著者

Masato Okada Koichi Inoue Koji Tanaka Yuichi Ninomiya Yuko Hirao Takafumi Oka Nobuaki Tanaka Hiroyuki Inoue Ryo Nakamaru Yasushi Koyama Atsunori Okamura Katsuomi Iwakura Yasushi Sakata Kenshi Fujii

出版者

The Japanese Circulation Society

雑誌

Circulation Journal (ISSN:13469843)

巻号頁・発行日

vol.82, no.4, pp.956-964, 2018-03-23 (Released:2018-03-23)

参考文献数

14

被引用文献数

14 17

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Background:This study evaluated the safety and efficacy of venous figure-of-eight (FoE) suture to achieve femoral venous hemostasis after radiofrequency (RF) catheter ablation (CA) for atrial fibrillation (AF).Methods and Results:We retrospectively examined 517 consecutive patients undergoing RFCA for AF. The control group (n=247) underwent manual compression for femoral venous hemostasis after sheath removal with 6 h of bed rest. The FoE group (n=270) underwent FoE suture technique with 4 h of bed rest. All patients achieved successful hemostasis within 24 h after CA. Although the incidence of hematoma was similar between the groups, the incidence of rebleeding was lower in the FoE group than in the control group (FoE vs. control, 3.7% vs. 18.6%, P<0.001). The post-procedural use of analgesic and/or anti-emetic agents was less frequent in the FoE group (19.3% vs. 32.0%, P<0.001). On multiple logistic regression analysis after adjustment for age and sex, the use of a vitamin K antagonist (OR, 2.42; 95% CI: 1.18–4.99, P=0.02) and the FoE suture technique (OR, 0.17; 95% CI: 0.08–0.35, P<0.001) were independent predictors of rebleeding after CA.Conclusions:FoE suture technique effectively achieved femoral venous hemostasis after RFCA for AF. It reduced the risk of rebleeding, shortened bed rest duration, and relieved patient discomfort.

著者

Nobuaki Tanaka Koji Tanaka Yuichi Ninomiya Yuko Hirao Takafumi Oka Masato Okada Hiroyuki Inoue Ryo Nakamaru Kohtaro Takayasu Ryo Kitagaki Yasushi Koyama Atsunori Okamura Katsuomi Iwakura Yasushi Sakata Kenshi Fujii Koichi Inoue

出版者

The Japanese Circulation Society

雑誌

Circulation Journal (ISSN:13469843)

巻号頁・発行日

pp.CJ-18-1035, (Released:2019-02-06)

参考文献数

25

被引用文献数

4

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Background: Automated ablation lesion annotation with optimal settings for parameters including contact force (CF) and catheter stability may be effective for achieving durable pulmonary vein isolation. Methods and Results: We retrospectively examined 131 consecutive patients who underwent initial catheter ablation (CA) for paroxysmal atrial fibrillation (PAF) by automatic annotation system (VISITAG module)-guided radiofrequency CA (RFCA) (n=61) and 2nd-generation cryoballoon ablation (CBA) (n=70) in terms of safety and long-term efficacy. The automatic annotation criteria for the RFCA group were as follows: catheter stability range of motion ≤1.5 mm, duration ≥5 s, and CF ≥5 g. We ablated for >20 s with a force-time integral >150 gs at each site, before moving to the next site. Each interlesion distance was <6 mm. Procedural complications were more frequent in the CBA group (1.6% vs. 10.0%, P=0.034). Across a median follow-up of 2.98 years, 88.5% and 70.0% of patients in the RFCA and CBA groups, respectively, were free from recurrence (log-rank test, P=0.0039). There was also a significant difference in favor of RFCA with respect to repeat ablations (3.3% vs. 24.3%, log-rank test, P=0.0003). Conclusions: RF ablation guided by an automated algorithm that includes CF and catheter stability parameters showed better long-term outcomes than CBA in the treatment of patients with PAF without increasing complications.

