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Nishinarita R, Niwano S, Niwano H, Nakamura H, Saito D, Sato T, Matsuura G, Arakawa Y, Kobayashi S, Shirakawa Y, Horiguchi A, Ishizue N, Igarashi T, Yoshizawa T, Oikawa J, Hara Y, Katsumura T, Kishihara J, Satoh A, Fukaya H, Sakagami H, Ako J. Canagliflozin Suppresses Atrial Remodeling in a Canine Atrial Fibrillation Model. J Am Heart Assoc 2021; 10:e017483. [PMID: 33399004 PMCID: PMC7955321 DOI: 10.1161/jaha.119.017483] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background Recent clinical trials have demonstrated the possible pleiotropic effects of SGLT2 (sodium–glucose cotransporter 2) inhibitors in clinical cardiovascular diseases. Atrial electrical and structural remodeling is important as an atrial fibrillation (AF) substrate. Methods and Results The present study assessed the effect of canagliflozin (CAN), an SGLT2 inhibitor, on atrial remodeling in a canine AF model. The study included 12 beagle dogs, with 10 receiving continuous rapid atrial pacing and 2 acting as the nonpacing group. The 10 dogs that received continuous rapid atrial pacing for 3 weeks were subdivided as follows: pacing control group (n=5) and pacing+CAN (3 mg/kg per day) group (n=5). The atrial effective refractory period, conduction velocity, and AF inducibility were evaluated weekly through atrial epicardial wires. After the protocol, atrial tissues were sampled for histological examination. The degree of reactive oxygen species expression was evaluated by dihydroethidium staining. The atrial effective refractory period reduction was smaller (P=0.06) and the degree of conduction velocity decrease was smaller in the pacing+CAN group compared with the pacing control group (P=0.009). The AF inducibility gradually increased in the pacing control group, but such an increase was suppressed in the pacing+CAN group (P=0.011). The pacing control group exhibited interstitial fibrosis and enhanced oxidative stress, which were suppressed in the pacing+CAN group. Conclusions CAN and possibly other SGLT2 inhibitors might be useful for preventing AF and suppressing the promotion of atrial remodeling as an AF substrate.
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Affiliation(s)
- Ryo Nishinarita
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Shinichi Niwano
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Hiroe Niwano
- Department of Education Tamagawa University, College of Education Machida Japan
| | - Hironori Nakamura
- Department of Cardiovascular Medicine Nerima Hikarigaoka Hospital Nerima Japan
| | - Daiki Saito
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Tetsuro Sato
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Gen Matsuura
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Yuki Arakawa
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Shuhei Kobayashi
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Yuki Shirakawa
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Ai Horiguchi
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Naruya Ishizue
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Tazuru Igarashi
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Tomoharu Yoshizawa
- Department of Cardiovascular Medicine Yamato Municipal Hospital Yamato Japan
| | - Jun Oikawa
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Yoshinobu Hara
- Department of Anatomy Kitasato University School of Medicine Sagamihara Japan
| | - Takafumi Katsumura
- Department of Anatomy Kitasato University School of Medicine Sagamihara Japan
| | - Jun Kishihara
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Akira Satoh
- Department of Cardiovascular Medicine Yokohama Asahi Central Hospital Yokohama Japan
| | - Hidehira Fukaya
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
| | - Hiroyuki Sakagami
- Department of Anatomy Kitasato University School of Medicine Sagamihara Japan
| | - Junya Ako
- Department of Cardiovascular Medicine Kitasato University School of Medicine Sagamihara Japan
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Nishinarita R, Niwano S, Ishizue N, Satoh T, Matsuura G, Arakawa Y, Kobayashi S, Shirakawa Y, Horiguchi A, Nakamura H, Oikawa J, Kishihara J, Fukaya H, Niwano H, Ako J. Novel risk factor for fatal arrhythmia in Brugada syndrome. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.0735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Brugada syndrome (BrS) is a genetic disease associated with increased risk of ventricular fibrillation (VF)/ventricular tachycardia (VT). The VF/VT in BrS occurs more frequently during a night time or at a rest with parasympathetic nerve activation. Some risk factors of VF/VT occurrence in BrS have been elucidated, however, it remains controversial about risk stratification. Salusin-β is an endogenous bioactive peptide that systemically exerts rapid and profound hypotensive and bradycardic activities and parasympathomimetic hemodynamic actions in vivo. Previous reports suggested that salusin-β is suppressed following physiological parasympathetic stimulation and appears to constitute a negative feedback relationship with the parasympathetic nervous system.
Purpose
We hypothesized that salusin-β is associated with the occurrence of VF/VT in BrS.
Methods
The study population consisted of 26 BrS patients with newly implantation of implantable cardioverter defibrillator (ICD) during 2003–2008. In all patients, salusin-β was measured in supine position after 20 minute rest. The date of salusin-β sampling was set as the registration point for this study. The VF/VT was defined as any episode of fatal ventricular tachyarrhythmia or any appropriate shock. In accordance with the presence or absence of VF/VT events within 5 years, all patients were divided into VF/VT group (n=6) and non-VF/VT group (n=20).Various clinical parameters were compared between the two groups. For analysis of autonomic nervous function, heart rate variability (HRV) and pupil function were evaluated.
Results
The mean age was 54±17 years old. There is no differences between the two groups in clinical parameters. In analysis of HRV, the high-frequency component (0.15–0.40 Hz; HF), low frequency component (0.04–0.15 Hz; LF) and the LF/HF ratio were analyzed over 24 h. LF/HF ratio was significantly lower over 24h in VF/VT groups in comparison with non-VF/VT groups [day-time; 1.8 (1.2–5.6) vs. 5.2 (3.4–8.8), p=0.048, night-time; 1.2 (1.1–1.3) vs. 3.9 (2.5–8.7), p=0.003]. Furthermore, in analysis of pupil function, right/left miosis ratio was higher in VT/VF groups in comparison with non-VT/VF groups [right pupil; 0.39 (0.37–0.59) vs. 0.34 (0.28–0.38), p=0.035, left pupil; 0.43 (0.36–0.50) vs. 0.33 (0.28–0.40), p=0.049]. In plasma total salusin-β levels, the VF/VT groups exhibited significantly lower than non-VF/VT groups (55.2±14.6 vs. 73.2±22.2, p=0.039, Figure).
Conclusions
Salusin-β was associated with the occurrence of VF/VT in Brugada syndrome. Salusin-β might be useful to identify high-risk patients for the occurrence of VT/VF events in Brugada syndrome.
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
- R Nishinarita
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - S Niwano
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - N Ishizue
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - T Satoh
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - G Matsuura
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - Y Arakawa
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - S Kobayashi
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - Y Shirakawa
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - A Horiguchi
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - H Nakamura
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - J Oikawa
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - J Kishihara
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - H Fukaya
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - H Niwano
- Tamagawa University, Department of Education, Machida, Japan
| | - J Ako
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
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Ishizue N, Niwano S, Niwano H, Oikawa J, Nakamura H, Hashikata T, Igarashi T, Fujiishi T, Yoshizawa T, Kishihara J, Satoh A, Fukaya H, Ako J. Linagliptin Suppresses Electrical and Structural Remodeling in the Isoproterenol Induced Myocardial Injury Model. Int Heart J 2019; 60:411-418. [PMID: 30745531 DOI: 10.1536/ihj.18-226] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effect of DPP-4 inhibitor on the electrical and structural remodeling in myocardial injury has not been evaluated. We hypothesized that linagliptin, DPP-4 inhibitor, suppresses myocardial remodeling in the isoproterenol (ISP)-induced myocardial injury model.Sprague-Dawley rats were assigned to 3 groups: 1) sham group, 2) ISP group (subcutaneous ISP injection of 70 mg/kg), and 3) ISP + linagliptin (ISP + Lin) (5 mg/kg/day, p.o.) group. Serum was sampled on day 1 (acute phase) and day 7 (sub-acute phase) to evaluate derivatives of reactive oxidative metabolites (d-ROMs). The electrophysiological study was performed in sub-acute phase for the evaluation of the ventricular effective refractory period (VERP) and monophasic action potential duration (MAPD). The VERP and MAPD were markedly prolonged in the ISP group in comparison with the sham (MAPD20: 14 ± 6 versus 11 ± 3 ms, MAPD90: 57 ± 8 versus 44 ± 7 ms, VERP: 74 ± 22 versus 38 ± 10 ms, P < 0.05). In contrast in the ISP + Lin group, such prolongations were suppressed, and the parameters were shorter than the ISP group (MAPD20: 9 ± 2 ms, MAPD90: 35 ± 6 ms, VERP: 52 ± 13 ms, P < 0.05). ISP treatment induced myocardial injury. The injured area was reduced in the ISP + Lin group in comparison with the ISP group (P < 0.05). Serum d-ROMs level in acute phase was higher in ISP group than the other 2 groups (sham: 214 ± 55 versus ISP: 404 ± 45 versus ISP + Lin: 337 ± 20 U.CARR, P < 0.05).Linagliptin suppressed structural and electrical changes, possibly through the antioxidative effect, in this myocardial injury model.
