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Dive into the research topics where Kenichi Amitani is active.

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Featured researches published by Kenichi Amitani.


Journal of Nippon Medical School | 2015

Long-term Hemodialysis Corrects Left Ventricular Dyssynchrony in End-stage Renal Disease: A Study with Gated Technetium-99m Sestamibi Myocardial Perfusion Single-photon Emission Computed Tomography

Naoto Takahashi; Naoki Sato; Masahiro Ishikawa; Arifumi Kikuchi; Daisuke Hanaoka; Shiro Ishihara; Kenichi Amitani; Yukinao Sakai; Shin-ichiro Kumita; Wataru Shimizu

INTRODUCTION Left ventricular (LV) dyssynchrony is common in patients with end-stage renal disease (ESRD), and echocardiographic assessment has shown that it can be improved by a single session of hemodialysis (HD). The aim of this study was to assess the effects of chronic HD on LV dyssynchrony in patients ESRD by means of gated technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography (GSPECT) with phase analysis. MATERIALS AND METHODS Twelve patients with ESRD underwent GSPECT and echocardiography before the start of long-term HD (baseline) and 3 months later. In addition, 7 control subjects matched for age and sex underwent GSPECT and echocardiography within a 2-month period. To evaluate LV dyssynchrony, both histogram bandwidth (HBW) and phase standard deviation (PSD) were determined with phase analysis of GSPECT images. The end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction were also measured with GSPECT, and the LV mass index (LVMI) was measured with echocardiography. The LV dyssynchrony, volume, function, and mass were compared among control subjects, patients with ESRD at baseline, and patients with ESRD after 3 months of chronic HD. RESULTS The LV dyssynchrony, volume, and mass at baseline were significantly greater in patients with ESRD than in control subjects (HBW, 65.5°±54.4° vs. 22.3°±7.5°, P<0.05; PSD, 21.0°±15.5° vs. 7.6°±5.5°, P<0.05; EDV, 105.7±29.2 vs. 72.3±13.9 mL, P<0.05; ESV, 44.3±22.1 vs. 20.9±10.3 mL, P<0.05; LVMI, 136.5±48.3 vs. 65.4±5.6 g/m(2), P<0.01). From baseline to the third month of chronic HD, there were significant increases in EDV (78.6±25.4 vs. 105.7±29.2 mL, P<0.01) and ESV (27.6±16.2 vs. 44.3±22.1 mL, P<0.01) and significant decreases in HBW (65.5°±54.4° vs. 31.0°±15.7°, P<0.01) and PSD (21.0°±15.5° vs. 10.0°±8.2°, P<0.01). CONCLUSION Chronic HD decreased LV dyssynchrony and volume in patients with ESRD. Serial phase analysis of GSPECT images is a useful method of assessing the effects of long-term HD on LV dyssynchrony and volume in patients with ESRD.


Journal of Cardiology Cases | 2015

Clinical usefulness of gated technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography with phase analysis for the management of patients with isolated ventricular noncompaction

Naoto Takahashi; Naoki Sato; Koji Takagi; Toshiya Omote; Arifumi Kikuchi; Daisuke Hanaoka; Eisei Yamamoto; Masahiro Ishikawa; Kenichi Amitani; Shin-ichiro Kumita; Wataru Shimizu

Gated Tc-99m sestamibi myocardial perfusion single-photon emission computed tomography (GMPS) with phase analysis provides information on myocardial perfusion, left ventricular (LV) function, and LV dyssynchrony. We present a case of isolated left ventricular noncompaction (IVNC) cardiomyopathy in which GMPS with phase analysis proved to be beneficial and reliable to monitor the long-term response to cardiac resynchronization therapy with defibrillator (CRT-D). The patient was an 84-year-old man with shortness of breath on minimal exertion (New York Heart Association class III) who had severe drug-refractory heart failure with hypotension and ventricular tachycardia. He was diagnosed with IVNC using echocardiography. At baseline, GMPS with phase analysis revealed a reduced ejection fraction (EF, 21%), large perfusion defects in the inferior and inferolateral walls, and severe LV dyssynchrony [histogram bandwidth (HBW) 120°]. Combination therapy with CRT-D and a titrated beta-blocker was initiated to induce LV reverse remodeling and reduce LV dyssynchrony. Two years after CRT-D implantation, GMPS with phase analysis showed marked improvement in LV function and LV dyssynchrony (EF 28%, HBW 36°). This case demonstrates that GMPS with phase analysis is an important and useful modality to evaluate LV function and LV dyssynchrony in IVNC patients undergoing CRT-D. <Learning objective: We experienced a rare case of heart failure with isolated left ventricular noncompaction (IVNC) treated with cardiac resynchronization therapy with defibrillator (CRT-D). We demonstrate that gated Tc-99m myocardial perfusion SPECT (GMPS) with phase analysis can simultaneously evaluate myocardial perfusion and left ventricular dyssynchrony to assess the indication and efficacy of CRT-D. This case demonstrates that GMPS with phase analysis is useful to monitor IVNC patients before and after CRT-D.>.


