Circulation Journal
Online ISSN : 1347-4820
Print ISSN : 1346-9843
ISSN-L : 1346-9843
Volume 68 , Issue 7
Showing 1-23 articles out of 23 articles from the selected issue
Clinical Investigation
  • Maki Kida, Takashi Kawamura, Toshio Fukuoka, Akiko Tamakoshi, Kenji Wa ...
    2004 Volume 68 Issue 7 Pages 603-609
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background The factors that influence survival of out-of-hospital cardiac arrest in Japan have not been fully investigated. Methods and Results The official emergency service record was used to investigate 1,600 patients for whom cardiopulmonary resuscitation was attempted by the city's emergency personnel. Only 45 (2.8%) patients survived for 1 month. The survival rate was 9.8% in the patients under 20 years of age, with a marked decreasing trend to 0.8% in the patients aged 80 years or older. The rate peaked at 4.8% on Sunday and bottomed out at 0.5% on Thursday, forming a distinct sine curve. The survival rate was 9.9% when an ambulance arrived at the scene within 4 min, with a steep drop to 2.5% when 4-7 min elapsed. However, the rate was not significantly different by the interval to hospital. Although bystander resuscitation did not significantly affect the survival, paramedics on board significantly improved the rate (3.5% vs 1.6%). Multivariate analysis confirmed that age, day of the week, place, interval to ambulance's arrival, and personnel on board were independently associated with the probability of survival. Conclusions Quick arrival of a paramedic team would improve the survival after out-of-hospital cardiac arrest. General education of lifesaving techniques would be another key factor. (Circ J 2004; 68: 603 - 609)
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  • Makoto Sekiguchi, Hiroshi Hoshizaki, Hitoshi Adachi, Shigeru Ohshima, ...
    2004 Volume 68 Issue 7 Pages 610-614
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background A prospective randomized study compared the preventive effects of ticlopidine plus aspirin therapy versus cilostazol plus aspirin therapy on subacute thrombosis (SAT) and restenosis after coronary stenting. Methods and Results After successful stenting of 327 coronary lesions in 282 consecutive patients, the patients were randomized to receive ticlopidine (200 mg/day) or cilostazol (200 mg/day). Aspirin (81 mg/day) was administered concomitantly in both groups. SAT occurred in 1 patient in the ticlopidine group (0.7%) and in 8 patients in the cilostazol group (5.6%, p=0.037). Based on follow-up angiography, restenosis occurred in 30 patients (23.3%) in the ticlopidine group and 35 patients (26.9%) in the cilostazol group (NS). The late loss was significantly smaller in the cilostazol group than the ticlopidine group (1.08±0.95 mm vs 0.78±0.93 mm, respectively, p=0.037). No significant differences between the 2 groups were observed with respect to the rates of total death, non-fatal cardiovascular events, or bleeding complications. Conclusion The ticlopidine group showed significantly less SAT after stenting compared with the cilostazol group. After 6 months of treatment, the inhibition of neointimal proliferation was greater in the cilostazol group than in the ticlopidine group, but the prevention of restenosis was not confirmed. (Circ J 2004; 68: 610 - 614)
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  • Tomonori Itoh, Hiroshi Nonogi, Shunichi Miyazaki, Akira Itoh, Satoshi ...
    2004 Volume 68 Issue 7 Pages 615-622
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background Effective pharmacological prevention of restenosis using the systemic administration of various drugs that were effective for the prevention of restenosis in experimental studies has not been reported. The purpose of this study was to evaluate whether the local delivery of a potent thrombin inhibitor, argatroban, using a local drug delivery device would prevent restenosis after plain old balloon angioplasty (POBA). Methods and Results Seventy patients with chronic coronary artery disease requiring POBA were randomly assigned to wither the control group (n=35) or the argatroban group (n=35). In the argatroban group, argatroban was administered intravenously for 30 min before the POBA and intracoronarily into the dilated site using a Dispatch catheter immediately after the POBA, followed by a postoperative intravenous infusion for 4 h. The angiographical lesion restenosis and clinical restenosis rates at follow-up were significantly lower in the argatroban group (27% and 14%) than in the control group (56% and 37%; p=0.02 and p=0.03, respectively). There was no major complication during the procedure. Conclusion The local delivery of argatroban is safe and effective in preventing restenosis after balloon angioplasty. (Circ J 2004; 68: 615 - 622)
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  • Kunimasa Yagi, Senshu Hifumi, Atushi Nohara, Toshinori Higashikata, Ak ...
