Circulation Journal
Online ISSN : 1347-4820
Print ISSN : 1346-9843
ISSN-L : 1346-9843
Volume 66 , Issue 12
Showing 1-21 articles out of 21 articles from the selected issue
Special Article
  • Ryuichi Morishita
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1077-1086
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    Gene therapy is emerging as a potential strategy for the treatment of cardiovascular diseases, such as peripheral arterial disease, ischemic heart disease, restenosis after angioplasty, vascular bypass graft occlusion and transplant coronary vasculopathy, for which no known effective therapy exists. The first human trial in cardiovascular disease started in 1994 treating peripheral vascular disease with vascular endothelial growth factor (VEGF) and since then, many different potent angiogenic growth factors have been tested in clinical trials for the treatment of peripheral arterial disease. In addition, therapeutic angiogenesis using the VEGF gene has been used to treat ischemic heart disease since 1997. The results from these clinical trials have exceeded expectations; improvement in the clinical symptoms of peripheral arterial disease and ischemic heart disease has been reported. Another strategy for combating the disease processes, targeting the transcriptional process, has been tested in a human trial. IN particular, transfection of cis-element double-stranded (ds) oligodeoxynucleotides (ODN) (= decoy) is a powerful tool in a new class of anti-gene strategies. Transfection of ds-ODN corresponding to the cis sequence will attenuate the authentic cis-trans interaction, leading to removal of trans-factors from the endogenous cis-elements and subsequent modulation of gene expression. Genetically modified vein grafts transfected with a decoy against E2F, an essential transcription factor in cell cycle progression, appear to have long-term potency in human patients. There is great potential in gene therapy for cardiovascular disease. (Circ J 2002; 66: 1077 - 1086)
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Clinical Investigation
  • Primary Prevention Cohort Study of the Japan Lipid Intervention Trial (J-LIT)
    Masunori Matsuzaki, Toru Kita, Hiroshi Mabuchi, Yuji Matsuzawa, Noriak ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1087-1095
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    Hyperlipidemia is a well-established risk factor for primary coronary heart disease (CHD). Although simvastatin is known to lower serum lipid concentrations, the protective effect of such lipid-lowering therapy against primary CHD has not been established in Japanese patients with hypercholesterolemia. The Japan Lipid Intervention Trial was a 6-year, nationwide cohort study of 47,294 patients treated with open-labeled simvastatin (5-10 mg/day) and monitored by physicians under standard clinical conditions. The aim of the study was to determine the relationship between the occurrence of CHD and the serum lipid concentrations during low-dose simvastatin treatment. Simvastatin reduced serum concentrations of total cholesterol (TC), low-density lipoprotein- cholesterol (LDL-C) and triglyceride (TG), by 18.4%, 26.8% and 16.1% on average, respectively, during the treatment period. The risk of coronary events was higher when the average TC concentration was ≥240 mg/dl and the average LDL-C concentration was ≥160 mg/dl. The incidence of coronary events increased in the patients with TG concentration ≥300 mg/dl compared with patients with TG concentration <150 mg/dl. The high-density lipoprotein cholesterol (HDL-C) inversely correlated with the risk of coronary events. The J-curve association was observed between average TC or LDL-C concentrations and total mortality. Malignancy was the most prevalent cause of death. The health of patients should be monitored closely when there is a remarkable decrease in TC and LDL-C concentrations with low-dose statin. A reasonable strategy to prevent coronary events in Japanese hypercholesterolemic patients without prior CHD under low-dose statin treatment might be regulating the serum lipid concentrations to at least <240 mg/dl for TC, <160 mg/dl for LDL-C, <300 mg/dl for TG, and >40 mg/dl for HDL-C. (Circ J 2002; 66: 1087 - 1095)
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  • Secondary Prevention Cohort Study of the Japan Lipid Intervention Trial (J-LIT)
    Hiroshi Mabuchi, Toru Kita, Masunori Matsuzaki, Yuji Matsuzawa, Noriak ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1096-1100
