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Dive into the research topics where Naoya Shirai is active.

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Featured researches published by Naoya Shirai.


Circulation | 2006

Percutaneous Transcatheter Balloon Valvuloplasty for Bioprosthetic Tricuspid Valve Stenosis

Kei Yunoki; Takahiko Naruko; Akira Itoh; Junko Ohashi; Kohei Fujimoto; Naoya Shirai; Koichi Shimamura; Ryushi Komatsu; Yuji Sakanoue; Kazuo Haze

A 59-year-old woman was admitted to our hospital because of exertional dyspnea, abdominal distension, and leg edema over the past 2 weeks. She had a history of rheumatic fever at the age of 12 years. In 1983, at the age of 37, she had undergone tricuspid valve replacement with a Carpentier-Edwards bioprosthesis for tricuspid stenosis and mitral valve replacement with a mechanical valve for mitral stenosis. The physical examination on admission revealed marked edema in both legs. There was also presystolic pulsation of the liver, which was palpable 4 cm below the right costal margin. A Levine grade III/VI, rough, diastolic rumble at the lower left sternal border was accentuated during inspiration. Echocardiography revealed severe tricuspid stenosis and a large amount of ascites. The leaflets were thickened, …


Jacc-cardiovascular Imaging | 2016

Detection of Deep Venous Thrombosis Using a Pocket-Size Ultrasound Examination Device

Koki Nakanishi; Shota Fukuda; Hajime Yamashita; Takuto Uetsuhara; Akiko Sakamoto; Koji Yamasaki; Michihiko Kosaka; Naoya Shirai; Hiroko Uono; Junichi Yoshikawa; Yutaka Otsuji; Kenei Shimada

Early and accurate diagnosis of deep vein thrombosis (DVT) is required for prognostication and appropriate clinical management. Ultrasound examination is well recognized as an initial screening imaging modality for the presence and extent of DVT [(1)][1]. Advances in electronic miniaturization have


Journal of Cardiology | 2010

A novel echocardiographic index of inefficient left ventricular contraction resulting from mechanical dyssynchrony

Yukio Abe; Daigo Yagishita; Yoshimi Tagawa; Atsuko Furukawa; Eiichiro Nakagawa; Kei Yunoki; Naoya Shirai; Ryushi Komatsu; Takahiko Naruko; Minoru Yoshiyama; Junichi Yoshikawa; Kazuo Haze; Akira Itoh

OBJECTIVES The purpose of this study was to explore the possibility of using our novel echocardiographic index of inefficient left ventricular (LV) contraction in patient selection for cardiac resynchronization therapy (CRT). METHODS Forty consecutive patients with LV ejection fraction < or = 35% were divided into 2 groups, 9 CRT candidates and 31 non-CRT candidates based on conventional criteria. A global LV time-area curve and regional LV time-area curves in 6 radial sectors were obtained using two-dimensional echocardiography in the short-axis view with speckle tracking. Fractional inefficient contraction (FIC, %) was calculated as follows: (1-global LV area change/sum of regional LV area changes) x 100. LV dyssynergy and dyssynchrony were quantified as the standard deviations of minimal values of circumferential speckle-tracking strain and their timings in the 6 sectors, respectively. RESULTS There was no significant difference in LV dyssynchrony between CRT candidates and non-CRT candidates (79 + or - 61 ms vs. 58 + or - 26 ms, respectively). In contrast, FIC was significantly larger in CRT candidates than in non-CRT candidates (15.7 + or - 11.0% vs. 5.4 + or - 3.5%, respectively, p=0.0018), with less overlap between groups. FIC showed a positive correlation with dyssynchrony (r=0.64) and a negative correlation with dyssynergy (r=-0.42). CONCLUSIONS Our novel echocardiographic index of inefficient LV contraction, which increases with more dyssynchrony or less dyssynergy, may prove more useful in patient selection for CRT than other indices that focus on LV temporal dyssynchrony alone.


