Ono; Shintaro Tanihata; Mami lida; Toshiyuki Noda; Sachiro Watanabe; Takatomo Watanabe; Masanori Kawasaki; Shinya Minatoguchi
Major advantage of 3-dimensional speckle tracking echocardiography (3-DSTE) is the improvement of accuracy in the evaluation of cardiac chamber volume without any geometrical assumption. However, there have been few studies regarding to left atrial (LA) structure and function using 3-DSTE. The aim
Journal of Cardiology | 2014
Noriyuki Onishi; Masanori Kawasaki; Ryuhei Tanaka; Hidemaro Sato; Maki Saeki; Maki Nagaya; Noriaki Sato; Shingo Minatoguchi; Takatomo Watanabe; Koji Ono; Masazumi Arai; Toshiyuki Noda; Kazuo Amano; Koshi Goto; Sachiro Watanabe; Shinya Minatoguchi
Cardiovascular Ultrasound | 2015
Takatomo Watanabe; Masanori Kawasaki; Ryuhei Tanaka; Koji Ono; Nobuo Kako; Maki Saeki; Noriyuki Onishi; Maki Nagaya; Noriaki Sato; Hirotaka Miwa; Masazumi Arai; Toshiyuki Noda; Sachiro Watanabe; Shinya Minatoguchi
Heart and Vessels | 2017
Shingo Minatoguchi; Masanori Kawasaki; R. Tanaka; Takashi Yoshizane; Koji Ono; Maki Saeki; Maki Nagaya; Hidemaro Sato; Kazuhiko Nishigaki; Toshiyuki Noda; Michael R. Zile; Shinya Minatoguchi
Cardiovascular Ultrasound | 2015
Masanori Kawasaki; Ryuhei Tanaka; Taiji Miyake; Reiko Matsuoka; Mayumi Kaneda; Shingo Minatoguchi; Takeshi Hirose; Koji Ono; Maki Nagaya; Hidemaro Sato; Yoshiaki Kawase; Shinji Tomita; Kunihiko Tsuchiya; Hitoshi Matsuo; Toshiyuki Noda; Shinya Minatoguchi
Circulation | 2018
Masanori Kawasaki; Ryuhei Tanaka; Akihiro Yoshida; Maki Nagaya; Shingo Minatoguchi; Takashi Yoshizane; Takatomo Watanabe; Hiromitsu Kanamori; Koji Ono; Takeshi Hirose; Toshiyuki Noda; Sachiro Watanabe