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    Hyperlipidemia is primarily implicated in the progression of coronary heart disease (CHD) and its treatment is essential for patients with a history of CHD. Statins such as simvastatin, the lipid-lowering agents, are well-known for their ability to normalize patient's serum lipid levels. The Japan Lipid Intervention Trial study of simvastatin is the first nationwide investigation of the relationship between serum lipid levels and the development of CHD in Japanese patients with hypercholesterolemia. Of 5,127 patients, exclusively with a history of documented CHD at enrollment, 4,673 were treated with open-labeled simvastatin at an initial dose of 5-10 mg/day and were monitored for 6 years. The risk of coronary events tended to be higher in patients with a serum total cholesterol (TC) ≥240 mg/dl compared with total cholesterol <240 mg/dl. The concentration of low-density lipoprotein cholesterol (LDL-C) positively correlated and that of high-density lipoprotein cholesterol (HDL-C) inversely correlated with the risk of CHD. Each 10 mg/dl decrease in LDL-C and each 10 mg/dl increase in HDL-C concentration reduced the risk of CHD by 8.0% (95% confidence interval 3.8-12.0) and 28.3% (95% CI 13.9-40.3), respectively. A reasonable therapeutic strategy to reduce CHD progression in patients with prior CHD under low-dose statin treatment might be regulating the serum LDL-C concentration to at least <120 mg/dl and HDL-C >40 mg/dl, respectively. (Circ J 2002; 66: 1096 - 1100)
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  • Akihiko Takagi, Kiyoshi Nakazawa, Tsuneharu Sakurai, Toshihiko Nanke, ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1101-1104
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    The electrophysiological mechanism of Brugada syndrome is unclear, but transmural dispersion of repolarization in the right ventricle is believed to be the most likely mechanism. On the other hand, the presence of a conduction delay region is considered to be related to the occurrence of ventricular fibrillation; that is, a relationship between the presence of a ventricular late potential (LP) and arrhythmogenic right ventricular cardiomyopathy. In this study, the LP from signal-averaged electrocardiography during isoproterenol (ISP) administration in patients with Brugada syndrome is discussed. The subjects were 11 patients with Brugada syndrome and 6 healthy individuals. In all subjects, the total filtered QRS duration (fQRS), root mean square voltage of the 40 ms terminal portion of the QRS (RMS40), duration of the low amplitude electric potential component (40 μV) of the terminal portion of the QRS (LAS40), and time duration of the fQRS-LAS40 difference were compared between when ISP was prescribed and when it was not. During ISP administration, a peculiar response, which resulted in an LAS40 prolongation, was observed in the patients with Brugada syndrome. With ISP, the fQRS remained unchanged, but the RMS40 and the fQRS-LAS40 decreased. Consequently another 3 patients with a positive LP were diagnosed using the ordinary standard because of the administration of ISP. We believe that the low-amplitude component was unmasked by shortening of the high-amplitude component. In patients with Brugada syndrome, a conduction delay in the ventricle may be present and may be related to the occurrence of ventricular fibrillation. (Circ J 2002; 66: 1101 - 1104)
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  • Hidefumi Yanagisawa, Taishiro Chikamori, Nobuhiro Tanaka, Tsuguhisa Ha ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1105-1109
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    Although a relationship between the coronary pressure-derived fractional flow reserve (FFR) and the presence of myocardial ischemia as demonstrated by radionuclide imaging has been reported in a select group of patients, it remains to be established whether this relation also holds true in actual clinical settings with a heterogeneous group of patients. Accordingly, 194 coronary vessels and their supply territories were evaluated in 165 consecutive patients with suspected or known coronary artery disease. An FFR <0.75, which is regarded as indicative of functionally important stenosis, showed a significant correlation with the redistribution of 201Tl (p<0.0001), with a sensitivity of 79% and specificity of 73%. In 70 infarct-related coronary arteries, the sensitivity and specificity were 79% and 75%, respectively, whereas in the 124 remaining vessels that were not related to the myocardial infarct, the sensitivity and specificity were 80% and 72%, respectively. In addition, the FFR exhibited a significant inverse correlation with the 201Tl reversibility score (r=-0.62; p<0.0001). These results suggest that the FFR has a significant relationship with scintigraphic evidence of myocardial ischemia and can be regarded as a marker of its presence or absence in patients in actual clinical settings. (Circ J 2002; 66: 1105 - 1109)
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  • Yukio Kioka, Atsusi Tanabe, Yasuhiro Kotani, Nobuyuki Yamada, Makoto N ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1110-1112
