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村山　迪史 (ムラヤマ　ミチト)

保健科学研究院　保健科学部門　病態解析学分野助教

 

平成27年04月30日取得：臨床検査技師免許（登録番号：184766号）

平成27年09月13日修了：厚生労働省大臣の指定する「検体採取並びに味覚検査及び嗅覚検査の実施に必要な知識及び技能取得講習会」（登録番号：14007号）

平成27年10月30日取得：第2種ME技術実力検定試験（登録番号：2151973号）

平成31年04月01日取得：日本超音波医学会超音波検査士（循環器）（登録番号：2019-0338号）

令和02年04月01日取得：日本超音波医学会超音波検査士（消化器）（登録番号：2020-0745号）

令和05年05月20日修了：厚生労働省大臣の指定する「タスク・シフト／シェアに関する厚生労働大臣指定講習会」（登録番号：13873号）

令和06年02月19日取得：日本心エコー図学会認定専門技師（Japanese Registered Diagnostic Cardiovascular Sonographer [JRDCS]）（認定技師番号：23-009）

令和07年12月09日取得：日本周術期経食道心エコー認定試験合格（Japanese Board of Perioperative Transesophageal Echocardiography [JB-POT]）（JB-POT ID: JB003061）

 

研究者基本情報

■ 学位
  • 博士（保健科学）, 北海道大学, 2022年03月
■ URL
researchmap URLホームページURL■ ID 各種
研究者番号
  • 10964497
ORCID IDJ-Global ID■ 研究キーワード・分野
研究キーワード
  • 超音波医学
  • 超音波検査
  • 心エコー
  • 血行動態
研究分野
  • ライフサイエンス, 医用システム
  • その他, その他, 病態検査学
  • ライフサイエンス, 内科学一般
■ 担当教育組織

経歴

■ 経歴
経歴
  • 2022年04月 - 現在
    北海道大学大学院保健科学研究院, 病態解析学分野, 助教, 日本国
  • 2017年04月 - 現在
    北海道大学病院, 超音波センター, 臨床検査技師, 日本国
  • 2015年04月 - 2017年03月
    北海道大学病院, 超音波センター, 診療補助従事者
学歴
  • 2019年04月 - 2022年03月, 北海道大学, 大学院保健科学院, 博士後期課程
  • 2015年04月 - 2017年03月, 北海道大学, 大学院保健科学院, 修士課程
  • 2011年04月 - 2015年03月, 北海道大学, 医学部 保健学科, 検査技術科学専攻
委員歴
  • 2025年04月 - 現在
    北海道弁膜症研究会, 世話人
  • 2024年04月 - 現在
    日本心エコー図学会, 若手心血管ソノグラファーの会
  • 2024年04月 - 現在
    国⽴⼤学臨床検査技師教育協議会, 国臨協将来問題検討ワーキング

研究活動情報

■ 受賞
  • 2026年04月, 一般社団法人日本心エコー図学会, 心エコー図クイズ王決定戦 準優勝
    村山迪史, 国内学会・会議・シンポジウム等の賞
  • 2026年04月, 一般社団法人日本心エコー図学会, Young Investigator’s Award 審査会 優秀賞
    仰臥位から座位への体位変換による上大静脈血流速度変化に基づく非侵襲的右房圧推定と肝うっ血の予測
    和田山萌絵;村山迪史;加賀早苗;西野久雄;安藤風歌;横山しのぶ;柳 裕介;後藤真奈;市川絢子;宮本郁未;田原 就;神林 諒;下野裕依;玉置陽生;石坂 傑;岩野弘幸;永井利幸;安斉俊久, 国内学会・会議・シンポジウム等の賞, 53485723;40002746
  • 2025年12月, キヤノンメディカルシステムズ株式会社, 画論33rd The Best Image 最優秀賞
    All in ONEで挑む収縮性心膜炎
    村山迪史;石坂 傑, 国内学会・会議・シンポジウム等の賞, 40002746
  • 2025年10月, Faculty of Health Sciences, Hokkaido University, The 7th FHS International Conference Best Poster Award
    Optimal cutoff value of pulmonary regurgitation velocity according to the new definition of pulmonary hypertension
    Muto R, Murayama M, Onoda A, Tateishi Y, Yanagimoto K, Wadayama M, Kimura K, Kaga S, 国内外の国際的学術賞
  • 2025年09月, 日本超音波医学会第55回北海道地方会学術集会, 優秀演題賞
    心臓リハビリテーションが早期の左室駆出率が保たれた心不全の左房機能に与える影響と運動耐容能との関連
    柳本幸太;村山迪史;樋岡拓馬;木村花海;種村明日香;皆川七穂;津田正哉;福島 拓;福島 新;加賀早苗, 国内学会・会議・シンポジウム等の賞, 47207794
  • 2025年04月, 一般社団法人日本心エコー図学会, 令和7年度 一般社団法人日本心エコー図学会 海外学会発表優秀論文賞
    Optimal cut plane for the measurement of tricuspid annular plane systolic excursion: how should we measure TASPE?
    村山迪史
  • 2024年09月, 日本超音波医学会第54回北海道地方会学術集会, 優秀演題賞
    Beyond severe TRにおける経胸壁三次元心エコー法を用いた重症度評価と三尖弁複合体の形態学的特徴の検討
    鈴木那奈;阪口景太;村山迪史;加賀早苗;柳 祐介;横山しのぶ;西野久雄;石坂 傑;岩野弘幸;安斉俊久, 国内学会・会議・シンポジウム等の賞, 42085911
  • 2024年09月, 日本超音波医学会第54回北海道地方会学術集会, 優秀演題賞
    心房細動例におけるVMTスコアによる左室充満圧推定精度の検証
    西野久雄;村山迪史;岩野弘幸;鍵山暢之;土岐美沙子;岡田大司;石坂 傑;加賀早苗;山下直樹;豊嶋崇徳;安斉俊久, 国内学会・会議・シンポジウム等の賞, 46865526;36847082
  • 2023年12月, キヤノンメディカルシステムズ株式会社, 画論31st The Best Image 優秀賞
    経胸壁三次元心エコー法による三尖弁逆流の重症度評価が治療効果判定に有用であった1例
    村山迪史;石坂 傑, 42085911
  • 2023年09月, 日本臨床検査医学会, 第57回日本臨床検査医学会北海道支部総会 学会賞
    健常人における門脈血流の拍動メカニズム
    小林澄夏;小野田愛梨;村山迪史;永井優衣;塚本真帆;工藤悠輔;加賀早苗
  • 2023年06月, 第48回日本超音波検査学会学術集会, Congress Chairperson's Award -THE YOUNG Generations Award- 準優秀賞
    超音波法を用いたスコアリングによるうっ血肝診断と予後予測
    小野田愛梨;村山迪史;加賀早苗;工藤悠輔;岩井孝仁;中鉢雅大;横山しのぶ;西野久雄;西田 睦;石坂 傑;岩野弘幸;安斉俊久
  • 2022年05月, 国立大学臨床検査技師教育協議会, 国立大学臨床検査学系博士後期課程 最優秀賞
    村山迪史
  • 2022年04月, 北海道大学大学院保健科学院, 保健科学院長賞
    村山迪史
  • 2022年03月, 北海道大学, 総代（令和3年度 博士学位記授与式）
    村山迪史
  • 2021年10月, 日本超音波医学会第51回北海道地方会学術集会, 優秀演題賞
    房室弁開放時相差の視覚的評価に基づいた新たな心エコー指標によるHFpEFの予後予測
    村山迪史,岩野弘幸,表 和徳,原田智成,辻永真吾,中鉢雅大,加賀早苗,西田 睦,小保方 優,安斉俊久, 36691110
  • 2021年10月, 第 25 回日本心不全学会学術集会, YIA審査講演（ハートチーム） 優秀賞
    心エコー法による新たな左房圧指標を用いたHFpEFの予後予測に関する検討
    村山迪史,岩野弘幸,表 和徳,原田智成,小保方優,加藤寿光,中鉢雅弘,西野久雄,横山しのぶ,辻永真吾,千葉泰之,石坂 傑,本居 昂,西田 睦,安斉俊久, 36691110
  • 2021年08月, 北海道大学大学院保健科学院, 研究奨励賞
    村山迪史
  • 2020年12月, 第45回日本超音波検査学会学術集会, YIA優秀賞
    Dual Gate Doppler法による左房収縮時の血流時相解析
    岡田一範;岡田由佳;加賀早苗;村山迪史;中鉢雅大;横山しのぶ;西野久雄;三神大世;更科美羽;辻永真吾;岩野弘幸;安斉俊久
  • 2020年12月, 日本超音波医学会第93回学術集会, 日本超音波医学会第21回奨励賞
    房室弁開放時相差の視覚的評価に基づいたスコアリングによる左室充満圧推定と予後予測
    村山迪史,岩野弘幸,辻永真吾,西野久雄,中鉢雅大,横山しのぶ,西田 睦,渋谷 斉,加賀早苗,安斉俊久, 36700548
  • 2020年10月, 日本超音波医学会第50回北海道地方会学術集会, 優秀演題賞
    Vector flow mapping法による拡張早期僧帽弁逆流発生機序の推察
    村山迪史;岩野弘幸;更科美羽;辻永真吾;西野久雄;横山しのぶ;中鉢雅大;加賀早苗;西田 睦;安斉俊久
  • 2019年05月, 一般社団法人日本心エコー図学会, 平成30年度海外学会発表優秀論文賞
    心房収縮期における肺動脈弁逆流速度波形の窪みと三尖弁輪移動距離の計測に基づく非侵襲的な右室 硬さの推定
    村山迪史;加賀早苗;岡田一範;西野久雄;横山しのぶ;中鉢雅大;更科美羽;辻永真吾;西田 睦;澁谷 斉;永井利幸;岩野弘幸;安斉俊久;三神大世
  • 2018年03月, 第25回北海道心血管エコー研究会, 優秀演題賞
    高度大動脈弁逆流により拡張末期の大動脈弁開放を認めた高安動脈炎の1例
    村山迪史;岩野弘幸;西野久雄;横山しのぶ;中鉢雅大;市川絢子;林 大知;辻永真吾;更科美羽;岡田一範;加賀早苗;西田 睦;澁谷 斉;山田 聡;安斉俊久
■ 論文
  • 北海道大学心血管エコー研究室における超音波医学を牽引する人材の育成
    村山迪史; 西野久雄; 横山しのぶ; 市川絢子; 柳 裕介; 後藤真奈; 安藤風歌; 田原 就; 宮本郁未; 神林 諒; 下野裕依; 玉置陽生; 石坂 傑; 加賀早苗
    臨床検査学教育, 18, 1, 78, 84, 2026年03月01日, ［査読有り］, ［招待有り］, ［筆頭著者, 責任著者］

