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Michito Murayama
Faculty of Health Sciences　Health Sciences　Medical Laboratory Science
Assistant Professor
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Last Updated :2024/05/16

Researcher Profile and Settings

Affiliation

  • Faculty of Health Sciences　Health Sciences　Medical Laboratory Science

Job Title

  • Assistant Professor

Degree

  • Ph.D.（2022/03 Hokkaido University）

URL

Research funding number

  • 10964497

ORCID ID

J-Global ID

Research Interests

  • 超音波医学   超音波検査   Echocardiography   血行動態   

Research Areas

  • Life sciences / Medical systems
  • Other / Other
  • Life sciences / Internal medicine - General

Educational Organization

Academic & Professional Experience

  • 2022/04 - Today Faculty of Health Sciences, Hokkaido University
  • 2017/04 - 2022/03 Hokkaido University Hospital Diagnostic Center for Sonography Sonographer

Education

  • 2019/04 - 2022/03  Hokkaido University  Graduate School of Health Sciences
  • 2015/04 - 2017/03  Hokkaido University  Graduate School of Health Sciences
  • 2011/04 - 2015/03  Hokkaido University

Association Memberships

  • 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   

Research Activities

Published Papers

  • 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 2024/04 [Refereed]
  • 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  2024/04 
    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.
  • 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 2024/03/27 [Refereed]
     
    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.
  • Kae Yasuda, Inaho Shishido, Michito Murayama, Sanae Kaga, Rika Yano
    Journal of physiological anthropology 42 (1) 23 - 23 2023/10/19 [Refereed]
     
    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).
  • 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 2023/08 [Refereed]
     
    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.
  • 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 2023/07 [Refereed]
     
    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.
  • 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 2023/06 [Refereed]
     
    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.
  • 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 2023/04 [Refereed]
     
    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.
  • Asuka Tanemura, Michito Murayama, Hiroyuki Iwano, Yasuyuki Chiba, Mutsumi Nishida, Takanori Teshima, Toshihisa Anzai
    Journal of echocardiography 21 (1) 50 - 52 1349-0222 2023/03 [Refereed]
  • Murayama Michito, Kaga Sanae, Onoda Airi, Okada Kazunori, Nakabachi Masahiro, Yokoyama Shinobu, Nishino Hisao, Aoyagi Hiroyuki, Tamaki Yoji, Motoi Ko, Ishizaka Suguru, Iwano Hiroyuki, Nagai Toshiyuki, Tsujino Ichizo, Anzai Toshihisa
    Japanese Journal of Medical Ultrasound Technology 一般社団法人 日本超音波検査学会 advpub (4) 384 - 397 1881-4506 2023 [Refereed][Invited]
     
    Purpose: Sonographic measurements of the inferior vena cava parameters are common noninvasive methods for estimating right atrial pressure. In intermediate cases in which the inferior vena cava parameters showed indeterminate value, the current guidelines of the American Society of Echocardiography recommended using secondary indices, which include restrictive right-sided diastolic filling pattern, the ratio of early-diastolic transtricuspid flow velocity to tricuspid annular velocity, and the hepatic venous systolic filling fraction. We aimed to clarify whether the above secondary indices improve the diagnostic ability of elevated right atrial pressure using inferior vena cava parameters and to test the incremental predictive value of right atrial area measurement. Subjects and Methods: In 128 consecutive patients with various cardiac diseases referred for cardiac catheterization, the elevated right atrial pressure was defined as greater than or equal to 8 mmHg. Based on the inferior vena cava morphology, the estimated right atrial pressure was determined as 3, 8, and 15 mmHg (model 1). Additionally, the restrictive filling pattern, the ratio of early-diastolic transtricuspid flow velocity to tricuspid annular velocity, and the systolic filling fraction were evaluated to reclassify the intermediate value of 8 mmHg (model 2). The right atrial minimum and maximum area and volume were measured at ventricular end diastole and end systole, respectively, and the expansion indices were calculated. Results: Elevated right atrial pressure was observed in 29 patients. Logistic regression analysis showed that estimated right atrial pressure based on the inferior vena cava indices and systolic filling fraction were significantly associated with elevated right atrial pressure (p＜0.05). Restrictive filling pattern was not observed in any of the patients, and the ratio of early-diastolic transtricuspid flow velocity to tricuspid annular velocity was not associated with elevated right atrial pressure. Right atrial morphological and functional parameters were significantly associated with elevated right atrial pressure (p＜0.05). Notably, the minimum right atrial area demonstrated the strongest association with right atrial pressure elevation (odds ratio adjusted for right ventricular systolic function: 10.64, p＜0.01). The predictive ability of model 2 was comparable to that of model 1 (global χ2 value＝9 for model 1, 11 for model 2; p＝0.28). In contrast, incorporated with systolic filling fraction and minimal right atrial area as secondary indices, the predictive ability of the new model was improved compared to that of model 1 (global χ2 value＝9 for model 1, 25 for the new model; p＜0.01). Conclusion: Reclassification using guideline-recommended secondary indices failed to improve the predictive ability of elevated right atrial pressure. In contrast, a combination of systolic filling fraction and minimal right atrial area with inferior vena cava indices improved the predictive ability of elevated right atrial pressure.
  • 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 2023/01 [Refereed]
     