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    In the process of establishing a less invasive assessment strategy for coronary artery disease (CAD) in patients with infrarenal abdominal aortic aneurysm (AAA), the incidence of CAD and the surgical and mid-term outcomes were reviewed. From January 1994 through September 2001, 94 elective surgical repairs of AAA were carried out. Preoperative coronary angiography showed 43 patients (45.7%) had CAD: 29 (67.4%) were asymptomatic, 23 had single-vessel disease (1VD), 12 had 2VD and 8 had 3VD. Of the 43 patients with CAD, 19 (44.2%) underwent coronary interventional therapy before aortic surgery (11 percutaneous transluminal coronary angioplasty (PTCA), 8 coronary artery bypass grafting). Eight asymptomatic patients underwent coronary interventional therapy. None of the patients died of cardiac causes or experienced a postoperative cardiac event. During the follow-up period, 10 late deaths occurred: 7 patients with CAD, and 3 cerebrovascular or cardiac deaths. There was no statistical difference in the survival rate between the groups with and without CAD. Two patients with CAD underwent PTCA during the follow-up period. The findings confirm the need for a less invasive assessment strategy of CAD that does not overlook asymptomatic myocardial ischemia, because the incidence of CAD in patients with AAA is high. (Circ J 2002; 66: 1110 - 1112)
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  • Analysis by Intracardiac Echocardiography
    Koichi Mizumaki, Akira Fujiki, Hidehiko Nagasawa, Kunihiro Nishida, Ma ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1113-1118
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    Although crista terminalis (CT) has been identified as the barrier to transverse conduction during typical atrial flutter (AFL), the relation between transverse conduction capabilities and anatomy of the CT remains unclear. The aim of the study was to evaluate that relation using intracardiac echocardiography (ICE). Ten patients with typical AFL (group AFL), 7 patients with paroxysmal atrial fibrillation (PAF) (group AF) and 8 patients without PAF or AFL (group N) underwent electrophysiologic testing. Using ICE images, the maximum diameter of the short axis of the CT (dCT) was measured and mapping and pacing catheters were positioned precisely. From extrastimulation delivered 1-2 cm anteriorly (free wall) or posteriorly (posterior wall) to the CT, the effective refractory period (CT-ERP) was determined as the longest coupling interval that resulted in split potentials at the mapping catheter positioned along the CT, a finding consistent with a transverse conduction block at the CT. The dCT was greater in group AFL than in groups AF and N (5.0±0.8 vs 4.3 ±0.7, p<0.05 and 4.2±0.4 mm, p<0.01, respectively). The CT-ERP was longer during pacing from the posterior wall than from the free wall (307±68 vs 266±29 ms, p<0.05) as a whole group. The CT-ERP for the posterior wall pacing was longer in group AFL than in group N (339±80 vs 255±13, p<0.05). CT-ERP did not correlate with dCT; however, dCT was greater in patients with split potentials at the CT than in patients without them (4.9 ±0.8 vs 4.1±0.5 mm, p<0.05). Therefore, the transverse conduction block of CT was more likely to occur in a thick CT. A limited transverse conduction capability of the CT is related to its thickness and might contribute to the development of typical AFL. (Circ J 2002; 66: 1113 - 1118)
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  • Akiyoshi Tsubokawa, Kinzo Ueda, Hiroki Sakamoto, Tomoyuki Iwase, Shun- ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1119-1123
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    A major limitation of the rotational atherectomy (RA) procedure is the occurrence of the no-reflow/slow flow phenomenon and the optimal strategy is still evolving. Recent clinical studies have demonstrated the beneficial effects of nicorandil, an adenosine triphosphate (ATP)-sensitive potassium channel opener, on no-reflow in patients with acute myocardial infarction. The purpose of this study was to evaluate the effect of nicorandil on no-reflow/slow flow phenomenon during RA procedures. Sixty-one patients who underwent RA of complex coronary lesions were randomly divided into 2 groups: (i) nicorandil cocktail (n=24 patients, 37 lesions) and (ii) verapamil cocktail (n=37 patients, 63 lesions). In each group, the drug cocktail mixed with pressurized saline was infused through the 4Fr Teflon sheath of the rotablator system during the RA procedure. In the nicorandil group, the drug cocktail consisted of 24 mg of nicorandil, 5 mg of nitroglycerin, and 10,000 U of heparin. In the verapamil group, the drug cocktail consisted of 10 mg