Ikutaro Nakajima

St. Marianna University School of Medicine

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Takashi Noda

Tohoku University Hospital

Hideo Okamura

Kobe University

Shiro Kamakura

National Cerebral and Cardiovascular Center

Wataru Shimizu

Nippon Medical School

Koji Miyamoto

National Cerebral and Cardiovascular Center

Takeshi Aiba

National Cerebral and Cardiovascular Center

Kazuhiro Satomi

Tokyo Medical University Hospital

Kohei Ishibashi

National Cerebral and Cardiovascular Center

Kengo Kusano

National Cerebral and Cardiovascular Center

Satoshi Yasuda

Tohoku University

Cooperative Institutions

National Cerebral and Cardiovascular Center

187

American Heart Association

118

Osaka University

107

The University of Tokyo

100

Kyoto University

Japanese Circulation Society

Itron (United States)

Bioengineering Center

Kobe University

National Cancer Registry

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Larger low voltage zone in endocardial unipolar map compared with that in epicardial bipolar map indicates difficulty in eliminating ventricular tachycardia by catheter ablation

Heart and Vessels (2015)

Koji Miyamoto Takashi Noda Kazuhiro Satomi Mitsuru Wada Ikutaro Nakajima

Ischemic Cardiomyopathy

Endocardium

Dilated Cardiomyopathy

10.1007/s00380-015-0732-7

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Significance of Non-Type 1 Anterior Early Repolarization in Patients With Inferolateral Early Repolarization Syndrome

Journal of the American College of Cardiology (2013)

Tsukasa Kamakura Hiro Kawata Ikutaro Nakajima Yuko Yamada Koji Miyamoto

Benign early repolarization

J wave

10.1016/j.jacc.2013.05.081

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Citations (49)

The precordial R-prime wave: a novel discriminator between cardiac sarcoidosis and arrhythmogenic right ventricular cardiomyopathy in patients presenting with ventricular tachycardia

EP Europace (2021)

Jarieke C. Hoogendoorn Jeroen Venlet Sumche Man Saurabh Kumar Marek Šramko

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): The department of cardiology from Leiden University Medical Center receives unrestricted grants from Edwards Lifesciences, Biotronik, Medtronik, Boston Scientific and BioSense Webster. MS was supported by the Research Fellowship of the European Society of Cardiology 2017/2018. Background Cardiac sarcoidosis (CS) with right ventricular (RV) involvement may mimic ARVC. Histopathological differences may result in disease specific RV activation patterns, detectable on the 12-lead electrocardiogram (ECG). Scar in ARVC progresses from epicardium to endocardium and may lead to delayed activation of areas with reduced voltages, translating into terminal activation delay and occasionally an (epsilon) wave with small amplitude on the ECG. On the contrary, patchy transmural RV scar in CS may lead to conduction block, and therefore late activated areas with preserved voltages, reflected as preserved R’-waves in the right precordial leads. Purpose To determine whether the terminal activation patterns in precordial leads V1-V3 distinguish CS with RV involvement from ARVC. Methods This is a multicenter retrospective study including patients with either 1) CS with RV involvement or 2) gene-positive ARVC referred for VT ablation. A non-ventricular paced 12-lead surface ECG prior to ablation was obtained (25mm/s and 10mm/mV). For detailed analysis, Leiden ECG Analysis and Decomposition Software (LEADS) was used. After detection of QRST complexes in the spatial velocity signal, LEADS generates a representative and low-noise averaged beat. Then, measurements per lead were performed using the measurement tool in Adobe Pro DC. Based on the hypothesis that conduction block in CS will lead to late activated areas with preserved voltages, we measured the surface area (SA) of the R’-wave in V1-V3. An R’-wave was defined as any positive deflection from baseline after an S-wave. Results 13 CS patients with RV involvement (54 ± 8years, 62% male) and 23 ARVC patients (37 ± 15years, 78% male) were included. A R’-wave in V1-V3 was present in all CS patients, compared to 11 (48%) of ARVC patients (p = 0.002). The maximum R’-wave SA in lead V1-V3 was 3.55 (IQR:2.18-5.81) mm2 in CS vs. 0.00 (IQR:0.00-0.43) mm2 in ARVC (p < 0.001; Figure A). By ROC-analysis, the maximum R’-wave SA in lead V1-V3 was an excellent discriminator (area under the curve 0.980 [95%CI: 0.945-1.000]). A cutoff of ≥1.65mm2 had a sensitivity of 85% and specificity of 96% for diagnosing CS. An algorithm was created including the presence of an R’-wave in V1-V3 and the SA of this R’-wave (Figure B). This was validated in a second cohort (18 CS and 40 ARVC) with 72% sensitivity and 88% specificity. Conclusion Transmural RV scars in CS may cause localized conduction block, leading to late activated areas with preserved voltages, reflected as large R’-wave on the 12-lead surface ECG. An easily applicable algorithm including the surface area of the largest R’-wave in lead V1-V3 ≥1.65mm2 distinguishes CS from ARVC with good sensitivity and specificity. The QRS terminal activation in precordial leads V1-V2 may reflect disease specific scar patterns (for examples: Figure C). Abstract Figure