著者

Masato Okada Koji Tanaka Yasuharu Matsunaga-Lee Yuichi Ninomiya Yuko Hirao Takafumi Oka Nobuaki Tanaka Hiroyuki Inoue Katsuomi Iwakura Kenshi Fujii Koichi Inoue

出版者

International Heart Journal Association

雑誌

International Heart Journal (ISSN:13492365)

巻号頁・発行日

vol.60, no.3, pp.761-767, 2019-05-30 (Released:2019-05-30)

参考文献数

16

被引用文献数

1 2

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A 70-year-old woman was admitted for treatment of supraventricular tachycardia. Ventriculoatrial conduction was revealed through programmed ventricular stimulation; the coronary sinus ostium (CSos) was the earliest atrial activation site. The fast-slow forms of atrioventricular nodal reentrant tachycardia (AVNRT) were induced by ventricular extra-stimuli. During tachycardia, the earliest atrial activation site was located at the bottom of CSos. Radiofrequency (RF) energy application to this site resulted in the delay of local electrical potential, prolongation of tachycardia cycle length, and a shift of the earliest retrograde activation site to the roof of CSos. Subsequent ablation induced a similar shift to the inferior tricuspid annulus and to the right posterior septum. Finally, RF energy application to the right posterior septum resulted in the termination of tachycardia, which was not induced afterward. Multiple shifts in the earliest retrograde atrial activation site along the tricuspid annulus after each slow pathway ablation suggested that annular tissue plays a substantial role as a substrate for AVNRT.

著者

Masato Okada Akio Hirata Kazunori Kashiwase Hiroyuki Nakanishi Ryohei Amiya Yasunori Ueda Yoshiharu Higuchi Yasushi Sakata

出版者

International Heart Journal Association

雑誌

International Heart Journal (ISSN:13492365)

巻号頁・発行日

vol.60, no.6, pp.1334-1343, 2019-11-30 (Released:2019-11-30)

参考文献数

34

被引用文献数

1

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The aim of this study was to examine the impact of the serum eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio on recurrence after catheter ablation (CA) for atrial fibrillation (AF).A total of 192 patients who underwent first-time radiofrequency CA for AF were enrolled in this study. They were divided into two groups based on the median serum EPA/AA ratio before CA: a LOW group (< 0.30; n = 96) and a HIGH group (≥ 0.30; n = 96). Patients in the LOW group were younger and had smaller left atrial diameter (LAD) than those in the HIGH group. Although pulmonary vein triggers initiating AF were more frequently observed in the LOW group than the HIGH group (63% versus 46%, respectively; P = 0.021), no significant between-group difference was observed regarding the incidence of AF recurrence since the last procedure (17% versus 17%, P = 0.78; median follow-up, 37 months). Multivariate Cox regression analysis after adjustment for age and LAD revealed that EPA/AA of < 0.30 was not a significant predictor of AF recurrence (hazard ratio, 1.12; 95% confidence interval 0.53-2.37; P = 0.76). However, in the non-paroxysmal AF subgroup (n = 65), the incidence of AF recurrence was significantly higher in the LOW group than in the HIGH group (25.7% versus 6.7%, respectively; P = 0.031).In conclusion, a lower preprocedural EPA/AA ratio, which was associated with younger age and small left atrium, was not a predictor for the risk of AF recurrence after CA for AF. The potential impact of the ratio on recurrence in non-paroxysmal AF subgroups should be examined with larger samples.

著者

Masato Okada Kazunori Kashiwase Akio Hirata Mayu Nishio Yasuharu Takeda Takayoshi Nemoto Ryohei Amiya Yasunori Ueda Yoshiharu Higuchi Yoshio Yasumura

出版者

The Japanese Circulation Society

雑誌

Circulation Journal (ISSN:13469843)

巻号頁・発行日

vol.83, no.1, pp.56-66, 2018-12-25 (Released:2018-12-25)

参考文献数

31

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Background: Identifying who among current Japanese patients with prior myocardial infarction (MI) would benefit from an implantable cardioverter-defibrillator (ICD) is imperative. Accordingly, this study seeks to determine whether single-photon emission computed tomography (SPECT) can help identify such patients. Methods and Results: This retrospective study enrolled 60 consecutive patients with prior MI who underwent stress thallium-201 SPECT and ICD implantation from February 2000 to October 2014. Occurrence of arrhythmic death and/or or appropriate ICD therapy, defined as shock or antitachycardia pacing for ventricular fibrillation or tachycardia, was identified until November 2016. During the median follow-up interval of 6.6 years, 18 (30%) patients experienced arrhythmic death and/or appropriate ICD therapy. Multivariate Cox proportional hazard regression analysis revealed that the summed stress score (SSS) [hazard ratio (HR)=1.14; P=0.005] and left ventricular ejection fraction (LVEF) at rest (HR=0.92; P=0.038) were significantly associated with the occurrence of arrhythmic events. Patients with SSS ≥21 and LVEF ≤30%, which were determined to be the best cutoff points, had significantly higher incidence of the arrhythmic events than the other patients (64% vs. 11%; HR=7.18; log-rank P=0.001). Conclusions: SSS using stress thallium-201 SPECT in combination with LVEF can help determine the need for ICD therapy among current Japanese patients with prior MI.

