Seiji Fukamizu

Publications (8)26.34 Total impact

• Article: Ambulatory Electrocardiogram-Based T-Wave Alternans in Patients With Vasospastic Angina During Asymptomatic Periods.

  Hiroshi Shimada, Mitsuhiro Nishizaki, Hiroyuki Fujii, Noriyoshi Yamawake, Seiji Fukamizu, Harumizu Sakurada, Masayasu Hiraoka
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  ABSTRACT: T-wave alternans (TWA) is a useful method for evaluating repolarization abnormalities and as a predictor of life-threatening ventricular arrhythmias. Although life-threatening ventricular arrhythmias are occasionally observed during ischemic attacks in patients with vasospastic angina (VSA), there have been no studies to detect repolarization abnormalities using TWA analysis in these patients during the asymptomatic phase. The aim of this study was to analyze modified moving average (MMA) TWA using Holter recordings in 40 patients with VSA and in 40 control subjects. The incidence of positive TWA was higher in the VSA group than in the control group (24 of 40 [60%] vs 0 of 40 [0%], p <0.01). The value of the maximum MMA TWA was also greater in the VSA group than in the control group (68.6 ± 21 vs 34.0 ± 11 μV, p <0.01). In the VSA group, although there was no significant difference in maximum MMA TWA values between patients with multiple- and single-vessel spasm, patients with ventricular tachycardias had higher values than those without (83.0 ± 15 vs 65.9 ± 20 μV, p <0.05). Patients taking calcium channel blockers exhibited decreased values of maximum MMA TWA compared with subjects not taking these drugs (73.8 ± 18 vs 59.5 ± 21 μV, p <0.05). In conclusion, high values and incidences of TWA events were observed in patients with VSA. In the VSA group, maximum values of MMA TWA were high in patients with ventricular tachycardias but decreased in those taking calcium channel blockers. The results suggest that the patients with VSA during asymptomatic phases exhibit repolarization abnormalities leading to a potential risk for life-threatening arrhythmias.
  The American journal of cardiology 08/2012; · 3.58 Impact Factor
• Source

  Available from: Takashi Nitta

  Article: Clinical and electrophysiological characteristics in patients with sustained monomorphic reentrant ventricular tachycardia associated with dilated-phase hypertrophic cardiomyopathy.

  Akiko Ueda, Seiji Fukamizu, Kyoko Soejima, Tamotsu Tejima, Mitsuhiro Nishizaki, Takashi Nitta, Youichi Kobayashi, Masayasu Hiraoka, Harumizu Sakurada
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  ABSTRACT: Little is known about sustained monomorphic ventricular tachycardia (SMVT) associated with dilated-phase hypertrophic cardiomyopathy (DHCM). The purpose of this study was to clarify the clinical characteristics and effectiveness of catheter ablation for SMVTs in DHCM patients. Five patients with DHCM (mean age; 67.0 years old, five males) who underwent catheter ablation for drug-refractory SMVTs were included the study. Four of five patients suffered from electrical storm. When the endocardial ablation failed, epicardial and/or intracoronary ethanol ablation, or surgical cryoablation was performed. We reviewed all ablation procedures and electrocardiogram (ECG) of targeted SMVTs. A total of 13 SMVTs were targeted for ablation. Mechanism of all ventricular tachycardias (VTs) was diagnosed as reentry. Endocardial ablation successfully eliminated all VTs in two patients. The remaining three patients needed epicardial ablation, intracoronary ethanol ablation, and surgical cryoablation. All but one VT arose from the basal septum, basal anterior to anterolateral left ventricle (LV). Although the ECGs demonstrated similar features of idiopathic outflow or mitral annulus VTs reflecting the origins, there were characteristic multiple QRS deflections. Following the ablation, four (80%) of the five patients are free from VT recurrence during 18 months of the follow-up period. In DHCM patients, VT circuits predominantly distributed in the basal septum and the basal anterior to anterolateral LV. In addition to the endocardial ablation, alternative approaches were required in some patients.
  Europace 11/2011; 14(5):734-40. · 1.98 Impact Factor
• Article: Catheter ablation in a patient with partial anomalous pulmonary venous return and atrial fibrillation.

  Seiji Fukamizu, Harumizu Sakurada, Mitsuhiro Nishizaki, Masayasu Hiraoka
  Heart rhythm: the official journal of the Heart Rhythm Society 02/2011; 9(6):1002-3. · 4.56 Impact Factor
• Article: Inappropriate ICD discharges due to noise oversensing as the first sign of repetitive perforations of the right ventricular lead.

  Akiko Ueda-Tatsumoto, Seiji Fukamizu, Mitsuhiro Nishizaki, Harumizu Sakurada, Masayasu Hiraoka
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  ABSTRACT: Acute lead perforation is one of the major complications associated with implantable cardioverter defibrillator (ICD) implantation. We describe a case with repetitive inappropriate ICD discharges due to noise oversensing as the first sign of lead perforation.
  Pacing and Clinical Electrophysiology 09/2009; 32(11):1481-4. · 1.35 Impact Factor
• Article: Characteristics of bundle branch reentrant ventricular tachycardia with a right bundle branch block configuration: feasibility of atrial pacing.

