著者
Shinichi Niwano Hiroe Niwano Sae Sasaki Hidehira Fukaya Masaru Yuge Ryuta Imaki Yoji Machida Tohru Izumi
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
vol.75, no.3, pp.662-671, 2011 (Released:2011-02-25)
参考文献数
34
被引用文献数
10 10

Background: Electrical and structural remodeling, characterized by prolonged action potential duration (APD), Kv4.2 downregulation and cellular infiltration were studied in rat experimental autoimmune myocarditis (EAM). Because the reactive oxygen species (ROS) has been speculated to play a role in the promotion of such remodeling, the effect of N-acetylcysteine (NAC) on the progression of ventricular remodeling was evaluated. Methods and Results: Six-week-old Lewis rats were immunized with porcine cardiac myosin. On Days 10-11 after the immunization, NAC (0, 1, 10, or 100mg) was injected intraperitoneally to EAM and control rats. On Day 14, the electrophysiological parameters were evaluated and the expression levels of the mRNA were examined by quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR).The EAM rats exhibited a typical acute myocarditis with prolonged APD and reduced Kv4.2 expression as previously reported. The myocarditis and electrical changes were significantly suppressed by NAC-treatment in a dose-dependent manner (P<0.05). In rats with 100mg NAC, the myocarditis was almost totally negated although the mortality increased. In rats with 1mg NAC, the suppression of myocarditis was not obvious, but APD prolongation and Kv4.2 reduction was attenuated (P<0.05). Conclusions: The NAC treatment suppressed ventricular remodeling in the EAM rats. This may indicate the role of oxidative stress in causing remodeling and myocarditis itself in the acute phase of myocarditis. (Circ J 2011; 75: 662-671)
著者
Koshiro Kanaoka Satoshi Okayama Michikazu Nakai Yoko Sumita Kunihiro Nishimura Rika Kawakami Hiroyuki Okura Yoshihiro Miyamoto Satoshi Yasuda Hiroyuki Tsutsui Issei Komuro Hisao Ogawa Yoshihiko Saito
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
vol.83, no.5, pp.1025-1031, 2019-04-25 (Released:2019-04-25)
参考文献数
21
被引用文献数
31 46

Background: With aging of the population, the economic burden associated with heart failure (HF) is expected to increase. However, little is known about the hospitalization costs associated with HF in Japan. Methods and Results: In this cross-sectional study, using data from The Japanese Registry of All Cardiac and Vascular Diseases (JROAD) and JROAD-Diagnosis Procedure Combination databases between 2012 and 2014, we evaluated hospitalization costs for acute cardiovascular diseases (CVDs), including HF. A total of &#36;1,187 million/year (44% of the hospitalization costs for acute CVDs) was spent on patients with HF. We identified 273,865 patients with HF and the median cost per patient was &#36;8,089 (&#36;5,362–12,787) per episode. The top 1% of spenders accounted for 8% (&#36;80 million/year), and the top 5% of spenders accounted for 22% (&#36;229 million/year) of the entire cost associated with HF. The costs associated with HF for patients over 75 years of age accounted for 68% of the total cost. Conclusions: The costs associated with HF were higher than the hospitalization cost for any other acute CVD in Japan. Understanding how the total hospitalization cost is distributed may allow health providers to utilize limited resources more effectively for patients with HF.
著者
Naoki Fujimura Hideaki Obara Kentaro Matsubara Susumu Watada Shintaro Shibutani Takurin Akiyoshi Hirohisa Harada Yuko Kitagawa
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
vol.80, no.1, pp.118-123, 2015-12-25 (Released:2015-12-25)
参考文献数
43
被引用文献数
17 20

