Journal of Arrhythmia
Online ISSN : 1883-2148
Print ISSN : 1880-4276
Volume 25, Issue 1
Displaying 1-8 of 8 articles from this issue
Editorial
Review Article
  • Yuji Nakazato
    2009 Volume 25 Issue 1 Pages 4-9
    Published: January 25, 2009
    Released on J-STAGE: June 01, 2009
    JOURNAL FREE ACCESS
    Bepridil hydrochloride is a multiple ion channel blocker with relatively strong suppressive effects for various K+ channels. Recent clinical studies mainly done in Japan have revealed the efficacy of the agent for the management of atrial fibrillation (AF). The pharmacological conversion effect for persistent AF seems particularly promising. The agent also has robust effects in maintaining sinus rhythm after pharmacological or electrical conversion, as well as suppressing recurrent attacks of paroxysmal AF. Though torsades de pointes may develop due to QT prolongation, an appropriate dosage and careful follow-up can prevent this serious complication. Now that the antiarrhythmic efficacy of bepridil for AF is recognized in Japan, the agent is poised to resurface on the world stage as a treatment for AF.
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Original Articles
  • Seiji Takashio, Toshihiro Honda, Junjiro Koyama, Yukinari Odagawa, Koi ...
    2009 Volume 25 Issue 1 Pages 10-15
    Published: January 25, 2009
    Released on J-STAGE: June 01, 2009
    JOURNAL FREE ACCESS
    Background: Brugada syndrome is a disease in which idiopathic ventricular fibrillation (VF) sometimes occurs and causes sudden death. However, the clinical characteristics are still not fully understood.
    Patients and Methods: Five patients with Brugada syndrome, and with spontaneous VF documented by electrocardiograms (ECGs), were included in this study. We examined their clinical and electrocardiographic characteristics.
    Results: The mean age at the first VF/syncope episode was 54.4±11.4 years. The mean follow-up duration of the study was 114.8±35.9 months. In 4 patients, typical coved-type ST-elevation with a circadian change in >1 right precordial lead (V1 to V3) was observed, and in the remaining patient it developed only after a pilsicainide test. VF was initiated by ventricular premature contractions (VPCs), which were almost identical to the preceding VPCs. While the isolated VPCs rarely occurred before VF in the patients whose late potentials were positive, in the patient whose late potential was negative, there were frequent episodes of VPCs before VF.
    Conclusion: In this study, we presented variable clinical and electrocardiographic characteristics of the patients. The differences might suggest that several mechanisms are involved in the onset of VF in Brugada syndrome.
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  • Abula Abulaiti, Yoshinari Goseki, Hiroshi Arata, Michihiko Morisaki, Y ...
    2009 Volume 25 Issue 1 Pages 16-23
    Published: January 25, 2009
    Released on J-STAGE: June 01, 2009
    JOURNAL FREE ACCESS
    Introduction: Right bundle branch block (RBBB) pattern is sometimes observed in right ventricular (RV) endocardial pacing. However, the true mechanism and the clinical meaning of this phenomenon are still unknown.
    Methods and results: Out of 218 consecutive patients with RV apex endocardial pacing, we studied 30 cases with RBBB pattern and 111 cases with left bundle branch block (LBBB) pattern. No significant differences were found between these 2 groups in age, sex, and pacing mode. However, the percentage of cardiomyopathy patients in the RBBB pattern group was significantly higher than in the LBBB pattern group (36.7% versus 1.8%, p<0.0001). The left ventricular diastolic dimension (52.2±9.3 mm versus 48.0±5.5 mm, p=0.05) was bigger and left ventricular ejection fraction (56.2±14.7% versus 66.4±11.6%, p=0.0003) was lower in the RBBB pattern group. In RBBB pattern group, 11 out of 13 patients with low cardiac function (ejection fraction <50%) showed a wide QRS duration greater than 160 ms in V1 and II leads.
    Conclusions: RBBB pattern, especially QRS duration wider than 160 ms in V1 and II leads, during RV endocardial pacing may represent left ventricular enlargement and dysfunction. These findings would help assess the cardiac function based on surface 12-lead electrocardiography even in RV pacing.