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  • High-resolution ultrasound imaging of scrotal metastasis from colorectal cancer
    Michito Murayama; Takahito Iwai; Satomi Omotehara; Yusuke Kudo; Yuya Hanada; Zen-ichi Tanei; Mutsumi Nishida
    Journal of Medical Ultrasonics, Springer Science and Business Media LLC, 2026年02月27日, ［査読有り］, ［筆頭著者］
    研究論文（学術雑誌）
  • Interobserver Reproducibility of the Visual Echocardiographic Scoring System for Left Ventricular Filling Pressure
    Yuka Uruma; Michito Murayama; Wahei Uemura; Namiko Sakai; Midori Shimomura; Kaori Nozaki; Yasuyuki Kunieda
    Cureus, Springer Science and Business Media LLC, 2026年02月16日, ［査読有り］
    研究論文（学術雑誌）
  • Echocardiographic Estimation of right ventricular stroke work index based on pulmonary regurgitant velocity in heart failure with reduced ejection fraction
    Yuta Tateishi; Michito Murayama; Sanae Kaga; Kie Yamazaki; Fuka Ando; Mana Goto; Yusuke Yanagi; Shinobu Yokoyama; Hisao Nishino; Makoto Kambayashi; Yui Shimono; Kosuke Nakamura; Yoji Tamaki; Suguru Ishizaka; Hiroyuki Iwano; Toshiyuki Nagai; Toshihisa Anzai
    Journal of Echocardiography, 2025年12月04日, ［査読有り］, ［筆頭著者, 責任著者］
    英語, 研究論文（学術雑誌）, 42085911
  • Acute effects of dynamic stretching on the mechanical properties of the triceps surae muscles assessed using shear wave ultrasound elastography.
    Kensuke Oba; Michito Murayama; Sanae Kaga; Mina Samukawa
    Journal of medical ultrasonics (2001), 2025年10月09日, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, PURPOSE: Dynamic stretching (DS), characterized by repeated movements through the joint range of motion via antagonist muscle contraction, is thought to reduce muscle stiffness through mechanisms such as reciprocal inhibition. However, whether DS effectively decreases muscle stiffness remains unclear. This study aimed to investigate the acute effects of DS on triceps surae muscle stiffness using shear wave elastography. METHODS: Sixteen healthy young adults performed both 120-s DS and control (no stretching) tasks. Shear wave velocities of the medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SOL) muscles were measured as indicators of muscle stiffness before and after DS. RESULTS: Our findings indicated that DS significantly reduced the shear wave velocity in the MG. However, no significant changes were observed in the shear wave velocities of the LG and SOL. CONCLUSION: DS effectively decreased MG stiffness, with no observed effects in the LG or SOL. These findings highlight inter-muscular variability in response to DS and suggest that DS may be particularly beneficial for targeting stiffness in the MG of the triceps surae muscles.
  • Physiological Mechanism of Pulsatility of Portal Venous Flow in Healthy Adults
    Airi Onoda; Michito Murayama; Moe Wadayama; Sumika Kobayashi; Maho Tsukamoto; Takahito Iwai; Satomi Omotehara; Yusuke Kudo; Mutsumi Nishida; Sanae Kaga
    Applied Sciences, 2025年08月25日, ［査読有り］, ［責任著者］, ［国際誌］
    研究論文（学術雑誌）
  • Role of Passive Leg Raise Stress Echocardiography in Latent Stiff Left Atrial Syndrome
    Michito Murayama; Hiroyuki Iwano; Satonori Tsuneta; Noriyuki Otsuka; Makoto Kambayashi; Yui Shimono; Yoji Tamaki; Suguru Ishizaka; Shinobu Yokoyama; Hisao Nishino; Sanae Kaga; Toshiyuki Nagai; Toshihisa Anzai
    Circulation: Cardiovascular Imaging, e018662, 2025年08月06日, ［査読有り］, ［筆頭著者, 責任著者］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • Investigation of Varying Durations of Dynamic Stretches on Muscle Stiffness of the Ankle Plantar Flexors Using Shear Wave Ultrasound Elastography.
    Kensuke Oba; Michito Murayama; Sanae Kaga; Mina Samukawa
    Journal of musculoskeletal & neuronal interactions, 25, 1, 68, 73, 2025年03月01日, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, OBJECTIVES: This study investigated the acute effects of dynamic stretch (DS) duration on the muscle stiffness of the ankle plantar flexor using shear wave ultrasound elastography. METHODS: Eighteen healthy young participants were enrolled in this study. DS with one set (DS1) or four sets (DS4) of 30 s each was performed randomly. Shear wave velocity in the medial gastrocnemius (MG) was measured before and after DS to assess muscle stiffness of the MG. RESULTS: Two-way repeated-measures analysis of variance (condition × time) showed a significant interaction with the shear wave velocity (p = 0.02). Shear wave velocity significantly decreased after the DS4 than before (before:3.09 ± 0.59 m/s; after: 2.86 ± 0.43 m/s). However, no significant differences were observed in shear wave velocity between before and after DS1 (before: 2.96 ± 0.56 m/s; after: 3.19 ± 0.56 m/s). There were no significant differences in shear wave velocity at baseline condition. After the intervention, significantly lower shear wave velocity was observed in DS4 than in DS1. CONCLUSIONS: The results of this study demonstrate that DS with four sets of 30 s effectively decreased the muscle stiffness of the MG.

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  • Optimal Cut Plane for Tricuspid Annular Plane Systolic Excursion Measurement.
    Michito Murayama; Sanae Kaga; Hisao Nishino; Yusuke Yanagi; Mana Goto; Fuka Ando; Shinobu Yokoyama; Marina Yamaguchi; Kazunori Okada; Masahiro Nakabachi; Makoto Kambayashi; Yui Shimono; Kosuke Nakamura; Yoji Tamaki; Suguru Ishizaka; Hiroyuki Iwano; Toshiyuki Nagai; Toshihisa Anzai
    Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography, 38, 6, 516, 519, 2025年01月14日, ［査読有り］, ［筆頭著者, 責任著者］, ［国際誌］
    英語, 研究論文（学術雑誌）, 42085911;40002746;46865526
  • Role of anatomical regurgitant orifice area of the tricuspid valve measurements in patients with beyond severe tricuspid regurgitation
    Michito Murayama; Suguru Ishizaka; Keita Sakaguchi; Rion Ando; Hisao Nishino; Sanae Kaga; Toshihisa Anzai
    Journal of Echocardiography, 23, 3, 219, 221, 2024年12月24日, ［査読有り］, ［筆頭著者, 責任著者］, ［国内誌］
    英語, 研究論文（学術雑誌）, 42085911
  • Validation of Left Ventricular Filling Pressure Evaluation by Order of Tricuspid and Mitral Valve Opening in Patients With Atrial Fibrillation
    Hisao Nishino; Michito Murayama; Hiroyuki Iwano; Nobuyuki Kagiyama; Yutaka Nakamura; Yuka Akama; Misako Toki; Sachiko Takamatsu; Taiji Okada; Yasuyuki Chiba; Masahiro Nakabachi; Shinobu Yokoyama; Mana Goto; Yukino Suzuki; Suguru Ishizaka; Ko Motoi; Yoji Tamaki; Hiroyuki Aoyagi; Kosuke Nakamura; Sanae Kaga; Chiaki Watanabe; Kiwamu Kamiya; Toshiyuki Nagai; Takanori Teshima; Toshihisa Anzai
    Circulation: Cardiovascular Imaging, 17, 11, e017134, 2024年11月13日, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）, BACKGROUND: Accurate assessment of left ventricular filling pressure in patients with atrial fibrillation or flutter (AF) remains difficult. A novel 2-dimensional scoring system, visually assessing time difference between mitral valve and tricuspid valve opening (VMT) score, based on temporal analysis of early diastolic valve opening, could be applied to these patients. We aimed to determine the usefulness of the VMT score in patients with AF. METHODS: We analyzed 119 consecutive patients with AF who underwent cardiac catheterization as a derivation cohort. The diagnostic performance of the VMT score was further evaluated in an external data set containing 189 patients with AF. Elevated left ventricular filling pressure was defined as a mean pulmonary arterial wedge pressure ≥15 mm Hg. The time sequence of atrioventricular valve opening was visually assessed and scored (0, tricuspid valve first; 1, simultaneous; 2, mitral valve first). When the inferior vena cava was dilated, 1 point was added, and the VMT score was finally graded as 0 to 3. Conventional Doppler parameters to estimate left ventricular filling pressure were also measured. RESULTS: Pulmonary arterial wedge pressure was elevated with an increase in the VMT score (0: 10±3, 1: 13±5, 2: 22±7, 3: 27±6 mm Hg; P<0.001), resulting in a significant rise in pulmonary arterial wedge pressure from VMT score 1 to 2. VMT≥2 predicted elevated pulmonary arterial wedge pressure with an accuracy of 87%, and the diagnostic accuracy of the VMT score was significantly higher than that of conventional Doppler parameters (C index, 0.88 versus 0.54-0.68; P<0.001). In addition, VMT ≥2 showed an incremental predictive value over plasma brain natriuretic peptide levels (C index, 0.79-0.93; P<0.001). In the external validation cohort, VMT≥2 demonstrated acceptable accuracy of 72%. CONCLUSIONS: VMT scoring was a useful echocardiographic marker of elevated left ventricular filling pressure and had an incremental benefit over practical biomarkers in patients with AF., 46865526;40002746;36847082;48730657