of verapamil, 5 mg of nitroglycerin, and 10,000 U of heparin. Baseline and procedure characteristics did not differ between the 2 groups. RA was performed successfully, and death, Q-wave myocardial infarction, or emergency coronary artery bypass surgery did not occur in any patients. The no-reflow/slow flow phenomenon was observed in 11/63 (17.4%) lesions of the verapamil group, but in only 1/37 (2.7%) lesions of the nicorandil group (p=0.03). No untoward complications were observed during nicorandil infusion. These data indicate that the intracoronary continuous infusion of nicorandil during RA procedures is easy and safe, and prevents no-reflow/slow flow phenomenon more effectively than infusion of verapamil. (Circ J 2002; 66: 1119 - 1123)
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  • Fabio Manfredini, Cristina Mangolini, Francesco Mascoli, Gianni Mazzon ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1124-1127
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    The purpose of this study was to develop a test for identifying the speed of onset of claudication, or pain threshold speed (PTS), in 16 patients affected by intermittent claudication. An echo-Doppler examination and the ankle - brachial index (ABI) determination were also performed. Test repeatability was evaluated in 10 patients retested within a few days. All 16 patients underwent the incremental walking test 3 times during a 6-month rehabilitation training program to verify the test's sensitivity in detecting the expected functional modifications. PTS was identified in all patients examined and the test - retest correlation coefficient (R) for PTS was 0.98. During the 6-month rehabilitation period, the ABI rose from 0.43 ±0.16 to 0.72±0.15 for the worst limb and PTS also rose significantly from 3.9±1.4 km/h to 6.1±1.1 km/h. The average increments of ABI and PTS were significantly correlated. An incremental walking test for the identification of the walking speed at which claudication occurs has been developed. The PTS is a reproducible parameter that can be combined with other test results to establish the severity of the disease and to check any modifications that occur during rehabilitation. (Circ J 2002; 66: 1124 - 1127)
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  • Daisuke Fukui, Hiroaki Urayama, Kenichi Tanaka, Seiji Kawasaki
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1128-1131
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    During abdominal aortic surgery, dynamic changes occur in the pelvic circulation. Near-infrared spectroscopy (NIRS) was used in this study to evaluate arterial flow in the buttocks as a monitor of arterial flow in the pelvic area during abdominal aortic surgery. Twenty-two patients who underwent abdominal aortic aneurysmectomy comprised the study group. The NIRS probe was mounted on the left buttock during surgery, and the changes in oxy- and deoxy-hemoglobin (Hb) concentration were measured. In all cases Hb values reflected decreased arterial flow caused by aortic clamping and increased arterial flow after reconstruction of the distal arteries. The recovery pattern of the Hb values varied, but all recovered to the baseline value recorded before aortic clamping. None of the patients exhibited postoperative claudication of vessels supplying the gluteal muscles or colonic ischemia, and recovery time varied in accordance with the patient's arterial condition. This method is simple and enables individual evaluation of blood flow recovery from reconstructed arteries. This method allows approximate evaluation of the pelvic arterial flow of individual arteries, helps to predict postoperative claudication of the gluteal muscles, and offers additional information for evaluating colonic ischemia. (Circ J 2002; 66: 1128 - 1131)
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  • Naoko Yasugi, Samon Koyanagi, Keizaburo Ohzono, Kikuo Sakai, Takahiro ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1132-1138
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    Discordance between the 123I-labelled 15-iodophenyl-3-R, S-methyl pentadecanoic acid (BMIPP) and 201Tl findings may indicate myocardial viability (MV). This study compared dobutamine stress echocardiography (DSE) and single-photon emission computed tomography (SPECT) using the dual tracers for assessment of MV and prediction of functional recovery after acute myocardial infarction (AMI). DSE and dual SPECT were studied in 35 patients after AMI, of whom 28 underwent percutaneous coronary intervention in the acute stage. Dual SPECT was performed to compare the defect score of BMIPP and 201Tl. The left ventricular wall motion score (WMS) was estimated during DSE and 6 months later to assess functional recovery of the infarct area. The rate of agreement of MV between dual SPECT and DSE