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Affiliation(s)
- Naruya Ishizue
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hiroe Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Jun Oikawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hironori Nakamura
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Takehiro Hashikata
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Tazuru Igarashi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Tamami Fujiishi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Tomoharu Yoshizawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Akira Satoh
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hidehira Fukaya
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Junya Ako
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
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4
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Yoshizawa T, Niwano S, Niwano H, Tamaki H, Nakamura H, Igarashi T, Oikawa J, Satoh A, Kishihara J, Murakami M, Fukaya H, Ako J. Antiremodeling Effect of Xanthine Oxidase Inhibition in a Canine Model of Atrial Fibrillation. Int Heart J 2018; 59:1077-1085. [PMID: 30158379 DOI: 10.1536/ihj.17-391] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In a canine rapid atrial stimulation model of atrial fibrillation (AF), we have demonstrated an increased production of reactive oxygen species (ROS) along with electrical and structural remodeling. In the present study, we hypothesized that antioxidants can suppress atrial remodeling canines with AF. We therefore evaluated the effect of febuxostat, a xanthine oxidase (XO) inhibitor and a pure antioxidant, on atrial remodeling.AF was produced by performing a 3-week rapid atrial pacing (400 bpm) in 13 dogs divided into three groups: pacing + febuxostat group (n = 5; atrial pacing with 50 mg/day of febuxostat (administration); pacing control group (n = 5; atrial pacing without any drug administration); and non-pacing group (n = 3). Electrophysiological studies were conducted in the first 2 groups every week. Atrial tissue fibrosis was evaluated by Azan and immunofluorescent staining of fibronectin. Oxidative stress was evaluated by DHE and FCF-DA staining.Shortening of the refractory period and increase in AF inducibility appeared gradually in the pacing control group, but such changes were suppressed in the pacing + febuxostat group (P = 0.05). The pacing control group showed increase in fibrosis, which was suppressed in the febuxostat group. In DHE and DCF-DA staining, the pacing control group showed an increase in oxidative stress, which was suppressed in the pacing + febuxostat group. The pacing control group exhibited fibronectin expression, which was suppressed in the pacing + febuxostat group.The antioxidant effect of febuxostat may achieve an inhibition of new-onset AF in canines.
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Affiliation(s)
- Tomoharu Yoshizawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine.,Department of Cardiology, Yamato Municipal Hospital
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hiroe Niwano
- Department of Education, Tamagawa University, Collage of Education
| | - Hideaki Tamaki
- Department of Anatomy, Kitasato University School of Medicine
| | - Hironori Nakamura
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Tazuru Igarashi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Jun Oikawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Akira Satoh
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Masami Murakami
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hidehira Fukaya
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Junya Ako
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
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5
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Nishinarita R, Niwano S, Niwano H, Nakamura H, Arakawa Y, Horiguchi A, Oikawa J, Kishihara J, Sato A, Fukaya H, Ako J. P2295SGLT 2 inhibitor suppresses atrial fibrillation in the canine model of atrial fibrillation. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.p2295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- R Nishinarita
- Kitasato University School of Medicine, Dept. of Cardiovascular Medicine, Sagamihara, Japan
| | - S Niwano
- Kitasato University School of Medicine, Dept. of Cardiovascular Medicine, Sagamihara, Japan
| | - H Niwano
- Tamagawa University, Dept. of Education, Machida, Japan
| | - H Nakamura
- Kitasato University School of Medicine, Dept. of Cardiovascular Medicine, Sagamihara, Japan
| | - Y Arakawa
- Kitasato University School of Medicine, Dept. of Cardiovascular Medicine, Sagamihara, Japan
| | - A Horiguchi
- Kitasato University School of Medicine, Dept. of Cardiovascular Medicine, Sagamihara, Japan
| | - J Oikawa
- Kitasato University School of Medicine, Dept. of Cardiovascular Medicine, Sagamihara, Japan
| | - J Kishihara
- Kitasato University School of Medicine, Dept. of Cardiovascular Medicine, Sagamihara, Japan
| | - A Sato
- Kitasato University School of Medicine, Dept. of Cardiovascular Medicine, Sagamihara, Japan
| | - H Fukaya
- Kitasato University School of Medicine, Dept. of Cardiovascular Medicine, Sagamihara, Japan
| | - J Ako
- Kitasato University School of Medicine, Dept. of Cardiovascular Medicine, Sagamihara, Japan
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6
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Nishinarita R, Niwano S, Fukaya H, Oikawa J, Nabeta T, Arakawa Y, Horiguchi A, Nakamura H, Kishihara J, Sato A, Niwano H, Ako J. P5776Burden of device-detected atrial high-rate episode is associated with heart failure events. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.p5776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- R Nishinarita
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - S Niwano
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - H Fukaya
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - J Oikawa
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - T Nabeta
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - Y Arakawa
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - A Horiguchi
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - H Nakamura
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - J Kishihara
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - A Sato
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
| | - H Niwano
- Tamagawa University, Department of Education, Machida, Japan
| | - J Ako
- Kitasato University School of Medicine, Department of Cardiovascular Medicine, Sagamihara, Japan
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Takahashi H, Tatewaki W, Wada K, Niwano H, Hanano M, Tsubouchi J, Nagai T, Shibata A. DDAVP Does not Induce the Release of Thrombomodulin from Endothelial Cells. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1648169] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Hoyu Takahashi
- First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
| | - Wataru Tatewaki
- First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
| | - Ken Wada
- First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
| | - Hiroe Niwano
- First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
| | - Masaharu Hanano
- First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
| | | | - Toshio Nagai
- Mitsubishi Gas Chemical Company, Inc. Niigata, Japan
| | - Akira Shibata
- First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
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Abstract
SummaryIn order to assess precisely the fibrinolytic state in disseminated intravascular coagulation (DIC), plasma levels of fibrinogenolysis products (FgDP), fibrinolysis products (FbDP) and fibrinogenolysis plus fibrinolysis products (TDP) were measured with newly developed enzyme-linked immunosorbent assays based on monoclonal antibodies in 72 patients with DIC at presentation. Not only FbDP and TDP but also FgDP were markedly elevated in patients with DIC. When analyzed according to the underlying disease categories, the relative proportion of FgDP to TDP was high in patients with acute promyelocytic leukemia and vascular diseases, and it was the lowest in patients with sepsis. Correlation analysis revealed that plasma levels of FgDP correlated negatively with alpha 2-antiplasmin and positively with plasmin-alpha 2-antiplasmin complex (PAP) and a ratio of PAP to thrombin-antithrombin III complex (TAT). These findings indicate that besides fibrinolysis, fibrinogenolysis is markedly accelerated in the majority of the patients with DIC.