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  • Head-to-Head Comparison of Hepatic Vein and Superior Vena Cava Flow Velocity Waveform Analyses for Predicting Elevated Right Atrial Pressure.
    Michito Murayama; Sanae Kaga; Airi Onoda; Hisao Nishino; Shinobu Yokoyama; Mana Goto; Yukino Suzuki; Yusuke Yanagi; Yui Shimono; Kosuke Nakamura; Hiroyuki Aoyagi; Yoji Tamaki; Suguru Ishizaka; Hiroyuki Iwano; Kiwamu Kamiya; Toshiyuki Nagai; Toshihisa Anzai
    Ultrasound in medicine & biology, 50, 9, 1352, 1360, 2024年06月03日, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）, OBJECTIVE: Blood flow in the hepatic veins and superior vena cava (SVC) reflects right heart filling; however, their Doppler profiles are often not identical, and no studies have compared their diagnostic efficacies. We aimed to determine which venous Doppler profile is reliable for detecting elevated right atrial pressure (RAP). METHODS: In 193 patients with cardiovascular diseases who underwent cardiac catheterization within 2 d of echocardiography, the hepatic vein systolic filling fraction (HV-SFF) and the ratio of the peak systolic to diastolic forward velocities of the SVC (SVC-S/D) were measured. HV-SFF < 55% and SVC-S/D < 1.9 were regarded as elevated RAP. We also calculated the fibrosis 4 index (FIB-4) as a serum liver fibrosis marker. RESULTS: HV-SFF and SVC-S/D were feasible in 177 (92%) and 173 (90%) patients, respectively. In the 161 patients in whom both venous Doppler waveforms could be measured, HV-SFF and SVC-S/D were inversely correlated with RAP (r = -0.350, p < 0.001; r = -0.430, p < 0.001, respectively). SVC-S/D > 1.9 showed a significantly higher diagnostic accuracy of RAP elevation compared with HV-SFF < 55% (area under the curve, 0.842 vs. 0.614, p < 0.001). Multivariate analyses showed that both FIB-4 (β = -0.211, p = 0.013) and mean RAP (β = -0.319, p < 0.001) were independent determinants of HV-SFF. In contrast, not FIB-4 but mean RAP (β = -0.471, p < 0.001) was an independent determinant of SVC-S/D. The diagnostic accuracy remained unchanged when HV-SFF < 55% was considered in conjunction with the estimated RAP based on the inferior vena cava morphology. Conversely, SVC-S/D showed an incremental diagnostic value over the estimated RAP. CONCLUSIONS: SVC-S/D enabled a more accurate diagnosis of RAP elevation than HV-SFF., 40002746