Background:Clinically distinct differences exist between East Asian and Caucasian subjects, but data for type 2 endoleak (T2EL) are limited in the East Asian population. The aim of this study was to analyze the characteristics of East Asian T2EL using a Japanese multicenter database.Methods and Results:Retrospective analysis of 832 endovascular aneurysm repairs performed from 2008 to 2014 were conducted. T2EL was observed in 234 cases (28.1%), and in 32 cases (3.8%) it led to sac expansion >5 mm caused by isolated T2EL (median follow-up, 35.6 months). On univariate and multivariate analysis, non-smoker status (odds ratio [OR], 2.216; P<0.001), Excluder stent graft (OR, 2.027; P<0.001), and T2EL at final angiogram (OR, 2.080; P<0.001) were risk factors for T2EL. On multivariate analysis for isolated T2EL with sac expansion, only non-smoker status remained (OR, 2.671; P<0.001). Other than T1EL, isolated T2EL was the most significant risk factor for sac expansion (OR, 18.486; P<0.001). Furthermore, out of 11 transarterial embolization procedures initiated, 4 led to rupture during follow-up.Conclusions:East Asian T2EL had a strong relationship with non-smoker status. Also, T2EL was a significant risk factor for sac expansion, which sometimes led to rupture even after intervention. Along with the high prevalence of T2EL observed, East Asian T2EL may not always be benign. (Circ J 2016; 80: 118–123)
著者
Kazuki Hisatomi Takashi Miura Kikuko Obase Ichiro Matsumaru Shun Nakaji Akihiko Tanigawa Shunsuke Taguchi Masayuki Takura Yuko Nakao Kiyoyuki Eishi
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
pp.CJ-22-0338, (Released:2022-10-05)
参考文献数
24
被引用文献数
1

Background: For elderly people, the benefit of minimally invasive cardiac surgery (MICS) is unclear, so we evaluated the safety, recovery, and long-term survival in elderly MICS patients.Methods and Results: 63 propensity score-matched pairs of 213 consecutive patients (≥70 years old) who underwent mitral and/or tricuspid valve surgery between 2010 and 2020 (121 right mini-thoracotomies vs. 92 full sternotomies) were compared. The primary outcome was safety (composite endpoint of in-hospital death or major complication). Secondary outcomes were early ambulation and discharge to home. There were no differences between the groups for in-hospital death (3.2% vs. 0.0%, P=0.157) and primary outcome (14.3% vs. 17.5%, P=0.617). The rate of early ambulation (73.0% vs. 55.6%, P=0.048) and discharge to home (66.7% vs. 49.2%, P=0.034) were significantly higher in the mini-thoracotomy group. Major complication was an independent negative predictor of early ambulation for mini-thoracotomy but not for a conservative approach. Survival was 87.8±4.4% vs. 86.8±4.7% at 5 years, which was not significantly different.Conclusions: Similar safety but better recovery were observed for mini-thoracotomy, and long-term survival was comparable between groups. Major complication was a negative predictor of early ambulation after mini-thoracotomy. Careful preoperative risk stratification would enhance the benefits of MICS in elderly patients.
著者
Ahmet Akcay Cemal Tuncer Talantbek Batyraliev Mustafa Gokce Beyhan Eryonucu Sedat Koroglu Remzi Yilmaz
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
vol.72, no.8, pp.1254-1258, 2008 (Released:2008-07-25)
参考文献数
22
被引用文献数
21 27

Background Isolated single coronary artery (SCA) is an extremely rare congenital coronary anomaly. Some subgroups of SCA can lead to angina pectoris, acute myocardial infarction or even sudden death in the absence of atherosclerosis. Young patients, especially, have the risk of serious clinical events, but middle-aged-to elderly patients have a variable clinical course. Methods and Results The aim of this study was to present the clinical and angiographic properties, relatively long-term follow-up (54±14 months) and management of adult patients (mean age 57±12 years) with SCA. The records of 70,850 patients undergoing coronary angiography between 1999 and 2005 were reviewed. Ten patients (0.024%) were found to have SCA, originating from the left sinus of Valsalva in 3 (30%) patients and from the right sinus of Valsalva in 7 patients (70%). No atherosclerotic involvement was seen in 7 (70%) patients. One patient was also treated by stent implantation to the SCA. Other patients were followed medically. All patients have been followed uneventfully. Conclusion Medical treatment is usually adequate for middle-aged to elderly patients with SCA in the absence of ischemia and/or acute coronary syndrome. (Circ J 2008; 72: 1254 - 1258)
著者
Yuta Seko Takao Kato Takeshi Morimoto Hidenori Yaku Yasutaka Inuzuka Yodo Tamaki Neiko Ozasa Masayuki Shiba Erika Yamamoto Yusuke Yoshikawa Yugo Yamashita Takeshi Kitai Ryoji Taniguchi Moritake Iguchi Kazuya Nagao Takafumi Kawai Akihiro Komasa Ryusuke Nishikawa Yuichi Kawase Takashi Morinaga Mamoru Toyofuku Yutaka Furukawa Kenji Ando Kazushige Kadota Yukihito Sato Koichiro Kuwahara Takeshi Kimura for the KCHF Study Investigators
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
vol.86, no.10, pp.1547-1558, 2022-09-22 (Released:2022-09-22)
参考文献数
30
被引用文献数
3

