Japanese Heart Journal
Online ISSN : 1348-673X
Print ISSN : 0021-4868
ISSN-L : 0021-4868
Volume 35, Issue 3
Displaying 1-15 of 15 articles from this issue
  • Cardiac Performance as Viewed Through the Pressure-Volume Window
    Hiroyuki SUGA
    1994 Volume 35 Issue 3 Pages 263-280
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Viewing canine left ventricular performance through the pressure-volume (P-V) window, I proposed a new index of ventricular contractility (Emax: endsystolic P-V ratio or maximum elastance) in my doctoral thesis at the University of Tokyo in 1969. After I joined Dr. Kiichi Sagawa (deceased in 1989) at Johns Hopkins University, we firmly established the Emax concept during 1971-1978. The concept was extended to derive the systolic P-V area (PVA) as a new measure of the total mechanical energy generated by ventricular contraction in 1978. Experiments have revealed that PVA closely correlates with cardiac oxygen (O2) consumption (Vo2) under various loading conditions at a constant Emax, the Vo2-PVA relation changes its elevation with Emax, and the O2 costs of PVA and Emax characterize the mechanoenergetics of cardiac contraction under various normal and abnormal conditions in an innovative manner (Suga: Physiol Rev 70: 247-277, 1990). Emax and PVA can also evaluate the ventriculo-arterial hydraulic and energetic matching in normal and failing hearts. Emax and PVA have thus widely opened the P-V window to the extent that human and animal normal and failing cardiac performance can be characterized in a physiologically sound manner.
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  • Masafumi NAKAYAMA, Munehiko TANNO, Hideo YAMADA, Shin-ichiro OHKAWA, S ...
    1994 Volume 35 Issue 3 Pages 281-294
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    The relationship between dipyridamole thallium-201 myocardial singlephoton emission computed tomography and clinical findings during stress testing was investigated in 57 patients (mean age 72 years), including 11 patients with normal coronary arteries. Systolic blood pressure decreased from 138.2±19.7 to 119.8±20.1mmHg (mean: -13.8±6.6%) after dipyridamole infusion (0.568mg/kg/4min). Scintigraphic sensitivity for the diagnosis of coronary artery disease was higher in 30 patients with a systolic blood pressure decrease above the average value than in 27 patients with a blood pressure reduction of less than 14% (88% vs. 60%, p<0.005). Reversible perfusion defects among stenosed coronary arteries were more frequent in the former group (73% vs. 27%, p<0.001) with no difference in other clinical findings. In conclusion, systolic blood pressure change during stress testing was significantly correlated with dipyridamole-induced perfusion defects and detectability of coronary stenosis.
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  • Sema ÖZER, Ergün ÇIL, Gül BALTACI, Nevin ERGUN, ...
    1994 Volume 35 Issue 3 Pages 295-300
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    The purpose of this study was to determine the differences in the left ventricular dimensions, mass index and function in school-aged swimmers by echocardiography. The study group consisted of 82 swimmers who participated in a systematic swimming training for at least six months, and the control group consisted of 41 sedentary children of similar age, sex and weight. In the study group, left ventricular dimensions and wall thicknesses, aortic root and left atrium diameters, and left ventricle mass index were significantly greater than the normal children (p<0.05). However, there was no difference in the left ventricular systolic function (ejection fraction, shortening fraction) or in the left ventricular filling characteristics (pp0.05).
    In conclusion, in childhood swimmers there was a significant increase in left ventricular dimensions, wall thicknesses and mass index, but no differences in the systolic function and filling characteristics of the left ventricle. Thus, information on endurance training participation is necessary to interpret quantitative echocardiographic data.
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  • Yasuhiko TANABE, Minoru TAKAHASHI, Takeshi MOMOTSU, Hirohiko KUKANO, M ...