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Affiliation(s)
- Hoyu Takahashi
- The First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
| | - Wataru Tatewaki
- The First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
| | - Ken Wada
- The First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
| | - Hiroe Niwano
- The First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
| | - Akira Shibata
- The First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan
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Igarashi T, Niwano S, Niwano H, Yoshizawa T, Nakamura H, Fukaya H, Fujiishi T, Ishizue N, Satoh A, Kishihara J, Murakami M, Ako J. Linagliptin prevents atrial electrical and structural remodeling in a canine model of atrial fibrillation. Heart Vessels 2018; 33:1258-1265. [PMID: 29721673 DOI: 10.1007/s00380-018-1170-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 04/20/2018] [Indexed: 12/21/2022]
Abstract
Dipeptidyl peptidase 4 (DPP-4) inhibitors have recently been reported to exhibit additional cardioprotective effects; however, their effect in atrial remodeling, such as in atrial fibrillation (AF), remains unclear. In this study, the effect of linagliptin on atrial electrical and structural remodeling was evaluated in a canine AF model. Sixteen beagle dogs with 3-week atrial rapid stimulation were divided into the linagliptin group (9 mg/kg/day, n = 8) and pacing control group (n = 8). Three additional dogs without rapid pacing were assigned into non-pacing group, which was used as sham in this study. In the dogs with rapid pacing, the atrial effective refractory period (AERP), conduction velocity (CV), and AF inducibility were evaluated and blood was sampled every week. After the entire protocol, atrial tissue was sampled for histological examinations using HE, Azan, and dihydroethidium (DHE) staining to evaluate any tissue damage or oxidative stress. The pacing control group exhibited a gradual AERP shortening and CV decrease along the time course as previously reported. In the linagliptin group, the AERP shortening was not affected, but the CV decrease was suppressed in comparison to the control group (p < 0.05). The AF inducibility was increased in the control group and suppressed in the linagliptin group (p < 0.05). The control group exhibited tissue fibrosis, the degree of which was suppressed in the linagliptin group. DHE staining exhibited suppression of the reactive oxygen species expression in the linagliptin group in comparison to the pacing control group. Linagliptin, a DPP-4-inhibitor, suppressed the AF inducibility, CV decrease, and overexpression of oxidative stress in the canine AF model. Such suppressive effects of linagliptin on AF in the canine model may possibly be related to the anti-oxidative effect.
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Affiliation(s)
- Tazuru Igarashi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan.
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - Hiroe Niwano
- Department of Education, Tamagawa University, College of Education, Machida, Japan
| | - Tomoharu Yoshizawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - Hironori Nakamura
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - Hidehira Fukaya
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - Tamami Fujiishi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - Naruya Ishizue
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - Akira Satoh
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - Masami Murakami
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - Junya Ako
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
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10
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Ishizue N, Niwano S, Fukaya H, Nakamura H, Igarashi T, Fujiishi T, Oikawa J, Kishihara J, Murakami M, Niwano H, Ako J. The J-wave as a Predictor of Life-Threatening Arrhythmia in ICD Patients. Int Heart J 2017; 58:36-42. [DOI: 10.1536/ihj.16-071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Naruya Ishizue
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hidehira Fukaya
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hironori Nakamura
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Tazuru Igarashi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Tamami Fujiishi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Jun Oikawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Masami Murakami
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hiroe Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Junya Ako
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
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11
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Satoh A, Niwano S, Niwano H, Kishihara J, Aoyama Y, Oikawa J, Fukaya H, Tamaki H, Ako J. Aliskiren suppresses atrial electrical and structural remodeling in a canine model of atrial fibrillation. Heart Vessels 2016; 32:90-100. [PMID: 27401739 DOI: 10.1007/s00380-016-0874-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 07/01/2016] [Indexed: 12/19/2022]
Abstract
Aliskiren, a direct renin inhibitor is expected to achieve sufficient suppression of renin-angiotensin system. We evaluated the effect of aliskiren on the electrical and structural remodeling in a canine atrial fibrillation (AF) model. Twenty-eight dogs were divided into three groups: (1) pacing control group (n = 12), with continuous atrial rapid pacing for 3 or 6 weeks, (2) pacing + aliskiren group (n = 12), with oral aliskiren (30 mg/kg/day), and (3) sham group (n = 4), no pacing nor drug administration. Electrophysiological properties and AF inducibility were evaluated every week. After the protocol, the left atrial tissue was sampled for the further histological and mRNA analysis. The electrical remodeling, AF inducibility, the left atrial enlargement and interstitial fibrosis were observed in pacing control group and were more prominent in the 6-week protocol (vs. 3 week, p < 0.05). The mRNA expressions of matricellular proteins exhibited upregulation in 3-week pacing control, but these upregulations became insignificant in 6 weeks. In contrast, collagen type 3 exhibited significant upregulation in 6 week but not in 3-week protocol. These changes were suppressed in the pacing + aliskiren group. Aliskiren suppressed the atrial remodeling in a canine AF model. This effect was accompanied by the suppression of tissue fibrosis.
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Affiliation(s)
- Akira Satoh
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0329, Japan.
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0329, Japan
| | - Hiroe Niwano
- Department of Education, Tamagawa University, College of Education, Machida, Japan
| | - Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0329, Japan
| | - Yuya Aoyama
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0329, Japan
| | - Jun Oikawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0329, Japan
| | - Hidehira Fukaya
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0329, Japan
| | - Hideaki Tamaki
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan
| | - Junya Ako
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0329, Japan
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12
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Ishizue N, Niwano S, Saito M, Fukaya H, Nakamura H, Igarashi T, Fujiishi T, Yoshizawa T, Oikawa J, Satoh A, Kishihara J, Murakami M, Niwano H, Miyaoka H, Ako J. Polytherapy with sodium channel-blocking antiepileptic drugs is associated with arrhythmogenic ST-T abnormality in patients with epilepsy. Seizure 2016; 40:81-7. [PMID: 27371909 DOI: 10.1016/j.seizure.2016.06.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 05/31/2016] [Accepted: 06/07/2016] [Indexed: 11/15/2022] Open
Abstract
PURPOSE Recent reports have documented the appearance of Brugada-type ST elevation in cases of overdose of antiepileptic drugs (AEDs). However, little is known about changes on electrocardiographs (ECGs) during AED use at therapeutic doses. AEDs may cause Brugada-type ST elevation or J-wave-like intraventricular conduction delays through an ion channel-blocking effect. In the present study, we sought to elucidate ECG abnormalities in patients on AED therapy. METHODS The study population consisted of 120 consecutive patients with epilepsy who continued to take AEDs and had ECGs recorded during these therapies. Their clinical background and ECGs were retrospectively analyzed. Brugada-type ST elevation was classified according to the consensus report on Brugada syndrome. A J-wave-like ECG abnormality was defined as the appearance of notching or slurring of the QRS complex (>0.1mV) in the inferior/lateral leads. RESULTS Of the 120 patients, 15 (12.5%) exhibited Brugada-type ST elevation and 35 (29.2%) showed a J-wave-like ECG abnormality. Polytherapy with sodium channel-blocking AEDs (e.g., carbamazepine, phenytoin, lamotrigine) was more frequently observed in patients with Brugada-type ST elevation (p=0.048). However, the serum concentrations of these medicines did not differ between patients with and without ECG abnormalities (carbamazepine: 7.9±4.1 vs. 7.2±5.9μg/dL; phenytoin: 12.7±4.1 vs. 15.5±9.5μg/dL, NS). CONCLUSION ST-T abnormalities were frequently seen in patients using AEDs. The presence of Brugada-type ST elevation was associated with polytherapy with sodium channel-blocking AEDs.
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Affiliation(s)
- Naruya Ishizue
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Masanori Saito
- Department of Psychiatry, Kitasato University School of Medicine, Sagamihara, Japan
| | - Hidehira Fukaya
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Hironori Nakamura
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Tazuru Igarashi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Tamami Fujiishi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Tomoharu Yoshizawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Jun Oikawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Akira Satoh
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Masami Murakami
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Hiroe Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Hitoshi Miyaoka
- Department of Psychiatry, Kitasato University School of Medicine, Sagamihara, Japan
| | - Junya Ako
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
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13
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Fujiishi T, Niwano S, Murakami M, Nakamura H, Igarashi T, Ishizue N, Oikawa J, Kishihara J, Fukaya H, Niwano H, Ako J. Efficacy and Limitations of Tachycardia Detection Interval Guided Reprogramming for Reduction of Inappropriate Shock in Implantable Cardioverter-Defibrillator Patients. Int Heart J 2016; 57:304-9. [PMID: 27181038 DOI: 10.1536/ihj.15-419] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The avoidance of inappropriate shock therapy is an important clinical issue in implantable cardioverter-defibrillator (ICD) patients. We retrospectively analyzed therapeutic events in ICD patients, and the effect of tachycardia detection interval (TDI) and tachycardia cycle length (TCL) guided reprograming on the reduction of inappropriate ICD therapy. The clinical determinants of after reprogramming were also evaluated.A total of 254 consecutive ICD patients were included in the study, and the incidence of antitachycardia therapy was evaluated during the follow-up period of 27.3 ± 18.7 months. When inappropriate antitachycardia therapy appeared, TDI was reprogrammed not to exceed the detected TCL and the patients continued to be followed-up. Various clinical parameters were compared between patients with and without inappropriate ICD therapy. During the initial follow-up period of 18.6 ± 15.6 months, ICD therapy occurred in 127/254 patients (50%) including inappropriate antitachycardia pacing (ATP) (12.9%) and shock (44.35%). Determinants of initial inappropriate therapy were dilated cardiomyopathy (DCM), history of therapeutic hypothermia, and QRS duration. Of the 61 patients with inappropriate therapy, 24 received TCL guided reprogramming. During the additional observation period of 17.0 ± 16.8 months, inappropriate therapy recurred in 5/24 patients (2 ATP, 3 shocks). The determinant of these inappropriate therapy events after reprogramming was the presence of supraventricular tachycardia.By applying simple TCL and TDI guided reprogramming, inappropriate therapy was reduced by 79%. The determinant of inappropriate therapy after reprogramming was the presence of supraventricular tachycardia.