Background: The clinical benefits of neurohormonal antagonists for patients with heart failure (HF) with mid-range and preserved ejection fraction (HFmrEF and HFpEF) are uncertain.Methods and Results: This study analyzed 858 consecutive patients with HFmrEF (EF: 40–49%) or HFpEF (EF ≥50%), who were hospitalized for acute HF, and who were discharged alive, and were not taking angiotensin-converting enzyme inhibitors (ACE)-I/ angiotensin II receptor blockers (ARB) or β-blockers at admission. The study population was classified into 4 groups according to the status of prescription of ACE-I/ARB and β-blocker at discharge: no neurohormonal antagonist (n=342, 39.9%), ACE-I/ARB only (n=128, 14.9%), β-blocker only (n=189, 22.0%), and both ACE-I/ARB and β-blocker (n=199, 23.2%) groups. The primary outcome measure was a composite of all-cause death or HF hospitalization. The cumulative 1-year incidence of the primary outcome measure was 41.2% in the no neurohormonal antagonist group, 34.0% in the ACE-I/ARB only group, 28.6% in the β-blocker only group, and 16.4% in the both ACE-I/ARB and β-blocker group (P<0.001). Compared with the no neurohormonal antagonist group, both the ACE-I/ARB and β-blocker groups were associated with a significantly lower risk for a composite of all-cause death or HF hospitalization (HR: 0.46, 95% CI: 0.28–0.76, P=0.002).Conclusions: In hospitalized patients with HFmrEF and HFpEF, starting both ACE-I/ARB and a β-blocker was associated with a reduced risk of the composite of all-cause death or HF hospitalization compared with patients not starting on an ACE-I/ARB or β-blocker.
著者
Koichi Sagawa Tsugutoshi Suzuki Kohta Takei Masaru Miura Hideaki Ueda Hitoshi Horigome Hiroshi Ono Naoki Ohashi Seiichi Sato Hideo Fukunaga Hisaaki Aoki Aya Miyazaki Heima Sakaguchi Eiichiro Morishima Kaori Oki Naokata Sumitomo
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
pp.CJ-21-0967, (Released:2022-08-18)
参考文献数
30
被引用文献数
1

Background: The prospective Control of HEART rate in inFant and child tachyarrhythmia with reduced cardiac function Using Landiolol (HEARTFUL) study investigated the effectiveness and safety of landiolol, a short-acting β1 selective blocker, in children.Methods and Results: Twenty-five inpatients aged ≥3 months to <15 years who developed supraventricular tachyarrhythmias (atrial fibrillation, atrial flutter, supraventricular tachycardia, and inappropriate sinus tachycardia) were treated with landiolol. The primary endpoint, the percent of patients with a reduction in heart rate ≥20% from the initial rate of tachycardia, or termination of tachycardia at 2 h after starting landiolol, was achieved in 12/25 patients (48.0%; 95% CI 28.4–67.6), which exceeded the predetermined threshold (38.0%). At 2 h after starting landiolol administration, heart rate had decreased by ≥20% in 45.8% (11/24) and recovery to sinus rhythm was achieved in 40.0% (6/15) of the patients. Adverse reactions (ARs) occurred in 24.0% (6/25) of patients, and the study was discontinued in 4.0% (1/25) of the patients; however, none of these ARs were considered serious. The most common AR was hypotension (20.0% [5/25] of patients).Conclusions: The HEARTFUL study has demonstrated the efficacy of landiolol, by reducing heart rate or terminating tachycardia, in pediatric patients with supraventricular tachyarrhythmias. Although serious ARs and concerns were not identified in this study, physicians should be always cautious of circulatory collapse due to hypotension.
著者
Toshiaki Toyota Takeshi Morimoto Satoshi Iimuro Retsu Fujita Hiroshi Iwata Katsumi Miyauchi Teruo Inoue Yoshihisa Nakagawa Yosuke Nishihata Hiroyuki Daida Yukio Ozaki Satoru Suwa Ichiro Sakuma Yutaka Furukawa Hiroki Shiomi Hirotoshi Watanabe Kyohei Yamaji Naritatsu Saito Masahiro Natsuaki Yasuo Ohashi Masunori Matsuzaki Ryozo Nagai Takeshi Kimura
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
pp.CJ-22-0168, (Released:2022-09-14)
参考文献数
20

