Papers - Takatsuki, Seiji

Preserved effects of potassium channel blockers in the pacing-induced remodeled canine atrium

Shiroshita-Takeshita Akiko, Mitamura Hideo, Sato Toshiaki, Shinagawa Kaori, Kurita Yasuo, Kanki Hideaki, Takatsuki Seiji, Hara Motoki, Ogawa Satoshi

Journal of Cardiovascular Pharmacology 41 ( 5 ) 678 - 685 2003.05

ISSN  0160-2446

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<p>This study was designed to evaluate the electrophysiologic effects of E4031 (a pure IKr blocker) and azimilide (AZ: a combined 1kr + IKs blocker) at various stages of atrial electrical remodeling. Twelve dogs underwent continuous rapid atrial pacing (400/min) for 14 days. The electrophysiologic study was performed on the day before as well as after 2, 7, and 14 days of rapid atrial pacing both before and after the administration of either E4031 (n = 6) or AZ (n = 6). In response to rapid atrial pacing, the atrial effective refractory period (ERP), conduction velocity, and wavelength decreased significantly at pacing cycle lengths (PCLs) of 200 and 400 ms (P &lt; 0.05). E4031 prolonged ERP in a reverse use-dependent manner throughout the study period. AZ also prolonged ERP during the 14 days of rapid pacing. ERP prolongation at a PCL of 200 ms was significantly greater with AZ than with E4031 (P &lt; 0.05). The effects of blocking IKr by E4031 and IKr + IKs by AZ were well preserved at various stages of atrial electrical remodeling. However, the effect of prolonging ERP at a shorter PCL was more prominent by AZ than by E4031. Thus, IKs blockade may add a favorable anti-fibrillatory effect to IKr blockade even in the remodeled atrium.</p>

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Mechanisms of ventricular arrhythmias in myocardial infarction

Takatsuki Seiji

Nippon rinsho. Japanese journal of clinical medicine 61 Suppl 5   365 - 370 2003

ISSN  0047-1852

心室頻拍

Takatsuki Seiji, Mitamura Hideo

循環器科 52 ( 2 ) 109-116 2002.08

Research paper (scientific journal), Joint Work

RR間隔およびQRS波形が一拍ごとに交代する頻拍症

Takatsuki Seiji, Mitamura Hideo

心電図 22 ( 3 ) 191-196 2002.05

Research paper (scientific journal), Joint Work

Discordant temporal changes in electrophysiological properties during electrical remodeling and its recovery in the canine atrium

Shiroshita-Takeshita Akiko, Mitamura Hideo, Shinagawa Kaori, Sato Toshiaki, Kurita Yasuo, Kanki Hideaki, Takatsuki Seiji, Hara Motoki, Ogawa Satoshi

Japanese Heart Journal 43 ( 2 ) 167-181 2002.03

Research paper (scientific journal), Joint Work

慢性不全例における心房細動合併の臨床的要因

Kurita Yasuo，Mitamura Hideo，Kanki Hideaki，Baba Akiyasu，Takeshita Akiko，Satou Toshiaki，Shinagawa Kaori，Hara Motoki，Takatsuki Seiji，Yoshikawa Tsutomu，Ogawa Satoshi

心臓 34 ( 1 ) 25-30 2002.01

Research paper (scientific journal), Joint Work

Discordant temporal changes in electrophysiological properties during electrical remodeling and its recovery in the canine atrium

Shiroshita-Takeshita Akiko, Mitamura Hideo, Shinagawa Kaori, Sato Toshiaki, Kurita Yasuo, Kanki Hideaki, Takatsuki Seiji, Hara Motoki, Ogawa Satoshi