Japanese Circulation Journal-english Edition | 2001

Effects of Smoking on Myocardial Injury in Patients With Conservatively Treated Acute Myocardial Infarction

Hiroyuki Yamagishi; Kaname Akioka; Naoya Shirai; Minoru Yoshiyama; Masakazu Teragaki; Kazuhide Takeuchi; Junichi Yoshikawa; Hironobu Ochi

Many reports have demonstrated that smokers who have suffered an acute myocardial infarction (AMI) have a better prognosis than nonsmokers. The present study investigated the effects of current smoking on myocardial injury with resting 123I-15-iodophenyl 3-methyl pentadecanoic acid (BMIPP)/201Tl myocardial single photon emission computed tomography in 103 patients with conservatively treated AMI. The left ventricular myocardium was divided into 9 segments and BMIPP and 201Tl defects were scored using a 5-point grading system (0 = normal and 4 = no uptake). The sum of the defect scores was defined as the total defect score. There was no significant difference in either the baseline severity of the coronary artery disease or the total defect scores for BMIPP and 201Tl between the current smoker and nonsmoker groups. The difference between the total defect scores for BMIPP and 201Tl tended to be larger in the current smoker group than in the nonsmoker group (2.0 +/- 1.9 vs 1.3 +/- 1.6, p = 0.056). Forty-one (53%) of 77 patients in the current smoker group exhibited a BMIPP/201Tl mismatch, whereas only 8 (31%) of 26 patients in the nonsmoker group did (p = 0.047). In conclusion, current smokers had more likelihood of salvageable myocardium in areas at risk, as demonstrated by BMIPP/201Tl mismatch, in AMI than nonsmokers.


Circulation | 2006

Hereditary Hemorrhagic Telangiectasia With Pulmonary Arteriovenous Fistulas

Kei Yunoki; Takahiko Naruko; Masaki Komiyama; Junko Ohashi; Kohei Fujimoto; Naoya Shirai; Koichi Shimamura; Ryushi Komatsu; Yuji Sakanoue; Akira Itoh; Kazuo Haze

A 65-year-old woman presented with exertional dyspnea and general fatigue that began 1 week ago. She had a family history of hereditary hemorrhagic telangiectasia manifesting as telangiectasia of gastrointestinal (GI) tract and nasal mucosa and of pulmonary arteriovenous fistulas (PAVFs). Her first PAVF was diagnosed in 1999 but was untreated at that time. Her medical history was significant for multiple GI bleeds, mild to moderate nosebleeds, and a minor cerebral stroke probably due …


The Journal of Nuclear Medicine | 2003

Identification of Cardiac Sarcoidosis with 13N-NH3/18F-FDG PET

Hiroyuki Yamagishi; Naoya Shirai; Masahiko Takagi; Minoru Yoshiyama; Kaname Akioka; Kazuhide Takeuchi; Junichi Yoshikawa


The Journal of Nuclear Medicine | 2002

Incremental Value of Left Ventricular Ejection Fraction for Detection of Multivessel Coronary Artery Disease in Exercise 201Tl Gated Myocardial Perfusion Imaging

Hiroyuki Yamagishi; Naoya Shirai; Minoru Yoshiyama; Masakazu Teragaki; Kaname Akioka; Kazuhide Takeuchi; Junichi Yoshikawa; Hironobu Ochi


The Journal of Nuclear Medicine | 2002

Incremental Value of Assessment of Regional Wall Motion for Detection of Multivessel Coronary Artery Disease in Exercise 201Tl Gated Myocardial Perfusion Imaging

Naoya Shirai; Hiroyuki Yamagishi; Minoru Yoshiyama; Masakazu Teragaki; Kaname Akioka; Kazuhide Takeuchi; Junichi Yoshikawa; Hironobu Ochi


American Heart Journal | 2005

Protective effect of high diastolic blood pressure during exercise against exercise-induced myocardial ischemia

Hiroyuki Yamagishi; Minoru Yoshiyama; Naoya Shirai; Kaname Akioka; Kazuhide Takeuchi; Junichi Yoshikawa


Journal of Atherosclerosis and Thrombosis | 2008

Small Coronary Calcium Deposits and Elevated Plasma Levels of Oxidized Low Density Lipoprotein are Characteristic of Acute Myocardial Infarction

Shoichi Ehara; Takahiko Naruko; Naoya Shirai; Akira Itoh; Eishu Hai; Yoshimi Sugama; Yoshihiro Ikura; Masahiko Ohsawa; Takuhiro Okuyama; Nobuyuki Shirai; Hajime Yamashita; Hiroyuki Itabe; Kazuo Haze; Minoru Yoshiyama; Makiko Ueda

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Kazuo Haze

University of Tokushima

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