Background: The relationship between very low on-treatment low-density lipoprotein cholesterol (LDL-C) level and cardiovascular event risk is still unclear in patients receiving the same doses of statins.Methods and Results: From the REAL-CAD study comparing high-dose (4 mg/day) with low-dose (1 mg/day) pitavastatin therapy in patients with stable coronary artery disease, 11,105 patients with acceptable statin adherence were divided into 3 groups according to the on-treatment LDL-C level at 6 months (<70 mg/dL, 70–100 mg/dL, and ≥100 mg/dL). The primary outcome measure was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal ischemic stroke, or unstable angina requiring emergent admission. The adjusted risks of the LDL-C <70 mg/dL group relative to the LDL-C 70–100 mg/dL group (reference) was not significantly different for the primary outcome measure in both 1 mg/day and 4 mg/day strata (HR 0.84, 95% CI 0.58–1.18, P=0.32, and HR 1.25, 95% CI 0.88–1.79, P=0.22). The adjusted risk of the LDL-C ≥100 mg/dL group relative to the reference group was not significant for the primary outcome measure in the 1 mg/day stratum (HR 0.82, 95% CI 0.60–1.11, P=0.21), whereas it was highly significant in the 4 mg/day stratum (HR 3.32, 95% CI 2.08–5.17, P<0.001).Conclusions: A very low on-treatment LDL-C level (<70 mg/dL) was not associated with lower cardiovascular event risk compared with moderately low on-treatment LDL-C level (70–100 mg/dL) in patients receiving the same doses of statins.
著者
Chun-Ka Wong Hayes Kam-Hei Luk Wing-Hon Lai Yee-Man Lau Ricky Ruiqi Zhang Antonio Cheuk-Pui Wong George Chi-Shing Lo Kwok-Hung Chan Ivan Fan-Ngai Hung Hung-Fat Tse Patrick Chiu-Yat Woo Susanna Kar-Pui Lau Chung-Wah Siu
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
vol.84, no.11, pp.2027-2031, 2020-10-23 (Released:2020-10-23)
参考文献数
10
被引用文献数
15 33

Background:SARS-CoV-2 infection is associated with myocardial injury, but there is a paucity of experimental platforms for the condition.Methods and Results:Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) infected by SARS-CoV-2 for 3 days ceased beating and exhibited cytopathogenic changes with reduced viability. Active viral replication was evidenced by an increase in supernatant SARS-CoV-2 and the presence of SARS-CoV-2 nucleocaspid protein within hiPSC-CMs. Expressions of BNP, CXCL1, CXCL2, IL-6, IL-8 and TNF-α were upregulated, while ACE2 was downregulated.Conclusions:Our hiPSC-CM-based in-vitro SARS-CoV-2 myocarditis model recapitulated the cytopathogenic effects and cytokine/chemokine response. It could be exploited as a drug screening platform.
著者
Kazumasa Kurogi Masanobu Ishii Kenji Sakamoto Soichi Komaki Hiroaki Kusaka Nobuyasu Yamamoto Seiji Takashio Yuichiro Arima Eiichiro Yamamoto Koichi Kaikita Kenichi Tsujita
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
vol.84, no.6, pp.917-925, 2020-05-25 (Released:2020-05-25)
参考文献数
31
被引用文献数
11 14