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  • Appropriate Body Position and Site for Diaphragm Ultrasound: Comparison with Inspiratory Mouth Pressure
    Kazunori Okada; Akiko Kamiya; Yusuke Yanagi; Masahiro Nakabachi; Yasuhiro Hayashi; Michito Murayama; Sanae Kaga
    WFUMB Ultrasound Open, 100052, 100052, Elsevier BV, 2024年06月, ［査読有り］
    研究論文（学術雑誌）
  • Exploratory analysis of the accuracy of echocardiographic parameters for the assessment of right ventricular function and right ventricular-pulmonary artery coupling.
    Hideki Shima; Ichizo Tsujino; Junichi Nakamura; Toshitaka Nakaya; Ayako Sugimoto; Takahiro Sato; Taku Watanabe; Hiroshi Ohira; Masaru Suzuki; Satonori Tsuneta; Yasuyuki Chiba; Michito Murayama; Isao Yokota; Satoshi Konno
    Pulmonary circulation, 14, 2, e12368, 2024年04月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, Echocardiography is a widely used modality for the assessment of right ventricular (RV) function; however, few studies have comprehensively compared the accuracy of echocardiographic parameters using invasively obtained reference values. Therefore, this exploratory study aimed to compare the accuracy of echocardiographic parameters of RV function and RV-pulmonary artery (PA) coupling. We calculated four indices of RV function (end-systolic elastance [Ees] for systolic function [contractility], τ for relaxation, and β and end-diastolic elastance [Eed] for stiffness), and an index of RV-PA coupling (Ees/arterial elastance [Ea]), using pressure catheterization, cardiac magnetic resonance imaging, and a single-beat method. We then compared the correlations of RV indices with echocardiographic parameters. In 63 participants (54 with pulmonary hypertension (PH) and nine without PH), Ees and τ correlated with several echocardiographic parameters, such as RV diameter and area, but the correlations were moderate (|correlation coefficients (ρ)| < 0.5 for all parameters). The correlations of β and Eed with echocardiographic parameters were weak, with |ρ| < 0.4. In contrast, Ees/Ea closely correlated with RV free wall longitudinal strain (RVFW-LS)/estimated systolic PA pressure (eSPAP) (ρ = -0.72). Ees/Ea also correlated with tricuspid annular plane systolic excursion/eSPAP, RV diameter, and RV end-systolic area, with |ρ | >0.65. In addition, RVFW-LS/eSPAP yielded high sensitivity (0.84) and specificity (0.75) for detecting reduced Ees/Ea. The present study indicated a limited accuracy of echocardiographic parameters in assessing RV systolic and diastolic function. In contrast to RV function, they showed high accuracy for assessing RV-PA coupling, with RVFW-LS/eSPAP exhibiting the highest accuracy.
  • Deep learning to assess right ventricular ejection fraction from two‐dimensional echocardiograms in precapillary pulmonary hypertension
    Michito Murayama; Hiroyuki Sugimori; Takaaki Yoshimura; Sanae Kaga; Hideki Shima; Satonori Tsuneta; Aoi Mukai; Yui Nagai; Shinobu Yokoyama; Hisao Nishino; Junichi Nakamura; Takahiro Sato; Ichizo Tsujino
    Echocardiography, 41, 4, e15812, 2024年04月, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）, BACKGROUND: Precapillary pulmonary hypertension (PH) is characterized by a sustained increase in right ventricular (RV) afterload, impairing systolic function. Two-dimensional (2D) echocardiography is the most performed cardiac imaging tool to assess RV systolic function; however, an accurate evaluation requires expertise. We aimed to develop a fully automated deep learning (DL)-based tool to estimate the RV ejection fraction (RVEF) from 2D echocardiographic videos of apical four-chamber views in patients with precapillary PH. METHODS: We identified 85 patients with suspected precapillary PH who underwent cardiac magnetic resonance imaging (MRI) and echocardiography. The data was divided into training (80%) and testing (20%) datasets, and a regression model was constructed using 3D-ResNet50. Accuracy was assessed using five-fold cross validation. RESULTS: The DL model predicted the cardiac MRI-derived RVEF with a mean absolute error of 7.67%. The DL model identified severe RV systolic dysfunction (defined as cardiac MRI-derived RVEF < 37%) with an area under the curve (AUC) of .84, which was comparable to the AUC of RV fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE) measured by experienced sonographers (.87 and .72, respectively). To detect mild RV systolic dysfunction (defined as RVEF ≤ 45%), the AUC from the DL-predicted RVEF also demonstrated a high discriminatory power of .87, comparable to that of FAC (.90), and significantly higher than that of TAPSE (.67). CONCLUSION: The fully automated DL-based tool using 2D echocardiography could accurately estimate RVEF and exhibited a diagnostic performance for RV systolic dysfunction comparable to that of human readers., 42909777
  • Non-invasive assessment of left ventricular filling pressure in aortic stenosis.
    Hiroyuki Aoyagi; Hiroyuki Iwano; Yoji Tamaki; Michito Murayama; Suguru Ishizaka; Ko Motoi; Kosuke Nakamura; Mana Goto; Yukino Suzuki; Shinobu Yokoyama; Hisao Nishino; Sanae Kaga; Kiwamu Kamiya; Toshiyuki Nagai; Toshihisa Anzai
    Echocardiography (Mount Kisco, N.Y.), 41, 4, e15808, 2024年04月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, BACKGROUND: The assessment of left ventricular (LV) filling pressure (FP) is important for the management of aortic stenosis (AS) patients. Although, it is often restricted for predict LV FP in AS because of mitral annular calcification and a certain left ventricular hypertrophy. Thus, we tested the predictive ability of the algorithm for elevated LV FP in AS patients and also applied a recently-proposed echocardiographic scoring system of LV FP, visually assessed time difference between the mitral valve and tricuspid valve opening (VMT) score. METHODS: We enrolled consecutive 116 patients with at least moderate AS in sinus rhythm who underwent right heart catheterization and echocardiography within 7 days. Mean pulmonary artery wedge pressure (PAWP) was measured as invasive parameter of LV FP. LV diastolic dysfunction (DD) was graded according to the ASE/EACVI guidelines. The VMT score was defined as follows: time sequence of opening of mitral and tricuspid valves was scored to 0-2 (0: tricuspid valve first, 1: simultaneous, 2: mitral valve first). When the inferior vena cava was dilated, one point was added and VMT score was finally calculated as 0-3. RESULTS: Of the 116 patients, 29 patients showed elevated PAWP. Ninety patients (93%) and 67 patients (63%) showed increased values for left atrium volume index (LAVI) and E/e', respectively when the cut-off values recommended by the guidelines were applied and thus the algorism predicted elevated PAWP with a low specificity and positive predictive value (PPV). VMT ≥ 2 predicted elevated PAWP with a sensitivity of 59%, specificity of 90%, PPV of 59%, and negative predictive value of 89%. An alternative algorithm that applied tricuspid regurgitation velocity and VMT scores was tested, and its predictive ability was markedly improved. CONCLUSION: VMT score was applicable for AS patients. Alternative use of VMT score improved diagnostic accuracy of guideline-recommended algorism.
  • Echocardiographic estimation of right ventricular diastolic stiffness based on pulmonary regurgitant velocity waveform analysis in precapillary pulmonary hypertension.
    Yui Nagai; Michito Murayama; Sanae Kaga; Hideki Shima; Satonori Tsuneta; Shinobu Yokoyama; Hisao Nishino; Mana Goto; Yukino Suzuki; Yusuke Yanagi; Suguru Ishizaka; Hiroyuki Iwano; Junichi Nakamura; Takahiro Sato; Ichizo Tsujino
    The international journal of cardiovascular imaging, 40, 5, 1123, 1134, 2024年03月27日, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）, Right ventricular (RV) diastolic stiffness is an independent predictor of survival and is strongly associated with disease severity in patients with precapillary pulmonary hypertension (PH). Therefore, a fully validated echocardiographic method for assessing RV diastolic stiffness needs to be established. This study aimed to compare echocardiography-derived RV diastolic stiffness and invasively measured pressure-volume loop-derived RV diastolic stiffness in patients with precapillary PH. We studied 50 consecutive patients with suspected or confirmed precapillary PH who underwent cardiac catheterization, magnetic resonance imaging, and echocardiography within a 1-week interval. Single-beat RV pressure-volume analysis was performed to determine the gold standard for RV diastolic stiffness. Elevated RV end-diastolic pressure (RVEDP) was defined as RVEDP ≥ 8 mmHg. Using continuous-wave Doppler and M-mode echocardiography, an echocardiographic index of RV diastolic stiffness was calculated as the ratio of the atrial-systolic descent of the pulmonary artery-RV pressure gradient derived from pulmonary regurgitant velocity (PRPGDAC) to the tricuspid annular plane movement during atrial contraction (TAPMAC). PRPGDAC/TAPMAC showed significant correlation with β (r = 0.54, p < 0.001) and RVEDP (r = 0.61, p < 0.001). A cut-off value of 0.74 mmHg/mm for PRPGDAC/TAPMAC showed 83% sensitivity and 93% specificity for identifying elevated RVEDP. Multivariate analyses indicated that PRPGDAC/TAPMAC was independently associated with disease severity in patients with precapillary PH, including substantial PH symptoms, stroke volume index, right atrial size, and pressure. PRPGDAC/TAPMAC, based on pulmonary regurgitation velocity waveform analysis, is useful for the noninvasive assessment of RV diastolic stiffness and is associated with prognostic risk factors in precapillary PH., 40464604
  • Correction: Venous dilation effect of hot towel (moist and dry heat) versus hot pack for peripheral intravenous catheterization: a quasi-experimental study.
    Kae Yasuda; Inaho Shishido; Michito Murayama; Sanae Kaga; Rika Yano
    Journal of physiological anthropology, 43, 1, 9, 9, 2024年02月13日, ［査読有り］, ［国際誌］
    英語
  • Venous dilation effect of hot towel (moist and dry heat) versus hot pack for peripheral intravenous catheterization: a quasi-experimental study.
    Kae Yasuda; Inaho Shishido; Michito Murayama; Sanae Kaga; Rika Yano
    Journal of physiological anthropology, 42, 1, 23, 23, 2023年10月19日, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, BACKGROUND: Heat application before peripheral intravenous catheterization is recommended for venous dilation. Hot pack application enlarges the venous diameter in healthy adults; however, hot towels (moist and dry heat) are used often in some medical cases. However, it is unclear whether hot towel application promotes venous dilation better than hot pack application. This study compared the venous dilation effect of using a hot towel (moist and dry heat) to a hot pack before applying the tourniquet at an access site for peripheral intravenous catheterization. METHODS: Eighty-eight healthy females aged 18-29 years were recruited for this quasi-experimental study. They underwent three types of heat applications (hot pack, moist hot towel, and dry hot towel [moist hot towel wrapped in a dry plastic bag], all of which were warmed to 40 ± 2 °C and performed for 7 min) to their forearm and tourniquet application for 30 s after each heating. Venous diameter and depth were measured using ultrasonography, and venous palpability and visibility (venous assessment score) was observed as venous dilatation effects. In addition, the skin temperature, stratum corneum hydration, and subjective evaluation of the warmth were measured. RESULTS: There were no significant differences in venous diameter and assessment scores after intervention between the dry hot towel and the hot pack groups, and the effect size was negligible (Cohen's d < 0.20). However, these measurements were significantly lower for the moist hot towel than for the other two heat applications (P < .001). Although there was no significant difference in skin temperature and warmth rating score between the dry hot towel and the hot pack, these were significantly lower for the moist hot towel than for the other two heat applications (P < .001). The amount of change in stratum corneum hydration of the dry hot towel was not significantly different from that of the hot pack; however, that of the moist hot towel was significantly larger than that of the other two heat applications (P < . 001.) CONCLUSIONS: A method in which a towel warmed in hot water is wrapped in a dry barrier may be an alternative to a hot pack. TRIAL REGISTRATION: This study was registered with University Hospital Medical Information Network in Japan (Registration No.: UMIN000048308. Registered on July 7, 2022).
  • Paradoxical increase in global longitudinal strain by handgrip exercise despite left ventricular diastolic dysfunction.
    Ko Motoi; Hiroyuki Iwano; Suguru Ishizaka; Kosuke Nakamura; Yoji Tamaki; Hiroyuki Aoyagi; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Michito Murayama; Sanae Kaga; Toshihisa Anzai
    Echocardiography (Mount Kisco, N.Y.), 40, 8, 810, 821, 2023年08月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, BACKGROUND: Although global longitudinal strain (GLS) is recognized as a sensitive marker of intrinsic left ventricular (LV) dysfunction, its afterload dependency has also been pointed. We hypothesized that decrease in GLS during handgrip exercise could be more sensitive marker of intrinsic myocardial dysfunction. METHODS: Handgrip exercise-stress echocardiography was performed in 90 cardiovascular disease patients with preserved LV ejection fraction. LV diastolic function was graded according to the guidelines. Diastolic wall stress (DWS) and ratio of left atrial (LA) volume index to late-diastolic mitral annular velocity (LAVI/a') were measured at rest as LV stiffness. As well, LA strains were measured to assess LA function. GLS was expressed as absolute value and significant changes in GLS by handgrip exercise was defined as changes over prespecified mean absolute test-retest variability (2.65%). RESULTS: While mean value of GLS did not change by the exercise, substantial patients showed significant changes in GLS: decreased (group I, n = 28), unchanged (group II, n = 34), and increased (group III, n = 28). Unexpectedly, patients in group I did not show any clinical and echocardiographic characteristics, while those in group III were characterized by elevated natriuretic peptide levels, blunted heart rate response to handgrip exercise, and advanced LV diastolic dysfunction. Multivariable analyses revealed that DWS, left atrial booster strain, and grade II or more diastolic dysfunction determined the increase in GLS even after adjustment for elevated natriuretic peptides and the changes in heart rate by the exercise. CONCLUSION: In contrast to our hypothesis, paradoxical increase in GLS by handgrip exercise could be associated with advanced LV diastolic dysfunction in cardiovascular patients with preserved LV ejection fraction. Our findings suggest that HG exercise for heart failure patients does not enhance the afterload straightforward, resulting in variable changes of GLS according to the individual conditions.
  • Application of an echocardiographic scoring system of left ventricular filling pressure to diagnose acute heart failure in patients complaining dyspnea.
    Yoji Tamaki; Hiroyuki Iwano; Michito Murayama; Suguru Ishizaka; Ko Motoi; Hiroyuki Aoyagi; Kosuke Nakamura; Mana Goto; Yukino Suzuki; Shinobu Yokoyama; Hisao Nishino; Masahiro Nakabachi; Sanae Kaga; Kiwamu Kamiya; Toshiyuki Nagai; Toshihisa Anzai
    Journal of cardiology, 82, 1, 62, 68, 2023年07月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, BACKGROUND: Dyspnea is a common symptom in acute heart failure (AHF) patients. Although an accurate and rapid diagnosis of AHF is essential to improve prognosis, estimation of left ventricular (LV) filling pressure (FP) remains challenging, especially for noncardiologists. We evaluated the usefulness of a recently-proposed parameter of LV FP, visually assessed time difference between the mitral valve and tricuspid valve opening (VMT) score, to detect AHF in patients complaining of dyspnea. METHODS: Echocardiography and lung ultrasonography (LUS) were performed in 121 consecutive patients (68 ± 14 years old, 75 males) presenting with dyspnea. The VMT score was determined from the atrioventricular valve opening phase (tricuspid valve first: 0, simultaneous: 1, mitral valve first: 2) and inferior vena cava dilatation (absent: 0, present: 1), and VMT ≥2 was judged as positive. LUS was performed with the 8 zones method and judged as positive if 3 or more B-lines were observed in bilateral regions. The AHF diagnosis was performed by certified cardiologists according to recent guidelines. RESULTS: Of the 121 patients, 33 were diagnosed with AHF. The sensitivity and specificity for diagnosing AHF were 64 % and 84 % for LUS and 94 % and 88 % for VMT score. In logistic regression analysis, VMT score showed a significantly higher c-index than LUS (0.91 vs 0.74, p = 0.002). In multivariable analyses, VMT score was associated with AHF independently of clinically relevant covariates and LUS. In addition, serial assessment of VMT score followed by LUS provided a diagnostic flow chart to diagnose AHF (VMT 3: AHF definitive, VMT 2 and LUS positive: AHF highly suspicious; VMT 2 and LUS negative: further investigation is needed; VMT ≤ 1: AHF rejected). CONCLUSIONS: VMT score showed high diagnostic accuracy in diagnosing AHF. Combined assessment of the VMT score and LUS could become a reliable strategy for diagnosis of AHF by non-cardiologists.
  • Impact of right ventricular stiffness on discordance between hemodynamic parameter and regurgitant volume in patients with pulmonary regurgitation.
    Ko Motoi; Hiroyuki Iwano; Satonori Tsuneta; Suguru Ishizaka; Yoji Tamaki; Hiroyuki Aoyagi; Kosuke Nakamura; Michito Murayama; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Sanae Kaga; Atsuhito Takeda; Toshihisa Anzai
    The international journal of cardiovascular imaging, 39, 6, 1133, 1142, 2023年06月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, BACKGROUND: Accurate detection of significant pulmonary regurgitation (PR) is critical in management of patients after right ventricular (RV) outflow reconstruction in Tetralogy of Fallot (TOF) patients, because of its influence on adverse outcomes. Although pressure half time (PHT) of PR velocity is one of the widely used echocardiographic markers of the severity, shortened PHT is suggested to be seen in conditions with increased RV stiffness with mild PR. However, little has been reported about the exact characteristics of patients showing discrepancy between PHT and PR volume in this population. METHODS: Echocardiography and cardiac magnetic resonance imaging (MRI) were performed in 74 TOF patients after right ventricular outflow tract (RVOT) reconstruction [32 ± 10 years old]. PHT was measured from the continuous Doppler PR flow velocity profile and PHT < 100 ms was used as a sign of significant PR. Presence of end-diastolic RVOT forward flow was defined as RV restrictive physiology. By using phase-contrast MRI, forward and regurgitant volumes through the RVOT were measured and regurgitation fraction was calculated. Significant PR was defined as regurgitant fraction ≥ 25%. RESULTS: Significant PR was observed in 54 of 74 patients. While PHT < 100 ms well predicted significant PR with sensitivity of 96%, specificity of 52%, and c-index of 0.72, 10 patients showed shortened PHT despite regurgitant fraction < 25% (discordant group). Tricuspid annular plane systolic excursion and left ventricular (LV) ejection fraction were comparable between discordant group and patients showing PHT < 100 ms and regurgitant fraction ≥ 25% (concordant group). However, discordant group showed significantly smaller mid RV diameter (30.7 ± 4.5 vs. 39.2 ± 7.3 mm, P < 0.001) and higher prevalence of restrictive physiology (100% vs. 42%, P < 0.01) than concordant group. When mid RV diameter ≥ 32 mm and presence of restrictive physiology were added to PHT, the predictive value was significantly improved (sensitivity: 81%, specificity: 90%, and c-index: 0.89, P < 0.001 vs. PHT alone by multivariable logistic regression model). CONCLUSION: Patients with increased RV stiffness and non-enlarged right ventricle showed short PHT despite mild PR. Although it has been expected, this was the first study to demonstrate the exact characteristics of patients showing discrepancy between PHT and PR volume in TOF patients after RVOT reconstruction.
  • Associations of right ventricular pulsatile load and cardiac power output to clinical outcomes in heart failure: Difference from systemic circulation.
    Yasuyuki Chiba; Hiroyuki Iwano; Hiroyuki Aoyagi; Yoji Tamaki; Ko Motoi; Suguru Ishizaka; Michito Murayama; Shinobu Yokoyama; Masahiro Nakabachi; Hisao Nishino; Sanae Kaga; Kiwamu Kamiya; Toshiyuki Nagai; Toshihisa Anzai
    Journal of cardiology, 81, 4, 404, 412, 2023年04月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, BACKGROUND: Although left ventricular (LV) cardiac power output (CPO) is a powerful prognostic indicator in heart failure (HF), the significance of right ventricular (RV) CPO is unknown. In contrast, RV pulsatile load is a key prognostic marker in HF. We investigated the impact of RV-CPO and pulsatile load on cardiac outcome and the prognostic performance of the combined systemic and pulmonary circulation parameters in HF. METHODS: Right heart catheterization and echocardiography were performed in 231 HF patients (62 ± 16 years, LV ejection fraction 42 ± 18 %). Invasive and noninvasive CPOs were calculated from mean systemic or pulmonary arterial pressure and cardiac output. LV-CPO was then normalized to LV mass (LV-P/M). Pulmonary arterial capacitance and the ratio of acceleration time to ejection time (AcT/ET) of RV outflow were used as parameters of RV pulsatile load. The primary endpoints, defined as a composite of cardiac death, HF hospitalization, ventricular arrythmia, and LVAD implantation after the examination, were recorded. RESULTS: Noninvasive CPOs were moderately correlated with invasive ones (LV: ρ = 0.787, RV: ρ = 0.568, and p < 0.001 for both). During a median follow-up period of 441 days, 57 cardiovascular events occurred. Lower LV-P/M and higher RV pulsatile load were associated with cardiovascular events; however, RV-CPO was not associated with the outcome. Echocardiographic LV-P/M and AcT/ET showed significant incremental prognostic value over the clinical parameters. CONCLUSIONS: RV pulsatile load assessed by AcT/ET may be a predictor of clinical events in HF patients. The combination of echocardiographic LV-P/M and AcT/ET could be a novel noninvasive prognostic indicator in HF patients.
  • Relevance of early-diastolic mitral regurgitation in dilated heart.
    Asuka Tanemura; Michito Murayama; Hiroyuki Iwano; Yasuyuki Chiba; Mutsumi Nishida; Takanori Teshima; Toshihisa Anzai
    Journal of echocardiography, 21, 1, 50, 52, 2023年03月, ［査読有り］, ［筆頭著者］, ［国内誌］
    英語, 研究論文（学術雑誌）
  • 心エコー法による右房圧推定精度の検証：ガイドラインに基づく副次的指標の再考
    村山 迪史; 加賀 早苗; 小野田 愛梨; 岡田 一範; 中鉢 雅大; 横山 しのぶ; 西野 久雄; 青柳 裕之; 玉置 陽生; 本居 昂; 石坂 傑; 岩野 弘幸; 永井 利幸; 辻野 一三; 安斉 俊久
    超音波検査技術, advpub, 4, 384, 397, 一般社団法人 日本超音波検査学会, 2023年, ［査読有り］, ［招待有り］, ［筆頭著者］
    日本語, 目的：アメリカ心エコー図学会のガイドラインには，下大静脈計測に基づく右房圧推定の精度を補完するものとして，拘束型の右室流入血流速波形，拡張早期の右室流入血流速度と三尖弁輪運動速度との比，肝静脈血流速波形のsystolic filling fractionが示されている．本研究では，これらの副次的指標が右房圧上昇の予測能を改善させるかを明らかにするとともに，右房面積計測の付加的価値を検討する．