  Yuka Mizusawa, Harumizu Sakurada, Mitsuhiro Nishizaki, Akiko Ueda-Tatsumoto, Seiji Fukamizu, Masayasu Hiraoka
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  ABSTRACT: We assessed the inducibility of bundle branch reentrant ventricular tachycardia (BBR-VT) with a right bundle branch block (RBBB) configuration in patients with BBR-VT. Eight consecutive patients (5 men, 45+/-18 years old) with inducible BBR-VT were included. We evaluated the clinical and electrophysiological characteristics in these patients to explore the inducible factors of BBR-VT with an RBBB configuration. Six of eight patients had inducible BBR-VT with an RBBB configuration, including four patients with a clinical VT with the same QRS morphology. All patients exhibited an LBBB or RBBB type intraventricular conduction disturbance during sinus rhythm. The mean HV interval at baseline was 79+/-18 ms. The reproducibility of the BBR-VT with an RBBB pattern was achieved by incremental atrial pacing during an isoproterenol infusion in 4/6 patients (67%) and by programmed ventricular stimulation in the other two. After a right bundle ablation, the BBR-VT was no longer inducible in any of the cases. Our results indicate that it is not rare to induce BBR-VT with an RBBB configuration. For the induction of an RBBB type BBR-VT, incremental atrial pacing may play a significant role in addition to ventricular pacing.
  Europace 09/2009; 11(9):1208-13. · 1.98 Impact Factor
• Article: Association of atrial arrhythmia and sinus node dysfunction in patients with catecholaminergic polymorphic ventricular tachycardia.

  Naokata Sumitomo, Harumizu Sakurada, Kazuo Taniguchi, Masaharu Matsumura, Osamu Abe, Michio Miyashita, Hiroshi Kanamaru, Kensuke Karasawa, Mamoru Ayusawa, Seiji Fukamizu, Iori Nagaoka, Minoru Horie, Kensuke Harada, Masayasu Hiraoka
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  ABSTRACT: This study was performed to investigate the frequency and importance of supraventricular arrhythmia and sinus node (SN) dysfunction in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT). Eight patients with CPVT (mean age: 16.8+/-8.1 years) underwent an electrophysiological study. SN recovery time (1,389+/-394 ms) was slightly prolonged, and 4 of 8 patients had abnormal values. Atrial flutter (AF) was induced by low-rate atrial pacing in 2 patients and by isoproterenol infusion in 1 patient. Atrial fibrillation (Af) was induced by isoproterenol infusion in 2 patients. One patient presented with Af during the follow-up period, and 2 of 4 patients with AF/Af presented with increased SN recovery time. Patients with CPVT frequently have associated with SN dysfunction, and inducible atrial tachyarrhythmias, which indicate that the pathogenesis of CPVT is limited not only to the ventricular myocardium, but also to broad regions of the heart, including the SN and atrial muscle.
  Circulation Journal 11/2007; 71(10):1606-9. · 3.77 Impact Factor
• Article: Left ventricular aneurysm associated with isolated noncompaction of the ventricular myocardium.

  Yuichi Sato, Naoya Matsumoto, Shunichi Yoda, Fumio Inoue, Satoshi Kunimoto, Seiji Fukamizu, Shigemasa Tani, Tadateru Takayama, Kotaro Tokai, Yuji Kasamaki, Satoshi Saito, Takahisa Uchiyama, Yasushi Koyama
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  ABSTRACT: A 66-year-old woman was admitted to our hospital because of left ventricular failure and nonsustained ventricular tachycardia. Two-dimensional echocardiography demonstrated prominent trabeculations and deep intertrabecular recesses, findings consistent with noncompaction of the ventricular myocardium. Myocardial perfusion scintigraphy demonstrated a defect in the anterobasal left ventricular segment. Coronary angiogram was normal, but the left ventriculogram showed an aneurysm in the anterior myocardial segments. This is the first reported case with isolated noncompaction of the ventricular myocardium associated with left ventricular aneurysm.
  Heart and Vessels 06/2006; 21(3):192-4. · 2.05 Impact Factor
• Article: Changes in body surface potential distributions induced by isoproterenol and Na channel blockers in patients with the Brugada syndrome.

  Naomi Izumida, Yuh Asano, Shouzaburoh Doi, Hiroko Wakimoto, Seiji Fukamizu, Takuro Kimura, Tsuyoshi Ueyama, Harumizu Sakurada, Seiko Kawano, Tohru Sawanobori, Masayasu Hiraoka
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  ABSTRACT: The characteristics of unique ECG findings in the Brugada syndrome have not been well explained. To clarify their characteristics and mechanisms, body surface maps (BSM) were recorded from patients with the Brugada syndrome (13 cases; a mean age of 48 years) before and after administration of isoproterenol (ISP) or Na channel blockers (12 cases). ST elevation in V1-V3 was decreased by 0.1 mV or more after ISP infusion in 8 of 11 cases and elevated after Na channel blockers in 8 of 12. In ventricular activation time (VAT) isochronal map, delayed conduction was noted on upper anterior chest in 11 and on anterior left chest in two. Delayed conduction areas were decreased by ISP and expanded by Na channel blockers. QRST isointegral map showed normal findings in baseline with minimal changes after ISP or Na channel blockers. Activation recovery interval (ARI) isochronal map showed prolonged area on upper anterior chest in baseline, being reduced by ISP and expanded by Na channel blockers. ARI dispersion (ARI-d), defined as difference between the maximum and minimum value of ARI, was larger in Brugada patients than that of normal subjects in baseline, and decreased after ISP and increased after Na channel blockers. ST elevation in the Brugada syndrome is primarily caused by abnormality in depolarization rather than in repolarization. BSM can provide better information to clarify a mechanism of ECG changes adding its diagnostic value for this unique syndrome.
  International Journal of Cardiology 07/2004; 95(2-3):261-8. · 7.08 Impact Factor