    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.
  • 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 2023/01 [Refereed]
     
    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.
  • 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 2022/09/10 [Refereed]
     
    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.
  • Okada Kazunori, Okada Yuka, Murayama Michito, Kaga Sanae, Masauzi Nobuo, Nishino Hisao, Yokoyama Shinobu, Nakabachi Masahiro, Nishida Mutsumi, Motoi Ko, Ishizaka Suguru, Chiba Yasuyuki, Tsujinaga Shingo, Iwano Hiroyuki, Anzai Toshihisa
    Japanese Journal of Medical Ultrasound Technology 一般社団法人 日本超音波検査学会 47 (4) 353 - 362 1881-4506 2022/08/01 [Refereed]
     
    Purpose: The difference in duration between pulmonary venous (PV) atrial systolic reversal wave (PVA) and atrial systolic wave (A) of transmitral flow (ΔAdur) reflects the late-diastolic left ventricular (LV) operating stiffness and has a limitation on reproducibility. Using the Dual Gate Doppler technique, simultaneous recording of PV and transmitral flows can be obtained, which may contribute to improving the accuracy and reproducibility of ΔAdur measurements. Methods and Results: We examined 80 patients who underwent echocardiography using Dual Gate Doppler recording. Using the conventional Doppler recording, we measured the difference in duration between the PVA and transmitral A-wave (S-ΔAdur). Additionally, the ratio of the time–velocity integral (TVI) of the PVA to that of the whole PV flow (FPVA) and the ratio of the TVI in transmitral A-wave of the whole transmitral flow (FA) were calculated, and FPVA/FA was obtained as an index of LV operating stiffness. From the Dual Gate Doppler recording of PV and transmitral flows, we measured ΔAdur (D-ΔAdur) and time from the end of transmitral A-wave to the end of PVA (D-ΔAend). Results: Each of S-ΔAdur, D-ΔAdur, and D-ΔAend significantly correlated with FPVA/FA (r＝0.50, 0.51, and 0.71, respectively), and the correlation between FPVA/FA and D-ΔAend was significantly greater than that between FPVA/FA and S-ΔAdur and between FPVA/FA and D-ΔAdur (p＜0.001 for both). The intraclass correlation coefficients for the inter- and intra-observer comparisons were excellent for D-ΔAend, adequate for D-ΔAdur, and fair for S-ΔAdur. Conclusion: Dual Gate Doppler-derived D-ΔAend has higher reproducibility and usefulness for assessing late-diastolic LV operating stiffness than the conventional Doppler-derived S-ΔAdur.
  • Michito Murayama, Hiroyuki Iwano, Ko Motoi, Suguru Ishizaka, Shingo Tsujinaga, Toshiyuki Nagai, Toshihisa Anzai
    Journal of medical ultrasonics (2001) 49 (3) 489 - 491 1346-4523 2022/07 [Refereed]
  • 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 2022/07 [Refereed]
     
    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.
  • 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 2022/04/18 [Refereed]
     
    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.
  • 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 1569-5794 2022/04 [Refereed]
     