    対象と方法：心疾患患者128例において右心カテーテル検査で平均右房圧を計測し，≧8 mmHgを上昇とした．下大静脈の径とsniffによる虚脱率から，推定右房圧を3, 8，15 mmHgに分類した（モデル1）．右室流入血流速波形の拘束型パターン，拡張早期の右室流入血流速度と三尖弁輪運動速度との比，systolic filling fractionを評価に加えて，推定右房圧の再分類を行った（モデル2）．右房の最小と最大面積および容積を計測し，それぞれのexpansion indexを算出した．

    結果：右房圧の上昇を29例に認めた．ロジスティック回帰分析で，モデル1における推定右房圧とsystolic filling fractionは，平均右房圧上昇と有意に関連した（ともにp＜0.05）．拘束型パターンを呈した例はなく，拡張早期の右室流入血流速度と三尖弁輪運動速度との比は右房圧上昇と関連しなかった．右房の形態・機能指標は，いずれも右房圧上昇と関連し（すべてp＜0.05），最小右房面積が最も強く関連した（右室面積変化率で補正後のオッズ比：10.64, p＜0.01）．尤度比検定では，モデル2の右房圧上昇の予測能はモデル1と同等であったが，systolic filling fractionと最小右房面積を用いた新しいモデルは，モデル1より良好に右房圧上昇を予測できた．

    結論：従来の副次的指標を用いた再分類により右房圧上昇の予測能は改善しなかった．肝静脈血流速波形のsystolic filling fractionと最小右房面積を右房圧の評価に加えると，右房圧上昇の予測能は改善した．, 36700601

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  • Determinants of exercise capacity in patients with heart failure without left ventricular hypertrophy.
    Suguru Ishizaka; Hiroyuki Iwano; Shingo Tsujinaga; Michito Murayama; Satonori Tsuneta; Hiroyuki Aoyagi; Yoji Tamaki; Ko Motoi; Yasuyuki Chiba; Asuka Tanemura; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Kazunori Okada; Brett A Meyers; Pavlos P Vlachos; Takuma Sato; Kiwamu Kamiya; Masaya Watanabe; Sanae Kaga; Toshiyuki Nagai; Noriko Oyama-Manabe; Toshihisa Anzai
    Journal of cardiology, 81, 1, 33, 41, 2023年01月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, BACKGROUND: Determinants of exercise intolerance in a phenotype of heart failure with preserved ejection fraction (HFpEF) with normal left ventricular (LV) structure have not been fully elucidated. METHODS: Cardiopulmonary exercise testing and exercise-stress echocardiography were performed in 44 HFpEF patients without LV hypertrophy. Exercise capacity was determined by peak oxygen consumption (peak VO2). Doppler-derived cardiac output (CO), transmitral E velocity, systolic (LV-s') and early diastolic mitral annular velocities (e'), systolic pulmonary artery (PA) pressure (SPAP), tricuspid annular plane systolic excursion (TAPSE), and peak systolic right ventricular (RV) free wall velocity (RV-s') were measured at rest and exercise. E/e' and TAPSE/SPAP were used as an LV filling pressure parameter and RV-PA coupling, respectively. RESULTS: During exercise, CO, LV-s', RV-s', e', and SPAP were significantly increased (p < 0.05 for all), whereas E/e' remained unchanged and TAPSE/SPAP was significantly reduced (p < 0.001). SPAP was higher and TAPSE/SPAP was lower at peak exercise in patients showing lower-half peak VO2. In univariable analyses, LV-s' (R = 0.35, p = 0.022), SPAP (R = -0.40, p = 0.008), RV-s' (R = 0.47, p = 0.002), and TAPSE/SPAP (R = 0.42, p = 0.005) were significantly correlated with peak VO2. In multivariable analyses, not only SPAP, but also TAPSE/SPAP independently determined peak VO2 even after the adjustment for clinically relevant parameters. CONCLUSIONS: In HFpEF patients without LV hypertrophy, altered RV-PA coupling by exercise could be associated with exercise intolerance, which might not be caused by elevated LV filling pressure.
  • Usefulness of the pulmonary venous flow waveform for assessing left atrial stiffness.
    Takehiro Abe; Kazunori Okada; Michito Murayama; Sanae Kaga; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Hiroyuki Aoyagi; Yoji Tamaki; Ko Motoi; Yasuyuki Chiba; Suguru Ishizaka; Shingo Tsujinaga; Hiroyuki Iwano; Kiwamu Kamiya; Toshiyuki Nagai; Toshihisa Anzai
    The international journal of cardiovascular imaging, 39, 1, 23, 34, Springer Science and Business Media LLC, 2023年01月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, PURPOSE: This study investigated the novel non-invasive left atrial (LA) stiffness parameter using pulmonary venous (PV) flow measurements and the clinical usefulness of the novel LA stiffness parameter. METHODS: We retrospectively analyzed 237 patients who underwent right heart catheterization and echocardiography less than one week apart. From the pulmonary artery wedge pressure waveform, the difference between x-descent and v-wave (ΔP) was measured. Using the echocardiographic biplane method of disks, the difference between LA maximum volume and that just before atrial contraction (ΔVMOD) was calculated, and the ΔP/ΔVMOD was calculated as a standard LA stiffness index. From the PV flow waveform, the peak systolic velocity (S), peak diastolic velocity (D), and minimum velocity between them (R) were measured, and S/D, S/R, and D/R were calculated. From the speckle tracking echocardiography-derived time-LA volume curve, the difference between LA maximum volume and that just before atrial contraction (ΔVSTE) was measured. Each patient's prognosis was investigated until three years after echocardiography. RESULTS: Among the PV flow parameters, D/R was significantly correlated with ΔP (r = 0.62), and the correlation coefficient exceeded that between S/D and ΔP (r =  - 0.39) or S/R and ΔP (r = 0.14). The [D/R]/ΔVSTE was significantly correlated with ΔP/ΔVMOD (r = 0.61). During the follow-up, 37 (17%) composite endpoints occurred. Kaplan-Meier analysis showed that patients with [D/R]/ΔVSTE greater than 0.13 /mL were at higher risk of cardiac events. CONCLUSION: The [D/R]/ΔVSTE was useful for assessing LA stiffness non-invasively and might be valuable in the prognostic evaluation of patients with cardiac diseases.
  • Determinants of altered left ventricular suction in pre-capillary pulmonary hypertension.
    Yasuyuki Chiba; Hiroyuki Iwano; Satonori Tsuneta; Shingo Tsujinaga; Brett Meyers; Pavlos Vlachos; Suguru Ishizaka; Ko Motoi; Hiroyuki Aoyagi; Yoji Tamaki; Asuka Tanemura; Michito Murayama; Shinobu Yokoyama; Masahiro Nakabachi; Hisao Nishino; Sanae Kaga; Kiwamu Kamiya; Hiroshi Ohira; Ichizo Tsujino; Toshihisa Anzai
    European heart journal. Cardiovascular Imaging, 23, 10, 1399, 1406, 2022年09月10日, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）, AIMS: Although the left ventricular (LV) dysfunction in pre-capillary pulmonary hypertension (PH) has been recently recognized, the mechanism of LV dysfunction in this entity is not completely understood. We thus aimed to elucidate the determinants of intraventricular pressure difference (IVPD), a measure of LV suction, in pre-capillary PH. METHODS AND RESULTS: Right heart catheterization and echocardiography were performed in 86 consecutive patients with pre-capillary PH (57 ± 18 years, 85% female). IVPD was determined using colour M-mode Doppler to integrate the Euler equation. In overall, IVPD was reduced compared to previously reported value in normal subjects. In univariable analyses, QRS duration (P = 0.028), LV ejection fraction (P = 0.006), right ventricular (RV) end-diastolic area (P < 0.001), tricuspid annular plane systolic excursion (P = 0.004), and LV early-diastolic eccentricity index (P = 0.009) were associated with IVPD. In the multivariable analyses, RV end-diastolic area and LV eccentricity index independently determined the IVPD. CONCLUSION: Aberrant ventricular interdependence caused by RV enlargement could impair the LV suction. This study first applied echocardiographic IVPD, a reliable marker of LV diastolic suction, to investigate the mechanism of LV diastolic dysfunction in pre-capillary PH.
  • Dual Gate Doppler法による左房収縮時の肺静脈血流と経僧帽弁血流の時相解析
    岡田 一範; 岡田 由佳; 村山 迪史; 加賀 早苗; 政氏 伸夫; 西野 久雄; 横山 しのぶ; 中鉢 雅大; 西田 睦; 本居 昂; 石坂 傑; 千葉 泰之; 辻永 真吾; 岩野 弘幸; 安斉 俊久
    超音波検査技術, 47, 4, 353, 362, 一般社団法人 日本超音波検査学会, 2022年08月01日, ［査読有り］
    日本語, 目的：肺静脈血流（PVF）と経僧帽弁血流（TMF）の心房収縮期（A）波の持続時間の差（ΔAdur）は拡張後期の左室硬さを反映する指標として知られるが，再現性に問題がある．最近，我々は，PVF全体に占める逆行性A波の割合とTMF全体に占めるA波の割合との比（FPVA/FA）が，侵襲的左室硬さ指標ときわめてよく対応することを報告したが，この計測はやや煩雑である．今回，Dual Gate Doppler（DD）法によるPVFとTMFの同時記録から得られる指標の有用性を検討した．