    2004 Volume 68 Issue 7 Pages 623-627
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background The aim of the present study was to clarify the risk factors of several types of arteriosclerosis lesions in Japanese individuals with heterozygous familial hypercholesterolemia (FH): renal arteriosclerosis (RAS), abdominal aortic sclerosis (AOS), iliac arteriosclerosis (IAS) and coronary artery disease (CAD). Methods and Results Coronary angiography (CAG) and abdominal aortic angiography (AAA) were performed in 117 consecutive heterozygous FH subjects (79 men, 38 women; age 22-76). RAS (stenotic lesion or aneurysm) was observed in 39 cases (33%), predominantly in the proximal portion (74%) and both sides equally (right/left = 27/23). Most cases of RAS (64%) presented with <25% stenosis. The differences in the contributing risk factors for the progression and development of RAS, AOS, IAS and CAD in FH were then analyzed. Multiple logistic regression analyses showed independent risk factors for formation of atherosclerosis in each artery were: age alone for RAS; age and plasma low-density lipoprotein cholesterol (LDL-C) for AOS; age, LDL-C and high-density lipoprotein cholesterol (HDL-C) for IAS; and HDL-C and diabetes mellitus for CAD. Conclusion In Japanese subjects with heterozygous FH, there are distinct risk factors for the development and progression of atherosclerosis in the renal, iliac, abdominal aorta, and coronary arteries. (Circ J 2004; 68: 623 - 627)
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  • Norio Miya, Sumito Oguchi, Ikuyoshi Watanabe, Katsuo Kanmatsuse
    2004 Volume 68 Issue 7 Pages 628-633
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background Recently it has become clear that inflammatory changes play a part in the development of atherosclerosis, including coronary artery disease, and Chlamydia pneumoniae (C. pneumoniae) is thought to be a proinflammatory factor. The plasma concentration of high-sensitive C-reactive protein (hs-CRP) is a potential predictor of outcome in atherosclerotic diseases. Recent interest has focused on secretory group IIA phospholipase A2 (sPLA 2) in regard to the progression of atherosclerotic disease. Methods and Results The concentrations of sPLA2, hs-CRP, and the titers of C. pneumoniae IgG and IgA antibodies were measured in blood samples. The study groups were an acute coronary syndrome (ACS) group, old myocardial infarction/angina pectoris (OMI/AP) group, and a control group. The concentrations of sPLA2 and hs-CRP in the ACS group and the OMI/AP group were higher than in the control group. The titers of C. pneumoniae IgG and IgA were higher in the ACS group than in the control group. The sPLA2 concentration was higher in those who were positive to C. pneumoniae IgG/IgA than in those who were negative. Conclusion Increased concentrations of sPLA2 reflect participation in the progression of coronary artery disease. The sPLA2 concentration was higher in patients positive for C. pneumoniae than in those negative for C. pneumoniae, so C. pneumoniae infection poses a greater risk for ACS in those individuals than in those who are free of such infection. (Circ J 2004; 68: 628 - 633)
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  • Grzegorz Raczak, Gian Domenico Pinna, Roberto Maestri, Ludmila Danilow ...
