The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
Tohru Izumi - One of the best experts on this subject based on the ideXlab platform.
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importance of morphological changes in t u waves during Bepridil therapy as a predictor of ventricular arrhythmic event
Circulation, 2010Co-Authors: Sayaka Kurokawa, Shinichi Niwano, Hiroe Niwano, Masahiko Moriguchi, Michiro Kiryu, Masami Murakami, Shoko Ishikawa, Yoshihiro Yumoto, Tomoko Kosukegawa, Tohru IzumiAbstract:Background: Although Bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during Bepridil therapy and was examined as a predictor of ventricular arrhythmic events. Methods and Results: The study population consisted of 113 patients on Bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V2-5. During Bepridil treatment, the QTc interval was prolonged from 0.45±0.01 to 0.49±0.01 s1/2 in all patients (P<0.0001) and any type of T-U wave change (fused U, slurred, bifid, biphasic or negative) appeared in 73% of event-free and 100% of event groups. In univariate analysis, QTc interval before Bepridil (P=0.028), a wide QRS complex (P=0.042) before Bepridil, biphasic (P=0.027) or negative (P=0.002) T-U waves in the stable phase, and the new appearance of biphasic (P=0.004) or negative (P<0.0001) T-U waves exhibited significant differences. In multivariate analysis, only newly appeared negative T-U wave exhibited a significant difference (odds ratio 10.13, 95% confidence interval = 0.031-2.302, P=0.041). Conclusions: In patients with stable Bepridil treatment, a change in T-U wave morphology might be a useful predictor of ventricular arrhythmia assisting the QT interval. (Circ J 2010; 74: 876 - 884)
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Importance of morphological changes in T-U waves during Bepridil therapy as a predictor of ventricular arrhythmic event.
Circulation Journal, 2010Co-Authors: Sayaka Kurokawa, Shinichi Niwano, Hiroe Niwano, Masahiko Moriguchi, Michiro Kiryu, Masami Murakami, Shoko Ishikawa, Yoshihiro Yumoto, Tomoko Kosukegawa, Tohru IzumiAbstract:Background: Although Bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during Bepridil therapy and was examined as a predictor of ventricular arrhythmic events. Methods and Results: The study population consisted of 113 patients on Bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V2-5. During Bepridil treatment, the QTc interval was prolonged from 0.45±0.01 to 0.49±0.01 s1/2 in all patients (P
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inhomogenic effect of Bepridil on atrial electrical remodeling in a canine rapid atrial stimulation model
Circulation, 2008Co-Authors: Hidehira Fukaya, Shinichi Niwano, Jisho Kojima, Daisuke Satoh, Yoshihiko Masaki, Hiroe Niwano, Masahiko Moriguchi, Tohru IzumiAbstract: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. (Circ J 2008; 72: 318 - 326)
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Bepridil prevents paroxysmal atrial fibrillation by a class iii antiarrhythmic drug effect
Pacing and Clinical Electrophysiology, 2003Co-Authors: Toru Yoshida, Shinichi Niwano, Kimiatsu Inuo, Junko Saito, Jisho Kojima, Kazuko Ikedamurakami, Hideyuki Hara, Tohru IzumiAbstract:YOSHIDA, T., et al.: Bepridil Prevents Paroxysmal Atrial Fibrillation by a Class III Antiarrhythmic Drug Effect.Background: Bepridil, a multiple ion-channel blocker, has been reported to prevent paroxysmal atrial fibrillation (PAF). The f-f interval of PAF during treatment with Bepridil versus class Ic antiarrhythmic drugs was compared. Methods: Fifty-two patients with PAF were randomized to Bepridil, 200 mg/day (n = 14)versus flecainide, 100 to 200 mg/day(n = 15)or pilsicainide, 75 to 150 mg/day(n = 23). The drug was considered effective when symptomatic episodes of PAF were decreased to < 50% during a follow-up of 2 to 6 months. The f-f interval was measured in 12-lead ECGs of initial PAF episodes. Results: Bepridil and Ic were effective in 10 of 14 (71.4%) and 24 of 38 patients (63.2%), respectively (ns). In the Ic group, the f-f interval was longer in successfully(114 ± 48 ms)than in unsuccessfully(68 ± 25 ms)treated patients(P = 0.002). In the Bepridil group, the f-f interval was shorter in successfully(84 ± 27 ms)than unsuccessfully(155 ± 68 ms)treated patients(P = 0.015). When comparing unsuccessfully treated patients, the f-f interval in the Bepridil group was significantly longer than in the Ic group(P = 0.007). Conclusions: Bepridil was as effective as Ic drugs in the prevention of PAF. Because it was more effective in smaller (functional) than larger (anatomical) reentrant circuits, the effect of Bepridil was considered to be mainly attributable to a class III antiarrhythmic action. (PACE 2003; 26[Pt. II]:314–317)