    対象と方法: DD法が施行された80例において，通常のパルスドプラ法でΔAdur（S-ΔAdur）を計測するとともにFPVA/FAを算出した．また，DD法によるPVFとTMFの同時記録から，ΔAdur（D-ΔAdur）と各々のA波の終了時相差（D-ΔAend）を計測した．

    結果: S-ΔAdur，D-ΔAdurおよびD-ΔAendはいずれもFPVA/FAと有意に相関した（順にr＝0.50, 0.51, 0.71）．このうち，D-ΔAendとFPVA/FAとの相関は，他2者より有意に良好であった．対象中の20例における検者間および検者内再現性は，S-ΔAdurよりもD-ΔAdurとD-ΔAendで良好であった．

    結論: DD法によるD-ΔAendは，通常のΔAdurよりも再現性よく拡張後期左室硬さを評価できると考えられた．
  • Two cases showing alterations of the order of tricuspid and mitral valve opening during loading manipulations: a new approach for quick assessment of stress-induced left ventricular filling pressure elevation.
    Michito Murayama; Hiroyuki Iwano; Ko Motoi; Suguru Ishizaka; Shingo Tsujinaga; Toshiyuki Nagai; Toshihisa Anzai
    Journal of medical ultrasonics (2001), 49, 3, 489, 491, 2022年07月, ［査読有り］, ［筆頭著者］, ［国内誌］
    英語, 研究論文（学術雑誌）
  • Clinical Utility of Superior Vena Cava Flow Velocity Waveform Measured from the Subcostal Window for Estimating Right Atrial Pressure.
    Michito Murayama; Sanae Kaga; Kazunori Okada; Hiroyuki Iwano; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Shingo Tsujinaga; Yasuyuki Chiba; Suguru Ishizaka; Ko Motoi; Kiwamu Kamiya; Mutsumi Nishida; Toshiyuki Nagai; Toshihisa Anzai
    Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography, 35, 7, 727, 737, 2022年07月, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）, BACKGROUND: The superior vena cava (SVC) flow velocity waveform from the supraclavicular window reflects right atrial pressure (RAP) status. Recent guidelines have stated that the subcostal window is an alternative view for recording SVC flow, but the validity of this approach remains unclear. The aim of this study was to determine the usefulness of SVC flow evaluation from the subcostal window for estimating RAP. METHODS: Differences in SVC flow characteristics between opposite approaches were examined in 38 healthy adults. In 115 patients with cardiovascular diseases who underwent cardiac catheterization and echocardiography within 48 hours, the ratio of peak systolic to diastolic forward SVC flow (SVC-S/D) was measured, and the diagnostic ability of SVC-S/D for elevated RAP was tested. A validation cohort was used to confirm the diagnostic ability of SVC-S/D in 48 patients who underwent both cardiac catheterization and echocardiography within 24 hours. In 59 patients in the derivation and validation cohorts, the relationship between SVC flow and RAP was compared between the opposite windows. RESULTS: Both systolic and diastolic SVC flow velocities were higher in the subcostal than in the supraclavicular approach, and effect of position change on subcostal SVC-S/D was smaller than that on supraclavicular SVC-S/D in healthy adults. Measurement of SVC-S/D from the subcostal window was feasible in 98 patients (85%). RAP was inversely correlated with SVC-S/D (r = -0.50, P < .001) and was an independent determinant of SVC-S/D after adjustment for right ventricular systolic function (β = -0.48, P < .001). A cutoff value of 1.9 for SVC-S/D showed 85% sensitivity and 74% specificity in identifying elevated RAP. Additionally, SVC-S/D showed an incremental diagnostic value combined with inferior vena cava size and collapsibility (P = .006). When a cutoff value of SVC-S/D < 1.9 was applied to the validation cohort, it showed acceptable accuracy of 72% and incremental diagnostic value combined with inferior vena cava parameters (P = .033). SVC-S/D from the subcostal window correlated better with RAP than that from the supraclavicular window (P < .001, Meng's test). CONCLUSIONS: Measurement of SVC flow velocity from the subcostal window was feasible, and SVC-S/D from the subcostal window could be an additive parameter for estimating RAP.
  • Visual echocardiographic scoring system of the left ventricular filling pressure and outcomes of heart failure with preserved ejection fraction.
    Michito Murayama; Hiroyuki Iwano; Masaru Obokata; Tomonari Harada; Kazunori Omote; Kazuki Kagami; Shingo Tsujinaga; Yasuyuki Chiba; Suguru Ishizaka; Ko Motoi; Yoji Tamaki; Hiroyuki Aoyagi; Masahiro Nakabachi; Hisao Nishino; Shinobu Yokoyama; Asuka Tanemura; Kazunori Okada; Sanae Kaga; Mutsumi Nishida; Toshiyuki Nagai; Masahiko Kurabayashi; Toshihisa Anzai
    European heart journal. Cardiovascular Imaging, 23, 5, 616, 626, 2022年04月18日, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）, AIMS: Elevated left ventricular filling pressure (LVFP) is a powerful indicator of worsening clinical outcomes in heart failure with preserved ejection fraction (HFpEF); however, detection of elevated LVFP is often challenging. This study aimed to determine the association between the newly proposed echocardiographic LVFP parameter, visually assessed time difference between the mitral valve and tricuspid valve opening (VMT) score, and clinical outcomes of HFpEF. METHODS AND RESULTS: We retrospectively investigated 310 well-differentiated HFpEF patients in stable conditions. VMT was scored from 0 to 3 using two-dimensional echocardiographic images, and VMT ≥2 was regarded as a sign of elevated LVFP. The primary endpoint was a composite of cardiac death or heart failure hospitalization during the 2 years after the echocardiographic examination. In all patients, Kaplan-Meier curves showed that VMT ≥2 (n = 54) was associated with worse outcomes than the VMT ≤1 group (n = 256) (P < 0.001). Furthermore, VMT ≥2 was associated with worse outcomes when tested in 100 HFpEF patients with atrial fibrillation (AF) (P = 0.026). In the adjusted model, VMT ≥2 was independently associated with the primary outcome (hazard ratio 2.60, 95% confidence interval 1.46-4.61; P = 0.001). Additionally, VMT scoring provided an incremental prognostic value over clinically relevant variables and diastolic function grading (χ2 10.8-16.3, P = 0.035). CONCLUSIONS: In patients with HFpEF, the VMT score was independently and incrementally associated with adverse clinical outcomes. Moreover, it could also predict clinical outcomes in HFpEF patients with AF., 36691110