著者

Masato Okada Kazunori Kashiwase Akio Hirata Yasuharu Takeda Ryohei Amiya Yasunori Ueda Yoshiharu Higuchi Yoshio Yasumura

出版者

International Heart Journal Association

雑誌

International Heart Journal (ISSN:13492365)

巻号頁・発行日

vol.59, no.6, pp.1275-1287, 2018-11-30 (Released:2018-11-28)

参考文献数

38

被引用文献数

2 2

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Right ventricular apical (RVA) pacing often causes left ventricular (LV) mechanical asynchrony, which is enhanced by impaired cardiac contraction and intrinsic conduction abnormality. However, data on patients with normal cardiac function and under RV non-apical (non-RVA) pacing are limited.We retrospectively investigated 97 consecutive patients with normal ejection fraction who received pacemaker implantation for atrioventricular block with the ventricular lead placed in a non-RVA position. We defined mechanical asynchrony as discoordinate contraction between opposing regions of the LV wall evaluated by echocardiography. Asynchrony was detected in 9 (9%) patients at baseline and in 38 (39%) under non-RVA pacing (P < 0.001). Asynchrony at baseline was significantly associated with complete left bundle branch block (CLBBB) [odds ratio (OR) = 20.8, P < 0.001]. Asynchrony under non-RVA pacing was significantly associated with left anterior fascicular block (LAFB) (OR = 7.14, P < 0.001) and CLBBB (OR = 13.3, P = 0.002) at baseline. New occurrence of asynchrony was significantly associated with LAFB at baseline (OR = 5.88, P = 0.001). During a median follow-up period of 4.8 years, the incidence of device-detected atrial fibrillation (AF) was more frequent in patients who developed asynchrony than in those who did not (53.3% versus 27.5%, hazard ratio = 2.17, 95% confidence interval = 1.02-4.61, P = 0.03).In patients with normal cardiac function, LAFB at baseline was significantly associated with new occurrence of mechanical asynchrony under non-RVA pacing. Abnormal contraction had a significant influence on the incidence of device-detected AF.

著者

Masato Okada Kazunori Kashiwase Akio Hirata Takayoshi Nemoto Koshi Matsuo Ayaka Murakami Yasunori Ueda

出版者

The Japanese Circulation Society

雑誌

Circulation Journal (ISSN:13469843)

巻号頁・発行日

vol.79, no.8, pp.1712-1718, 2015-07-24 (Released:2015-07-24)

参考文献数

25

被引用文献数

3 7

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Background:Bacterial cultures of cardiovascular implantable electronic devices removed from patients without clinical infection are often positive, and the cultured bacteria are different from those at the time of clinical infection. This discrepancy has not been adequately explained. We hypothesized that the cause is bacterial contamination at operation and compared the results of bacterial cultures between patients with de novo pacemaker implantation and those with pacemaker replacement.Methods and Results:We prospectively enrolled consecutive 100 patients who underwent cardiac pacemaker implantation (49 de novo implantations, 51 replacements). We took swab cultures from inside the generator pocket (1) immediately after the creation of new pocket or removal of old generator, (2) after connection of leads to new generator, and (3) after pocket lavage. Swab cultures were positive in 272 (45%) of 600 samples. The majority of the cultured bacteria werePropionibacteriumspecies. No statistical difference was detected between de novo implantations and replacements in the positive ratio of swab cultures. The positive ratio was not correlated with the number of previous device replacements.Conclusions:The positive ratio of swab cultures was not different between new implantations and replacements, suggesting that a positive culture merely indicates contamination of bacteria during operation rather than colonization. (Circ J 2015; 79: 1712–1718)

著者

Nobuaki Tanaka Koichi Inoue Koji Tanaka Yuko Toyoshima Takafumi Oka Masato Okada Hiroyuki Inoue Ryo Nakamaru Yasushi Koyama Atsunori Okamura Katsuomi Iwakura Yasushi Sakata Kenshi Fujii