    We aimed to investigate left atrial (LA) myocardial dynamics during reservoir phase using three-dimensional speckle-tracking echocardiography (3DSTE) focusing on its longitudinal-circumferential relationship in patients with left ventricular (LV) hypertrophy and clarifying the difference in LA myocardial reservoir dynamics between hypertrophic cardiomyopathy (HCM) and hypertension with LV hypertrophy (HT-LVH). We studied 4 age-matched groups consisting of 27 patients with HCM, 16 with HT-LVH, 22 hypertensive patients without LV hypertrophy (HT), and 18 normal controls. Using 3DSTE, we measured LA global longitudinal strain (LA-LSR), global circumferential strain (LA-CSR), and global area strain (LA-AS(R)) during the reservoir phase, as well as LV global longitudinal strain (LV-LS), global circumferential strain (LV-CS), and global area strain (LV-AS). LA-LSR was significantly lower in the HCM and HT-LVH groups than in the controls, but there was no significant difference between the HCM and HT-LVH groups. LA-CSR and LA-AS(R) were significantly lower in the HCM group than in the other three groups, among which no significant difference was detected. In all subjects, LA-LSR was significantly correlated with LV-LS but not with LV-CS. LA-CSR was correlated with neither LV-LS nor LV-CS. In conclusion, both longitudinal and circumferential LA myocardial expansion during reservoir phase were reduced in HCM, while only the longitudinal one was reduced in HT-LVH. Reduction of LA circumferential expansion may reflect a more serious and intrinsic impairment of LA myocardial distensibility in HCM. Measuring LA-CSR and LA-AS(R) using 3DSTE would contribute to a more accurate understanding of LA reservoir function abnormality in HCM.
  • 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 0910-8327 2022/04 [Refereed]
     
    Although the echocardiographic effective orifice area (EOA) calculated using the continuity equation is widely used for the assessment of severity in aortic stenosis (AS), the existence of high flow velocity at the left ventricular outflow tract (LVOT) potentially causes its overestimation. The proximal isovelocity surface area (PISA) method could be an alternative tool for the estimation of EOA that limits the influence of upstream flow velocity. EOA was calculated using the continuity equation (EOACont) and PISA method (EOAPISA), respectively, in 114 patients with at least moderate AS. The geometric orifice area (GOA) was also measured using the planimetry method in 51 patients who also underwent three-dimensional transesophageal echocardiography. Patients were divided into two groups according to the median LVOT flow velocity. EOAPISA could be obtained in 108 of the 114 patients (95%). Although there was a strong correlation between EOACont and EOAPISA (r = 0.78, P < 0.001), EOACont was statistically significantly larger than EOAPISA (0.86 ± 0.33 vs 0.75 ± 0.29 cm2, P < 0.001). Both EOACont and EOAPISA similarly correlated with GOA (r = 0.70, P < 0.001 and r = 0.77, P < 0.001, respectively). However, a fixed bias, which is hydrodynamically supposed to exist between EOA and GOA, was not observed between EOACont and GOA. In contrast, there was a negative fixed bias between EOAPISA and GOA with smaller EOAPISA than GOA. The difference between EOACont and GOA was significantly greater with a larger EOACont relative to GOA in patients with high LVOT flow velocity than in those without (0.16 ± 0.25 vs - 0.07 ± 0.10 cm2, P < 0.001). In contrast, the difference between EOAPISA and GOA was consistent regardless of the LVOT flow velocity (- 0.07 ± 0.12 vs - 0.07 ± 0.15 cm2, P = 0.936). The PISA method was applied to estimate EOA in patients with AS. EOAPISA could be an alternative parameter for AS severity grading in patients with high LVOT flow velocity in whom EOACont would potentially overestimate the orifice area.
  • 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 2022/04 [Refereed]
     
    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.
  • 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 0914-5087 2021/10 [Refereed]
     
    BACKGROUND: Although the time difference between peak of left ventricular (LV) and aortic systolic pressures (TLV-Ao), which is considered to in part reflect pulsus tardus, is reported to be associated with clinical outcome in aortic stenosis (AS), its physiological determinants remain to be elucidated. We hypothesized that not only AS severity but also LV systolic dysfunction could be associated with occurrence of pulsus tardus. METHODS: TLV-Ao was measured by simultaneous LV and aortic pressure tracing in 74 AS patients and prolonged TLV-Ao was defined as ≥66 ms according to the previous report. Mean transaortic valvular pressure gradient (mPG) and effective orifice area index (EOAI) were estimated by Doppler echocardiography and severe AS was defined as EOAI ≤0.60 cm2/m2. Global longitudinal strain (GLS) was measured by using speckle-tracking method. RESULTS: Although a weak correlation was observed between EOAI and TLV-Ao, there was substantial population showing discordance between the parameters: severe AS despite normal TLV-Ao (10 of 47 patients) and moderate AS despite prolonged TLV-Ao (9 of 17 patients). In severe AS, mPG was significantly higher in patients showing prolonged TLV-Ao (57±20 vs 36±10 mmHg, p<0.0001) whereas GLS was comparable between the groups (-15.2±3.5% vs -14.8±3.2%). In contrast, in moderate AS, GLS was significantly smaller in patients showing prolonged TLV-Ao (-12.6±4.7% vs -17.4±3.4%, p=0.0271) while mPG was comparable (34±7 mmHg vs 35±8 mmHg). Multivariable analysis revealed that not only mPG but also GLS was an independent determinant of TLV-Ao. CONCLUSIONS: The occurrence of pulsus tardus could be associated with not only AS severity but also LV systolic dysfunction in AS patients.
  • 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 0894-7317 2021/07 [Refereed]
     