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Affiliation(s)
- Tamami Fujiishi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
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14
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Igarashi T, Niwano S, Fukaya H, Yoshizawa T, Nakamura H, Fujiishi T, Ishizue N, Oikawa J, Kishihara J, Murakami M, Niwano H, Ako J. Discrimination of Paroxysmal and Persistent Atrial Fibrillation in Patients With New-Onset Atrial Fibrillation. Int Heart J 2016; 57:573-9. [DOI: 10.1536/ihj.15-476] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Tazuru Igarashi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hidehira Fukaya
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Tomoharu Yoshizawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hironori Nakamura
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Tamami Fujiishi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Naruya Ishizue
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Jun Oikawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Masami Murakami
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hiroe Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Junya Ako
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
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15
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Hashikata T, Yamaoka-Tojo M, Namba S, Kitasato L, Kameda R, Murakami M, Niwano H, Shimohama T, Tojo T, Ako J. Rivaroxaban Inhibits Angiotensin II-Induced Activation in Cultured Mouse Cardiac Fibroblasts Through the Modulation of NF- κB Pathway. Int Heart J 2015; 56:544-50. [DOI: 10.1536/ihj.15-112] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
| | - Minako Yamaoka-Tojo
- Kitasato University Graduate School of Medical Sciences
- Department of Rehabilitation, Kitasato University School of Allied Health Sciences
| | - Sayaka Namba
- Kitasato University Graduate School of Medical Sciences
| | - Lisa Kitasato
- Kitasato University Graduate School of Medical Sciences
| | - Ryo Kameda
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Masami Murakami
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hiroe Niwano
- Department of Education, Tamagawa University College of Education
| | - Takao Shimohama
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Taiki Tojo
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Junya Ako
- Kitasato University Graduate School of Medical Sciences
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
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16
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Kurokawa S, Niwano S, Niwano H, Murakami M, Ishikawa S, Masaki Y, Tamaki H, Toda T, Noda Y, Shimizu T, Izumi T, Ako J. Cardiomyocyte-derived mitochondrial superoxide causes myocardial electrical remodeling by downregulating potassium channels and related molecules. Circ J 2014; 78:1950-9. [PMID: 24859499 DOI: 10.1253/circj.cj-13-1587] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND This study was designed to investigate the role of a primary hyperoxidative stress in myocardial electrical remodeling using heterozygous heart/muscle-specific manganese superoxide dismutase-deficient (H/M-Sod2(+/-)) mice treated with L-buthionine-sulfoximine (BSO). METHODS AND RESULTS Both H/M-Sod2(+/-)and wild-type (WT) mice were treated with intra-peritoneal BSO or saline for 7 days, and divided into 4 groups: H/M-Sod2(+/-)+BSO, WT+BSO, H/M-Sod2(+/-)control, and WT control. The ventricular effective refractory period (ERP) and the monophasic action potential duration (MAPD) were determined. Levels of oxidative stress, potassium channel-related molecules, and K(+)channel-interacting protein-2 (KChIP2) were also evaluated. The H/M-Sod2(+/-)+BSO group exhibited markedly prolonged MAPD20, MAPD90 and ERP in comparison with the other groups (MAPD20: 14 ± 1 vs. 11 ± 1 ms, MAPD90: 77 ± 7 vs. 58 ± 4 ms, ERP: 61 ± 6 vs. 41 ± 3 ms, H/M-Sod2(+/-)+BSO vs. WT control; P<0.05). Mitochondrial superoxide and hydrogen peroxide formation in the myocardium increased in the H/M-Sod2(+/-)+BSO group in comparison with the WT+BSO group (P<0.05). Real-time RT-PCR and Western blotting revealed that Kv4.2 expression was downregulated in both BSO-treated groups, whereas KChIP2 expression was downregulated only in the H/M-Sod2(+/-)+BSO group (P<0.05). CONCLUSIONS BSO treatment caused hyperoxidative stress in the myocardium of H/M-Sod2(+/-)mice. Changes in the expression and function of potassium channels were considered to be involved in the mechanism of electrical remodeling in this model.
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Affiliation(s)
- Sayaka Kurokawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
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17
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Kishihara J, Niwano S, Niwano H, Aoyama Y, Satoh A, Oikawa J, Kiryu M, Fukaya H, Masaki Y, Tamaki H, Izumi T, Ako J. Effect of carvedilol on atrial remodeling in canine model of atrial fibrillation. Cardiovasc Diagn Ther 2014; 4:28-35. [PMID: 24649422 DOI: 10.3978/j.issn.2223-3652.2014.02.03] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 02/07/2014] [Indexed: 11/14/2022]
Abstract
AIMS We evaluated the effect of carvedilol, a beta-blocker with anti-oxidative action, against the atrial fibrillation (AF) inducibility, the development of atrial remodeling and the oxidative stress markers in a canine AF model. METHODS AND RESULTS AF model was produced by performing 6-week rapid atrial stimulation in 15 dogs. The animals were divided into the following three groups: (I) pacing + carvedilol group (n=5); (II) pacing control group (n=5); and (III) non-pacing group (n=5). AF inducibility was gradually increased along the time course in the pacing control group. In the pacing + carvedilol group, the AF inducibility was suppressed especially in the latter phase of protocol in comparison with the pacing control group. Although carvedilol has beta-blocking effect, pacing control and pacing + carvedilol groups did not exhibit difference in the heart rate (177±13 vs. 155±13 bpm, P=0.08). On 8-hydroxy-2'-deoxyguanosine (8-OHdG), dihydroethidium and dichlorodihydrofluorescein diacetate staining, enhanced oxidative stress was observed in the atrial tissue in the pacing control, but not in the pacing + carvedilol group. CONCLUSIONS Carvedilol suppressed AF inducibility and oxidative stress in the canine AF model.
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Affiliation(s)
- Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Hiroe Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Yuya Aoyama
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Akira Satoh
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Jun Oikawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Michiro Kiryu
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Hidehira Fukaya
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Yoshihiko Masaki
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Hideaki Tamaki
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Tohru Izumi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Junya Ako
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
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18
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Yoshizawa T, Niwano S, Niwano H, Igarashi T, Fujiishi T, Ishizue N, Oikawa J, Satoh A, Kurokawa S, Hatakeyama Y, Fukaya H, Ako J. Prediction of New Onset Atrial Fibrillation Through P Wave Analysis in 12 Lead ECG. Int Heart J 2014; 55:422-7. [DOI: 10.1536/ihj.14-052] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Tomoharu Yoshizawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hiroe Niwano
- Department of Education, Tamagawa University, Collage of Education
| | - Tazuru Igarashi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Tamami Fujiishi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Naruya Ishizue
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Jun Oikawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Akira Satoh
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Sayaka Kurokawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Yuko Hatakeyama
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Hidehira Fukaya
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Junya Ako
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
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19
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Oikawa J, Niwano S, Niwano H, Ishizue N, Yoshizawa T, Satoh A, Kurokawa S, Hatakeyama Y, Fukaya H. Prophylactic statin administration may prevent shortening of the fibrillation cycle length in patients with new-onset atrial fibrillation. Int Heart J 2013; 54:371-6. [PMID: 24309446 DOI: 10.1536/ihj.54.371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Patients with recently diagnosed atrial fibrillation (AF) tend to exhibit a longer fibrillation cycle length (FCL) than those having a longer clinical history. However, the electrophysiological properties of new-onset AF may vary because of the clinical background of patients. In this study, we evaluated clinical factors to identify the determinants of FCL in new-onset AF. Electrocardiograms (ECGs) recorded from 2008 through 2011 were analyzed using our digital ECG-profiling system. In the 1,578 AF episodes recorded, 466 new-onset AF episodes were identified using clinical referral history and previous ECGs. After evaluating FCL in these new-onset AF episodes, using a customized fibrillation wave analyzer with fast Fourier transform analysis, we divided the patients into a longer-FCL group and a shorter-FCL group using the median FCL (158 ms). Propensity score matching yielded 135 matched pairs of patients with comparable mean ages between the two groups. Four factors (brain natriuretic peptide levels, and use of angiotensin receptor blockers, calcium channel blockers or statins) exhibited a significant difference between the two groups. Multivariate analysis revealed that statin use was the only significant independent predictor of longer FCL (Odds ratio, 3.86; 95% CI, 1.659.63; P = 0.003). Among various clinical parameters, statin use was related to longer FCL at the time of new-onset AF in patients with AF.