Background:The excessive volume of contrast needed is a significant limitation of optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI). Low-molecular-weight dextran (LMWD) has been used for OCT image acquisition instead of contrast media. This study compared the effects of OCT-guided PCI using LMWD on renal function and clinical outcomes to those of intravascular ultrasound (IVUS)-guided PCI.Methods and Results:In all, 1,183 consecutive patients who underwent intracoronary imaging-guided PCI were enrolled in this single-center, retrospective, observational study. After propensity score matching, 133 pairs of patients were assigned to undergo either OCT-guided PCI using LMWD or IVUS-guided PCI. There was no significant change from baseline in the primary endpoint, serum creatinine concentrations, after the procedure in either group. There were no significant differences between the OCT and IVUS groups in the volume of contrast medium, the incidence of contrast-induced nephropathy (1.5% vs. 2.3%; P=0.65), and major adverse cardiovascular events (MACE) at 30 days (2.3% vs. 6.0%; P=0.12) and 12 months (2.3% vs. 3.0%; P=0.70) after the procedure. Kaplan-Meier analysis at the 12-month follow-up revealed no significant difference in the incidence of MACE between the 2 groups (P=0.75).Conclusions:OCT-guided PCI using LMWD did not negatively affect renal function and achieved similar short- and long-term clinical outcomes to IVUS-guided PCI.
著者
Makoto Miyake Misa Takegami Yuki Obayashi Masashi Amano Takeshi Kitai Tomoyuki Fujita Tadaaki Koyama Hidekazu Tanaka Kenji Ando Tatsuhiko Komiya Masaki Izumo Hiroya Kawai Kiyoyuki Eishi Kiyoshi Yoshida Takeshi Kimura Ryuzo Nawada Tomohiro Sakamoto Yoshisato Shibata Toshihiro Fukui Kenji Minatoya Kenichi Tsujita Yasushi Sakata Tetsuya Kimura Kumiko Sugio Atsushi Takita Atsushi Iwakura Toshihiro Tamura Kunihiro Nishimura Yutaka Furukawa Chisato Izumi for the BPV-AF Registry Group
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
pp.CJ-22-0226, (Released:2022-07-08)
参考文献数
28
被引用文献数
2

Background: Current guidelines equally recommend direct oral anticoagulants (DOACs) and warfarin for atrial fibrillation (AF) patients with a bioprosthetic valve (BPV); however, there are limited data comparing DOACs and warfarin in AF patients with an aortic BPV.Methods and Results: This post-hoc subgroup analysis of a multicenter, prospective, observational registry (BPV-AF Registry) aimed to compare DOACs and warfarin in AF patients with an aortic BPV. The primary outcome was a composite of stroke, systemic embolism, major bleeding, heart failure requiring hospitalization, all-cause death, or BPV reoperation. The analysis included 479 patients (warfarin group, n=258; DOAC group, n=221). Surgical aortic valve replacement was performed in 74.4% and 36.7% of patients in the warfarin and DOAC groups, respectively. During a mean follow up of 15.5 months, the primary outcome occurred in 45 (17.4%) and 32 (14.5%) patients in the warfarin and DOAC groups, respectively. No significant difference was found in the primary outcome between the 2 groups (adjusted hazard ratio: 0.88, 95% confidence interval: 0.51–1.50). No significant multiplicative interaction was observed between the anticoagulant effects and type of aortic valve procedure (P=0.577).Conclusions: Among AF patients with an aortic BPV, no significant difference was observed in the composite outcome of adverse clinical events between patients treated with warfarin and those treated with DOACs, suggesting that DOACs can be used as alternatives to warfarin in these patients.
著者
Nobutoyo Masunaga Hisashi Ogawa Kimihito Minami Kenjiro Ishigami Syuhei Ikeda Kosuke Doi Yasuhiro Hamatani Takashi Yoshizawa Yuya Ide Akiko Fujino Mitsuru Ishii Moritake Iguchi Hiromichi Wada Koji Hasegawa Hikari Tsuji Masahiro Esato Mitsuru Abe Masaharu Akao on behalf of the Fushimi AF Registry Investigators
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
pp.CJ-22-0180, (Released:2022-07-01)
参考文献数
22
被引用文献数
2