    BACKGROUND: When left ventricular filling pressure (LVFP) increases, the mitral valve opens early and precedes tricuspid valve opening in early diastole. The authors hypothesized that a visually assessed time sequence of atrioventricular valve opening could become a new marker of elevated LVFP. The aim of this study was to test the diagnostic ability of a novel echocardiographic scoring system, the visually assessed time difference between mitral valve and tricuspid valve opening (VMT) score, in patients with heart failure. METHODS: One hundred nineteen consecutive patients who underwent cardiac catheterization within 24 hours of echocardiographic examination were retrospectively analyzed as a derivation cohort. In addition, a prospective study was conducted to validate the diagnostic ability of the VMT score in 50 patients. Elevated LVFP was defined as mean pulmonary artery wedge pressure (PAWP) ≥ 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 VMT score was ultimately graded as 0 to 3. Cardiac events were recorded for 1 year after echocardiography. RESULTS: In the derivation cohort, PAWP was elevated with higher VMT scores (score 0, 10 ± 5; score 1, 12 ± 4; score 2, 22 ± 8; score 3, 28 ± 4 mm Hg; P < .001, analysis of variance). VMT score ≥ 2 predicted elevated PAWP with accuracy of 86% and showed incremental predictive value over clinical variables and guideline-recommended diastolic function grading. These observations were confirmed in the prospective validation cohort. Importantly, VMT score ≥ 2 discriminated elevated PAWP with accuracy of 82% in 33 patients with monophasic left ventricular inflow in the derivation cohort. Kaplan-Meier analysis demonstrated that patients with VMT scores ≥ 2 were at higher risk for cardiac events than those with VMT scores ≤ 1 (P < .001). CONCLUSIONS: VMT scoring could be a novel additive marker of elevated LVFP and might also be associated with adverse outcomes in patients with 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 2021/06 [Refereed]
  • 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 0091-2751 2021/05 [Refereed]
     
    PURPOSE: To investigate the influence of changes in vortices within the left ventricle (LV) on energy efficiency (EE) in normal and diseased hearts. METHODS: We performed vector flow mapping echocardiography in 36 normal participants (N), 36 patients with dilated cardiomyopathy (D), and 36 patients with LV hypertrophy (H). The circulation of the main anterior vortex was measured as a parameter of vortex strength. Energy loss (EL) was measured for one cardiac cycle, and EE was calculated as EL divided by stroke work (SW), which represents the loss of kinetic energy per unit of LV external work. RESULTS: Circulation increased in the order of N, H, and D (N: 15 ± 4, D: 19 ± 8, H: 17 ± 6 × 10-3 m2 /s; analysis of variance [ANOVA] P < .01). Conversely, EE increased in the order of N, D, and H (N: 0.22 ± 0.07, D: 0.26 ± 0.16, H: 0.30 ± 0.16 10-5 J/mm Hg mL m s; ANOVA P = .04), suggesting worst EE in group H. We found a positive correlation between circulation and SW only in group N, and positive correlation between circulation and EE only in diseased groups (D: R = 0.55, P < .01; H: R = 0.44, P < .01). Multivariable analyses revealed that circulation was the independent determinant of EE in groups D and H. CONCLUSIONS: Enhanced vortices could be associated with effective increase in LV external work in normal hearts. Conversely, they were associated with loss of EE without an optimal increase in external work in failing hearts, regardless of the LV morphology.
  • 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 2045-8932 2021 [Refereed]
     