Japanese Heart Journal 43 ( 2 ) 167 - 181 2002

ISSN  0021-4868

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<p>Prolonged rapid atrial excitation gives rise to atrial electrical remodeling, which perpetuates atrial fibrillation (AF). However, there has been controversy regarding the nature of temporal changes in conduction characteristics during the development and recovery of electrical remodeling. This study was designed to clarify the nature of the development and recovery of electrical remodeling in relation to AF inducibility in dogs subjected to rapid atrial pacing. Eleven dogs underwent rapid atrial pacing (400/min) for 28 days. The electrophysiological study was performed on the day just prior to the commencement of pacing, on days 2, 7, 14, and 28 of rapid pacing, as well as 1 and 7 days after the cessation of pacing. In response to rapid atrial pacing, atrial effective refractory period (ERP), conduction velocity and wavelength decreased significantly (p&lt;0.05). ERP had shortened significantly and rapidly within 2 days of pacing, while conduction velocity decreased more gradually. During the recovery, ERP returned to almost baseline levels within a day, whereas conduction velocity returned to baseline by day 7. Sustained AF became inducible in 37% of the dogs from 7 days of pacing until 1 day after the cessation, when wavelength fell below 8.7 cm. In conclusion, rapid atrial excitation causes a progressive but discordant temporal pattern of a decrease in ERP and conduction velocity. The resultant shortening of the wavelength determines the inducibility and maintenance of AF. The electrophysiological changes produced by one month of rapid atrial pacing can be fully reversed within a week, although in a discordant temporal pattern. Copyright © 2002 by the Japanese Heart Journal.</p>

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Daily oral verapamil before but not after rapid atrial excitation prevents electrical remodeling

Kurita Y, Mitamura H, Shiroshita-Takeshita A, Yamane A, Ieda M, Kinebuchi O, Sato T, Miyoshi S, Hara M, Takatsuki S, Ogawa S

Cardiovascular research 54   447-455 2002

Research paper (scientific journal), Joint Work

Discordant Temporal Changes in Electrophysiological Properties during Electrical Remodeling and Its Recovery in the Canine Atrium

Shiroshita-Takeshita A, Mitamura H, Shinagawa K, Sato T, Kurita Y, Kanki H, Takatsuki S, Hara M, Ogawa S

Japanese Heart Journal 43 ( 2 ) 167-181 2002

Research paper (scientific journal), Joint Work

心房高頻度刺激による心房筋の電気的および機械的リモデリングの形成過程

Kinnebuchi Osamu, Mitamura Hideo, Takeshita Akiko, Kurita Yasuo, Oohashi Narutaka, Tanimoto Kojirou, Fukuda Yukiko, Ieda Masaki, Satou Toshiaki, Miyoshi Shunichirou, Takatsuki Seiji, Hara Motoki, Nagumo Miyako, Ogawa Satoshi

不整脈 18   481-489 2002

Research paper (scientific journal), Joint Work

副伝導路を遮断せずに心房細動を抑制できるか：WPW症候群のアブレーションにおける薬物併用療法

Fukuda Yukiko, Takatsuki Seiji, Mitamura Hideo, Tanimoto Koujirou, Oohashi Narutaka, Kinebuchi Osamu, Ida Masaki, Kurita Yasuo, Miyoshishunichirou, Hara Motoki, Ogawa Satoshi

Progress in medicine 22   2531-2535 2002

Research paper (scientific journal), Joint Work

CS musculatureと副伝導路の結合が推測された不顕性WPW症候群の1例

Takatsuki Seiji，Mitamura Hideo，Tanimoto Koujirou，Fukuda Yukiko，Oohashi Narutaka，Ieda Masaki，Kinebuchi Osamu，Kurita Yasuo，Miyoshi Shunichirou，Hara Motoki，Ogawa Satoshi

臨床心臓電気生理 25 ( 5 ) 139-146 2002

Research paper (scientific journal), Joint Work

ICD植込み患者でPVC後の抗徐拍ペーシングにより誘発された心室細動

Tanimoto Koujirou, Mitamura Hideo, Takatsuki Seiji, Oohashi Narutaka, Fukuda Yukiko, Kinebuchi Osamu, Ieda Masaki, Kurita Yasuo, Miyoshishunichirou, Hara Motoki, Ogawa Satoshi

心臓 34 ( suppl.4 ) 166-171 2002

Research paper (scientific journal), Joint Work

Daily oral verapamil before but not after rapid atrial excitation prevents electrical remodeling

Kurita Yasuo, Mitamura Hideo, Shiroshita-Takeshita Akiko, Yamane Akiko, Ieda Masaki, Kinebuchi Osamu, Sato Toshiaki, Miyoshi Shunichiro, Hara Motoki, Takatsuki Seiji, Ogawa Satoshi