Background: Atrial fibrillation (AF) patients often have concomitant coronary artery disease (CAD); however, there are little data on clinical characteristics and outcomes of such patients in daily clinical practice in Japan.Methods and Results: The Fushimi AF Registry is a community-based prospective survey of AF patients in Fushimi-ku, Kyoto, Japan. Follow-up data were available for 4,464 patients, and the median follow up was 5.1 (interquartile range: 2.3–8.0) years. History of CAD was present in 647 patients (14%); of those patients, 267 (41%) had history of myocardial infarction (MI). Patients with CAD were older and had more comorbidities than those without CAD. The crude incidences (% per patient-year) of cardiovascular events were significantly higher in patients with CAD than those without CAD (cardiac death: 1.8 vs. 0.7, stroke or systemic embolism [SE]: 2.9 vs. 2.1, MI: 0.6 vs. 0.1, composite of those events: 5.1 vs. 2.8, respectively, all log-rank P<0.01). After multivariate adjustment, concomitant CAD was associated with incidence of cardiac events, and history of MI was associated with incidence of MI; however, neither history of CAD nor MI was associated with the incidence of stroke/SE.Conclusions: In Japanese AF patients, concomitant CAD was associated with higher prevalences of major co-morbidities and higher incidences of cardiovascular events; however, history of CAD was not associated with the incidence of stroke/SE.
著者
Kazufumi Nakamura Toru Miyoshi Satoshi Akagi Norihisa Toh Yukihiro Saito Yoichi Takaya Masatoki Yoshida Koji Nakagawa Satoshi Kawada Hironobu Toda Takashi Miki Rie Nakayama Fumi Yokohama Keishi Ichikawa Masashi Yoshida Makiko Taniyama Nobuhiro Nishii Teiji Akagi Hiroshi Morita Hiroshi Ito
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
pp.CJ-22-0349, (Released:2022-06-29)
参考文献数
3
被引用文献数
1

The 86thAnnual Scientific Meeting of the Japanese Circulation Society was held in a web-based format on March 11–13, 2022. In accordance with the internationalization policy of the JCS, the meeting was held with the Asian Pacific Society of Cardiology Congress 2022. The main theme was “Cardiology Spreading its Wings”. The number of patients with heart failure and other cardiovascular diseases is increasing dramatically, and the fields dealt with by cardiovascular medicine are also greatly expanding. This conference was both intellectually satisfying and exciting for all participants, who numbered over 14,900. The meeting was completed with great success, and the enormous amount of cooperation and support from all involved was greatly appreciated.
著者
SOS-KANTO Committee
出版者
The Japanese Circulation Society
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
vol.69, no.10, pp.1157-1162, 2005 (Released:2005-09-25)
参考文献数
30
被引用文献数
31 31

Background Although there is a close connection between emergency medical services (EMS) system and the outcome of out-of-hospital ventricular fibrillation (VF), few data are available regarding the situation in Japan. Methods and Results A prospective multicenter study of out-of-hospital cardiac arrest was conducted according to the Utstein guidelines. A total of 4,383 patients who were given cardiopulmonary resuscitation (CPR) by EMS personnel for out-of-hospital cardiac arrest were enrolled. The proportion of VF or pulseless ventricular tachycardia (VT) as the first cardiac rhythm after cardiac arrest was 16.2% with a mean call-to-initial-recorded-electrocardiogram (ECG) interval of 11.1 min. In a subgroup of patients with witnessed collapse, the predicted incidence of VF or pulseless VT was 62.7% at the time of cardiac arrest, and the decline accelerated with every minute that the collapse-to-initial ECG interval was delayed. Multivariate analysis showed that the odds ratio for VF or pulseless VT after collapse-to-initial ECG interval was 0.91 (95% confidence interval (CI), 0.89-0.94, p<0.001), and 1.54 (95%CI, 1.24-1.97, p<0.001) after bystander CPR. Conclusions In Japan, VF occurred in 63% of cases at the time of cardiac arrest and the performance of bystander CPR appeared to prolong VF. (Circ J 2005; 69: 1157 - 1162)