    Evaluation of left ventricular filling pressure plays an important role in the clinical management of pulmonary hypertension. However, the accuracy of echocardiographic parameters for the determination of left ventricular filling pressure in the presence of pulmonary vascular lesions has not been fully addressed. We retrospectively investigated 124 patients with pulmonary hypertension due to pulmonary vascular lesions (noncardiac pulmonary hypertension group) and 113 patients with ischemic heart disease (control group) who underwent right heart catheterization and echocardiography. The noncardiac pulmonary hypertension group was subdivided into less-advanced and advanced groups according to median pulmonary vascular resistance. Pulmonary artery wedge pressure was determined as left ventricular filling pressure. As echocardiographic parameters of left ventricular filling pressure, the ratio of early- (E) to late-diastolic transmitral flow velocity (E/A), ratio of E to early-diastolic mitral annular velocity (E/e′), and left atrial volume index were measured. In the less-advanced noncardiac pulmonary hypertension and control groups, positive correlations were observed between pulmonary artery wedge pressure and late-diastolic transmitral flow velocity (R = 0.41, P = 0.002 and R = 0.71, P < 0.001, respectively) and left atrial volume index (R = 0.53, P < 0.001 and R = 0.41, P < 0.001), whereas in the advanced noncardiac pulmonary hypertension group, pulmonary artery wedge pressure was only correlated with left atrial volume index (R = 0.27, P = 0.032). In the controls, only pulmonary artery wedge pressure determined E (β = 0.48, P < 0.001), whereas both pulmonary artery wedge pressure and pulmonary vascular resistance were independent determinants of E (β = 0.29, P < 0.001 and β = –0.28, P = 0.001, respectively) in the noncardiac pulmonary hypertension group. In conclusion, in the presence of advanced pulmonary vascular lesions, conventional echocardiographic parameters may not accurately reflect left ventricular filling pressure. Elevated pulmonary vascular resistance would lower the E, even when pulmonary artery wedge pressure is elevated, resulting in blunting of echocardiographic parameters for the detection of elevated left ventricular filling pressure.
  • Michito Murayama, Hiroyuki Iwano, Miwa Sarashina, Toshihisa Anzai
    Circulation journal : official journal of the Japanese Circulation Society 84 (11) 2036 - 2036 1346-9843 2020/10/23 [Refereed]
  • 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 0009-7322 2020/08 [Refereed]
     
    BACKGROUND: A v wave on pulmonary artery wedge (PAW) pressure sometimes augments and appears on pulmonary artery (PA) pressure wave in patients with heart failure (HF). However, the significance of PA v wave in HF remains to be elucidated. METHODS: We retrospectively analyzed pressure waveforms in 61 HF patients (left ventricular ejection fraction 35 ± 15%). On the PAW and PA pressure waveforms, mean pressure as well as peak and amplitude of v waves (ampPAWv and ampPAv, respectively) were measured. Occurrence of worsening HF and cardiac death was recorded for 2 years after the catheterization. RESULTS: The ampPAWv did not correlate with ampPAv. When the patients were divided into 4 groups: I (high-ampPAWv/high-ampPAv), II (high-ampPAWv/low-ampPAv), III (low-ampPAWv/high-ampPAv), and IV (low-ampPAWv/low-ampPAv), the prevalence of group III was low (I: 13, II: 17, III: 4, IV: 27). Mean pressures of PAW and PA were similarly elevated in groups I and II. Cardiac index was lowest (I: 2.0 ± 0.4, II: 2.8 ± 0.6, III: 2.2 ± 0.2, IV: 2.4 ± 0.6 L/min/m2, ANOVA P < 0.01, P < 0.01 for I vs II) and tricuspid annular plane systolic excursion / systolic PA pressure was impaired (I: 0.27 ± 0.07, II: 0.48 ± 0.22, III: 0.59 ± 0.35, IV: 0.68 ± 0.35 mm/mmHg, ANOVA P < 0.01) in group I. During the follow-up, 13 events were observed. Kaplan-Meier analysis showed that patients in group I were at highest risk of cardiac events. CONCLUSIONS: PA v was observed mainly in patients with augmented PAW v wave and decreased cardiac index, suggesting an advanced stage of HF. Moreover, augmented PAv was associated with worse outcome in HF patients.
  • 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 2020/04/07 [Refereed]
     
    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.
  • 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 2020/01 [Refereed]
     