    2004 Volume 68 Issue 7 Pages 634-638
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background Recent data suggest that the electrophysiological study (EPS) has limited value in the identification of high risk patients, so the aim of the present study was to evaluate if non-invasive measurement of baroreflex sensitivity (BRS), a marker of autonomic balance, provides additional prognostic information in patients surviving a sustained arrhythmic episode. Methods and Results The study group comprised 112 post myocardial infarction patients consecutively referred for EPS following documented ventricular fibrillation (VF) (20), sustained ventricular tachycardia (VT) (74) or a syncopal episode with subsequently documented non-sustained VT at Holter monitoring (18). BRS was assessed according to the transfer function method. A cardioverter - defibrillator (ICD) was implanted in 97 patients. During follow-up (median 315 days), appropriate ICD discharge occurred in 53 patients, and 3 more patients died suddenly. Sustained VT was induced in 84% and 77% of patients who did or did not develop arrhythmia at follow-up (p=0.34). No differences were found in age, sex, infarct site, drug therapy, resting RR interval or cycle of induced VT. Left ventricular ejection fraction (LVEF) ≤35%, New York Heart Association (NYHA) class >2 and BRS ≤3.3 ms/mmHg were found to be univariate predictors of arrhythmia recurrence. Multivariate models were obtained after grouping patients according to a moderately or severely depressed LVEF. Among the patients with LVEF ≤35%, BRS ≤3.3 ms/mmHg emerged as the only significant risk predictor of arrhythmia occurrence (sensitivity, specificity, positive and negative predictive value = 79%, 74%, 83% and 68%, respectively), whereas NYHA class >2 was a significant predictor among patients with LVEF >35%. Conclusions Noninvasive BRS, but not EPS, is of value in predicting VT/VF episode recurrence in patients surviving a major arrhythmic event. (Circ J 2004; 68: 634 - 638)
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  • Masashi Yamamoto, Nobuyuki Komiyama, Tomomi Koizumi, Mizuo Nameki, Yut ...
    2004 Volume 68 Issue 7 Pages 639-644
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background New equipment, the Cardiac ReaderTM, which can measure blood concentrations of troponin T (T) and myoglobin (M) in only 15 min at the bedside was evaluated for early diagnosis of acute myocardial infarction (AMI). Methods and Results A total of 34 consecutive patients with AMI who came to hospital within 24 h after onset were studied. Blood samples were collected from the patients at admission and 6, 12, 24, 48 h after onset to qualitatively and quantitatively measure T, M and creatine kinase-MB fraction. There were 20 patients with positive results by qualitative troponin T test and 29 with positive results by quantitative test. Of the patients who visited hospital within 3 h of onset, 17% were positive by the qualitative test and 67% cases had positive results in the quantitative test. The patients were divided into 2 groups according to the flow grade in the infarct-related coronary artery. In the TIMI 0-1 group (n=28), serum myoglobin concentrations were higher than in the TIMI 3-4 group (n=6) at admission and at their peak. Conclusion The rapid quantitative test of T and M is useful for early diagnosis of AMI and as an indicator of its severity, which can be evaluated from the myoglobin concentration in the hyper-acute phase. (Circ J 2004; 68: 639 - 644)
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  • Noritake Hata, Akira Matsumori, Shinya Yokoyama, Takayoshi Ohba, Takur ...
    2004 Volume 68 Issue 7 Pages 645-649
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background Hepatocyte growth factor (HGF) has been reported as a marker of atherosclerosis and of thrombi synthesis, but the relationship between HGF and proven coronary thrombi has not been described. The aim of this study was to investigate this relationship in patients with chest pain. Methods and Results The study group comprised 107 patients with chest pain (61 acute myocardial infarction (AMI), 18 unstable angina, 15 stable angina, and 13 others; 65 males, 42 females; 66±11 years old). The presence of thrombi was evaluated by angiography, intravascular ultrasonography, angioscopy, and computed tomography. Serum HGF concentrations were measured using a new enzyme-linked immunosorbent assay. Serum HGF was significantly higher in the patients with AMI (335.0 ±197.5 pg/ml), unstable angina (269.1±152.7 pg/ml), acute aortic dissection (320.3±116.5 pg/ml), and pulmonary thromboembolism (292.5±101.9 pg/ml), than in those with stable angina (171.2±56.1 pg/ml). Serum HGF concentration was also higher in those patients with proven thrombi than in those patients without (326.7±189.7 pg/ml vs 226.9±110.8 pg/ml). Conclusion Increased serum HGF concentrations correlate with the presence of thrombi in patients with acute coronary syndrome, acute aortic dissection, and pulmonary thromboembolism. (Circ J 2004; 68: 645 - 649)
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  • Kazuo Murakami, Yuji Shigematsu, Mareomi Hamada, Jitsuo Higaki
    2004 Volume 68 Issue 7 Pages 650-655
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background The aim of the present study was to investigate whether or not insulin resistance is present in hypertrophic cardiomyopathy (HCM), and also whether it is related to the clinical manifestations of HCM. Methods and Results The study group comprised 55 patients with HCM, 35 with essential hypertension (EHT) and 15 normotensive control subjects (NC). An insulin resistance index was estimated using the homeostasis model assessment (HOMA-IR) of fasting insulin - glucose interactions. In patients with HCM, prognosis and cardiovascular events were also checked. The HOMA-IR values in the HCM group (2.90±1.22) were significantly higher than those in the EHT (1.69±0.77) and NC groups (0.91±0.24). The HOMA-IR values in the EHT group were significantly higher than those in the NC group. Multiple regression analyses determined that left ventricular pressure gradient without provocation (p<0.0001), interventricular septal thickness (p=0.0143) and body mass index (p=0.0412) were independent determinants of insulin resistance in patients with HCM. During a mean follow-up of 105±50 months, 4 patients with HCM died suddenly and all of them had high HOMA-IR values. Conclusions The results suggest that patients with HCM without apparent diabetes mellitus or hypertension have insulin resistance and that insulin resistance may be related to the manifestations of HCM. (Circ J 2004; 68: 650 - 655)
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  • Masato Furuhashi, Nobuyuki Ura, Koichi Hasegawa, Kazufumi Tsuchihashi, ...
