Norikazu Yamada

Publications (87) View all

• Article: Ventricular Function and Dyssynchrony Quantified by Speckle-Tracking Echocardiography in Patients with Acute and Chronic Right Ventricular Pressure Overload.

  Kazuhide Ichikawa, Kaoru Dohi, Emiyo Sugiura, Tadafumi Sugimoto, Takeshi Takamura, Yoshito Ogihara, Hiroshi Nakajima, Katsuya Onishi, Norikazu Yamada, Mashio Nakamura, Tsutomu Nobori, Masaaki Ito
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  ABSTRACT: BACKGROUND: The aim of this study was to noninvasively investigate right ventricular and left ventricular (LV) adaptation to right ventricular pressure overload in patients with acute pulmonary thromboembolism (APTE) and chronic pulmonary artery hypertension (CPAH). METHODS: Thirty-seven patients with APTE, 36 patients with CPAH, and 33 controls were retrospectively enrolled. Myocardial deformation and wall motion were analyzed using speckle-tracking strain and displacement imaging echocardiography in the right and left ventricles. The standard deviation of the heart rate-corrected intervals from QRS onset to peak systolic strain and peak systolic displacement (PSD) for the six segments was used to quantify right ventricular and LV mechanical dyssynchrony (peak systolic strain dyssynchrony and PSD dyssynchrony). The myocardial performance index in both ventricles was also evaluated. RESULTS: The APTE and CPAH groups had reduced ventricular performance (LV myocardial performance index, 0.40 ± 0.10, 0.66 ± 0.18 [P < .05 vs controls], and 0.58 ± 0.19 [P < .05 vs controls] in the control, APTE, and CPAH groups, respectively) and large mechanical dyssynchrony (LV longitudinal PSD dyssynchrony, 58 ± 41 msec, 119 ± 49 msec [P < .05 vs controls], and 83 ± 37 msec [P < .05 vs controls and the APTE group] in the control, APTE, and CPAH groups, respectively) in both ventricles. Multiple regression analysis indicated that LV longitudinal PSD dyssynchrony in the APTE group and the LV eccentricity index in the CPAH group were independent determinants of LV myocardial performance index. CONCLUSIONS: Pathophysiologic mechanisms that regulate ventricular performance vary depending on whether the ventricles are exposed to acute or chronic right ventricular pressure overload.
  Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 03/2013; · 2.98 Impact Factor
• Article: Use of corticosteroids in the treatment of cholesterol crystal embolism after cardiac catheterization: a report of four Japanese cases.

  Jun Masuda, Takashi Tanigawa, Shiro Nakamori, Toshiki Sawai, Tomohiro Murata, Eiji Ishikawa, Norikazu Yamada, Mashio Nakamura, Masaaki Ito
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  ABSTRACT: Cholesterol crystal embolism (CCE) is a serious complication associated with invasive vascular procedures. The prognosis of the renal involvement type of CCE is very poor, and there is currently no established treatment, other than supportive therapy. We herein report four cases of CCE with severe atherosclerosis wherein the renal function progressively deteriorated after cardiac catheterization. In three of the four patients, low-dose corticosteroids (0.3 mg/kg/day) improved the renal function, whereas the fourth patient died from CCE of the digestive system. This report reviews the literature on CCE and discusses possible therapeutic options.
  Internal Medicine 01/2013; 52(9):993-8. · 0.94 Impact Factor
• Article: The impact of preprocedural hemoglobin A1c on the efficacy of sirolimus-eluting and paclitaxel-eluting stents.

