Hiroshi Kuwaki
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Featured researches published by Hiroshi Kuwaki.
European Journal of Heart Failure | 2011
Nobuhiko Haruki; Masaaki Takeuchi; Kyoko Kaku; Hidetoshi Yoshitani; Hiroshi Kuwaki; Masahito Tamura; Haruhiko Abe; Masahiro Okazaki; Akizumi Tsutsumi; Yutaka Otsuji
The aim of this study was to determine differences in the acute and chronic impact of adaptive servo‐ventilation (ASV) on left chamber geometry and function in patients with chronic heart failure (CHF).
Jacc-cardiovascular Imaging | 2013
Victor Chien-Chia Wu; Masaaki Takeuchi; Hiroshi Kuwaki; Mai Iwataki; Yasufumi Nagata; Kyoko Otani; Nobuhiko Haruki; Hidetoshi Yoshitani; Masahito Tamura; Haruhiko Abe; Kazuaki Negishi; Fen-Chiung Lin; Yutaka Otsuji
OBJECTIVES The hypothesis of this study was that minimal left atrial volume index (LAVImin) by 3-dimensional echocardiography (3DE) is the best predictor of future cardiovascular events. BACKGROUND Although maximal left atrial volume index (LAVImax) by 2-dimensional echocardiography (2DE) is a robust index for predicting prognosis, the prognostic value of LAVImin and the superiority of measurements by 3DE over 2DE have not been determined in a large group of patients. METHODS In protocol 1, we assessed age and sex dependency of LAVIs using 2DE and 3DE in 124 normal subjects and determined their cutoff values (mean + 2 SD). In protocol 2, 2-dimensional (2D) and 3-dimensional (3D) LAVImax/LAVImin were measured in 556 patients with high prevalence of cardiovascular disease. After excluding patients with atrial fibrillation, mitral valve disease, and age <18 years, 439 subjects were followed to record major adverse cardiovascular events (MACE). Patients were divided into 2 groups by the cutoff criteria of LAVI in each method. RESULTS In protocol 1, there was no significant age and sex dependency for each 2D and 3D LAVI. In protocol 2, during a mean of 2.5 years of follow-up, MACE developed in 88 patients, including 32 cardiac deaths. Kaplan-Meier survival analyses showed that all 4 LAVI cutoff criteria had significant predictive power of MACE. After variables were adjusted for clinical variables and left ventricular ejection fraction, all 4 methods were still independently and significantly associated with MACE, but 3D-derived LAVImin had the highest risk ratio. 3D LAVImin also had an incremental prognostic value over 3D LAVImax. CONCLUSIONS LAVIs by both 2DE and 3DE are powerful predictors of future cardiac events. 3D LAVImin tended to have a stronger and additive prognostic value than 3D LAVImax.
Open Heart | 2014
Mai Iwataki; Masaaki Takeuchi; Kyoko Otani; Hiroshi Kuwaki; Hidetoshi Yoshitani; Haruhiko Abe; Roberto M. Lang; Robert A. Levine; Yutaka Otsuji
Objective Mitral annular/leaflet calcification (MALC) is frequently observed in patients with degenerative aortic stenosis (AS). However, the impact of MALC on mitral valve function has not been established. We aimed to investigate whether MALC reduces mitral annular area and restricts leaflet opening, resulting in non-rheumatic mitral stenosis. Methods Real-time three-dimensional transoesophageal images of the mitral valve were acquired in 101 patients with degenerative AS and 26 control participants. The outer and inner borders of the mitral annular area (MAA) and the maximal leaflet opening angle were measured at early diastole. The mitral valve area (MVA) was calculated as the left ventricular stroke volume divided by the velocity time integral of the transmitral flow velocity. Results Although the outer MAA was significantly larger in patients with AS compared to control participants (8.2±1.3 vs 7.3±0.9 cm2, p<0.001), the inner MAA was significantly smaller (4.5±1.1 vs 5.9±0.9 cm2, p<0.001), resulting in an average decrease of 45% in the effective MAA. The maximal anterior and posterior leaflet opening angle was also significantly smaller in patients with AS (64±10 vs 72±8°, p<0.001, 71±12 vs 87±7°, p<0.001). Thus, MVA was significantly smaller in patients with AS (2.5±1.0 vs 3.8±0.8 cm2, p<0.001). Twenty-four (24%) patients with AS showed MVA <1.5 cm2. Multivariate regression analysis including parameters for mitral valve geometry revealed that a decrease in effective MAA and a reduced posterior leaflet opening angle were independent predictors for MVA. Conclusions Calcific extension to the mitral valve in patients with AS reduced effective MAA and the leaflet opening, resulting in a significant non-rheumatic mitral stenosis in one-fourth of the patients.