    2004 Volume 68 Issue 7 Pages 656-659
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background The serum ratio of heart-type fatty acid-binding protein to myoglobin (F/M) has been shown to be a new marker for cardiac damage and volume overload in hemodialysis patients. We evaluated the utility of F/M in hemodialysis patients compared to control subjects. Methods and Results Twenty-one hemodialysis patients and 17 control subjects with normal renal function were investigated. Using a cutoff point of mean + 2SD of the F/M in the controls (value: 0.147), the hemodialysis patients were divided into 2 groups. The concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide after hemodialysis in the high F/M group were higher than those in the low F/M group. The mean level of ANP in the low F/M group was almost the upper limit of normal range. The values of left ventricular end-diastolic dimension and left ventricular mass index in the high F/M group were higher than those in the low F/M group, and the mean levels of those in the low F/M group were almost the same as those in the controls. Conclusions The F/M can be evaluated by the absolute value regardless of renal dysfunction, and the value of 0.147 might be useful for determining the cutoff level of cardiac involvement. (Circ J 2004; 68: 656 - 659)
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  • Tsuyoshi Shinozaki, Jun Watanabe, Junichi Kikuchi, Kenji Tamaki, Nobuo ...
    2004 Volume 68 Issue 7 Pages 660-664
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background High mortality and a high readmission rate characterize diastolic heart failure (DHF), but evidence-based therapeutic strategies have not been established for DHF. Methods The aim of a multicenter, randomized open trial (the Diastolic Heart Failure Assessment Study in Tohoku District, DIAST) is to evaluate the safety and prognostic efficacy of the multiple action non-selective β-blocker carvedilol in 160 patients with DHF (left-ventricular ejection fraction ≥50%). The target dose of carvedilol is 10 mg twice a day and the mean follow-up is estimated to be 2 years. The primary endpoints are to evaluate (1) all-cause mortality or hospitalization, (2) cardiovascular mortality or hospitalization and (3) worsening heart failure. The secondary endpoints are to assess (1) cardiovascular events, (2) the individual components of the above combined endpoints, (3) the duration of hospitalization, (4) the functional class and exercise capacity and (5) the safety and tolerability. All patients' data are processed using an original registration system on an internet homepage. Several substudies to assess neurohumoral factors, heart rate variability, oxidative stress and sleep apnea will clarify the pathophysiology of DHF. Conclusions The DIAST will contribute to establish therapeutic guidelines for DHF. (Circ J 2004; 68: 660 - 664)
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  • Junko Sano, Shigenobu Inami, Koji Seimiya, Takayoshi Ohba, Shunta Saka ...