was 89% (p<0.01), and the sensitivity and specificity of DSE for dual SPECT in MV assessment was 86% and 93%, respectively. The positive and negative predictive values for functional recovery by dual SPECT were 76% and 67%, respectively, and by DSE were 90% and 79%, respectively. Four of 5 patients with positive MV by dual SPECT, but without functional recovery, had residual stenosis of the infarct-related artery. The WMS and defect scores of BMIPP and 201Tl were significantly smaller in patients with functional recovery than in those without. Assessment of MV using DSE concords with the results of dual SPECT in the early stage of AMI. DSE may have a higher predictive value for long-term functional recovery at the infarct area. However, a finding of positive MV by dual SPECT, without functional recovery, may indicate residual stenosis of the infarct-related artery, although the number of cases was small. Combined assessment by dual SPECT and DSE may be useful for detecting MV and jeopardized myocardium. Furthermore, the results suggest that functional recovery of dysfunctional myocardium may depend on the size of the infarct and risk area. (Circ J 2002; 66: 1132 - 1138)
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  • Yuji Hara, Mareomi Hamada, Tomoaki Ohtsuka, Akiyoshi Ogimoto, Hideyuki ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1139-1143
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    This study was performed to evaluate whether thallium-201 myocardial scintigraphy (Tl-201) and iodine-123-metaiodobenzylguanidine (MIBG) myocardial scintigraphy could predict the usefulness of β-blocker therapy in patients with dilated cardiomyopathy (DCM). Tl-201 and MIBG were performed in 47 patients before β-blocker therapy. Patients were classified into group A, if their cardiac function improved, and group B, whose function remained unchanged. Two types of extent score (ES) by Tl-201 were proposed to quantitate myocardial damage, mean - 2SD (ES-2) and mean - 3SD (ES-3). The ES difference between ES-2 and ES-3 was calculated, and according to ES and ES difference, DCM cases were classified into 3 groups: mild-defect type (mild-type), moderate-defect type (moderate-type) and severe-defect type (severe-type). The heart-to-mediastinum (H/M) MIBG uptake ratio was evaluated, and the percent washout ratio of myocardial MIBG was obtained from these data. Group A comprised 18 mild-type, 14 moderate-type and 1 severe-type cases, and group B comprised 5 mild-type, 4 moderate-type and 5 severe-type cases. A significant relation was observed between the defect type on Tl-201 and the response to β-blocker therapy (p=0.0090). Both H/M MIBG uptake ratios and washout ratio were not significantly different in the 2 groups. Tl-201 may be useful for predicting the response to β-blocker therapy in patients with DCM. (Circ J 2002; 66: 1139 - 1143)
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  • Masahito Sakuma, Yuji Konno, Kunio Shirato
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1144-1149
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    In the United States, annual mortality rates from pulmonary embolism (PE) tended to increase from the 1960s to the mid 1980s, but thereafter began to decrease. In Japan, PE is not yet widespread and there have not been any reports of the time-trend of its mortality rate. The present study calculated the annual age-adjusted and age-specific PE mortality rates for Japanese residents during 1951 to 2000 from the `Vital Statistics of Japan' and the census data and population estimates for the intercensal years. Throughout the study period, the age-adjusted deaths and mortality rates from PE continued to increase, and between 1976 and 1996 the increases in the annual age-specific mortality rates were substantial in males 45-49 years of age and 55 years or older, and in females 30 years of age or older. The age-specific PE death rates increased throughout the life span in general and according to the decade. Male mortality was greater at most ages. In Poisson regression analysis, the relative risk of death from PE was increased in males, the aged, and in recent years. Overall, mortality from PE in Japan increased significantly during 1951 to 2000. (Circ J 2002; 66: 1144 - 1149)
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Experimental Investigation
  • Masahiko Yoneyama, Atsushi Sugiyama, Yoshioki Satoh, Akira Takahara, Y ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1150-1154