Cardiovascular Research 54 ( 2 ) 447 - 455 2002

ISSN  0008-6363

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<p>Background: Intravenous verapamil has been reported to prevent electrical remodeling induced by rapid atrial excitation of several minutes to several hours. However, the clinical efficacy of verapamil when taken orally and daily remains controversial. Purpose: We attempted to demonstrate our hypothesis that if verapamil prevents calcium (Ca) overload, its efficacy would be greater when taken before, rather than after, the onset of rapid atrial excitation. Methods: In 24 dogs, pacing and recording electrodes were sutured onto the right atrium. After a 5-day recovery period, rapid atrial pacing at 400 ppm was started, followed 2 days later by oral verapamil (8 mg/kg per day) in eight dogs (After group; A). In another eight dogs, oral verapamil administration was begun 1 week before the initiation of rapid pacing (Before group; B). In the remaining eight dogs, only rapid atrial pacing was started, without oral verapamil (Control group; C). We measured the effective refractory period (ERP) and conduction velocity (CV), and calculated wavelength (WL) at cycle lengths 200 and 300 ms on the day before (P0), and after 2 (P2), 7 (P7), 14(P14) days of rapid pacing. Results: In response to rapid atrial pacing, ERP, CV, WL decreased and progressively and comparably in A and C (P&lt;0.05 vs. P0). In contrast, in B, these parameters did not change significantly and remained greater than those in A and C (P&lt;0.05). Moreover, the adaptation of ERP to rate was preserved only in B. The duration of atrial fibrillation (AF) was shorter in B than in A and C (P&lt;0.05). The inducibility of AF tended to be lower, and the fibrillation cycle length was longer in B than in A and C. Conclusions: Oral verapamil started before but not after rapid atrial excitation prevents electrical remodeling. Verapamil may exert beneficial effects when it is taken during sinus rhythm, but not after more than 2 days of atrial tachyarrhythmia. © 2002 Elsevier Science B.V. All rights reserved.</p>

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同一症例連続72回の心房細動発作の出現様式とNaチャネル遮断薬頓服による停止様式の解析

Fukuda Yukiko，Mitamura Hideo，Takatsuki Seiji，Oohashi Narutaka，Kinebuchi Osamu，Ieda Masaki，Kurita Yasuo，Ogawa Satoshi

心臓 33 ( suppl 5 ) 18-23 2001.12

Research paper (scientific journal), Joint Work

心房細動持続時間の電気的除細動後ポーズ長に与える影響

Yamane Akiko，Mitamura Hideo，Kanki Hideaki，Satou Toshiaki，Kurita Yasuo，Takeshita Akiko，Takatsuki Seiji，Ogawa Satoshi

不整脈 17 ( 5 ) 551-555 2001.12

Research paper (scientific journal), Joint Work

高度房室ブロックと非持続性心室頻拍を認める運動時失神例

Kurita Yasuo，Mitamura Hideo，Takatsuki Seiji，Iwata Michikado，Hayashida Kentarou，Oohashi Narutaka，Fukuda Yukiko，Ieda Masaki，Kinebuchi Osamu，Miyoshi Shunichirou，Hara Motoki，Ogawa Satoshi

心臓 33 ( suppl 3 ) 19-23 2001.11

Research paper (scientific journal), Joint Work

Respiratory cycle-dependent left atrial tachycardia

Takatsuki Seiji, Mitamura Hideo, Miyoshi Shunichiro, Ogawa Satoshi

Journal of Cardiovascular Electrophysiology 12 ( 10 ) 1202-1202 2001.10

Research paper (scientific journal), Joint Work

植込み型除細動器誤作動の予知：過剰感知の原因解析

Kurita Yasuo，Mitamura Hideo，Takatsuki Seiji，Ieda Masaki，Kinebuchi Osamu，Takeshita Akiko，Miyoshi Shunichirou，Hara Motoki，Ogawa Satoshi，Mitsumaru Atsuhiro，Shin Hankei，Kawada Shiaki

不整脈 17 ( 4 ) 483-489 2001.10

Research paper (scientific journal), Joint Work

Accessory pathway associated with an anomalous coronary vein in a patient with Wolff-Parkinson-White syndrome

Takatsuki Seiji, Mitamura Hideo, Ieda Masaki, Ogawa Satoshi

Journal of Cardiovascular Electrophysiology 12 ( 9 ) 1080-1082 2001.09

Research paper (scientific journal), Joint Work