Circulation-cardiovascular Imaging | 2016
Shota Fukuda; Jae-Kwan Song; Keitaro Mahara; Hiroshi Kuwaki; Jeong Yoon Jang; Masaaki Takeuchi; Byung Joo Sun; Yun Jeong Kim; Tetsu Miyamoto; Yasushi Oginosawa; Shinjo Sonoda; Masataka Eto; Yosuke Nishimura; Shuichiro Takanashi; Robert A. Levine; Yutaka Otsuji
Background—Prominent mitral valve (MV) annular dilatation with only modest left ventricular (LV) dilatation in patients with MV prolapse (MVP) suggests predominant dilatation in adjacent basal LV, which may augment regional wall tension and attenuate contraction by Laplace’s law. We hypothesized that MV annular dilatation in patients with MVP is associated with the basal predominance of LV dilatation and attenuated contraction, which can be altered by surgical MV plasty with annulus reduction. Methods and Results—Echocardiography with speckle-tracking analysis to assess regional cross-sectional short-axis area and longitudinal contraction (strain) of basal, middle, and apical LV was performed in 30 controls and 130 patients with MVP. The basal value/averaged middle and apical values (B/M·A ratio) of LV cross-sectional area and strain were obtained. Patients with MVP showed significantly greater MV annular area (6.4±1.6 versus 3.7±0.6 cm2/m2), increased B/M·A LV area ratio (2.4±0.5 versus 1.8±0.2), and reduced B/M·A LV strain ratio (0.83±0.14 versus 0.96±0.09) than controls (P<0.001). Multivariable analyses identified that MV annular dilatation was independently associated with increased B/M·A LV area ratio (&bgr;=0.60, P<0.001), which was associated with reduced B/M·A LV strain ratio (&bgr;=−0.32, P<0.001). In 35 patients with MVP, B/M·A LV area and strain ratio significantly altered after surgical MV plasty with annulus reduction (2.5±0.5–1.8±0.3 and 0.73±0.10–0.89±0.17, P<0.001, respectively). Conclusions—In patients with MVP, MV annular dilatation was associated with the basal predominance of LV dilatation and reduced contraction, which can be altered by surgical MV plasty with annulus reduction, suggesting unfavorable influence from MV annular dilatation on basal LV.Background— Prominent mitral valve (MV) annular dilatation with only modest left ventricular (LV) dilatation in patients with MV prolapse (MVP) suggests predominant dilatation in adjacent basal LV, which may augment regional wall tension and attenuate contraction by Laplace’s law. We hypothesized that MV annular dilatation in patients with MVP is associated with the basal predominance of LV dilatation and attenuated contraction, which can be altered by surgical MV plasty with annulus reduction. Methods and Results— Echocardiography with speckle-tracking analysis to assess regional cross-sectional short-axis area and longitudinal contraction (strain) of basal, middle, and apical LV was performed in 30 controls and 130 patients with MVP. The basal value/averaged middle and apical values (B/M·A ratio) of LV cross-sectional area and strain were obtained. Patients with MVP showed significantly greater MV annular area (6.4±1.6 versus 3.7±0.6 cm2/m2), increased B/M·A LV area ratio (2.4±0.5 versus 1.8±0.2), and reduced B/M·A LV strain ratio (0.83±0.14 versus 0.96±0.09) than controls ( P <0.001). Multivariable analyses identified that MV annular dilatation was independently associated with increased B/M·A LV area ratio (β=0.60, P <0.001), which was associated with reduced B/M·A LV strain ratio (β=−0.32, P <0.001). In 35 patients with MVP, B/M·A LV area and strain ratio significantly altered after surgical MV plasty with annulus reduction (2.5±0.5–1.8±0.3 and 0.73±0.10–0.89±0.17, P <0.001, respectively). Conclusions— In patients with MVP, MV annular dilatation was associated with the basal predominance of LV dilatation and reduced contraction, which can be altered by surgical MV plasty with annulus reduction, suggesting unfavorable influence from MV annular dilatation on basal LV.