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10.1093/europace/euab116.016

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A Predictor of Recurrence after the 2nd Standard Circumferential PV Isolation in Patients with Paroxysmal Atrial Fibrillation

Japanese Journal of Electrocardiology (2015)

Hiroshi Kawakami Kazuhiro Satomi Kohei Ishibashi Ikutaro Nakajima Koji Miyamoto

発作性心房細動（PAF）に対する肺静脈隔離術（PVI）の有用性は確立されている．しかし，複数回のPVIを行ったにもかかわらず，再発をきたす症例は存在する．今回われわれは，当施設でPAFに対し2度目のカテーテルアブレーション（セカンドセッション）を行った連続61例を対象に，その患者背景，最終アブレーション成績，再発因子を後ろ向きに検討した．セカンドセッション後1年間で，61例のうち，21例に再発（AF 12例，心房頻拍9例）を認めた．再発群（n＝21）と非再発群（n＝40）の間に，年齢・性別・AF罹患期間・CHADS2スコア・心房径などの患者背景に差は認めなかった．しかし，セカンドセッション時にPV再伝導を認めた割合は，非再発群で有意に多かった（非再発群：39/40；97.5％ vs. 再発群：17/21；80.9％, p＝0.025）．また，両群間でNon-PV fociの合併率には差はなかったが（再発群：14/21；66.7％vs. 非再発群：17/40；42.5％, p＝0.073），Non-PV fociの起源を特定し，最終的に消失し得た割合は非再発群に有意に多かった（再発群：7/14；50％ vs. 非再発群：15/17；88％, p＝0.019）．結論として，Non-PV fociの存在はAFアブレーションの成績に大きく関与しており，可能な限りその起源を特定し，消失を目指すことが重要であることが示された．

Paroxysmal atrial fibrillation

10.5105/jse.35.15

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Abstract 15888: Noninvasive Evaluation of Arrhythmic Substrate in the Brugada Syndrome using High Resolution Magnetocardiography

Circulation (2012)

Takeshi Aiba Teruki Yokoyama Shiro Kamakura Hiroshi Takaki Ikutaro Nakajima

Conduction abnormalities in the right ventricular outflow tract (RVOT) are likely to be an electrophysiological substrate of ventricular fibrillation (VF) in patients with the Brugada syndrome (BrS). We hypothesized high spatio-temporal resolution magnetocardiography (MCG) noninvasively evaluated the substrate of VT/VF in the BrS. Methods: 64-channel MCG and 12-lead ECG were simultaneously recorded in 90 patients with BrS (45 spontaneous type-1 Brugada-ECG, 3 resuscitated from VF, 17 with syncope, and 70 asymptomatic) and 20 control subjects. We analyzed 2-D current map under baseline and after administration of pilsicainide. Results : Patients with type-1 BrS-ECG had longer QRS duration (108±20 vs. 101±10 ms; p 50ms) but rare in those without delay (83% vs. 16%; p SCN5A was performed in 23 BrS patients and 6 (26%) of them are positive ( SCN5A + ). QRS duration was longer in SCN5A + patients than in SCN5A - patients, but no difference was observed in RVOT conduction time, maximum current at QRS-end between with and without SCN5A mutation. Conclusion : MCG could noninvasively demonstrate the substrate of VF, which may help us to stratify the risk of sudden arrhythmic death in the Brugada syndrome.

Magnetocardiography

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The precordial R′ wave: A novel discriminator between cardiac sarcoidosis and arrhythmogenic right ventricular cardiomyopathy in patients presenting with ventricular tachycardia

Heart Rhythm (2021)