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evaluation of the effect of Bepridil on paroxysmal atrial fibrillation relationship between efficacy and the f f interval in surface ecg recordings
Circulation, 2003Co-Authors: Toru Yoshida, Shinichi Niwano, Kimiatsu Inuo, Junko Saito, Jisho Kojima, Kazuko Ikedamurakami, Hideyuki Hara, Tohru IzumiAbstract:Bepridil, a multi-ion channel blocker, is effective for some types of cardiac arrhythmias, and so its effect on the paroxysmal atrial fibrillation (PAF) was evaluated in the present study, comparing it with class Ic antiarrhythmic drugs. The relationship between efficacy and the f-f interval in the surface ECG recording was also analyzed. Sixty-one symptomatic PAF patients were randomized to a Bepridil group (200 mg/day, n=23) or class Ic drug group (flecainide 100-200 mg/day or pilsicainide 75-150 mg/day, n=38). The drug was considered effective for PAF prevention when symptomatic episodes of PAF were decreased to less than 50% during the follow-up period of 2-6 months. The f-f interval in the surface 12-lead ECG trace was evaluated during a PAF episode. Both Bepridil and the class Ic drugs were effectively prevented PAF (15/23 (65.2%) vs 24/38 (63.1%) patients, NS). In the class Ic drug group, the f-f interval was longer in the effective cases (114+/-48 ms) than in the non-effective cases (68+/-26 ms, p=0.0002). In contrast, in the Bepridil group the f-f interval was shorter in the effective cases (85+/-26 ms) than in the non-effective ones (152+/-45 ms, p=0.0005). When comparing the non-effective cases in the 2 groups, the Bepridil group showed a significantly longer f-f interval than the class Ic drug group (p=0.0003). As a result of drug administration, the class Ic drugs prolonged the f-f interval from 78+/-33 ms to 128+/-46 ms (p=0.0004) whereas Bepridil showed no change (109+/-39 ms vs 135+/-47 ms). For clinical PAF prevention, the effect of Bepridil matched that of class Ic antiarrhythmic drugs. Because Bepridil was effective in PAF patients with relatively shorter f-f intervals without prolonging the f-f interval, Bepridil is considered to work mainly as a class III antiarrhythmic drug.
Shinichi Niwano - One of the best experts on this subject based on the ideXlab platform.
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importance of morphological changes in t u waves during Bepridil therapy as a predictor of ventricular arrhythmic event
Circulation, 2010Co-Authors: Sayaka Kurokawa, Shinichi Niwano, Hiroe Niwano, Masahiko Moriguchi, Michiro Kiryu, Masami Murakami, Shoko Ishikawa, Yoshihiro Yumoto, Tomoko Kosukegawa, Tohru IzumiAbstract:Background: Although Bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during Bepridil therapy and was examined as a predictor of ventricular arrhythmic events. Methods and Results: The study population consisted of 113 patients on Bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V2-5. During Bepridil treatment, the QTc interval was prolonged from 0.45±0.01 to 0.49±0.01 s1/2 in all patients (P<0.0001) and any type of T-U wave change (fused U, slurred, bifid, biphasic or negative) appeared in 73% of event-free and 100% of event groups. In univariate analysis, QTc interval before Bepridil (P=0.028), a wide QRS complex (P=0.042) before Bepridil, biphasic (P=0.027) or negative (P=0.002) T-U waves in the stable phase, and the new appearance of biphasic (P=0.004) or negative (P<0.0001) T-U waves exhibited significant differences. In multivariate analysis, only newly appeared negative T-U wave exhibited a significant difference (odds ratio 10.13, 95% confidence interval = 0.031-2.302, P=0.041). Conclusions: In patients with stable Bepridil treatment, a change in T-U wave morphology might be a useful predictor of ventricular arrhythmia assisting the QT interval. (Circ J 2010; 74: 876 - 884)
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Importance of morphological changes in T-U waves during Bepridil therapy as a predictor of ventricular arrhythmic event.