    2004 Volume 68 Issue 7 Pages 665-670
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background Green tea, a popular beverage in Japan, contains many polyphenolic antioxidants, which might prevent atherosclerosis. This study was designed to determine whether the consumption of green tea is proportionately associated with a decreased incidence of coronary artery disease (CAD) and the cardiovascular and cerebrovascular prognosis. Methods and Results The study group comprised 203 patients who underwent coronary angiography (109 patients with significant coronary stenosis and 94 patients without). Predictors for CAD were analyzed and the patients' cardiovascular and cerebrovascular events were followed. Green tea consumption was significantly higher in patients without CAD than in those with CAD (5.9±0.5 vs 3.5±0.3 cups/day; p<0.001). An inverse relationship between the intake of green tea and the incidence of CAD was observed (p<0.001). The green tea intake per day was an independent predictor for CAD based on a multivariate logistic regression analysis (odds ratio: 0.84 and 95% confidence interval: 0.76-0.91). In contrast, the green tea intake was not a predictor of cardiovascular and cerebrovascular events based on the Cox proportional hazard model. Conclusions Green tea consumption was associated with a lower incidence of CAD in the present study population in Japan. Therefore, the more green tea patients consume, the less likely they are to have CAD. (Circ J 2004; 68: 665 - 670)
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  • Kengo Fukushima Kusano, Kazufumi Nakamura, Hitoshi Kusano, Nobuhiro Ni ...
    2004 Volume 68 Issue 7 Pages 671-676
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background Monocyte chemoattractant protein-1 (MCP-1), a potent chemoattractant for monocytes, plays an important role in the earliest events of atherogenesis. However, direct evidence of the effects of MCP-1 on atherosclerosis in chronic hemodialysis (HD) patients has not been reported. Methods and Results The serum MCP-1 concentrations and the intimal - medial thickness (IMT) in the carotid arteries were measured in 42 non-diabetic chronic HD patients and 20 age-matched controls. The expression of MCP-1 was examined immunohistochemically in radial arterial tissues obtained from the HD patients. IMT and the serum concentration of MCP-1 in the HD patients were both significantly greater than in controls. Multiple regression analysis revealed that the serum concentration of MCP-1 was an independent factor influencing IMT. Tissue immunostaining showed that MCP-1 is expressed in both endothelial and smooth muscle cells and that its level of expression correlates with the serum concentration of MCP-1. Conclusions An increase in MCP-1 may be an important factor in the progression of atherosclerosis in non-diabetic HD patients. (Circ J 2004; 68: 671 - 676)
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Experimental Investigation
  • Satoko Takata, Hiroshi Nakamura, Seiji Umemoto, Kazuhito Yamaguchil, T ...
    2004 Volume 68 Issue 7 Pages 677-682
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background The hypothesis that viral myocarditis causes an autoimmune response and subsequent dilated cardiomyopathy is controversial. To further investigate the autoimmune mechanism of cardiac dilatation and dysfunction after repeated episodes of viral myocarditis, the cardiac autoantigens induced by repetitive coxsackievirus B3 (CVB3) infection were examined. Methods and Results Male inbred A/J mice were inoculated intraperitoneally with CVB3 at 3 and 40 weeks of age. At 8 weeks after the second inoculation, the mortality of the repetitive CVB3 group was significantly increased compared with that of the control group, and was associated with a significant reduction in fractional shortening and marked left ventricular dilatation without inflammatory cell infiltration. The cardiac antigens in the repetitive CVB3 infection were identified by 2-dimensional electrophoresis and subsequent liquid chromatography/tandem mass spectrometry (LC-MS/MS) using the serum at 2 weeks after the second inoculation. LC-MS/MS and immunohistochemistry demonstrated α-cardiac actin and heat shock protein 60 (HSP60) as cardiac near-surface antigens induced by the repetitive CVB3 infection. Immunoelectron microscopy disclosed the selective localization of anti-IgM antibody on the membrane of the myocytes in the repetitive CVB3 group. Conclusions IgM antibodies against α-cardiac actin and HSP60, which were induced by repetitive CVB3 infection, may play an important role in the pathophysiology of the subsequent cardiac dysfunction and dilatation. (Circ J 2004; 68: 677 - 682)
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  • Hitoshi Suzuki, Kazuhira Maehara, Hiroyuki Yaoita, Yukio Maruyama
    2004 Volume 68 Issue 7 Pages 683-690
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background Inhibition of the sympathetic nervous and renin - angiotensin systems has become an important strategy in the treatment of chronic heart failure. However, direct evidence of how inhibition of the renin - angiotensin system alters sympathetic activity in a diseased heart is lacking. Methods and Results Four weeks after abdominal aorto-caval (AV) shunting or sham operation in rats, the hearts were retrogradely perfused in vivo and the left ventricles contracted isovolumetrically at 300 beats/min. Sympathetic nerve stimulation (SNS) was performed in the baseline state and repeated with an infusion of the angiotensin II (A-II) type 1 receptor (AT1-R) blocker, losartan, the A-II type 2 receptor (AT2-R) blocker, PD123319, or A-II. Norepinephrine (NE) overflow and left ventricular (LV) inotropic responses during baseline SNS were lower in the AV shunt rats. Losartan did not change the NE overflow or the LV inotropic responses to SNS in the sham rats, but did increase them in the AV shunt rats. PD123319 changed neither parameter in the sham rats, but decreased both in the AV shunt rats. A-II enhanced the NE overflow but attenuated the LV inotropic responses to SNS in the sham rats, but attenuated both in the AV shunt rats. Conclusions The effects of A-II via the AT1-R and AT2-R on the adrenergic drive in the heart were altered significantly in volume overload hypertrophy induced by AV shunting. (Circ J 2004; 68: 683 - 690)
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  • Takao Kawai, Tomoyuki Takahashi, Masayasu Esaki, Hiroaki Ushikoshi, Sa ...