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  • Takeshi Yamaguchi, Shuang-Qin Yi, Shigenori Tanaka, Katsushige Ono, Ta ...
    2009 Volume 25 Issue 1 Pages 24-31
    Published: January 25, 2009
    Released on J-STAGE: June 01, 2009
    JOURNAL FREE ACCESS
    Recently, the Bachmann’s bundle (BB) has been examined in connection with atrial fibrillation. However, the morphological properties of the BB remain to be clarified.
    In this study, the BB in hearts of monkeys and sheep was investigated by immuno-histochemistry, scanning (SEM) and transmission (TEM) electron microscopy.
    Immuno-histochemically, BB myocytes showed a strong positive reaction for desmin antibody and that connexin (Cx) 40 and Cx43 were distributed at the intercalated disks. BB myocytes were characterized by a dense network of intermediate filaments which enveloped nucleus, myofibrils and mitochondria, respectively. The intercalated disks showed an irregular stair-like profile. Microprojections on the steps were smaller in number and larger in size than those in auricular myocytes.
    In conclusion, BB myocytes were different ultrastructurally from auricular myocytes, showing morphological properties of the conduction system.
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Case Reports
  • Takekuni Hayashi, Haruo Mitani, Kosaku Goto, Rieko Ishimura, Susumu Ta ...
    2009 Volume 25 Issue 1 Pages 32-35
    Published: January 25, 2009
    Released on J-STAGE: June 01, 2009
    JOURNAL FREE ACCESS
    A 37-year-old man lost consciousness suddenly due to ventricular fibrillation (VF). After cardioversion, twelve-lead ECG showed a pattern characteristic of type 1 Brugada. An implantable cardioverter defibrillator (ICD) was implanted for Brugada syndrome. In the following three years, VF occurred eight times after consumption of alcohol. Association between the Brugada syndrome and alcohol consumption has rarely been reported. Recently, it was reported that alcohol has inhibitory effect on single cardiac sodium channel gating and it may be that alcohol acted as a sodium channel blocker in this patient. Here we report a case of alcohol-induced VF in Brugada syndrome.
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  • Koji Miyamoto, Takeshi Tsuchiya, Chie Yasuoka, Yoshito Tanioka
    2009 Volume 25 Issue 1 Pages 36-41
    Published: January 25, 2009
    Released on J-STAGE: June 01, 2009
    JOURNAL FREE ACCESS
    We describe here a 72-year-old man with ventricular tachycardia (VT) associated with an old myocardial infarction, in whom noncontact mapping guided radiofrequency catheter ablation (RFCA) successfully eliminated the VT. Right ventricular pacing induced 3 VTs with different QRS morphologies and axes, 2 of which were hemodynamically unstable. A dynamic virtual activation map constructed during the VTs superimposed on a virtual voltage map constructed during sinus rhythm demonstrated that all VTs shared a single large myocardial scar in the inferolateral portion of the left ventricle which served as a slow conduction zone. All VTs were eliminated by RFCA at the exit or within the critical slow conduction zone. The patient has been free from any VT recurrences during a follow-up period of 22 months.
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  • Sumito Narita, Takeshi Tsuchiya, Keiichi Ashikaga, Koji Miyamoto, Izum ...
    2009 Volume 25 Issue 1 Pages 42-48
    Published: January 25, 2009
    Released on J-STAGE: June 01, 2009
    JOURNAL FREE ACCESS
    We present case reports of 2 patients with scar-related intra-atrial reentrant tachycardia (IART) associated with previous open-heart surgeries, in which standard ablation strategies failed to eliminate atrial tachycardia (AT). The strategies targeted a narrow conducting channel between the right atrial scars or between the scar and inferior vena cava. In these patients, an alternative approach to transect another narrow conducting pathway between the scar and crista terminalis (CT), which was revealed by a noncontact mapping system, successfully terminated and eliminated the IART. Both the cases were free of recurrent AT at the 24- and 25-month follow up visits, respectively. Transection of the corridor between the CT and the incision scar appears to be an effective technique for eliminating scar-related IART and can be considered as a second-line procedure for radiofrequency catheter ablation to eliminate IART.
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