    1994 Volume 35 Issue 3 Pages 301-310
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    The purpose of this investigation was to evaluate the effect of digoxin on aerobic performance in mildly symptomatic patients with congestive heart failure and sinus rhythm. Ten patients (8 men and 2 women) with idiopathic dilated cardiomyopathy (ejection fraction 17 to 33%, mean 27±4%) who were stable and mildly symptomatic with maintenance digoxin and diuretic therapy were studied. All patients underwent maximal symptom-limited ergometer exercise with analysis of respiratory gases during maintenance digoxin therapy, 4 weeks after digoxin withdrawal, and 4 weeks after digoxin readministration. Exercise capacity was assessed by peak oxygen uptake and anaerobic threshold. Serum digoxin concentration was 1.0 to 1.8 (mean 1.3±0.2) ng/ml during digoxin therapy, and less than the detectable level after digoxin withdrawal. No patients showed clinical deterioration after digoxin withdrawal. Peak oxygen uptake after digoxin withdrawal (23.7±3.0ml/kg/min) did not differ significantly from that during maintenance digoxin therapy (23.8±2.5ml/kg/min) or after digoxin readministration (24.1±2.9ml/kg/min). The anaerobic threshold after digoxin withdrawal (14.9±2.5ml/kg/min) did not differ significantly from that during maintenance digoxin therapy (15.0±2.1ml/kg/min) or after digoxin readministration (14.9±2.2ml/kg/min). No differences in heart rate and diastolic blood pressure were observed during exercise, but systolic blood pressure during exercise was significantly higher with digoxin therapy (p<0.05).
    These results suggest that digoxin has no effect on aerobic performance in mildly symptomatic patients with idiopathic dilated cardiomyopathy and sinus rhythm.
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  • Kazuo OHSATO, Masami SHIMIZU, Norihiko SUGIHARA, Hidekazu INO, Hiroyuk ...
    1994 Volume 35 Issue 3 Pages 311-321
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Basement membrane of myocytes from patients with hypertrophic cardiomyopathy who died suddenly, seemed to be discontinuous by immunohistochemical methods. With the use of the sandwich immunoassay technique, we determined the frequency of type IV collagen and its influence on functional abnormality in 31 patients with hypertrophic cardiomyopathy and controls. Hypertrophic cardiomyopathy exhibited significantly increased serum type IV collagen compared with controls. A significant correlation was observed between serum type IV collagen and fractional shortening (r=-0.42 p<0.05), and end-diastolic volume (r=0.40 p<0.05), DT (r=-0.50 p<0.05). These data suggest that serum type IV collagen enhances clusters of cell-surface type IV collagen, including an alteration of the cytoskeleton, which may account for functional abnormalities in hypertrophic cardiomyopathy. Considering the fact that microscopic examination is unable to resolve the structure of the myocardial basement membrane, measurement of serum type IV collagen is thought to be useful in the diagnosis of myocardial basement membrane injury and the progression of hypertrophic cardiomyopathy.
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  • Akira NOZAKI, Iku TODA, Saburo MASHIMA, Tsuneaki SUGIMOTO
    1994 Volume 35 Issue 3 Pages 323-332
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Myocardial injury causes electric current at the border of injured muscle and the surrounding intact region. In order to determine the magnitude of the injury current, experiments were performed with the isolated canine heart per-fused with Tyrode's solution. The anterior descending branch of the left coro-nary artery was perfused selectively with high potassium (K+) solution and the resulting injury current was reflected in the ST shift of the orthogonal electrocardiogram, derived from the surface of a cubic container in which the heart was placed. After measurement of the ST vector with different K+ concentrations, the heart has fixed with formalin and the injury zone was delineated with serial sections. The boundaries of the selectively perfused region were recon-structed. The algebraic sum of orthogonal components of boundary surfaces determined the average direction normal to the boundary, which was found to be parallel with the ST vector. With increasing K+ concentrations, the ST shift became more marked. However, it was saturated at about 30mEq/L K+. The maximum injury current, calculated from the saturated value of the ST magnitude, amounted to 0.10mA•cm per unit area of the boundary surface. Additional experiments were performed with right ventricular papillary muscle preparations. Injuries were caused by a cotton pad containing high K+ solution placed in two directions to make the border along and across the long axis of the papillary muscle. The results indicate that the injury currrent in an anisotropic structure was essentially directed along the fiber orientation.
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  • Marina Politi OKOSHI, Carlos Roberto PADOVANI, Silvio Cesar NARDI, Ant ...