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    Colforsin daropate is a recently developed water-soluble derivative of forskolin that directly stimulates adenylate cyclase, unlike the catecholamines. The chronotropic, inotropic and coronary vasodilator actions of colforsin daropate were compared with those of isoproterenol, dopamine and dobutamine, using canine isolated, blood-perfused heart preparations. The stimulating effect of each drug on adenylate cyclase activity was also assessed. Colforsin daropate, as well as each of the catecholamines, exerted positive chronotropic, inotropic and coronary vasodilator actions. The order of selectivity for the cardiovascular variables of colforsin daropate was coronary vasodilation >> positive inotropy > positive chronotropy; whereas that of isoproterenol, dopamine and dobutamine was positive inotropy >> coronary vasodilation > positive chronotropy. Thus, a marked characteristic of colforsin daropate is its potent coronary vasodilator action. On the other hand, each drug significantly increased the adenylate cyclase activity in a dose-related manner: colforsin daropate >> isoproterenol > dopamine = dobutamine. These results suggest that colforsin daropate may be preferable in the treatment of severe heart failure where the coronary blood flow is reduced and β-adrenoceptor-dependent signal transduction pathway is down-regulated. (Circ J 2002; 66: 1150 - 1154)
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  • Effects on Nitric Oxide Synthesis
    Shiro Uemura, Jonathan B Rothbard, Hidetsugu Matsushita, Philip S Tsao ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1155-1160
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    The present study was designed to determine the efficiency of translocation of short polymers of arginine into vascular smooth muscle cells (VSMC) and to determine their effect on nitric oxide (NO) synthesis. Immunostaining revealed that heptamers of L-arginine (R7) rapidly translocated into the VSMC. This rapid transport was not observed with shorter polymers of L-arginine (R5) nor heptamers of lysine (K7). Translocation of R7 was not inhibited by the addition of free L-arginine into the media. When cells were transiently pretreated with R7 or a nonamer of arginine (R9), NO2 production from cytokine stimulated VSMC was significantly increased, whereas incubation with R5 and K7 had no effect. Short polymers of arginine not only have a unique ability of rapid VSMC translocation but once internalized enhance NO production. Heptamers (or larger polypeptides) of arginine may be useful in therapy to enhance NO production in the vascular system. (Circ J 2002; 66: 1155 - 1160)
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  • Influences of Cardiac Hypertrophy and Isoproterenol
    Keita Odashiro, Shin-ichi Hiramatsu, Nobuhito Yanagi, Takeshi Arita, T ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1161-1167
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    Although the arrhythmogenic effects of interferon (IF) have been reported in clinical practice, the experimental data are limited. Therefore, these effects were investigated in in vivo and Langendorff-perfusion studies using 3 different groups of rats (ie, control, aorta-banded, and deoxycorticosterone acetate (DOCA)-salt hypertension groups) in the presence or absence of isoproterenol. In the perfusion study, human recombinant IF-α (≤15,000 U/ml) alone induced irreversible atrioventricular blockade in all groups, whereas this agent (≤1,500 U/ml) caused negative inotropism and ventricular tachyarrhythmias (arrhythmic score greater in the order of DOCA-salt>aorta-banded = control group) in the preparations pretreated with isoproterenol (10-9 mol/L). In an in vivo study, IF-α (6×10 6 U/kg) resulted in ventricular tachyarrhythmias only in the presence of isoproterenol (10 mg/kg), as in the perfusion study (arrhythmic score; DOCA-salt>aorta-banded>control). In conclusion, the arrhythmogenesis of IF-α is potentiated in pathophysiological conditions such as cardiac hypertrophy or elevated sympathetic activity. (Circ J 2002; 66: 1161 - 1167)
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  • Effects of Angiotensin Converting Enzyme Inhibition
    Yasuyuki Shimada, Metin Avkiran
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1168-1172
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    The circulation in the left and right coronary beds in pressure overload-induced left ventricular (LV) hypertrophy was studied in Wistar male rats (n=6/group) that were subjected to abdominal aortic constriction or to sham-operation. From 3 to 6 weeks after surgery, the animals with aortic constriction received vehicle or 0.01, 0.1, or 1 mg/kg per day po of the angiotensin converting enzyme (ACE) inhibitor, ramipril. At 6 weeks, after measuring blood pressure in the carotid artery in vivo, the hearts were isolated and the left and right coronary beds subjected to independent perfusion. Minimum coronary vascular resistance per unit heart weight (MCVR/g) was determined in both beds during simultaneous infusion of 10 μmol/L adenosine. Aortic constriction resulted in a significant increase in blood pressure, LV weight/body weight ratio, and bilateral MCVR/g. Ramipril lowered arterial pressure in a dose-dependent manner and reversed the increased right MCVR/g at the anti-hypertensive dose, but it did not affect LV mass or left MCVR/g. These results suggest that both coronary hypertension and myocardial hypertrophy contribute to the global impairment of coronary circulation in LV hypertrophy. ACE inhibitors may improve coronary circulation in LV hypertrophy when administrated at an appropriate dose and for a sufficient period. (Circ J 2002; 66: 1168 - 1172)