Circulation Journal, 2010Co-Authors: Sayaka Kurokawa, Shinichi Niwano, Hiroe Niwano, Masahiko Moriguchi, Michiro Kiryu, Masami Murakami, Shoko Ishikawa, Yoshihiro Yumoto, Tomoko Kosukegawa, Tohru IzumiAbstract:Background: Although Bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during Bepridil therapy and was examined as a predictor of ventricular arrhythmic events. Methods and Results: The study population consisted of 113 patients on Bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V2-5. During Bepridil treatment, the QTc interval was prolonged from 0.45±0.01 to 0.49±0.01 s1/2 in all patients (P
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inhomogenic effect of Bepridil on atrial electrical remodeling in a canine rapid atrial stimulation model
Circulation, 2008Co-Authors: Hidehira Fukaya, Shinichi Niwano, Jisho Kojima, Daisuke Satoh, Yoshihiko Masaki, Hiroe Niwano, Masahiko Moriguchi, Tohru IzumiAbstract: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. (Circ J 2008; 72: 318 - 326)
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Bepridil prevents paroxysmal atrial fibrillation by a class iii antiarrhythmic drug effect
Pacing and Clinical Electrophysiology, 2003Co-Authors: Toru Yoshida, Shinichi Niwano, Kimiatsu Inuo, Junko Saito, Jisho Kojima, Kazuko Ikedamurakami, Hideyuki Hara, Tohru IzumiAbstract:YOSHIDA, T., et al.: Bepridil Prevents Paroxysmal Atrial Fibrillation by a Class III Antiarrhythmic Drug Effect.Background: Bepridil, a multiple ion-channel blocker, has been reported to prevent paroxysmal atrial fibrillation (PAF). The f-f interval of PAF during treatment with Bepridil versus class Ic antiarrhythmic drugs was compared. Methods: Fifty-two patients with PAF were randomized to Bepridil, 200 mg/day (n = 14)versus flecainide, 100 to 200 mg/day(n = 15)or pilsicainide, 75 to 150 mg/day(n = 23). The drug was considered effective when symptomatic episodes of PAF were decreased to < 50% during a follow-up of 2 to 6 months. The f-f interval was measured in 12-lead ECGs of initial PAF episodes. Results: Bepridil and Ic were effective in 10 of 14 (71.4%) and 24 of 38 patients (63.2%), respectively (ns). In the Ic group, the f-f interval was longer in successfully(114 ± 48 ms)than in unsuccessfully(68 ± 25 ms)treated patients(P = 0.002). In the Bepridil group, the f-f interval was shorter in successfully(84 ± 27 ms)than unsuccessfully(155 ± 68 ms)treated patients(P = 0.015). When comparing unsuccessfully treated patients, the f-f interval in the Bepridil group was significantly longer than in the Ic group(P = 0.007). Conclusions: Bepridil was as effective as Ic drugs in the prevention of PAF. Because it was more effective in smaller (functional) than larger (anatomical) reentrant circuits, the effect of Bepridil was considered to be mainly attributable to a class III antiarrhythmic action. (PACE 2003; 26[Pt. II]:314–317)
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evaluation of the effect of Bepridil on paroxysmal atrial fibrillation relationship between efficacy and the f f interval in surface ecg recordings
Circulation, 2003Co-Authors: Toru Yoshida, Shinichi Niwano, Kimiatsu Inuo, Junko Saito, Jisho Kojima, Kazuko Ikedamurakami, Hideyuki Hara, Tohru IzumiAbstract:Bepridil, a multi-ion channel blocker, is effective for some types of cardiac arrhythmias, and so its effect on the paroxysmal atrial fibrillation (PAF) was evaluated in the present study, comparing it with class Ic antiarrhythmic drugs. The relationship between efficacy and the f-f interval in the surface ECG recording was also analyzed. Sixty-one symptomatic PAF patients were randomized to a Bepridil group (200 mg/day, n=23) or class Ic drug group (flecainide 100-200 mg/day or pilsicainide 75-150 mg/day, n=38). The drug was considered effective for PAF prevention when symptomatic episodes of PAF were decreased to less than 50% during the follow-up period of 2-6 months. The f-f interval in the surface 12-lead ECG trace was evaluated during a PAF episode. Both Bepridil and the class Ic drugs were effectively prevented PAF (15/23 (65.2%) vs 24/38 (63.1%) patients, NS). In the class Ic drug group, the f-f interval was longer in the effective cases (114+/-48 ms) than in the non-effective cases (68+/-26 ms, p=0.0002). In contrast, in the Bepridil group the f-f interval was shorter in the effective cases (85+/-26 ms) than in the non-effective ones (152+/-45 ms, p=0.0005). When comparing the non-effective cases in the 2 groups, the Bepridil group showed a significantly longer f-f interval than the class Ic drug group (p=0.0003). As a result of drug administration, the class Ic drugs prolonged the f-f interval from 78+/-33 ms to 128+/-46 ms (p=0.0004) whereas Bepridil showed no change (109+/-39 ms vs 135+/-47 ms). For clinical PAF prevention, the effect of Bepridil matched that of class Ic antiarrhythmic drugs. Because Bepridil was effective in PAF patients with relatively shorter f-f intervals without prolonging the f-f interval, Bepridil is considered to work mainly as a class III antiarrhythmic drug.