    2004 Volume 68 Issue 7 Pages 691-702
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background Despite the pluripotency of embryonic stem (ES) cells, the specific control of their cardiomyogenic differentiation remains difficult. The aim of the present study was to investigate whether growth factors may efficiently enhance the in vitro cardiac differentiation of ES cells. Methods and Results Recombinant growth factors at various concentrations or their inhibitors were added according to various schedules during the cardiomyogenic differentiation of ES cells. Cardiomyogenic differentiation was assessed by mRNA and protein expressions of several cardiomyocyte-specific genes. Basic fibroblast growth factor-2 (FGF-2) and/or bone morphogenetic protein-2 (BMP-2) efficiently enhanced the cardiomyogenic differentiation, but only when they were added at the optimal concentration (1.0 ng/ml in FGF-2 and 0.2 ng/ml in BMP-2; relatively lower than expected in both cases) for the first 3 days. Inhibition of FGF-2 and/or BMP-2 drastically suppressed the cardiomyogenic differentiation. Conclusion FGF-2 and BMP-2 play a crucial role in early cardiomyogenesis. The achievement of efficient cardiac differentiation using both growth factors may facilitate ES cell-derived cell therapy for heart diseases as well as contribute to developmental studies of the heart. (Circ J 2004; 68: 691 - 702)
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  • Junichiro Miake, Yasutaka Kurata, Kazuhiko Iizuka, Hitomi Furuichi, Ka ...
    2004 Volume 68 Issue 7 Pages 703-711
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background Azimilide reportedly blocks Na+ channels, although its mechanism remains unclear. Methods and Results The kinetic properties of the azimilide block of the wild-type human Na+ channels (WT: hH1) and mutant ΔKPQ Na+ channels (ΔKPQ) expressed in COS7 cells were investigated using the whole-cell patch clamp technique and a Markovian state model. Azimilide induced tonic block of WT currents by shifting the h∞ curve in the hyperpolarizing direction and caused phasic block of WT currents with intermediate recovery time constant. The peak and steady-state ΔKPQ currents were blocked by azimilide, although with only a slight shift in the h∞ curve. The phasic block of peak and steady-state ΔKPQ currents by azimilide was significantly larger than the blocking of the peak WT current. The affinity of azimilide predicted by a Markovian state model was higher for both the activated state (KdA =1.4 μmol/L), and the inactivated state (KdI =1.4 μmol/L), of WT Na+ channels than that for the resting state (KdR =102.6 μmol/L). Conclusions These experimental and simulation studies suggest that azimilide blocks the human cardiac Na+ channel in both the activated and inactivated states. (Circ J 2004; 68: 703 - 711)
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Case Report
  • Mariko Arai, Kiyoshi Nakazawa, Akihiko Takagi, Ryoji Kishi, Keizo Osad ...