    Gout, which is characterized by the deposition of monosodium urate monohydrate (MSU) in the synovial fluid and other tissues, is the most common form of inflammatory arthritis. Unlike the easily recognized acute and monoarticular gouty arthritis, advanced gout induces multiple finger joint disorders and may sometimes mimic rheumatoid arthritis (RA) or vice versa. The gold standard for gout diagnosis is the identification of MSU crystals via aspiration in the symptomatic joints or nodules; however, its feasibility and specificity may be inadequate. Recently, there have been important advances in imaging techniques, assisting in the non-invasive diagnosis of gout. Ultrasonography (US) has been known to have the ability to detect deposition of MSU crystals in patients with gout. Herein, we report an evocative case of long-standing gout with precisely detected specific US features indicating MSU crystal deposition and inflammation in multiple joints. Comprehensive US assessment included the bone, hyaline cartilage, soft tissue, subcutaneous nodules and tendon; we also discriminated gouty arthritis from RA.
  • 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 1569-5794 2019/10 [Refereed]
     
    It was recently shown that invasively determined right ventricular (RV) stiffness was more closely related to the prognosis of patients with pulmonary hypertension than RV systolic function. So far, a completely noninvasive method to access RV stiffness has not been reported. We aimed to clarify the clinical usefulness of our new echocardiographic index of RV operating stiffness using atrial-systolic descent of the pulmonary artery-RV pressure gradient derived from pulmonary regurgitant velocity (PRPGDAC) and tricuspid annular plane movement during atrial contraction (TAPMAC). We studied 81 consecutive patients with various cardiac diseases who underwent echocardiography and cardiac catheterization. We measured PRPGDAC and TAPMAC using continuous-wave Doppler and M-mode echocardiography, respectively, and calculated PRPGDAC/TAPMAC. RV end-diastolic pressure (RVEDP) and RV pressure increase during atrial contraction (ΔRVPAC) were invasively measured, and RV volume change during atrial contraction (ΔVAC) was calculated from echocardiographic late-diastolic transtricuspid flow time-velocity integral and tricuspid annular area; thus ΔRVPAC/ΔVAC was used as the standard index for RV operating stiffness. PRPGDAC/TAPMAC well correlated with ΔRVPAC/ΔVAC (r = 0.84, p < 0.001) and RVEDP (r = 0.80, p < 0.001), and the area under the receiver operating characteristic curve to discriminate RVEDP > 12 mmHg was 0.94. Multivariate regression analysis revealed that PRPGDAC/TAPMAC was the single independent determinant of ΔRVPAC/ΔVAC (β = 0.86, p < 0.001). PRPGDAC/TAPMAC is useful to estimate RV operating stiffness and a good practical indicator of RVEDP.
  • 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 (一社)日本臨床検査学教育協議会 11 (2) 219 - 226 1883-3144 2019/09 [Refereed]
     
    かつては医師が担ってきた超音波(エコー)検査は、現在、そのほとんどを臨床検査技師を中心とする技師(ソノグラファー)が担うようになってきた。ソノグラファーは、検査装置の管理・調整、検査手技、計測・画像法に習熟することはもちろん、検査対象となる疾患や病態についての十分な知識に基づき、個々例の所見や病態に応じて検査を自ら組み立てる必要がある。このため、超音波検査の検者依存性は、他の検査に比べてたいへん大きい。本学院・研究院の心血管エコー研究室では、超音波検査の実技に精通したうえで、その研究者としても活躍できる指導的な人材の育成を目的とし、北海道大学病院検査・輸血部、超音波センターならびに医学研究院循環病態内科学教室の協力を得つつ、教育・研究活動を行っている。本稿では、その取り組みの一端を紹介する。(著者抄録)
  • 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 0742-2822 2019/09 [Refereed]
     
    Although the presence and physiological significance of late-diastolic tricuspid regurgitation (TR) have been reported, those in TR occurring in early diastole have not been well known. We herein first presented a case of heart failure due to dilated cardiomyopathy showing functional TR occurring in the early-diastolic phase in whom the mechanism for its genesis could be precisely assessed from echocardiographic findings and intra-cardiac pressure recordings.
  • 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 1071-9164 2019/04 [Refereed]
     
