Miyuki Kawakubo
Chiba University
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Featured researches published by Miyuki Kawakubo.
International Journal of Cardiology | 2009
Yumi Shiina; Nobusada Funabashi; Kwangho Lee; Masao Daimon; Tai Sekine; Miyuki Kawakubo; Maiko Takahashi; Rei Yajima; Nobuhiro Tanabe; Takayuki Kuriyama; Issei Komuro
PURPOSE We evaluated right atrial (RA) contractility and right ventricular (RV) diastolic function in adult patients with acquired chronic pulmonary hypertension (PH) by pulsed Tissue Doppler Imaging (TDI) and assessed their relationship with serum brain natriuretic peptide (BNP). MATERIALS AND METHODS Systolic myocardial wave (Sa), early diastolic myocardial wave (Ea), and late diastolic myocardial wave (Aa) at the tricuspid annulus were recorded in 77 consecutive patients with acquired PH. Early (E) RV inflow waves were recorded from 4-chamber views. RV Aa was regarded as the parameter of RA contractility and RV E/Ea was taken as the parameter of RV diastolic function using TDI. RESULTS All subjects had elevated BNP (mean 188.9 +/- 244.0 pg/dl) and pulmonary arterial systolic pressure (PASP) estimated at 62.9 +/- 26.7 mm Hg. BNP levels were positively correlated with RV E/Ea, Aa and PASP (r = 0.47, p < 0.0001 and r = 0.35, p < 0.01, respectively) but negatively with Aa (r = -0.29, p < 0.05). Next, all predictor variables were used in a multiple regression model with serum BNP values as dependent variables, refined to include 3 predictors: RV E/Ea, Aa, and PASP, which were all found to influence serum BNP values (p < 0.0001) by the formula Y = 34.1X1**-19.11X2**+2.95X3* (**p < 0.001, *p < 0.01) where Y = BNP, X1 = E/Ea of RV, X2 = Aa, and X3 = PASP (standard regression coefficients were 0.37, -0.34 and 0.34, respectively). CONCLUSION Serum BNP correlates with RA contractility and RV diastolic dysfunction by RV TDI in adults with acquired PH. Increased BNP may be related to decreased RA systolic function and RV diastolic function in these patients.
Circulation | 2009
Yoshiyuki Hama; Nobusada Funabashi; Marehiko Ueda; Tomonori Kanaeda; Masae Uehara; Koki Nakamura; Taichi Murayama; Yoko Mikami; Hiroyuki Takaoka; Miyuki Kawakubo; Kwangho Lee; Hiroyuki Takano; Issei Komuro
An asymptomatic healthy 65-year-old man was referred to a hospital for inverted T waves in the precordial leads (Figure 1) with paroxysmal advanced atrioventricular block in the ECG. Chest x-ray showed mild cardiac enlargement (Figure 2), and an echocardiogram showed right ventricular (RV) wall thickening (arrow in Figure 3). Five months later, the patient was referred to another hospital complaining of chest discomfort. Coronary angiogram was normal, but sustained monomorphic ventricular tachycardia (VT) occurred. Suffering from incessant VT, the patient was transferred to our hospital. The ECG and echocardiogram were …
International Journal of Cardiology | 2009
Yumi Shiina; Nobusada Funabashi; Kwangho Lee; Masao Daimon; Tai Sekine; Miyuki Kawakubo; Yukiko Sekine; Maiko Takahashi; Rei Yajima; Yu Wakatsuki; Nobuhiro Tanabe; Takayuki Kuriyama; Issei Komuro
PURPOSE We evaluated whether right ventricular (RV) diastolic dysfunction assessed by pulsed tissue Doppler imaging (TDI) predicts cardiac events in patients with chronic pulmonary thromboembolism (CPTE). MATERIALS AND METHODS In 63 consecutive patients with CPTE, early diastolic myocardial velocity (Ea) at the tricuspid annulus by TDI and early diastolic tricuspid inflow (E) by conventional pulsed Doppler were obtained, and E/Ea was calculated as an indicator of RV diastolic dysfunction. Brain natriuretic peptide (BNP) and other echo parameters were also obtained. A cardiac event (rehospitalization caused by congestive heart failure or cardiac death) was the study endpoint. Incidence of cardiac events was determined over a 374+/-451 day follow-up period. RESULTS In the follow-up period twelve patients had cardiac events. We divided patients into group A with cardiac events and group B without events. E/Ea was significantly increased in group A as compared with group B (8.3+/-4.1 vs. 5.7+/-2.6, p<0.01). BNP was higher in group A than group B (221+/-191 vs. 121+/-140 mg/dl, p<0.05), and in addition E/Ea was significantly positively correlated with BNP (r=0.48, p<0.001). A logistic regression model for predicting cardiac events was constructed and E/Ea was associated with an increased incidence of cardiac events (relative risk=1.33, 95% CI 1.00-1.75). CONCLUSION Elevated values of E/Ea obtained by TDI may predict cardiac events in patients with CPTE. BNP may also be a significant predictor.