    1994 Volume 35 Issue 3 Pages 333-343
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Isolated papillary muscles have often been used in myocardial mechanical function studies. The objective of the present study was to compare the mechanical function of papillary muscle isolated from left ventricle between Wistar (W) and Wistar-Kyoto (WKY) rats of different ages (1, 3, 6 and 12 months), in order to examine whether there is a difference in intrinsic mechanical properties of muscle between the two rat strains. Muscles were perfused with Krebs-Henseleit solution at 28°C and studied isometrically and isotonically at a stimulation rate of 0.2Hz. The W and WKY showed statistically significant differences during both isometric and isotonic contractions. During isometric contraction, (1) the peak developed tension (DT) and +dT/dt were lower in WKY rats in the 1mo groups, (2) the resting tension (RT) was greater in WKY at 3, 6 and 12mo, (3) time to peak tension (TPT) was greater in WKY at 3 and 12mo, (4) time for tension to fall from peak to 50% of peak tension RT 1/2) was greater in WKY at 3mo and (5)-dT/dt was lower in WKY at 1 and 3mo. During isotonic contraction, (1) the peak shortening (PS) and -dL/dt were lower in WKY at 12mo, (2) the time to peak shortening (TPS) was greater in WKY at 3 and 12mo; (3) +dL/dt was lower in WKY at 3, 6, and 12mo and (4) the relative variation of length (Lmax-PS)/Lmax was greater in WKY at 6 and 12mo. These data showed a difference in mechanical behaviour of the papillary muscle between Wistar and Wistar-Kyoto rats of different age.
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  • Waree KEATISUWAN, Masataka KINJO, Tomiyasu KOYAMA
    1994 Volume 35 Issue 3 Pages 345-351
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    The time course of the recovery of cardiac mitochondrial phospholipids was investigated in rats subjected to a 3 hour loaded swim. The 3 hour swim caused a 50% reduction in mitochondrial phospholipids compared with the level in sedentary controls. During the first 12 hours of the recovery period, phospholipids tended to increase but fell again before reaching control values by 120 hours after the swim ended. Phospholipid recovery in microsomes was completed in 12 hours. Total mRNA in cardiac tissue decreased by about 15% in rats subjected to a 3 hour loaded swim but recovered to control levels in the first 12 hours of the sedentary recovery period. Thus, fluctuations in cardiac mitochondrial phospholipids do not parallel the changes in total mRNA in cardiac tissue.
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  • Yoshiichi OGAWA, Toshihiko ISHIMITSU, Hiroki TSUKADA, Shigeru YAGI
    1994 Volume 35 Issue 3 Pages 353-361
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    This study examined the protective effects of a calcium channel blocker, nisoldipine (NSL), against organ damage secondary to severe hypertension. Severe hypertension was induced in male 7-week-old spontaneously hypertensive rats (n=21) by heminephrectomy and substitution of 1% NaCl solution for drinking water. They were fed a chow containing 0%, 0.03% (low dose) or 0.1% (high dose) NSL for 12 weeks. The systolic blood pressures after 12 weeks were 228mmHg in the control group, 201 in the low dose NSL group and 188 in the high dose NSL group. Body weight gain was blunted in the high dose NSL group (at 12 weeks: control 289g; low dose NSL 286; high dose NSL 263, p<0.04). Although a further reduction in cardiac weight was seen in the high dose NSL rate (low NSL -5.2%, p<0.05; high NSL -9%, p<0.01), reductions in aortic thickness did not differ between the 2 doses (low NSL -18%, p<0.001; high NSL -17%, p<0.001). Moreover, dose-dependent effects of NSL treatment were absent for such endpoints as plasma creatinine (low NSL -15%, p<0.04; high NSL -17%, p<0.05), glomerular filtration rate (low NSL +21 %, p<0.05; high NSL +20%, p<0.03) and urinary protein excretion (low NSL -22%, p<0.05; high NSL -29%, p<0.02). Thus, a high dose calcium channel blocker hampered growth and did not further improve vascular wall thickening or renal injury in severely hypertensive rats. Therefore, in treating hypertension, combination of other antihypertensive drugs may be recommended rather than using high doses of calcium channel blockers.
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  • Tetsuya NAKAMURA, Tetsuo SAKAMAKI, Kunio SATO, Zenpei ONO, Russell L. ...