Circulation | 2008

Assessment of Left Ventricular Dyssynchrony During Development of Heart Failure by a Novel Program Using ECG-Gated Myocardial Perfusion SPECT

Naoto Takahashi; Akira Yamamoto; Shingo Tezuka; Masahiro Ishikawa; Junko Abe; Kenichi Amitani; Tomoyoshi Yamaguchi; Naomi Kawaguchi; Takahiro Uchida; Shin-ichiro Iwahara; Kazuo Munakata


Journal of Nippon Medical School | 2000

Two Cases of Myocardial Bridge Associated with Myocardial Ischemia

Kenichi Amitani; Tomoyoshi Yamaguchi; Naoto Takahashi; Takahiro Uchida; Yoshifumi Kushikata; Kazuo Munakata; Sakae Masuda; Tuneyasu Orii; Yoshio Iedokoro; Masafumi Hioki; Akira Yamamoto


Journal of Cardiac Failure | 2013

What Dose Copeptin Indicate in Acute Heart Failure

Hideo Tokuyama; Naoki Sato; Kenji Nakama; Toshiya Omote; Arifumi Kikuchi; Eisei Yamamoto; Masahiro Ishikawa; Kenichi Amitani; Naoto Takahashi; Wataru Shimizu


Heart and Vessels | 2018

Effects of tolvaptan on urine output in hospitalized heart failure patients with hypoalbuminemia or proteinuria

Koji Takagi; Naoki Sato; Shiro Ishihara; Michiko Sone; Hideo Tokuyama; Kenji Nakama; Toshiya Omote; Arifumi Kikuchi; Masahiro Ishikawa; Kenichi Amitani; Naoto Takahashi; Yuji Maruyama; Hajime Imura; Wataru Shimizu


Society of Nuclear Medicine Annual Meeting Abstracts | 2012

Assessment of left ventricular mechanical dyssynchrony in patients with end-stage renal disease

Masahiro Ishikawa; Naoto Takahashi; Daisuke Hanaoka; Arifumi Kikuchi; Eisei Yamamoto; Kenichi Amitani; Takahiro Uchida; Naoki Sato; Kazuo Munakata; Kyoichi Mizuno


Journal of the American College of Cardiology | 2012

POTENTIAL ABILITY OF HEMODIALYSIS THERAPY FOR IMPROVEMENT OF LEFT VENTRICULAR MECHANICAL DYSSYNCHRONY IN PATIENTS WITH END-STAGE RENAL DISEASE

Naoto Takahashi; Masahiro Ishikawa; Arifumi Kikuchi; Eisei Yamamoto; Kenichi Amitani; Takahiro Uchida; Naoki Sato; Kazuo Munakata; Kyoichi Mizuno


Journal of the American College of Cardiology | 2012

TRANSIENT MYOCARDIAL ISCHEMIA INDUCED LEFT VENTRICULAR MECHANICAL DYSSYNCHRONY IN PATIENTS WITH CORONARY ARTERY DISEASE

Naoto Takahashi; Masahiro Ishikawa; Arifumi Kikuchi; Eisei Yamamoto; Kenichi Amitani; Takahiro Uchida; Naoki Sato; Kazuo Munakata; Kyoichi Mizuno


Journal of Cardiac Failure | 2008

The Assessment of Diastolic Dyssynchrony by Tc99 m-sestamibi-gated-SPECT using a Novel Program “cardioGRAF” in Heart Failure with Preseerved Ejection Fraction

Masahiro Ishikawa; Naoto Takahashi; Jyunnko Abe; Kenichi Amitani; Tomoyoshi Yamaguchi; Naomi Kawaguchi; Takahiro Uchida; Akira Yamamoto; Kazuo Munakata

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Akira Yamamoto

Kyoto Pharmaceutical University

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Takahiro Uchida

Beth Israel Deaconess Medical Center

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Junko Abe

Nippon Medical School

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