International Journal of Cardiology | 2009
Yu Wakatsuki; Nobusada Funabashi; Yoko Mikami; Yumi Shiina; Miyuki Kawakubo; Maiko Takahashi; Rei Yajima; Masae Uehara; Hiroyuki Takaoka; Issei Komuro
PURPOSE To evaluate left atrial (LA) function in subjects with early stage primary hypertension (HT) and without enlargement of LA, we used transthoracic echocardiogram and measured LA volumetric emptying fraction and compared the results with those in healthy volunteers. MATERIALS AND METHODS 42 subjects with early stage primary HT (21 males, aged 61+/-12 years), within 1 year of HT diagnosis and starting initial treatment, were enrolled in the study. An additional inclusion criterion was normal sinus rhythm electrocardiogram without enlargement of LA. As the control group, 31 healthy volunteers with normal sinus rhythm electrocardiogram (13 male, aged 57+/-11 years) were enrolled. Maximum and minimum volume of LA (LAV max and min, respectively) were selected manually and visually in B mode images acquired from a four-chamber view from apex of left ventricle (LV) using a modified Simpson method, and the LA emptying fraction (LAEF) was calculated by the following formula: LAV min/LAV max x 100 (%). RESULTS There were no significant differences in age, male:female ratio, end-diastolic and end-systolic LV diameter, LA maximum volume, LV ejection fraction and E/A in mitral annulus between the two groups. However, we found that end-diastolic inter-ventricular septum thickness and end-diastolic LV posterior wall thickness were significantly larger in the HT group in comparison with the control group (P<0.01), but the HT group did not fit the classical criteria of LV myocardial hypertrophy. The systolic and diastolic blood pressure, the end-diastolic and end-systolic volume of LV, the total weight of LV myocardium and the LAEF were significantly higher in the HT group than in the control group (P<0.05). CONCLUSIONS In subjects with early stage primary HT with normal sinus rhythm, in spite of a normal LAV, the LAEF may increase. This increase of LAEF may be regarded as one of the compensatory reactions against preload to the left side of the heart and precedes the occurrence of LA enlargement.
International Journal of Cardiology | 2010
Miyuki Kawakubo; Nobusada Funabashi; Maiko Takahashi; Makoto Sueishi; Yasufumi Motoyoshi; Takashi Mikata; Idai Uchida; Takehiro Asakawa; Riyo Takahashi; Midori Takamatsu; Yukie Matsuoka; Masaaki Minegishi; Hideki Naga; Rei Yajima; Akihisa Kataoka; Kwangho Lee; Issei Komuro
Abstract Purpose To examine the usefulness of plasma atrial (ANP) and brain natriuretic peptide (BNP) levels and transthoracic echocardiogram (TTE) findings in predicting left ventricular (LV) dysfunction in muscular dystrophies (MD). Materials and methods 135 MD subjects (83 Duchenne MD (DMD), all males, mean age 22±7years, 20 Becker MD (BMD), all males, 45±16years, 21 limb-girdle MD (LGMD), 14 males, 52±13years, and 11 facioscapulohumeral MD (FSHD), all males, 58±13years) underwent TTE and measurement of BNP and ANP. Results In DMD, TTE revealed asynergy of the LV posterior-wall (72%), interventricular septum (IVS) (29%) and LV apex-wall (24%); in BMD subjects: TTE revealed asynergy of LV posterior-wall (50%) and IVS (25%); in LGMD and FSHD subjects: TTE revealed asynergy of LV posterior-wall (33 and 27%, respectively). LV end-diastolic (LVDdI) and end-systolic diameter index (LVDsI) were significantly larger in DMD than FSHD, and LV ejection fraction (LVEF) was significantly lower in DMD than LGMD and FSHD. In DMD, when LVEF was >=35%, BNP and ANP levels remained low, but when LVEF R 2 =0.69 and 0.55, respectively, p −2.897 , ANP=5716.6×EF −1.422 , respectively. When LVDdI>=40mm/m 2 or LVDsI>=35mm/m 2 , LVEF Conclusion In DMD, LVEF was significantly lower, asynergy of LV posterior-wall was more frequent and BNP and ANP levels were dramatically higher when LVDdI>=40mm/m 2 , LVDsI>=35mm/m 2 or LVEF
Circulation | 2006
Miyuki Kawakubo; Nobusada Funabashi; Keiichi Nakagawa; Issei Komuro
A 57-year-old man went to a hospital complaining of chest pain and was diagnosed with a Stanford Type-A aortic dissection that continued through the aortic arch and descending aorta to the whole abdominal aorta. He therefore underwent graph replacement of the ascending aorta. After 1 month, he experienced dyspnea and came to our hospital. Chest x-ray revealed cardiac enlargement. Transthoracic echocardiogram revealed massive pericardial effusion (PE) but no cardiac tamponade. An enhanced multislice computed tomography …
International Journal of Cardiology | 2007
Miyuki Kawakubo; Nobusada Funabashi; Masae Uehara; Marehiko Ueda; Hiroshi Hasegawa; Tai Sekine; Eiji Ichimoto; Kumi Yasukawa; Osahiro Takahashi; Yayoi Yamamoto; Issei Komuro
International Journal of Cardiology | 2007
Yoshihito Kameda; Nobusada Funabashi; Miyuki Kawakubo; Masae Uehara; Hiroshi Hasegawa; Yoshio Kobayashi; Issei Komuro
International Journal of Cardiology | 2009
Yumi Shiina; Nobusada Funabashi; Kiyomi Teramoto; Masae Uehara; Hiroyuki Takaoka; Yoko Mikami; Akiyo Takahashi; Mariko Saito; Masao Daimon; Kwangho Lee; Miyuki Kawakubo; Yukiko Sekine; Maiko Takahashi; Rei Yajima; Akiko Tani; Issei Komuro
Japanese Circulation Journal-english Edition | 2008
Maiko Okuma; Nobusada Funabashi; Yumi Shiina; Koko Ri; Masao Daimon; Miyuki Kawakubo; Rei Yukiko; Yukiko Tsuru; Issei Komuro