  Toshiki Sawai, Masatoshi Miyahara, Hiroshi Nakajima, Shiro Nakamori, Masataka Sakai, Hiroya Tamada, Takashi Tanigawa, Norikazu Yamada, Mashio Nakamura, Masaaki Ito
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  ABSTRACT: Several reports have shown contrary results regarding the efficacy of sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) in diabetic patients. The association between hemoglobin A1c (A1c) before coronary intervention and the midterm clinical outcomes of patients treated with these stents is unclear. The enrolled population was 415 patients with diabetes or impaired glucose tolerance (IGT) who underwent follow-up angiography after being implanted with a SES (n = 282) or PES (n = 133). The enrolled population was classified into the optimal glycemic control group (n = 213) and suboptimal glycemic control group (n = 202), and the predictors of restenosis were examined in each group. In the optimal glycemic control group, the use of PES was an independent predictor of restenosis [odds ratio (OR) 9.98, 95% confidence interval (CI) 3.08-38.9, p < 0.0001]; on the other hand, the use of SES was a positive independent predictor of restenosis prevention (OR 0.10, 95% CI 0.03-0.32, p < 0.0001). In the suboptimal glycemic control group, neither stent was predictive of restenosis. In a subanalysis, preprocedural A1c (≥7.0%) was found to be an independent predictor of restenosis in the SES group (OR 3.61, 95% CI 1.14-12.8, p = 0.03), but not the PES group. Postprocedural A1c (≥7.0%) was not an independent predictor of restenosis in either stent group. This study showed that the superiority of SES compared to PES was attenuated in the suboptimal glycemic control group. Preprocedural A1c (≥7.0%) was found to be an independent predictor of restenosis in the SES group, but not in the PES group.
  Cardiovascular intervention and therapeutics. 05/2012; 27(2):72-83.
• Article: Comparison of coronary flow velocity reserve measurement by transthoracic Doppler echocardiography with 320-row multidetector computed tomographic coronary angiography in the detection of in-stent restenosis in the three major coronary arteries.

  Kentaro Kakuta, Kaoru Dohi, Tomomi Yamada, Takashi Yamanaka, Masaki Kawamura, Shiro Nakamori, Hiroshi Nakajima, Takashi Tanigawa, Katsuya Onishi, Norikazu Yamada, Mashio Nakamura, Tsutomu Nobori, Masaaki Ito
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  ABSTRACT: We sought to compare the diagnostic accuracy and feasibility of coronary flow velocity reserve (CFVR) measurement using transthoracic Doppler echocardiography (TTDE) and 320-row multidetector computed tomographic coronary angiography (CTCA) for predicting in-stent restenosis (ISR). We enrolled 126 consecutive patients with 309 implanted coronary stents in the 3 major coronary arteries. TTDE and CTCA were performed within the 2-week period before follow-up invasive coronary angiography. Binary ISR was defined as percent diameter stenosis ≥50% on invasive coronary angiogram. A CFVR <2.0 using TTDE and a narrowing of ≥50% measured with CTCA were the thresholds indicating the presence of binary ISR. Presence of ISR using invasive coronary angiography was observed in 26 (8%) stents and 26 (14%) vessels. Feasibilities of CFVR measurement and CTCA for predicting ISR in the 3 major vessels were 94% and 91%, respectively. A CFVR <2.0 revealed a 95% diagnostic accuracy with sensitivity of 87%, specificity of 96%, positive predictive value of 77%, and negative predictive value of 98%. Diagnostic accuracy of CTCA was comparable to that of CFVR measurement; however, CTC angiographic results were confounded by metal artifacts in the assessment of small-diameter stents. In conclusion, noninvasive CFVR measurement has high feasibility and accuracy for predicting ISR and is comparable to 320-row CTCA.
  The American journal of cardiology 03/2012; 110(1):13-20. · 3.58 Impact Factor
• Article: Increased fibrinolysis increases bleeding in orthopedic patients receiving prophylactic fondaparinux.

  Kakunoshin Yoshida, Hideo Wada, Masahiro Hasegawa, Hiroki Wakabayashi, Takeshi Matsumoto, Yuji Shimokariya, Katsura Noma, Norikazu Yamada, Atsumasa Uchida, Tsutomu Nobori, Akihiro Sudo
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  ABSTRACT: We evaluated hemostatic markers in patients who underwent major orthopedic surgery, including total hip and total knee arthroplasty, and were treated for the prophylaxis of deep vein thrombosis (DVT) with or without fondaparinux (anti-Xa group, n = 98 and without anti-Xa group, n = 20). The frequency of DVT was significantly higher in the without anti-Xa group than in the anti-Xa group, but the reduction of hemoglobin and fibrinolytic marker levels was significantly lower in the without anti-Xa group than in the anti-Xa group. Eighteen patients in the anti-Xa group showed a reduction in hemoglobin of more than 2 g/dl, and those individuals were considered to be the increased bleeding (IB) group. The concentration of fibrinolytic markers in the anti-Xa group was significantly higher in the IB group than in the non-IB group. There were also no significant differences in the levels of anti-Xa activity, plasminogen activator inhibitor-I, soluble fibrin and antithrombin between the IB and non-IB groups. In conclusion, elevated fibrinolysis induced by increased bleeding may lead to further increases in bleeding in patients receiving thromboprophylaxis with fondaparinux following major orthopedic surgery.
  International journal of hematology 02/2012; 95(2):160-6. · 1.17 Impact Factor