Masahiko Moriguchi - One of the best experts on this subject based on the ideXlab platform.
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importance of morphological changes in t u waves during Bepridil therapy as a predictor of ventricular arrhythmic event
Circulation, 2010Co-Authors: Sayaka Kurokawa, Shinichi Niwano, Hiroe Niwano, Masahiko Moriguchi, Michiro Kiryu, Masami Murakami, Shoko Ishikawa, Yoshihiro Yumoto, Tomoko Kosukegawa, Tohru IzumiAbstract:Background: Although Bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during Bepridil therapy and was examined as a predictor of ventricular arrhythmic events. Methods and Results: The study population consisted of 113 patients on Bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V2-5. During Bepridil treatment, the QTc interval was prolonged from 0.45±0.01 to 0.49±0.01 s1/2 in all patients (P<0.0001) and any type of T-U wave change (fused U, slurred, bifid, biphasic or negative) appeared in 73% of event-free and 100% of event groups. In univariate analysis, QTc interval before Bepridil (P=0.028), a wide QRS complex (P=0.042) before Bepridil, biphasic (P=0.027) or negative (P=0.002) T-U waves in the stable phase, and the new appearance of biphasic (P=0.004) or negative (P<0.0001) T-U waves exhibited significant differences. In multivariate analysis, only newly appeared negative T-U wave exhibited a significant difference (odds ratio 10.13, 95% confidence interval = 0.031-2.302, P=0.041). Conclusions: In patients with stable Bepridil treatment, a change in T-U wave morphology might be a useful predictor of ventricular arrhythmia assisting the QT interval. (Circ J 2010; 74: 876 - 884)
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Importance of morphological changes in T-U waves during Bepridil therapy as a predictor of ventricular arrhythmic event.
Circulation Journal, 2010Co-Authors: Sayaka Kurokawa, Shinichi Niwano, Hiroe Niwano, Masahiko Moriguchi, Michiro Kiryu, Masami Murakami, Shoko Ishikawa, Yoshihiro Yumoto, Tomoko Kosukegawa, Tohru IzumiAbstract:Background: Although Bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during Bepridil therapy and was examined as a predictor of ventricular arrhythmic events. Methods and Results: The study population consisted of 113 patients on Bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V2-5. During Bepridil treatment, the QTc interval was prolonged from 0.45±0.01 to 0.49±0.01 s1/2 in all patients (P
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inhomogenic effect of Bepridil on atrial electrical remodeling in a canine rapid atrial stimulation model
Circulation, 2008Co-Authors: Hidehira Fukaya, Shinichi Niwano, Jisho Kojima, Daisuke Satoh, Yoshihiko Masaki, Hiroe Niwano, Masahiko Moriguchi, Tohru IzumiAbstract: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. (Circ J 2008; 72: 318 - 326)
Hiroe Niwano - One of the best experts on this subject based on the ideXlab platform.