    BACKGROUND: Although the enhancement of early-diastolic intra-left ventricular pressure difference (IVPD) during exercise is considered to maintain exercise capacity, little is known about their relationship in heart failure (HF). METHODS AND RESULTS: Cardiopulmonary exercise testing and exercise-stress echocardiography were performed in 50 HF patients (left ventricular [LV] ejection fraction 39 ± 15%). Echocardiographic images were obtained at rest and submaximal and peak exercise. Color M-mode Doppler images of LV inflow were used to determine IVPD. Thirty-five patients had preserved exercise capacity (peak oxygen consumption [VO2] ≥14 mL·kg-1·min-1; group 1) and 15 patients had reduced exercise capacity (group 2). During exercise, IVPD increased only in group 1 (group 1: 1.9 ± 0.9 mm Hg at rest, 4.1 ± 2.0 mm Hg at submaximum, 4.7 ± 2.1 mm Hg at peak; group 2: 1.9 ± 0.8 mm Hg at rest, 2.1 ± 0.9 mm Hg at submaximum, 2.1 ± 0.9 mm Hg at peak). Submaximal IVPD (r = 0.54) and peak IVPD (r = 0.69) were significantly correlated with peak VO2. Peak IVPD determined peak VO2 independently of LV ejection fraction. Moreover, submaximal IVPD could well predict the reduced exercise capacity. CONCLUSION: Early-diastolic IVPD during exercise was closely associated with exercise capacity in HF. In addition, submaximal IVPD could be a useful predictor of exercise capacity without peak exercise in HF patients.
  • Michito Murayama, Hiroyuki Iwano, Yusuke Kudo, Mutsumi Nishida, Koji Akizawa, Hitoshi Shibuya, Toshihisa Anzai
    CASE (Philadelphia, Pa.) 2 (6) 248 - 253 2018/12 [Refereed]
  • 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 2047-2404 2018/11/01 [Refereed]
     
    Aims: The detection of increased left ventricular (LV) chamber stiffness may play an important role in assessing cardiac patients with potential but not overt heart failure. A non-invasive method to estimate it is not established. We investigated whether the echocardiographic backward/forward flow volume ratio from the left atrium (LA) during atrial contraction reflects the LV chamber stiffness. Methods and results: We studied 62 patients who underwent cardiac catheterization and measured their left ventricular end-diastolic pressure (LVEDP) and pressure increase during atrial contraction (ΔPa) from the LV pressure waveform. Using the echocardiographic biplane method of disks, we measured the LV volume change during atrial contraction indexed to the body surface area (ΔVa), and ΔPa/ΔVa was calculated as a standard for the LV operating chamber stiffness. Using pulsed Doppler echocardiography, we measured the time-velocity integral (TVI) of the backward pulmonary venous (PV) flow during atrial contraction (IPVA) and the ratio of IPVA to the PV flow TVI throughout a cardiac cycle (FPVA). We also measured the TVI of the atrial systolic forward transmitral flow (IA) and the ratio of the IA to the transmitral TVI during a cardiac cycle (FA) and calculated IPVA/IA and FPVA/FA. IPVA/IA and FPVA/FA were well correlated with ΔPa/ΔVa (r = 0.79 and r = 0.81) and LVEDP (r = 0.73 and r = 0.77). The areas under the ROC curve to discriminate LVEDP >18 mmHg were 0.90 for IPVA/IA and 0.93 for FPVA/FA. Conclusion: The FPVA/FA, the backward/forward flow volume ratio from the LA during atrial contraction, is useful for non-invasive assessments of LV chamber stiffness and elevated LVEDP.
  • 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 2017/07 [Refereed]
     
    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.
  • 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 0301-5629 2017/05 [Refereed]
     
    In our new echocardiographic method, pulmonary regurgitant velocity immediately before right atrial (RA) contraction is used to estimate pulmonary artery diastolic pressure (PADP) and mean PA wedge pressure (MPAWP). Our aim here was to compare the usefulness of this new method with that of the conventional method, which uses pulmonary regurgitant velocity at end diastole. We studied 55 consecutive patients who underwent echocardiography and right-sided heart catheterization. The pulmonary regurgitant velocities just before RA contraction and at end diastole were measured to obtain echocardiographic estimates of PADP (EPADPpreA and EPADPED, respectively) by adding the pressure gradients to the echocardiographically estimated RA pressure. Compared with EPADPED, EPADPpreA correlated better with PADP (r = 0.87) and MPAWP (r = 0.80), and direct fixed biases were detected for EPADPED but not for EPADPpreA. The area under the receiver operating characteristic curve distinguishing patients with MPAWP ≥18 mm Hg was greater for EPADPpreA (0.97) than for E/e' (0.94) and E/A (0.83). EPADPpreA is thus useful in estimating PADP and MPAWP in patients with heart disease.
  • 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 1569-5794 2017/01 [Refereed]
     