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  • Difference in left atrial myocardial dynamics during reservoir phase between hypertrophic cardiomyopathy and hypertensive heart determined using three-dimensional speckle tracking echocardiography
    Yusuke Yanagi; Kazunori Okada; Sanae Kaga; Taisei Mikami; Miho Aiba; Nobuo Masauzi; Michito Murayama; Asuka Tanemura; Shinobu Yokoyama; Hisao Nishino; Masahiro Nakabachi; Yoji Tamaki; Hiroyuki Aoyagi; Ko Motoi; Suguru Ishizaka; Yasuyuki Chiba; Shingo Tsujinaga; Hiroyuki Iwano; Toshihisa Anzai
    INTERNATIONAL JOURNAL OF CARDIOVASCULAR IMAGING, 38, 8, 1781, 1791, 2022年04月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • Application of the proximal isovelocity surface area method for estimation of the effective orifice area in aortic stenosis.
    Masahiro Nakabachi; Hiroyuki Iwano; Michito Murayama; Hisao Nishino; Shinobu Yokoyama; Shingo Tsujinaga; Yasuyuki Chiba; Suguru Ishizaka; Ko Motoi; Kazunori Okada; Sanae Kaga; Mutsumi Nishida; Takanori Teshima; Toshihisa Anzai
    Heart and vessels, 37, 4, 638, 646, 2022年04月, ［査読有り］, ［国内誌］
    英語, 研究論文（学術雑誌）
  • Prognostic value of an echocardiographic index reflecting right ventricular operating stiffness in patients with heart failure.
    Ryosuke Fujisawa; Kazunori Okada; Sanae Kaga; Michito Murayama; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Asuka Tanemura; Nobuo Masauzi; Ko Motoi; Suguru Ishizaka; Yasuyuki Chiba; Shingo Tsujinaga; Hiroyuki Iwano; Toshihisa Anzai
    Heart and vessels, 37, 4, 583, 592, 2022年04月, ［査読有り］, ［国内誌］
    英語, 研究論文（学術雑誌）, PURPOSE: We recently reported a noninvasive method for the assessment of right ventricular (RV) operating stiffness that is obtained by dividing the atrial-systolic descent of the pulmonary artery-RV pressure gradient (PRPGDAC) derived from the pulmonary regurgitant velocity by the tricuspid annular plane movement during atrial contraction (TAPMAC). Here, we investigated whether this parameter of RV operating stiffness, PRPGDAC/TAPMAC, is useful for predicting the prognosis of patients with heart failure (HF). METHODS: We retrospectively included 127 hospitalized patients with HF who underwent an echocardiographic examination immediately pre-discharge. The PRPGDAC/TAPMAC was measured in addition to standard echocardiographic parameters. Patients were followed until 2 years post-discharge. The endpoint was the composite of cardiac death, readmission for acute decompensation, and increased diuretic dose due to worsening HF. RESULTS: 58 patients (46%) experienced the endpoint during follow-up. Univariable and multivariable Cox regression analyses demonstrated that the PRPGDAC/TAPMAC was associated with the endpoint. In a Kaplan-Meier analysis, the event rate of the greater PRPGDAC/TAPMAC group was significantly higher than that of the lesser PRPGDAC/TAPMAC group. In a sequential Cox analysis for predicting the endpoint's occurrence, the addition of PRPGDAC/TAPMAC to the model including age, sex, NYHA functional classification, brain natriuretic peptide level, and several echocardiographic parameters including tricuspid annular plane systolic excursion significantly improved the predictive power for prognosis. CONCLUSION: A completely noninvasive index of RV operating stiffness, PRPGDAC/TAPMAC, was useful for predicting prognoses in patients with HF, and it showed an incremental prognostic value over RV systolic function.
  • Influence of left ventricular systolic dysfunction on occurrence of pulsus tardus in patients with aortic stenosis.
    Suguru Ishizaka; Hiroyuki Iwano; Ko Motoi; Yasuyuki Chiba; Shingo Tsujinaga; Asuka Tanemura; Michito Murayama; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Kazunori Okada; Sanae Kaga; Kiwamu Kamiya; Toshiyuki Nagai; Toshihisa Anzai
    Journal of cardiology, 78, 4, 322, 327, 2021年10月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • Simple Two-Dimensional Echocardiographic Scoring System for the Estimation of Left Ventricular Filling Pressure.
    Michito Murayama; Hiroyuki Iwano; Hisao Nishino; Shingo Tsujinaga; Masahiro Nakabachi; Shinobu Yokoyama; Miho Aiba; Kazunori Okada; Sanae Kaga; Miwa Sarashina; Yasuyuki Chiba; Suguru Ishizaka; Ko Motoi; Mutsumi Nishida; Hitoshi Shibuya; Kiwamu Kamiya; Toshiyuki Nagai; Toshihisa Anzai
    Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography, 34, 7, 723, 734, 2021年07月, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）, 36700548

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  • Presence and Relevance of Midsystolic Notching on Right Ventricular Outflow Tract Flow Velocity Envelopes in Pulmonary Hypertension due to Heart Failure.
    Yasuyuki Chiba; Hiroyuki Iwano; Michito Murayama; Sanae Kaga; Ko Motoi; Suguru Ishizaka; Shingo Tsujinaga; Asuka Tanemura; Shinobu Yokoyama; Masahiro Nakabachi; Hisao Nishino; Kazunori Okada; Kiwamu Kamiya; Toshiyuki Nagai; Toshihisa Anzai
    Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography, 34, 6, 690, 692, 2021年06月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • Functional significance of intra-left ventricular vortices on energy efficiency in normal, dilated, and hypertrophied hearts.
    Miwa Sarashina-Motoi; Hiroyuki Iwano; Ko Motoi; Suguru Ishizaka; Yasuyuki Chiba; Shingo Tsujinaga; Michito Murayama; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Kazunori Okada; Sanae Kaga; Toshihisa Anzai
    Journal of clinical ultrasound : JCU, 49, 4, 358, 367, 2021年05月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • Influence of advanced pulmonary vascular remodeling on accuracy of echocardiographic parameters of left ventricular filling pressure
    Yasuyuki Chiba; Hiroyuki Iwano; Sanae Kaga; Mio Shinkawa; Michito Murayama; Hiroshi Ohira; Suguru Ishizaka; Miwa Sarashina; Shingo Tsujinaga; Shinobu Yokoyama; Masahiro Nakabachi; Hisao Nishino; Kazunori Okada; Kiwamu Kamiya; Toshiyuki Nagai; Toshihisa Anzai
    Pulmonary Circulation, 11, 1, 2045894020983723, 2045894020983723, 2021年, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • Mechanism of Early-Diastolic Mitral Regurgitation.
    Michito Murayama; Hiroyuki Iwano; Miwa Sarashina; Toshihisa Anzai
    Circulation journal : official journal of the Japanese Circulation Society, 84, 11, 2036, 2036, 2020年10月23日, ［査読有り］, ［筆頭著者］, ［国内誌］
    英語, 研究論文（学術雑誌）
  • Significance and prognostic impact of v wave on pulmonary artery pressure in patients with heart failure: beyond the wedge pressure.
    Hiroyuki Iwano; Shinobu Yokoyama; Kiwamu Kamiya; Toshiyuki Nagai; Shingo Tsujinaga; Miwa Sarashina; Suguru Ishizaka; Yasuyuki Chiba; Masahiro Nakabachi; Hisao Nishino; Michito Murayama; Kazunori Okada; Sanae Kaga; Toshihisa Anzai
    Heart and vessels, 35, 8, 1079, 1086, 2020年08月, ［査読有り］, ［国内誌］
    英語, 研究論文（学術雑誌）
  • Heart Failure With Preserved Ejection Fraction vs. Reduced Ejection Fraction - Mechanisms of Ventilatory Inefficiency During Exercise in Heart Failure.
    Shingo Tsujinaga; Hiroyuki Iwano; Yasuyuki Chiba; Suguru Ishizaka; Miwa Sarashina; Michito Murayama; Masahiro Nakabachi; Hisao Nishino; Shinobu Yokoyama; Kazunori Okada; Sanae Kaga; Toshihisa Anzai
    Circulation reports, 2, 5, 271, 279, 2020年04月07日, ［査読有り］, ［国内誌］
    英語, 研究論文（学術雑誌）, Background: Ventilatory inefficiency during exercise assessed using the lowest minute ventilation/carbon dioxide production (V̇E/V̇CO2) ratio was recently proven to be a strong prognostic marker of heart failure (HF) regardless of left ventricular ejection fraction (LVEF). Its physiological background, however, has not been elucidated. Methods and Results: Fifty-seven HF patients underwent cardiopulmonary exercise testing and exercise-stress echocardiography. The lowest V̇E/V̇CO2 ratio was assessed on respiratory gas analysis. Echocardiography was obtained at rest and at peak exercise. LVEF was measured using the method of disks. Cardiac output (CO) and the ratio of transmitral early filling velocity (E) to early diastolic tissue velocity (e') were calculated using the Doppler method. HF patients were divided into preserved EF (HFpEF) and reduced EF (HFrEF) using the LVEF cut-off 40% at rest. Twenty-four patients were classified as HFpEF and 33 as HFrEF. In HFpEF, age (r=0.58), CO (r=-0.44), e' (r=-0.48) and E/e' (r=0.45) during exercise correlated with the lowest V̇E/V̇CO2 ratio (P<0.05 for all). In contrast, in HFrEF, age (r=0.47) and CO (r=-0.54) during exercise, but not e' and E/e', correlated with the lowest V̇E/V̇CO2 ratio. Conclusions: Loss of CO augmentation was associated with ventilatory inefficiency in HF regardless of LVEF, although lung congestion determined ventilatory efficiency only in HFpEF.
  • Case with long-standing gout showing various ultrasonographic features caused by monosodium urate monohydrate crystal deposition.
    Michito Murayama; Mutsumi Nishida; Yusuke Kudo; Takahiro Deguchi; Katsuji Marukawa; Yuichiro Fujieda; Nobuya Abe; Masaru Kato; Hitoshi Shibuya; Yoshihiro Matsuno; Tatsuya Atsumi
    Modern rheumatology case reports, 4, 1, 110, 115, 2020年01月, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • Simple and noninvasive method to estimate right ventricular operating stiffness based on echocardiographic pulmonary regurgitant velocity and tricuspid annular plane movement measurements during atrial contraction.
    Michito Murayama; Kazunori Okada; Sanae Kaga; Hiroyuki Iwano; Shingo Tsujinaga; Miwa Sarashina; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Mutsumi Nishida; Hitoshi Shibuya; Nobuo Masauzi; Toshihisa Anzai; Taisei Mikami
    The international journal of cardiovascular imaging, 35, 10, 1871, 1880, 2019年10月, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • これからの超音波検査を牽引する人材の育成を目指す大学院教育
    岡田 一範; 加賀 早苗; 政氏 伸夫; 三神 大世; 中鉢 雅大; 村山 迪史; 横山 しのぶ; 西野 久雄; 西田 睦; 澁谷 斉; 更科 美羽; 辻永 真吾; 岩野 弘幸; 安斉 俊久
    臨床検査学教育, 11, 2, 219, 226, (一社)日本臨床検査学教育協議会, 2019年09月, ［査読有り］
    日本語
  • Tricuspid regurgitation occurring in the early-diastolic phase in a case of heart failure: Insights from echocardiographic and invasive hemodynamic findings.
    Michito Murayama; Hiroyuki Iwano; Shingo Tsujinaga; Miwa Sarashina; Suguru Ishizaka; Yasuyuki Chiba; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Kazunori Okada; Sanae Kaga; Hitoshi Shibuya; Mutsumi Nishida; Toshihisa Anzai
    Echocardiography (Mount Kisco, N.Y.), 36, 9, 1771, 1775, 2019年09月, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • Diastolic Intra-Left Ventricular Pressure Difference During Exercise: Strong Determinant and Predictor of Exercise Capacity in Patients With Heart Failure.
    Shingo Tsujinaga; Hiroyuki Iwano; Miwa Sarashina; Taichi Hayashi; Michito Murayama; Ayako Ichikawa; Masahiro Nakabachi; Hisao Nishino; Shinobu Yokoyama; Arata Fukushima; Takashi Yokota; Kazunori Okada; Sanae Kaga; Pavlos P Vlachos; Toshihisa Anzai
    Journal of cardiac failure, 25, 4, 268, 277, 2019年04月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • A Case of Severe Aortic Regurgitation Caused by Takayasu's Arteritis Showing End-Diastolic Opening of Aortic Valve.
    Michito Murayama; Hiroyuki Iwano; Yusuke Kudo; Mutsumi Nishida; Koji Akizawa; Hitoshi Shibuya; Toshihisa Anzai
    CASE (Philadelphia, Pa.), 2, 6, 248, 253, 2018年12月, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）, • Diastolic opening of the AV rarely occurs in severe AR. • Echocardiography plays a role in evaluation of the unique hemodynamics of severe AR. • A patient with Takayasu’s arteritis showed diastolic opening of the AV. • Serial echocardiographic findings suggested unique hemodynamics in this patient.