出版者

The Japanese Circulation Society

雑誌

Circulation Journal (ISSN:13469843)

巻号頁・発行日

vol.81, no.11, pp.1596-1602, 2017-10-25 (Released:2017-10-25)

参考文献数

21

被引用文献数

2 24

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Background:Durable pulmonary vein isolation (PVI) is critical in reducing recurrence after radiofrequency catheter ablation for atrial fibrillation (AF). The VISITAG Module, an automatic annotation system that takes account of catheter stability and contact force (CF), might be useful in accomplishing this.Methods and Results:In 49 patients undergoing VISITAG-guided AF ablation (group A), we set the following automatic annotation criteria: catheter stability range of motion ≤1.5 mm, duration ≥5 s, CF ≥5 g, time ≥25% and tag diameter at 6 mm. We used ablation >20 s and force-time integral >150 gs at each site, then moved to the next site where a new tag appeared that overlapped with the former tag. Results and outcome were retrospectively compared for 42 consecutive patients undergoing CF-guided AF ablation without this algorithm (group B). Successful PVI at completion of the initial anatomical line was more frequent in group A than B (66.3% vs. 36.9%, P=0.0006) while spontaneous PV reconnection was less frequent (14.2% vs. 30.9%, P=0.0014) and procedure time was shorter (138±35 min vs. 180±44 min, P<0.001). One-year success rate off anti-arrhythmic drugs was higher in group A (91.8% vs. 69.1%, log rank P=0.0058).Conclusions:An automated annotation algorithm with an optimal setting reduced acute resumption of left atrium-PV conduction, shortened procedure time, and improved AF ablation outcome.

著者

Tatsu KUWATANI Kenji NAGATA Kenta YOSHIDA Masato OKADA Mitsuhiro TORIUMI

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

pp.170923, (Released:2018-04-19)

被引用文献数

5

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Geothermometry and geobarometry are used to study the equilibration of mineral inclusions and their zoned host minerals, which provide information on the P–T conditions of inclusions at the time of their entrapment. However, reconstructing detailed P–T paths remains difficult, owing to the sparsity of inclusions suitable for geothermometry and geobarometry. We developed a stochastic inversion method for reconstructing precise P–T paths from chemically zoned structures and inclusions using the Markov random field (MRF) model, a type of Bayesian stochastic method often used in image restoration. As baseline information for P–T path inversion, we introduce the concepts of pressure and temperature continuity during mineral growth into the MRF model. To evaluate the proposed model, it was applied to a P–T inversion problem using the garnet–biotite geothermometer and the garnet–Al2SiO5–plagioclase–quartz geobarometer for mineral compositions from published datasets of host garnets and mineral inclusions in pelitic schist. Our method successfully reconstructed the P–T path, even after removing a large part of the inclusion dataset. In addition, we found that by using a probability distribution of the most probable P–T path, rather than a single solution, an objective discussion of the validity of the thermodynamic analysis is possible.

著者

Jun Kitazono Toshiaki Omori Toru Aonishi Masato Okada

出版者

一般社団法人 情報処理学会

雑誌

IPSJ Online Transactions (ISSN:18826660)

巻号頁・発行日

vol.5, pp.186-191, 2012 (Released:2012-10-03)

参考文献数

22

被引用文献数

1 3

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With developments in optical imaging over the past decade, statistical methods for estimating dendritic membrane resistance from observed noisy signals have been proposed. In most of previous studies, membrane resistance over a dendritic tree was assumed to be constant, or membrane resistance at a point rather than that over a dendrite was investigated. Membrane resistance, however, is actually not constant over a dendrite. In a previous study, a method was proposed in which membrane resistance value is expressed as a non-constant function of position on dendrite, and parameters of the function are estimated. Although this method is effective, it is applicable only when the appropriate function is known. We propose a statistical method, which does not express membrane resistance as a function of position on dendrite, for estimating membrane resistance over a dendrite from observed membrane potentials. We use the Markov random field (MRF) as a prior distribution of the membrane resistance. In the MRF, membrane resistance is not expressed as a function of position on dendrite, but is assumed to be smoothly varying along a dendrite. We apply our method to synthetic data to evaluate its efficacy, and show that even when we do not know the appropriate function, our method can accurately estimate the membrane resistance.