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Case Report
  • Go Hiasa, Mareomi Hamada, Yuji Shigematsu, Yuji Hara, Tomoaki Ohtsuka, ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1173-1175
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    An 18-year-old male patient with biventricular hypertrophic obstructive cardiomyopathy (HOCM) had successful reduction of the pressure gradients by cibenzoline. At 11 months after birth, he was first diagnosed with cardiac murmurs and by the age of 5 years, he was diagnosed with subpulmonic infundibular stenosis with a pressure gradient of 10 mmHg by cardiac catheterization. At the age of 14, re-catherterization revealed hypertrophic cardiomyopathy with isolated obstruction of the right ventricular outflow tract, with a pressure gradient of 70 mmHg, but no obstruction in the left ventricle. He began daily treatment with 30 mg propranolol. At the age of 18, he was admitted for cardiac evaluation. An echocardiogram revealed left mid-ventricular and subpulmonic obstructions associated with pressure gradients of 88 mmHg and 65 mmHg, respectively. A single oral dose of 200 mg of cibenzoline decreased the pressure gradients in the left and right ventricles (38 mmHg and 36 mmHg, respectively). He was then given 300 mg daily of cibenzoline, and both pressure gradients remained low without any complications 8 months later at the time of discharge. (Circ J 2002; 66: 1173 -1175)
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  • Hideki Teshima, Nobuhiko Hayashida, Hidetoshi Akashi, Shigeaki Aoyagi
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1176-1177
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    A 63-year-old male with atrial fibrillation and mild mitral valve regurgitation was referred to hospital because of a descending aortic aneurysm. During the evaluation, he developed an encephalopathy because of hyperammoniaemia. Further examination revealed a portal systemic shunt, perhaps caused by the noncirrhotic portal hypertension. The patient underwent successful replacement of the aneurysm after controlling the blood ammonia level by eliminating protein from the diet and removal of nitrogen from the gastrointestinal tract. Cardiovascular surgery in a patient with noncirrhotic portal hypertension and a portal systemic shunt has not been previously reported. Meticulous management of the perioperative blood ammonia concentration is essential. (Circ J 2002; 66: 1176 - 1177)
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  • Satsuki Yamada, Keiji Tsukada, Tsuyoshi Miyashita, Yasuyuki Oyake, Kei ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1178-1180
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    A 59-year-old woman with partial atrial standstill was studied using magnetocardiograms (MCGs), which revealed through QRS-T subtraction and time-frequency analysis that there was a high-frequency (6 Hz) magnetic source at the low atrial septum. MCGs are useful for noninvasively evaluating the clinical course of patients with atrial fibrillation. (Circ J 2002; 66: 1178 - 1180)
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  • Three Cases
    Michifumi Kyuma, Kazufumi Tsuchihashi, Yasuyuki Shinshi, Mamoru Hase, ...
    Type: None
    Subject area: None
    2002 Volume 66 Issue 12 Pages 1181-1184
    Published: 2002
    Released: November 25, 2002
    JOURNALS FREE ACCESS
    The precise etiological basis of transient left ventricular apical ballooning without coronary artery stenosis (ampulla or so-called `takotsubo' cardiomyopathy) remains unknown, so the present study examined the acute effects of intravenous propranolol (2-4 mg) in 3 female patients (age range, 61-76 years) with the condition. Although one patient who did not have any intraventricular pressure gradients showed no improvement in the electrocardiographic and left ventricular wall motion abnormalities, the other 2 patients, who had significant intraventricular pressure gradients, did show improvement. Dynamic intraventricular obstruction might play a role in maintaining apical ballooning, at least, in patients exhibiting an intraventricular pressure gradient. (Circ J 2002; 66: 1181 - 1184)
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