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Affiliation(s)
- Jun Oikawa
- Department of Cardio-Angiology, Kitasato University School of Medicine
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20
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Oikawa J, Niwano S, Ishizue N, Yoshizawa T, Satoh A, Kurokawa S, Hatakeyama Y, Fukaya H, Niwano H. Use of statins suppress the shorting of the fibrillation cycle length in patients with new-onset atrial fibrillation -Possible anti-remodeling effect of statin for atrial structural remodeling. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht310.p4964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Murakami M, Niwano S, Koitabashi T, Inomata T, Satoh A, Kishihara J, Ishikawa S, Aoyama Y, Niwano H, Izumi T. Author's reply. J Cardiol 2013; 61:95-6. [DOI: 10.1016/j.jjcc.2012.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 10/31/2012] [Indexed: 10/27/2022]
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22
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Ishikawa S, Niwano S, Kishihara J, Imaki R, Murakami M, Aoyama Y, Satoh A, Niwano H, Izumi T. Usefulness of ST elevation score by using vector-projected virtual 187-channel ECG for risk stratification in patients with Brugada-type ECG pattern. J Arrhythm 2012. [DOI: 10.1016/j.joa.2011.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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23
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Kiryu M, Niwano S, Niwano H, Kishihara J, Aoyama Y, Fukaya H, Masaki Y, Izumi T. Angiotensin II-mediated up-regulation of connective tissue growth factor promotes atrial tissue fibrosis in the canine atrial fibrillation model. Europace 2012; 14:1206-14. [PMID: 22454409 PMCID: PMC3404558 DOI: 10.1093/europace/eus052] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
AIMS Remodelling of the extracellular matrix (ECM) plays an important role in the production of arrhythmogenic substrate for atrial fibrillation (AF), and is considered to be promoted by the connective tissue growth factor (CTGF). Our objective was to assess the relationship between CTGF and ECM synthesis, and the effect of olmesartan on these processes. METHODS AND RESULTS Fifteen canine AF models were produced by rapid atrial stimulation. They were divided into three groups: pacing control (n = 5): 6-week pacing, pacing + olmesartan (n = 5): pacing with olmesartan (2 mg/kg/day), and non-pacing group (n = 5). In the pacing control group, messenger ribonucleic acid expressions of CTGF and collagen types 1 and 3 were up-regulated in comparison with the non-pacing group (P < 0.05) while transforming growth factor-β (TGF-β) did not exhibit a significant difference. In the pacing + olmesartan group, these up-regulations were suppressed (P < 0.05). In fluorescent immunostaining, the expression of CTGF was localized in the cytoplasm. The protein level of collagen type 3 was increased in the pacing control and it was suppressed in the pacing + olmesartan group. CONCLUSIONS CTGF and associated genes were up-regulated in the atria with the appearance of fibrosis. Because this up-regulation was independent of TGF-β and suppressed by olmesartan, CTGF up-regulation was considered to be mediated by angiotensin II.
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Affiliation(s)
- Michiro Kiryu
- Department of Cardio-Angiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0374, Japan.
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24
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Murakami M, Niwano S, Koitabashi T, Inomata T, Satoh A, Kishihara J, Ishikawa S, Aoyama Y, Niwano H, Izumi T. Evaluation of the impact of atrial fibrillation on rehospitalization events in heart failure patients in recent years. J Cardiol 2012; 60:36-41. [PMID: 22429679 DOI: 10.1016/j.jjcc.2012.01.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 01/10/2012] [Accepted: 01/25/2012] [Indexed: 11/26/2022]
Abstract
BACKGROUND Although we have previously reported that the presence of paroxysmal atrial fibrillation (AF) is an independent risk factor for rehospitalization in patients with congestive heart failure (CHF) in a population from 1996 to 2002, the impact of AF configuration as a risk factor in a more recent population remains to be clarified. METHODS AND RESULTS 319 patients with CHF admitted to our institute in 2006-2007 were retrospectively evaluated. The patients were divided into 3 groups in accordance with their basic cardiac rhythm, i.e. sinus rhythm (n=210), chronic AF (n=68), and paroxysmal AF (n=41). During the follow-up period of 19 ± 17 months, there was no significant difference in mortality or rehospitalization events among the 3 groups (p=0.542). In the multivariate analysis, no administration of β-blockers was the only independent risk factor for rehospitalization due to CHF exacerbation. CONCLUSIONS The clinical impact of AF configuration as a risk factor of rehospitalization due to CHF exacerbation was considered to be decreased in recent years.
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Affiliation(s)
- Masami Murakami
- Department of Cardio-Angiology, Kitasato University School of Medicine, Kanagawa, Japan.
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Aoyama Y, Niwano S, Niwano H, Satoh A, Kishihara J, Ishikawa S, Murakami M, Fukumoto K, Ueno K, Izumi T. Repetitive evaluation of fibrillation cycle length predicts the efficacy of bepridil for interruption of long-lasting persistent atrial fibrillation. Int Heart J 2012; 52:353-8. [PMID: 22188708 DOI: 10.1536/ihj.52.353] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Although bepridil is effective for conversion of long-lasting persistent atrial fibrillation (AF) to sinus rhythm, it sometimes takes a long time to interrupt AF and there is no feasible index to predict its efficacy.In 60 patients with long-lasting persistent AF, bepridil (100-200 mg/day) was administered and continued for 8 weeks while body surface ECG was recorded every 2 weeks. The fibrillation cycle length (FCL) was evaluated using the spectral analysis of the fibrillation waves in each ECG. AF was interrupted in 32 patients receiving bepridil. The conversion was observed at 2 weeks in 4, at 4 weeks in 7, at 6 weeks in 7, and at 8 weeks in 14 patients. When comparing these responders and nonresponders, clinical background characteristics other than the dosage of bepridil did not show any difference and neither did temporal changes in QT parameters and heart rate. In contrast, the FCL and ΔFCL (prolongation in FCL from baseline) became significantly larger in responders than in nonresponders at later observation points (FCL: 177 ± 17 versus 164 ± 19 ms, P = 0.018, and ΔFCL: 38 ± 16 versus 22 ± 12 ms, P < 0.001, at 4-week point; FCL: 188 ± 17 versus 169 ± 19 ms, P = 0.004, and ΔFCL: 49 ± 18 versus 27 ± 14 ms, P < 0.001, at 6-week point).Repetitive evaluation of FCL using spectral analysis of fibrillation waves can be a feasible index to predict the efficacy of bepridil therapy.