Jarieke C. Hoogendoorn Jeroen Venlet Yannick N.J. Out Sumche Man Saurabh Kumar

Cardiac sarcoidosis (CS) with right ventricular (RV) involvement can mimic arrhythmogenic right ventricular cardiomyopathy (ARVC). Histopathological differences may result in disease-specific RV activation patterns detectable on the 12-lead electrocardiogram. Dominant subepicardial scar in ARVC leads to delayed activation of areas with reduced voltages, translating into terminal activation delay and occasionally (epsilon) waves with a small amplitude. Conversely, patchy transmural RV scar in CS may lead to conduction block and therefore late activated areas with preserved voltages reflected as preserved R' waves.The purpose of this study was to evaluate the distinct terminal activation patterns in precordial leads V1 through V3 as a discriminator between CS and ARVC.Thirteen patients with CS affecting the RV and 23 patients with gene-positive ARVC referred for ventricular tachycardia ablation were retrospectively included in a multicenter approach. A non-ventricular-paced 12-lead surface electrocardiogram was analyzed for the presence and the surface area of the R' wave (any positive deflection from baseline after an S wave) in leads V1 through V3.An R' wave in leads V1 through V3 was present in all patients with CS compared to 11 (48%) patients with ARVC (P = .002). An algorithm including a PR interval of ≥220 ms, the presence of an R' wave, and the surface area of the maximum R' wave in leads V1 through V3 of ≥1.65 mm2 had 85% sensitivity and 96% specificity for diagnosing CS, validated in a second cohort (18 CS and 40 ARVC) with 83% sensitivity and 88% specificity.An easily applicable algorithm including PR prolongation and the surface area of the maximum R' wave in leads V1 through V3 of ≥1.65 mm2 distinguishes CS from ARVC. This QRS terminal activation in precordial leads V1 through V3 may reflect disease-specific scar patterns.

Precordial examination

10.1016/j.hrthm.2021.04.032

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Citations (16)

Device Therapy for Ventricular Arrhythmias in Patients with Ischemic Heart Disease

Japanese Journal of Electrocardiology (2014)

Ikutaro Nakajima Takashi Noda Kohei Ishibashi Yuko Yamada Koji Miyamoto

欧米を中心に行われた虚血性心疾患を主とする大規模臨床試験では,植込み型除細動器(ICD)が収縮不全心において高い突然死予防効果を示すことが明らかにされている.また,心臓再同期療法(CRT)は慢性心不全患者の症状・生命予後を改善する有効な治療であるが,虚血性心筋症(ICM)患者では非虚血性に比して効果が限局的との報告もある.CRTのICM患者への有効な反応が得られれば,それに付随して抗不整脈作用も期待されるが,ICM患者における致死性不整脈予防効果には一定した見解がない.そこで,ICM患者に対するICDおよびCRTの選択という観点で,両者の位置付けを再考すべく,自施設での症例を対象に症例背景や予後の検討を行った.後ろ向きに検討したところ,左室駆出率が同等という条件下では,心不全がより軽症例・QRS幅の狭い例・突然死2次予防を目的とする例で,CRTよりもICDが選択されていた.平均観察期間871日間で,両群間に生存率や心不全回避率に差を認めなかった.致死性不整脈の発生に関しては,2次予防目的で植込みを行った患者では差が認められなかったが,1次予防目的に限定すると,CRT群で有意に低率であった.ICM患者の約半数でCRTへの有効な反応を示したが,慢性腎臓病,永続性心房細動,非左脚ブロック症例では,あまり効果がみられなかった.したがって,一定の条件を満たせば,ICMにおいてもCRTは有効であり,心不全に対する効果と同様に抗不整脈作用も期待される.

10.5105/jse.34.137

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Diagnostic Value of Right Ventricular Dysfunction in Tachycardia-Induced Cardiomyopathy Using Cardiac Magnetic Resonance Imaging

Circulation Journal (2016)

Atsushi Okada Ikutaro Nakajima Yoshiaki Morita Yuko Inoue Tsukasa Kamakura

Background:Predicting tachycardia-induced cardiomyopathy (TIC) in patients presenting with left ventricular (LV) dysfunction and tachyarrhythmias remains challenging. We assessed the diagnostic value of early right ventricular (RV) dysfunction to predict TIC using cardiac magnetic resonance (CMR) imaging.

Dilated Cardiomyopathy

10.1253/circj.cj-16-0532

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Comparative study of CO2 Laser scalpel with electroscalpel

Nippon Laser Igakkaishi (1980)

Ryuzaburo Tanino Mikio Nishimura M. Miyasaka H. Yamaguchi Ikutaro Nakajima

The most useful advantage of CO2 Laser scalpel is its hemostatic effect which may enable the dry field operation, therefore, comparison with electroscalpel is quite interesting, while their adverse effect of thermal damage against surrounding tissues cannot be ignored.We performed the comparative study of thermal damage of rat liver minovasculature after cutting with these two instruments by means of total replacement of blood with India ink.

10.2530/jslsm1980.1.1_517

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Acoustic emission during advance boring associated with the prevention of coal and gas outbursts

Ikutaro Nakajima Yuichiro Watanabe Tetsu FUKAI

In this research, the fracturing activity in coal seam during advance boring was observed by applying the acoustic emission technique in order to ascertain its preventive effect for coal and gas outbursts. In the test sites, two transducers were installed at some distance along prearranged boreholes. The detected signals associated with coal fractures were separated from drilling noises, and presented for the analyses on the parameters of acoustic emission activities and their one-dimensional source locations. Consequently, it was confirmed that these observational results offered the sufficient informations to estimate the effect of relaxation to coal seam by the boring and to determine the location of a local stress concentration.

Acoustic Emission

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