    2004 Volume 68 Issue 7 Pages 712-714
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    The patient was a 53 year-old male who had 3 syncopal episodes over a 6-month period. In the electrophysiological study, ventricular fibrillation (VF) was repeatedly induced by the ventricular extrastimulus method. Intravenous pilsicainide was administered, and the J-point and ST-segment in the right precordial leads became slightly elevated just following drug administration. Five min later, the patient experienced severe nausea and then vomited twice, at which point the electrocardiogram (ECG) showed increased elevation of the J-point and ST-segment. These ECG changes recovered to normal 30 min later. The cause of his syncope was strongly suspected to be related to the VF associated with Brugada syndrome. An interesting aspect of this case was the particular type of J-point and ST-segment elevation that was induced when the patient experienced nausea and vomiting. It is proposed that this phenomenon originated from the vagal stimulation associated with the nausea and vomiting. (Circ J 2004; 68: 712 - 714)
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  • Satoru Kase, Shu Nakamoto, Shigeto Miyasaka, Hisato Moritani, Takashi ...
    2004 Volume 68 Issue 7 Pages 715-718
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Chondrosarcoma is a malignant tumor characterized by the formation of cartilage. A case of primary cardiac chondrosarcoma of the left atrium developed in a middle-aged male. The preoperative serum concentrations of C-parathyroid hormone-related protein (PTHrP) and calcium were high (413.2 pmol/L and 12.2 mg/dl, respectively), but normalized after resection of the tumor, which measured 7×5 ×3.5 cm. The tumor was histopathologically diagnosed as chondrosarcoma, composed of outer atypical chondroid cells and inner pleomorphic and spindle mesenchymal cells mimicking malignant fibrous histiocytoma. Half of the cartilaginous tumor cells and a few pleomorphic cells showed cytoplasmic immunoreactivity for PTHrP. The tumor is a possible example of the functional pleiotropy of chondrosarcoma. (Circ J 2004; 68: 715 - 718)
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  • Hiroki Mani, Takeshi Shirayama, Midori Yamamura, Takashi Sakamoto, Aki ...
    2004 Volume 68 Issue 7 Pages 719-721
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    A 64-year-old man was admitted to our hospital because of palpitation, dyspnea on effort, and facial edema. The echocardiographic diagnosis was Ebstein anomaly. Although the 12-lead electrocardiogram showed an atrial rate of 150 beats/min and no typical flutter wave, the electrophysiological study showed counterclockwise rotation of excitation along the tricuspid annulus. Because of sinus arrest and syncope, a permanent pacemaker was implanted, but the right atrium was not captured by electrical stimulation at 5V/0.4 ms, except for the orifice of coronary sinus, and the intracardiac P wave was only 0.2 mV or less. This is a rare case of Ebstein anomaly characterized by unusually prolonged conduction in the atrium, the basis of which was global myocardial damage, including the ventricles. (Circ J 2004; 68: 719 - 721)
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  • Hiroaki Kawano, Yuji Koide, Takeshi Baba, Reiichiro Nakamizo, Genji To ...
    2004 Volume 68 Issue 7 Pages 722-723
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Although stents reduce the rate of vessel restenosis, in-stent restenosis is a recognized clinical problem and it appears that patients positive for allergic patch-test reactions to the stent components nickel and molybdenum have increased rates of it. A patient with angina pectoris had repeated episodes of restenosis after stent implantation and histological examination demonstrated granulation tissue with eosinophil infiltration in the restenotic lesion of the coronary artery. The patient was positive for an allergic reaction to the stent components. (Circ J 2004; 68: 722 - 723)
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Rapid Communication
  • Kasumi Manabe, Junichiro Miake, Norihito Sasaki, Hitomi Furuichi, Shui ...
    2004 Volume 68 Issue 7 Pages 724-726
    Published: 2004
    Released: June 25, 2004
    JOURNALS FREE ACCESS
    Background It is controversial which subtypes of T type Ca2+ channels are implicated in automaticity of cardiac cells during the embryonic period.Method and Results The effect of Ni2+ on the automaticity of Nkx2.5-positive cardiac precursor cells sorted from embryonic stem cells during their differentiation was examined using patch clamp techniques. Although 40μmol/L Ni2+, which is enough to block Ni2+sensitive T type-Ca2+ channels, decreased the spontaneous beating rate in all cells in the early and intermediate stage, Ni2+ did not show any effects on the automaticity of 50% of the cells in the late stage. Conclusion These results indicate that Ni2+-sensitive T-type Ca2+ channels expressed in the Nkx2.5-positive cardiac precursor cells are developmentally regulated. (Circ J 2004; 68: 724 - 726)
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Corrigendum
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