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  • Novel echocardiographic method to assess left ventricular chamber stiffness and elevated end-diastolic pressure based on time-velocity integral measurements of pulmonary venous and transmitral flows.
    Kazunori Okada; Sanae Kaga; Rika Abiko; Michito Murayama; Takuma Hioka; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Ayako Ichikawa; Ayumu Abe; Mutsumi Nishida; Naoya Asakawa; Shingo Tsujinaga; Taichi Hayashi; Hiroyuki Iwano; Satoshi Yamada; Nobuo Masauzi; Taisei Mikami
    European heart journal. Cardiovascular Imaging, 19, 11, 1260, 1267, 2018年11月01日, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • Overestimation by echocardiography of the peak systolic pressure gradient between the right ventricle and right atrium due to tricuspid regurgitation and the usefulness of the early diastolic transpulmonary valve pressure gradient for estimating pulmonary artery pressure.
    Takuma Hioka; Sanae Kaga; Taisei Mikami; Kazunori Okada; Michito Murayama; Nobuo Masauzi; Masahiro Nakabachi; Hisao Nishino; Shinobu Yokoyama; Mutsumi Nishida; Hiroyuki Iwano; Mamoru Sakakibara; Satoshi Yamada; Hiroyuki Tsutsui
    Heart and vessels, 32, 7, 833, 842, 2017年07月, ［査読有り］, ［国内誌］
    英語, 研究論文（学術雑誌）, We investigated the influence of tricuspid regurgitation (TR) severity on the echocardiographic peak systolic transtricuspid pressure gradient (TRPG) and evaluated the usefulness of the peak early diastolic transpulmonary valve pressure gradient (PRPG) for estimating pulmonary artery (PA) pressure. In 55 consecutive right heart-catheterized patients, we measured the peak systolic right ventricular (RV)-right atrial (RA) pressure gradient (RV-RACATH), peak early diastolic PA-RV pressure gradient (PA-RVCATH), and mean PA pressure (MPAPCATH). Using echocardiography, we obtained the TRPG, PRPG, and an estimate of the mean PA pressure (EMPAP) as the sum of PRPG and the estimated RA pressure, and measured the vena contracta width of TR (VCTR). The difference between the TRPG and RV-RACATH was significantly greater in the very severe TR group (VCTR > 11 mm) than in the mild, moderate, and severe TR groups, and significantly greater in the severe TR group (7 < VCTR ≤ 11 mm) than in the mild TR group. The overestimation of the pressure gradient >10 mmHg by TRPG was not seen in the mild or moderate TR groups, but was observed in the severe and very severe TR groups (22 and 83%, respectively). In the ROC analysis, EMPAP could distinguish patients with MPAPCATH ≥ 25 mmHg with the area under the curve of 0.93, 100% sensitivity, and 87% specificity. In conclusion, TRPG frequently overestimated RV-RACATH when VCTR was >11 mm and sometimes did when VCTR was >7 mm, where EMPAP using PRPG was useful for estimating PA pressure.
  • Usefulness of the Continuous-Wave Doppler-Derived Pulmonary Arterial-Right Ventricular Pressure Gradient Just before Atrial Contraction for the Estimation of Pulmonary Arterial Diastolic and Wedge Pressures.
    Michito Murayama; Taisei Mikami; Sanae Kaga; Kazunori Okada; Takuma Hioka; Nobuo Masauzi; Masahiro Nakabachi; Hisao Nishino; Shinobu Yokoyama; Mutsumi Nishida; Hiroyuki Iwano; Mamoru Sakakibara; Satoshi Yamada; Hiroyuki Tsutsui
    Ultrasound in medicine & biology, 43, 5, 958, 966, 2017年05月, ［査読有り］, ［筆頭著者］, ［国際誌］
    英語, 研究論文（学術雑誌）
  • A new method to estimate pulmonary vascular resistance using diastolic pulmonary artery-right ventricular pressure gradients derived from continuous-wave Doppler velocity measurements of pulmonary regurgitation.
    Sanae Kaga; Taisei Mikami; Michito Murayama; Kazunori Okada; Nobuo Masauzi; Masahiro Nakabachi; Hisao Nishino; Shinobu Yokoyama; Mutsumi Nishida; Taichi Hayashi; Daisuke Murai; Hiroyuki Iwano; Mamoru Sakakibara; Satoshi Yamada; Hiroyuki Tsutsui
    The international journal of cardiovascular imaging, 33, 1, 31, 38, 2017年01月, ［査読有り］, ［国際誌］
    英語, 研究論文（学術雑誌）
■ その他活動・業績
■ 講演・口頭発表等
■ 主な担当授業
  • チーム医療演習, 2024年, 学士課程, 医学部
  • 技能修得到達度評価, 2024年, 学士課程, 医学部
  • 画像検査学Ⅱ, 2024年, 学士課程, 医学部
  • 生体機能学実習, 2024年, 学士課程, 医学部
  • 臨床生理画像学実習Ⅱ, 2024年, 学士課程, 医学部
  • 臨地実習（生理検査）, 2024年, 学士課程, 医学部
  • 画像検査学Ⅱ, 2024年, 学士課程, 医学部
  • 保健生理学, 2024年, 学士課程, 医学部
  • 臨床生理画像学実習, 2024年, 学士課程, 医学部
  • 臨床生理画像学実習Ⅰ, 2024年, 学士課程, 医学部
  • 臨床生理学Ⅰ, 2024年, 学士課程, 医学部
  • 生体機能学, 2024年, 学士課程, 医学部
  • チーム医療論, 2024年, 学士課程, 医学部
  • 保健・医療概論, 2024年, 学士課程, 医学部
  • 臨床病態学Ⅰ, 2024年, 学士課程, 医学部
  • 一般教育演習(ﾌﾚｯｼｭﾏﾝｾﾐﾅｰ), 2024年, 学士課程, 全学教育
■ 所属学協会
  • European Association of Cardiovascular Imaging
  • 日本心不全学会
  • 日本心エコー図学会
  • 日本超音波検査学会
  • 日本循環器学会
  • 日本臨床衛生検査技師会
  • 日本超音波医学会
■ 共同研究・競争的資金等の研究課題
■ 学術・社会貢献活動／その他
社会貢献活動
  • ハンズオンセミナー1（心臓エコー）日常検査の悩み解決！（心臓編）-基礎から応用まで-
    2026年04月24日 - 2026年04月24日
    講師
    一般社団法人日本心エコー図学会第37回学術集会
    「心エコーを始めたばかりだけど、自分の計測が正しいのかどうか確認したい。うまく描出するtipsを学びたい。」「きれいな3D画像を取得するための方法を学びたい。」日々心エコーに携わる中で、このような悩みをお持ちの先生方もいらっしゃるのではないでしょうか。近年、心エコー機器の進歩は目覚ましく、私たちの日常診療の大きな助けとなっています。例えば3D心エコー図検査、ストレイン計測などが日常検査でも使用されるようになってきました。しかし検査時間やマンパワーの問題、解析方法が煩雑であるという印象もあり、まだまだ一般化しているとは言い難い状態です。そこで本セミナーでは、日常臨床で心エコーを中心に幅広く活躍されているプロフェッショナルの先生方にご登壇いただきます。ベーシックコースとアドバンスコースに分かれて、実機に触れながら日常検査における課題解決をサポートさせていただきます。

    ベーシックコース（4名）：基本断面の描出、心腔計測、ドプラ計測の基本と注意点、POCUSなど
    アドバンスコース（8名）：3D、ストレインなど
    ※本セッションでは、実際に被検者への走査を行っていただきます。
  • 北海道札幌西高等学校「北海道大学研究室訪問」
    2024年09月30日
    講師, 実演
    北海道大学
    北海道大学 大学院保健科学研究院 病態解析学分野 心血管エコー研究室
    高校生
    46865526
  • 心エコーハンズオンセミナー
    2024年06月08日
    講師
    フクダ電子北海道販売株式会社／GEヘルスケア・ジャパン株式会社
  • タスクシフト／シェアに関する厚生労働大臣指定講習会
    2023年12月02日
    運営参加・支援
    北海道臨床検査技師会
  • 令和5年度札臨技心エコーハンズオンセミナー
    2023年09月24日
    講師
    札幌臨床検査技師会
  • 札幌肝がん検診
    2020年02月16日
    その他
  • 検査deフェスティバル
    2019年08月25日
    運営参加・支援
    札幌臨床検査技師会
  • 札幌肝がん検診
    2019年02月17日
    その他
  • 札幌肝がん検診
    2018年02月18日
    その他
その他
  • 2024年12月
    心房細動の心不全診断に簡便な新規心エコー指標が有用～心不全診断のイメージングバイオバーカーとして期待～
    北海道大学病院から研究成果プレスリリース

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