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Affiliation(s)
- Yuya Aoyama
- Department of Cardio-Angiology, Kitasato University School of Medicine, Kanagawa, Japan
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Niwano S, Hirasawa S, Niwano H, Sasaki S, Masuda R, Sato K, Masuda T, Izumi T. Cardioprotective Effects of Sarcolemmal and Mitochondrial K-ATP Channel Openers in an Experimental Model of Autoimmune Myocarditis. Int Heart J 2012; 53:139-45. [DOI: 10.1536/ihj.53.139] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Shinichi Niwano
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Shoji Hirasawa
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Hiroe Niwano
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Sae Sasaki
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | | | - Kiyotaka Sato
- Department of Neurology, Kitasato University School of Medicine
| | - Takashi Masuda
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Tohru Izumi
- Department of Cardio-Angiology, Kitasato University School of Medicine
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Satoh A, Niwano S, Niwano H, Kamiya K, Kishihara J, Aoyama Y, Kameda R, Oikawa J, Yuge M, Izumi T. Prediction of Inappropriate Implantable Cardioverter-Defibrillator Therapies Through Parameters Obtained in a Simple Exercise Stress Test. Int Heart J 2012; 53:276-81. [DOI: 10.1536/ihj.53.276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Akira Satoh
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Shinichi Niwano
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Hiroe Niwano
- Department of Education, College of Education, Tamagawa University
| | - Kentaro Kamiya
- Cardiac Rehabilitation Room, Kitasato University Hospital
| | - Jun Kishihara
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Yuya Aoyama
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Ryo Kameda
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Jun Oikawa
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Masaru Yuge
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Tohru Izumi
- Department of Cardio-Angiology, Kitasato University School of Medicine
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Kurokawa S, Niwano S, Niwano H, Ishikawa S, Kishihara J, Aoyama Y, Kosukegawa T, Masaki Y, Izumi T. Progression of ventricular remodeling and arrhythmia in the primary hyperoxidative state of glutathione-depleted rats. Circ J 2011; 75:1386-93. [PMID: 21498908 DOI: 10.1253/circj.cj-10-1089] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Although oxidative stress is considered to promote arrhythmogenic substrates in diseased model animals, it is difficult to evaluate its primary role. In this study, we evaluated the promotion of arrhythmogenic substrates in the primary hyperoxidative state. METHODS AND RESULTS Sprague-Dawley rats were treated with L-buthionine-sulfoximine (BSO, 30 mmol · L(-1) · day(-1)) for 14 days. On day 7 or 14, the serum levels of derivatives of reactive oxygen metabolites (d-ROM) were measured, and immune staining of 8-hydroxy-2'-deoxyguanosine (8O HdG) was performed to assess oxidative stress. The ventricular effective refractory period (ERP), monophasic action potential duration (MAPD), and the inducibility of ventricular arrhythmia were also evaluated. BSO rats exhibited higher serum d-ROM and clearer 8OHdG staining than the controls. The inducibility of ventricular arrhythmia was higher in the BSO rats than in the controls. The ERP was shorter in the BSO rats than the control (day 14, 32 ± 1 vs. 36 ± 1 ms, P<0.05), whereas the MAPD(90) was longer in the BSO rats (day 14, 76 ± 5 vs. 55 ± 4 ms, P<0.05). The mRNA levels of Kv4.2, erg, and SERCA2a were downregulated in the BSO rats (P < 0.05), and Western blot analysis exhibited the downregulation of erg and SERCA2 expression in the BSO rats (P < 0.05). CONCLUSIONS Systemic oxidative stress might be one of the primary factors promoting cardiac electrophysiological remodeling and increasing the inducibility of arrhythmia independently of major organ disorders.
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Affiliation(s)
- Sayaka Kurokawa
- Department of Cardio-Angiology, Kitasato University School of Medicine, Sagamihara, Japan.
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Aoyama Y, Niwano S, Niwano H, Yumoto Y, Sato A, Kishihara J, Izumi T. Repetitive Evaluation of Fibrillation Cycle Length Predicts the Effect of Bepridil for Conversion of Long-Lasting Persistent Atrial Fibrillation to Sinus Rhythm. J Arrhythm 2011. [DOI: 10.4020/jhrs.27.op51_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Kishihara J, Niwano S, Niwano H, Satoh A, Aoyama Y, Izumi T. Extracellular Matrix Gene Up-Regulation Was Observed Only in the Atria, Not in the Ventricle in the Canine Atrial Fibrillation Model. J Arrhythm 2011. [DOI: 10.4020/jhrs.27.op22_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Satoh A, Niwano S, Niwano H, Kishihara J, Aoyama Y, Izumi T. Direct Renin Inhibitor Suppresses the Atrial Remodeling and AF Inducibility in the Canine AF Model. J Arrhythm 2011. [DOI: 10.4020/jhrs.27.op51_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Niwano S, Niwano H, Sasaki S, Fukaya H, Yuge M, Imaki R, Machida Y, Izumi T. N-Acetylcysteine Suppresses the Progression of Ventricular Remodeling in Acute Myocarditis - Studies in an Experimental Autoimmune Myocarditis (EAM) Model -. Circ J 2011; 75:662-71. [DOI: 10.1253/circj.cj-10-0673] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Shinichi Niwano
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Hiroe Niwano
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Sae Sasaki
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Hidehira Fukaya
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Masaru Yuge
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Ryuta Imaki
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Yoji Machida
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Tohru Izumi
- Department of Cardio-Angiology, Kitasato University School of Medicine
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Kiryu M, Niwano S, Niwano H, Aoyama Y, Kurokawa S, Yamaoka-Tojo M, Izumi T. Plasma Connective Tissue Growth Factor (CTGF) Would Be a Novel Potential Biomarker of Atrial Structural Remodeling in Patients with Atrial Fibrillation. J Arrhythm 2011. [DOI: 10.4020/jhrs.27.pj1_035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Kurokawa S, Niwano S, Kiryu M, Murakami M, Ishikawa S, Yumoto Y, Moriguchi M, Niwano H, Kosukegawa T, Izumi T. Importance of Morphological Changes in T-U Waves During Bepridil Therapy as a Predictor of Ventricular Arrhythmic Event. Circ J 2010; 74:876-84. [DOI: 10.1253/circj.cj-09-0937] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sayaka Kurokawa
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Shinichi Niwano
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Michiro Kiryu
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Masami Murakami
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Shoko Ishikawa
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Yoshihiro Yumoto
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | | | - Hiroe Niwano
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Tomoko Kosukegawa
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Tohru Izumi
- Department of Cardio-Angiology, Kitasato University School of Medicine
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Hatakeyama Y, Niwano S, Niwano H, Kosukegawa T, Izumi T. Risks and Benefits of Combined Use of Bucolome and Warfarin in Anticoagulation Therapy. Int Heart J 2010; 51:399-403. [DOI: 10.1536/ihj.51.399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Yuko Hatakeyama
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Shinichi Niwano
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Hiroe Niwano
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Tomoko Kosukegawa
- Department of Cardio-Angiology, Kitasato University School of Medicine
| | - Tohru Izumi
- Department of Cardio-Angiology, Kitasato University School of Medicine
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Niwano S, Sasaki T, Kurokawa S, Kiryu M, Fukaya H, Hatakeyama Y, Niwano H, Fujiki A, Izumi T. Predicting the efficacy of antiarrhythmic agents for interrupting persistent atrial fibrillation according to spectral analysis of the fibrillation waves on the surface ECG. Circ J 2009; 73:1210-8. [PMID: 19436116 DOI: 10.1253/circj.cj-08-1139] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Spectral analysis of the fibrillation waves was performed in patients with persistent atrial fibrillation (PAF) to clarify the usefulness of this method of predicting the efficacy of antiarrhythmic agents. METHODS AND RESULTS The 59 patients with PAF were randomly assigned to pilsicainide (150 mg/day) or bepridil (200 mg/day) therapy for 4 weeks under optimal anticoagulation therapy. When the first therapy did not interrupt PAF, the drugs were changed in a cross-over manner. The fibrillation cycle length (FCL) was calculated using spectral analysis of the fibrillation waves on the body-surface ECG every 2 weeks. Pilsicainide and bepridil were effective in 19 and 20 patients, respectively. The FCL at the basic state was longest in the pilsicainide-effective group, moderate in the bepridil-effective group and shortest in the failure group (P<0.05). The change in FCL with drug administration (DeltaFCL) was larger in the effective than in the ineffective cases (P<0.01). Successful interruption of the atrial fibrillation (AF) with pilsicainide could be expected for patients with a FCL >148 ms (sensitivity =0.917, specificity =0.612, P=0.007) and DeltaFCL >41 ms (sensitivity =0.875, specificity =0.833, P=0.001). CONCLUSIONS The FCL reflects the electrophysiological properties of the AF substrate and is considered useful for predicting the efficacy of antiarrhythmic agents.
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Affiliation(s)
- Shinichi Niwano
- Department of Cardio-Angiology, Kitasato University School of Medicine, Kitasato, Sagamihara, Japan.