Heart Lung and Circulation | 2013
Nobuhiko Haruki; Masaaki Takeuchi; Hidetoshi Yoshitani; Kyoko Otani; Hiroshi Kuwaki; Mai Iwataki; Haruhiko Abe; Masahito Tamura; Masahiro Okazaki; Yutaka Otsuji
echanical pulsus alternans is sometimes seen inpatients with severe heart failure. This case reportdescribes a patient with medically refractory acute heartfailure due to severe left ventricular (LV) systolic dys-function withpulsusalternans,whereshort-termadaptiveservo-ventilation (ASV)therapyimmediatelyamelioratedthe mechanical pulsus alternans.A 52 year-old male was admitted to the hospitaldue to progressive exertional dyspnoea. Auscultationof the chest revealed fine crackles over both lungs.An S3 gallop rhythm and a grade 2/6 of pansystolicmurmur were audible at the apex. His blood pres-sure was 110/70mmHg and heart rate was 120bpm.Chest X ray showed cardiomegaly with bilateral pul-monary congestion. The electrocardiogram showed sinustachycardia with normal QRS duration. Blood exami-nation on admission revealed remarkable elevation inthe serum level of brain natriuretic peptide (BNP) of1740 pg/dl (<18.4pg/ml). Echocardiography showed aseverely dilated left ventricle (LV) with an ejection frac-tion of 15% (Movie 1). Estimated systolic pulmonaryartery pressure from tricuspid regurgitation velocity was64 mmHg. Initial treatment with angiotensin II recep-tor blockers, intravenous diuretics, and carperitide failedto provide a favourable response. Subsequently, intra-venous phosphodiesterase III inhibitor for three daysdid not improve his condition. Radial pulse revealedalternating strong and weak beats, indicating mechanicalpulsus alternans. Repeated echocardiography demon-strated alternating pulsed Doppler flow velocities acrossthe LV outflow tract (LVOT) with no significant change ofLV size and systolic function compared to the previousstudy (Fig. 1). Although oxygen saturation was preservedby
Journal of The American Society of Echocardiography | 2012
Mai Iwataki; Masaaki Takeuchi; Kyoko Otani; Hiroshi Kuwaki; Nobuhiko Haruki; Hidetoshi Yoshitani; Masahito Tamura; Haruhiko Abe; Yutaka Otsuji
Jacc-cardiovascular Imaging | 2014
Hiroshi Kuwaki; Masaaki Takeuchi; Victor Chien-Chia Wu; Kyoko Otani; Yasufumi Nagata; Atsushi Hayashi; Mai Iwataki; Shota Fukuda; Hidetoshi Yoshitani; Haruhiko Abe; Yutaka Otsuji
Jacc-cardiovascular Imaging | 2014
Hiroshi Kuwaki; Masaaki Takeuchi; Victor Chien-Chia Wu; Kyoko Otani; Yasufumi Nagata; Atsushi Hayashi; Mai Iwataki; Shota Fukuda; Hidetoshi Yoshitani; Haruhiko Abe; Yutaka Otsuji
Circulation | 2011
Hiroshi Kuwaki; Masaaki Takeuchi; Kyoko Kaku; Nobuhiko Haruki; Hidetoshi Yoshitani; Masahito Tamura; Masahiro Okazaki; Haruhiko Abe; Yutaka Otsuji
Circulation-cardiovascular Imaging | 2016
Shota Fukuda; Jae-Kwan Song; Keitaro Mahara; Hiroshi Kuwaki; Jeong Yoon Jang; Masaaki Takeuchi; Byung Joo Sun; Yun Jeong Kim; Tetsu Miyamoto; Yasushi Oginosawa; Shinjo Sonoda; Masataka Eto; Yosuke Nishimura; Shuichiro Takanashi; Robert A. Levine; Yutaka Otsuji
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University of Occupational and Environmental Health Japan
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