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importance of morphological changes in t u waves during Bepridil therapy as a predictor of ventricular arrhythmic event
Circulation, 2010Co-Authors: Sayaka Kurokawa, Shinichi Niwano, Hiroe Niwano, Masahiko Moriguchi, Michiro Kiryu, Masami Murakami, Shoko Ishikawa, Yoshihiro Yumoto, Tomoko Kosukegawa, Tohru IzumiAbstract:Background: Although Bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during Bepridil therapy and was examined as a predictor of ventricular arrhythmic events. Methods and Results: The study population consisted of 113 patients on Bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V2-5. During Bepridil treatment, the QTc interval was prolonged from 0.45±0.01 to 0.49±0.01 s1/2 in all patients (P<0.0001) and any type of T-U wave change (fused U, slurred, bifid, biphasic or negative) appeared in 73% of event-free and 100% of event groups. In univariate analysis, QTc interval before Bepridil (P=0.028), a wide QRS complex (P=0.042) before Bepridil, biphasic (P=0.027) or negative (P=0.002) T-U waves in the stable phase, and the new appearance of biphasic (P=0.004) or negative (P<0.0001) T-U waves exhibited significant differences. In multivariate analysis, only newly appeared negative T-U wave exhibited a significant difference (odds ratio 10.13, 95% confidence interval = 0.031-2.302, P=0.041). Conclusions: In patients with stable Bepridil treatment, a change in T-U wave morphology might be a useful predictor of ventricular arrhythmia assisting the QT interval. (Circ J 2010; 74: 876 - 884)
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Importance of morphological changes in T-U waves during Bepridil therapy as a predictor of ventricular arrhythmic event.
Circulation Journal, 2010Co-Authors: Sayaka Kurokawa, Shinichi Niwano, Hiroe Niwano, Masahiko Moriguchi, Michiro Kiryu, Masami Murakami, Shoko Ishikawa, Yoshihiro Yumoto, Tomoko Kosukegawa, Tohru IzumiAbstract:Background: Although Bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during Bepridil therapy and was examined as a predictor of ventricular arrhythmic events. Methods and Results: The study population consisted of 113 patients on Bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V2-5. During Bepridil treatment, the QTc interval was prolonged from 0.45±0.01 to 0.49±0.01 s1/2 in all patients (P
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inhomogenic effect of Bepridil on atrial electrical remodeling in a canine rapid atrial stimulation model
Circulation, 2008Co-Authors: Hidehira Fukaya, Shinichi Niwano, Jisho Kojima, Daisuke Satoh, Yoshihiko Masaki, Hiroe Niwano, Masahiko Moriguchi, Tohru IzumiAbstract: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. (Circ J 2008; 72: 318 - 326)
Sayaka Kurokawa - One of the best experts on this subject based on the ideXlab platform.
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importance of morphological changes in t u waves during Bepridil therapy as a predictor of ventricular arrhythmic event
Circulation, 2010Co-Authors: Sayaka Kurokawa, Shinichi Niwano, Hiroe Niwano, Masahiko Moriguchi, Michiro Kiryu, Masami Murakami, Shoko Ishikawa, Yoshihiro Yumoto, Tomoko Kosukegawa, Tohru IzumiAbstract:Background: Although Bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during Bepridil therapy and was examined as a predictor of ventricular arrhythmic events. Methods and Results: The study population consisted of 113 patients on Bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V2-5. During Bepridil treatment, the QTc interval was prolonged from 0.45±0.01 to 0.49±0.01 s1/2 in all patients (P<0.0001) and any type of T-U wave change (fused U, slurred, bifid, biphasic or negative) appeared in 73% of event-free and 100% of event groups. In univariate analysis, QTc interval before Bepridil (P=0.028), a wide QRS complex (P=0.042) before Bepridil, biphasic (P=0.027) or negative (P=0.002) T-U waves in the stable phase, and the new appearance of biphasic (P=0.004) or negative (P<0.0001) T-U waves exhibited significant differences. In multivariate analysis, only newly appeared negative T-U wave exhibited a significant difference (odds ratio 10.13, 95% confidence interval = 0.031-2.302, P=0.041). Conclusions: In patients with stable Bepridil treatment, a change in T-U wave morphology might be a useful predictor of ventricular arrhythmia assisting the QT interval. (Circ J 2010; 74: 876 - 884)
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Importance of morphological changes in T-U waves during Bepridil therapy as a predictor of ventricular arrhythmic event.
Circulation Journal, 2010Co-Authors: Sayaka Kurokawa, Shinichi Niwano, Hiroe Niwano, Masahiko Moriguchi, Michiro Kiryu, Masami Murakami, Shoko Ishikawa, Yoshihiro Yumoto, Tomoko Kosukegawa, Tohru IzumiAbstract:Background: Although Bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during Bepridil therapy and was examined as a predictor of ventricular arrhythmic events. Methods and Results: The study population consisted of 113 patients on Bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V2-5. During Bepridil treatment, the QTc interval was prolonged from 0.45±0.01 to 0.49±0.01 s1/2 in all patients (P