    Pulmonary vascular resistance (PVR) is an important hemodynamic parameter in patients with heart failure, especially when the pulmonary arterial pressure is lower due to reduced stroke volume. Several echocardiographic methods to estimate PVR have been proposed, but their applications in patients with organic left-sided heart diseases have been limited. The aim of the present study was to examine the usefulness of our new method to estimate PVR (PVRPR) based on the continuous-wave Doppler velocity measurements of pulmonary regurgitation in these patients. In 43 patients who underwent right heart catheterization, PVRPR was calculated as the difference between the Doppler-derived early- and end-diastolic pulmonary artery (PA)-right ventricular (RV) pressure gradients divided by the cardiac output measured in the left ventricular outflow tract by echocardiography. The PVRPR correlated well with invasive PVR (PVRCATH) (r = 0.81, p < 0.001) without any fixed bias in Bland-Altman analysis. The conventional echocardiographic PVRs showed inadequate correlations with PVRCATH, or a obvious overestimation of PVRCATH. In the receiver operating characteristic analyses to determine the patients with abnormal elevation of PVRCATH (>3 Wood units, WU), the area under the curve was the greatest for PVRPR (0.964) compared to the conventional PVRs (0.649-0.839). PVRPR had 83 % sensitivity and 100 % specificity at the optimal cut-off value of 3.10 WU in identifying patients with PVRCATH >3 WU. Our simple and theoretical PVRPR is useful for the noninvasive estimation of PVR.

MISC

Awards & Honors

  • 2023/12 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 
    受賞者: 村山迪史;石坂 傑
  • 2023/09 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 
    受賞者: 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
  • 2023/06 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 
    受賞者: 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
  • 2022/05 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
     
    受賞者: 村山迪史
  • 2022/04 北海道大学大学院保健科学院 保健科学院長賞
     
    受賞者: 村山迪史
  • 2022/03 Hokkaido University 総代
     
    受賞者: 村山迪史
  • 2021/10 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 
    受賞者: 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
  • 2021/10 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 
    受賞者: 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
  • 2021/08 北海道大学大学院保健科学院 研究奨励賞
     
    受賞者: 村山迪史
  • 2020/12 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 
    受賞者: 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
  • 2020/12 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 
    受賞者: 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
  • 2020/10 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 
    受賞者: 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
  • 2019/05 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 
    受賞者: 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
  • 2018/03 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 
    受賞者: 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

Research Grants & Projects

Educational Activities

Teaching Experience

  • チーム医療論チーム医療論 Hokkaido University
  • 保健生理学保健生理学 Hokkaido University
  • 健康と社会 メディカルLab．サイエンスの世界健康と社会 メディカルLab．サイエンスの世界 Hokkaido University
  • 画像検査学Ⅱ画像検査学Ⅱ Hokkaido University
  • 生体機能学生体機能学 Hokkaido University
  • 臨床病態学Ⅰ臨床病態学Ⅰ Hokkaido University
  • 臨床生理画像学実習Ⅰ臨床生理画像学実習Ⅰ Hokkaido University
  • 生体機能学実習生体機能学実習 Hokkaido University
  • 臨床生理学Ⅰ臨床生理学Ⅰ Hokkaido University
  • 保健・医療概論保健・医療概論 Hokkaido University
  • 卒業研究卒業研究 Hokkaido University
  • Practice in Clinical Physiology and Imaging Ⅰ
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 超音波検査、脈波検査、眼底検査、心音図検査

Social Contribution

Social Contribution

Social Contribution

  • タスクシフト／シェアに関する厚生労働大臣指定講習会
    Date (from-to) : 2023/12/02
    Role : Organizing member
    Sponser, Organizer, Publisher  : 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
    Date (from-to) : 2023/09/24
    Role : Lecturer
    Sponser, Organizer, Publisher  : 札幌臨床検査技師会
  • 札幌肝がん検診
    Date (from-to) : 2020/02/16
    Role : Others
  • 検査deフェスティバル
    Date (from-to) : 2019/08/25
    Role : Organizing member
    Sponser, Organizer, Publisher  : 札幌臨床検査技師会
  • 札幌肝がん検診
    Date (from-to) : 2019/02/17
    Role : Others
  • 札幌肝がん検診
    Date (from-to) : 2018/02/18
    Role : Others

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