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Niwano S, Wakisaka Y, Niwano H, Fukaya H, Kurokawa S, Kiryu M, Hatakeyama Y, Izumi T. Prognostic significance of frequent premature ventricular contractions originating from the ventricular outflow tract in patients with normal left ventricular function. Heart 2009; 95:1230-7. [DOI: 10.1136/hrt.2008.159558] [Citation(s) in RCA: 204] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Fukaya H, Niwano S, Sasaki T, Kiryu M, Kurokawa S, Hatakeyama Y, Sato D, Yumoto Y, Moriguchi M, Niwano H, Fujiki A, Izumi T. Attenuating Effects of Anti-Arrhythmic Agents on Changes in Fibrillation Cycle Length in Very Early Phase Paroxysmal Atrial Fibrillation —Spectral Analysis of Fibrillation Waves in Surface ECG—. J Arrhythm 2009. [DOI: 10.1016/s1880-4276(09)80012-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Fukaya H, Niwano S, Sasaki T, Kiryu M, Kurokawa S, Hatakeyama Y, Sato D, Yumoto Y, Moriguchi M, Niwano H, Fujiki A, Izumi T. Attenuating Effects of Anti-Arrhythmic Agents on Changes in Fibrillation Cycle Length in Very Early Phase Paroxysmal Atrial Fibrillation-Spectral Analysis of Fibrillation Waves in Surface ECG-. J Arrhythm 2009. [DOI: 10.4020/jhrs.25.135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Fukaya H, Niwano S, Niwano H, Masaki Y, Kiryu M, Sato D, Moriguchi M, Izumi T. Angiotensin II receptor blocker suppresses the Oxidative Stress, Tissue Inflammation, and Atrial Electrical Remodeling in the Canine Experimental Model. J Mol Cell Cardiol 2008. [DOI: 10.1016/j.yjmcc.2008.09.633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Fukaya H, Niwano S, Satoh D, Masaki Y, Niwano H, Kojima J, Moriguchi M, Izumi T. Inhomogenic effect of bepridil on atrial electrical remodeling in a canine rapid atrial stimulation model. Circ J 2008; 72:318-26. [PMID: 18219173 DOI: 10.1253/circj.72.318] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The antiarrhythmic or reverse remodeling effects of bepridil, a multi-ion channel blocker, have been recently reported, but inhomogeneity of the electrical remodeling and effects of bepridil have been observed in previous reports. In this study, the effect of long-term administration of bepridil on atrial electrical remodeling was evaluated in a comparison of the right and left atrium (RA and LA) in a canine rapid atrial stimulation model. METHODS AND RESULTS In 10 beagle dogs, rapid atrial pacing (400 beats/min) was delivered for 6 weeks and the atrial effective refractory period (AERP), conduction velocity (CV) and inducibility of atrial fibrillation (AF) were evaluated every week. In 5 of the pacing dogs, bepridil (10 mg . kg(-1) . day(-1)) was administered orally, starting 2 weeks after the initiation of the rapid pacing. At the end of the protocol, the hemodynamic parameters and extent of tissue fibrosis were evaluated and the mRNA of SCN5A, Kv4.3, the L-type Ca2+ channel (LCC) and connexin (Cx) 40, 43, and 45 in both atria were examined by quantitative real-time reverse transcriptase-polymerase chain reaction. In the pacing control group, AERP shortening, decreased CV, increased AF inducibility and downregulation of the expression of SCN5A and LCC were observed. In the bepridil group, the AERP exhibited a relatively quick recovery after bepridil was started in the first week and continued to recover gradually until the end of the protocol, but that recovery was smaller in the LA than in the RA. The CV was not affected by bepridil administration. AF inducibility was well suppressed in the RA in the bepridil group, but the induction of short-duration AF could not be suppressed in the LA. The mRNA downregulation of the LCC and SCN5A was negated by bepridil administration in the RA; but not in the LA; however, the data showed similar tendencies. There were no significant differences in the hemodynamic parameters or tissue fibrosis and the mRNA expression of Kv4.3, Cx40, 43, and 45 between the pacing control and bepridil groups. CONCLUSION Bepridil exhibited an anti-electrical remodeling effect in this study as previously reported, but the effect was inhomogeneous between the RA and LA, with the LA appearing to be more resistant to the effect of bepridil.
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Affiliation(s)
- Hidehira Fukaya
- Department of Cardio-Angiology, Kitasato University School of Medicine, 1-15-1 Kitasato,Sagamihara 228-8555, Japan.
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Imaki R, Niwano S, Niwano H, Satoh D, Yoshida T, Masaki Y, Izumi T. Neutral endopeptidase inhibitor suppresses the early phase of atrial electrical remodeling in a canine rapid atrial pacing model. Indian Pacing Electrophysiol J 2008; 8:102-13. [PMID: 18379655 PMCID: PMC2267894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION We examined the acute effects of neutral endopeptidase inhibitor on the hemodynamics and electrical properties of dogs subjected to rapid atrial pacing. METHODS Ten beagle dogs were used and divided into two groups with and without candoxatril, a neutral endopeptidase inhibitor preadministration. Before and after the 6 hours rapid atrial pacing from the right atrial appendage, the hemodynamics, atrial effective refractory period, and monophasic action potential duration of the right atrial appendage were measured and blood samples were collected. Atrial tissue was also excised after the experiment. RESULTS Candoxatril significantly increased plasma ANP levels (Control: 88.4 +/- 50.25 vs. Candoxatril: 197.1 +/- 32.09 pg/ml, p = 0.004) and prevented reductions in atrial effective refractory period and monophasic action potential duration. We further demonstrated that the treated animals exhibited significantly higher levels of atrial tissue cyclic GMP (Control: 28.1 +/- 1.60 fmol/mg vs. Candoxatril: 44.5 +/- 12.28 fmol/mg, p = 0.034) as well as that of plasma cyclic GMP (Control: 32 +/- 5.5 vs. Candoxatril: 42 +/- 7.1 pg/ml, p = 0.028). CONCLUSION Candoxatril suppressed the shortening of atrial effective refractory period and monophasic action potential duration in the rapid atrial pacing model. As plasma ANP and the atrial tissue levels of cyclic GMP were higher in the Candoxatril group than the control, this effect was considered to appear through the reduction of calcium overload caused by ANP and cyclic GMP.
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Niwano S, Sasaki S, Niwano H, Fukaya H, Izumi T. Radical scavengers prevent the development of myocarditis and cardiac remodeling in rat experimental model. J Mol Cell Cardiol 2007. [DOI: 10.1016/j.yjmcc.2007.03.445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Hirasawa S, Niwano S, Sasaki S, Wakisaka Y, Niwano H, Izumi T. Cardioprotective effect of low-dose K-ATP channel opener in myocarditis. J Mol Cell Cardiol 2007. [DOI: 10.1016/j.yjmcc.2007.03.444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Fukaya H, Niwano S, Niwano H, Satoh D, Izumi T. Mechanism of atrial reverse remodeling by combination of multi-ion channel blocker and angiotensine receptor blocker. J Mol Cell Cardiol 2007. [DOI: 10.1016/j.yjmcc.2007.03.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Yoshida T, Niwano S, Niwano H, Imaki R, Satoh D, Masaki Y, Nakazato K, Soma K, Izumi T. Atrial natriuretic peptide (ANP) suppresses acute atrial electrical remodeling in the canine rapid atrial stimulation model. Int J Cardiol 2007; 123:147-54. [PMID: 17376550 DOI: 10.1016/j.ijcard.2006.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Revised: 11/06/2006] [Accepted: 12/11/2006] [Indexed: 11/24/2022]
Abstract
OBJECTIVES Atrial electrical remodeling is considered to play an important role in the appearance of atrial fibrillation. The effect of atrial natriuretic peptide (ANP) on atrial electrical remodeling was evaluated in a canine atrial stimulation model. METHODS In 15 beagle dogs, electrodes for pacing and recording were fixed on the atrial surface. In 10/15 dogs, rapid atrial stimulation (400 bpm) was performed for 7 h at the right atrial appendage (RAA) and the remaining 5 were used as the sham without rapid pacing. In 5/10 dogs with rapid pacing, human atrial natriuretic peptide (ANP) was infused (1.0 microg/kg/min). The effective refractory period (ERP) and the monophasic action potential duration (MAP) were evaluated at 0, 3, and 7 h after rapid pacing. The expression levels of mRNAs of ion channels or transporters were evaluated from the atrial samples of sham and after a 7 hour pacing. RESULTS In the control group with rapid pacing (n=5), the atrial ERP and MAP duration were shortened at all atrial sites, e.g., ERP from 148+/-14 ms to 109+/-8 ms at RAA, P=0.006. In contrast in the ANP group, neither the ERP nor MAP duration showed a significant shortening and the effect of ANP on hemodynamic parameter was relatively small. Expression levels of the mRNA were not significantly different between the control and ANP groups. CONCLUSIONS Administration of ANP prevented the shortening of the ERP and MAP duration in the rapid atrial stimulation model. The effect of ANP on atrial electrical remodeling was considered to be due to its direct action on the myocardium.
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Affiliation(s)
- Toru Yoshida
- Department of Emergency and Critical Care Medicine, Kitasato University School of Medicine, 1-15-1, Kitasato, Sagamihara, Kanagawa, 228-8555, Japan.
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Niwano S, Kojima J, Fukaya H, Sato D, Moriguchi M, Niwano H, Masaki Y, Izumi T. Arrhythmogenic Difference Between the Left and Right Atria During Rapid Atrial Activation in a Canine Model of Atrial Fibrillation. Circ J 2007; 71:1629-35. [PMID: 17895563 DOI: 10.1253/circj.71.1629] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Continuous rapid atrial stimulation causes atrial remodeling, but little is known about the difference in the arrhythmogenicity of the left (LA) and right atria (RA). METHODS AND RESULTS In 14 beagle dogs, continuous rapid pacing (400 beats/min) was delivered from the right (n=7) or left (n=7) atrial appendage (RAA or LAA) for 2 weeks. The atrial effective refractory period (ERP), ERP dispersion, and inducibility of atrial fibrillation (AF) were evaluated along the time course from 4 atrial sites: (1) RAA, (2) area close to the inferior vena cava (IVC), (3) Bachmann's bundle (BB) and (4) LA. The ERP exhibited progressive shortening at all sites, but the degree of shortening differed among them. In the RA stimulation group, ERP shortening was more prominent in the RAA and LA than in the IVC or BB. In contrast, in the LA stimulation group, ERP shortening was more prominent in the LA than in the other sites. As a result, ERP dispersion was larger in the LA stimulation group than in the RA stimulation group and the AF inducibility was higher in the LA stimulation group than in the RA stimulation group, especially at the LA site (p<0.05). CONCLUSION LAA stimulation was more arrhythmogenic than RAA stimulation in this model. This result may partly explain the importance of premature contractions occurring from the pulmonary veins in clinical cases of AF.
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Affiliation(s)
- Shinichi Niwano
- Department of Cardio-angiology, Kitasato University School of Medicine, Sagamihara, Japan.
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Nishii M, Inomata T, Niwano H, Takehana H, Takeuchi I, Nakano H, Shinagawa H, Naruke T, Koitabashi T, Nakahata JI, Izumi T. Beta2-Adrenergic agonists suppress rat autoimmune myocarditis: potential role of beta2-adrenergic stimulants as new therapeutic agents for myocarditis. Circulation 2006; 114:936-44. [PMID: 16908771 DOI: 10.1161/circulationaha.105.607903] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The therapeutic potential of beta2-adrenergic receptor (AR) agonists in the treatment of autoimmune diseases has been reported. However, the role of these drugs in the myocardial structure-induced autoimmune process, which is thought to play a crucial role in the progression of myocarditis to subsequent complications, has not been elucidated. METHODS AND RESULTS Experimental autoimmune myocarditis (EAM) was induced in rats by immunization with cardiac myosin. On daily administration from day 0 after immunization, the beta2-selective AR agonists formoterol or salbutamol ameliorated EAM on day 21 and increased myocardial interleukin-10/interferon-gamma mRNA levels. Propranolol, a nonselective beta-AR antagonist, aggravated EAM on day 21 and decreased mRNA levels, whereas metoprolol, a beta1-selective AR antagonist, showed no effect. These results were reflected in vivo by the proliferation of cardiac myosin-primed lymph node cells from drug-treated rats. In vitro addition of beta2-selective AR agonists inhibited the activation of cardiac myosin fragment-specific myocarditogenic T lymphocytes, and this effect was reversed by ICI118,551, a beta2-selective AR antagonist. Furthermore, treatment with 2 different beta2-selective AR agonists starting on day 14 also ameliorated EAM on day 21. CONCLUSIONS beta2-AR stimulation suppressed the development of EAM by inhibiting cardiac myosin-specific T-lymphocyte activation in lymphoid organs and by shifting the imbalance in Th1/Th2 cytokine toward Th2 cytokine. Furthermore, it also ameliorated established myocardial inflammation. beta2-AR-stimulating agents may represent important immunomodulators of the cardiac myosin-induced autoimmune process and have potential as a new therapy for myocarditis.
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Affiliation(s)
- Mototsugu Nishii
- Department of Internal Medicine and Cardiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara, 228-8555 Japan.
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Sato D, Niwano S, Imaki R, Masaki Y, Sasaki S, Yuge M, Hirasawa S, Sasaki T, Moriguchi M, Niwano H, Yoshimura H, Izumi T. Bepridil inhibits sub-acute phase of atrial electrical remodeling in canine rapid atrial stimulation model. Circ J 2006; 70:206-13. [PMID: 16434817 DOI: 10.1253/circj.70.206] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Background The effect of bepridil, a multichannel blocker, on atrial electrical remodeling was evaluated in a canine rapid atrial stimulation model. Methods and Results In 10 beagle dogs, the right atrial appendage (RAA) was paced at 400 beats/min for 2 weeks. The atrial electrophysiological parameters, including effective refractory period (AERP), were evaluated at three atrial sites: RAA, the right atrium close to the inferior vena cava (IVC) and the left atrium (LA), during the time course of rapid pacing. Five of the dogs were given bepridil (10 mg . kg (-1) . day(-1) po). In the control group, AERP was significantly shortened at all atrial sites and the AERP shortening (DeltaAERP) was larger for the RAA and LA than at the IVC site (p<0.05). In the bepridil group, DeltaAERP was smaller than that of the controls at all atrial sites, and the AERP started to return slowly to the pre-pacing level in the second week, regardless of the continuation of rapid pacing. Conclusions In a canine rapid atrial stimulation model, bepridil suppressed AERP shortening. Bepridil might have a reverse electrical remodeling effect, at least for AERP shortening, because it showed slow recovery of AERP in the subacute phase of rapid atrial pacing. (Circ J 2006; 70: 206 - 213).
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Affiliation(s)
- Daisuke Sato
- Departments of Angiocardiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara 228-8555, Japan.
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Kawada H, Niwano S, Niwano H, Yumoto Y, Wakisaka Y, Yuge M, Kawahara K, Izumi T. Tumor Necrosis Factor-.ALPHA. Downregulates the Voltage Gated Outward K+ Current in Cultured Neonatal Rat Cardiomyocytes A Possible Cause of Electrical Remodeling in Diseased Hearts. Circ J 2006; 70:605-9. [PMID: 16636498 DOI: 10.1253/circj.70.605] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Inflammatory cytokines have been reported to contribute to the progression of cardiac remodeling in various heart diseases and a remarkable prolongation of the monophasic action potential duration and reductions in the expression of Kv4.2 and K+ channel-interacting protein-2 (KChIP-2) in a rat autoimmune myocarditis model have been documented. In this study, the effect of tumor necrosis factor-alpha (TNF-alpha) on cultured cardiomyocytes was evaluated, focusing on the change in the voltage-gated outward K+ current and expression of related molecules. METHODS AND RESULTS Cardiomyocytes isolated from 1-day-old Lewis rats were cultured for 72 h and treated with TNF-alpha (50 ng/ml) for an additional 48 h. The myocytes treated with TNF-alpha showed a 22% reduction in the peak K+ current, which consisted of a transient outward K+ current (Ito) and 1.4-fold enhancement of the cell-capacitance in comparison with the control. Among the cardiac ion channel related molecules evaluated in this study, Kv4.2 and KChIP-2 mRNA exhibited remarkable reductions (p < 0.05). CONCLUSIONS Treatment with TNF-alpha induced reductions in Ito as well as cellular hypertrophy in neonatal cultured myocytes, which indicates that TNF-alpha might play a role in promoting electrical remodeling of cardiomyocytes under inflammatory conditions.
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MESH Headings
- Action Potentials
- Animals
- Animals, Newborn
- Cells, Cultured
- Disease Models, Animal
- Down-Regulation/drug effects
- Down-Regulation/genetics
- Heart Diseases/pathology
- Heart Diseases/physiopathology
- Hypertrophy/chemically induced
- Hypertrophy/pathology
- Kv Channel-Interacting Proteins/drug effects
- Kv Channel-Interacting Proteins/genetics
- Myocarditis/immunology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Potassium/metabolism
- Potassium Channels, Voltage-Gated/drug effects
- Potassium Channels, Voltage-Gated/genetics
- RNA, Messenger/analysis
- Rats
- Rats, Inbred Lew
- Shal Potassium Channels/drug effects
- Shal Potassium Channels/genetics
- Tumor Necrosis Factor-alpha/pharmacology
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Affiliation(s)
- Hideaki Kawada
- Department of Angio-cardiology, Kitasato University School of Medicine, Sagamihara, Japan
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