    1994 Volume 35 Issue 3 Pages 363-368
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    This study investigated the effects of intravenous injection of the specific inhibitor of nitric oxide (NO) formation, NEffect of NG-Monomethyl-L-Arginine on Regional Vascular Resistance in Rats-monomethyl-L-arginine (L-NMMA), on mean arterial pressure and regional vascular resistance in rats (n=7). Regional vascular resistances of brain, heart, left kidney, intestine (jejunum), left testis and right testis were measured using radiolabelled microspheres before and after injection of 12.5mg/kg of L-NMMA. Injection of L-NMMA raised mean arterial pressure significantly (p<0.05) from 119±4 (mean±SEM) mmHg to 139±7mmHg, accompanied by a significant (p<0.05) decrease in both heart rate and cardiac index and an increase in total peripheral resistance. Regional vascular resistances in brain, heart, kidney and intestine increased significantly (p<0.05) with L-NMMA, but no change was observed in the testes. The results indicate that the resistance of vascular beds is affected by NO synthesis, while the extent of regulation may differ among the various vascular beds.
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  • Masahiro TOYAMA, Shigeyuki WATANABE, Toshitaka KOBAYASHI, Kaname IIDA, ...
    1994 Volume 35 Issue 3 Pages 369-373
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Thrombosis is a rare complication in patients with aplastic anemia because of the presence of coincidental thrombocytopenia. We have recently treated two cases, a 61-year-old male and a 59-year-old female, with acute myocardial infarction associated with aplastic anemia. Although their platelet counts were lower than normal in spite of treatment with anabolic steroids for aplastic anemia, the coronary angiographic findings strongly suggested coronary thrombosis in both cases. Anabolic steroids, which have been commonly used for the treatment of aplastic anemia, are a possible risk factor for coronary thrombosis because they have an accelerating effect on thrombus formation. We report two very rare but clinically important cases.
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  • Takashi UEYAMA, Takuzo HANO, Ken KASAMATSU, Osamu MOHARA, Hiroki SHIMA ...
    1994 Volume 35 Issue 3 Pages 375-382
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    A case of orthostatic and postexertional hypotension with ischemic electrocardiographic changes is reported. The etiology was considered to be the partial dysfunction of efferent sympathetic nerve endings. Peripheral adrenergic receptors (α and β) were up-regulated, which might have caused pseudoischemic electrocardiographic changes and abnormal vasodilation after exercise.
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  • Bunji KAKU, Masami SHIMIZU, Yoshihito KITA, Hiroyuki YOSHIO, Hidekazu ...
    1994 Volume 35 Issue 3 Pages 383-388
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Anomalous origin of the left coronary artery can lead to angina pectoris, acute myocardial infarction or even sudden death, especially during exercise. We present a patient in whom the anomalous origin of the left coronary artery from the posterior aortic (non-coronary) sinus produced ischemic chest pain. The anomaly was identified by transesophageal echocardiography (TEE) and magnetic resonance imaging (MRI) as well as by coronary angiography. TEE and MRI are useful for detecting anomalies of the coronary artery both clearly and noninvasively and for evaluating the mechanism of ischemia.
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  • Akira HOSHIO, Kinya SHIROTA, Tetsuya DOI, Yoshihiro SAWADA, Masaharu F ...
    1994 Volume 35 Issue 3 Pages 389-394
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    A 50-year-old Japanese woman with annuloaortic ectasia was found to have total coronary artery ectasia without evident atherosclerosis. The coronary ectasia may have been secondary to or of similar etiology to the annuloaortic ectasia. There was neither stigmata of Marfan's syndrome nor any sign of dissection of the ascending aorta or coronary arteries. Furthermore, the patient was not elderly, and had no hyperlipidemia, diabetes mellitus, or history of smoking. There was a marked blood pressure difference between the arms, and linear calcification was present in the aortic wall. A stenotic lesion was present in the right mid-subclavian artery. Although it is impossible to rule out atherosclerosis as the etiology of these findings, the possibility that they may be a manifestation of Takayasu's arterits is discussed.
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  • Athanasios KRANIDIS, Gerasimos FILIPPATOS, Sofia MAVROGENI, Konstantin ...
    1994 Volume 35 Issue 3 Pages 395-402
    Published: 1994
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    We present a Mediterranean female patient with abnormal electrocardiographic findings and a history of shortness of breath during excessive effort (NYHA I) in whom apical hypertrophic cardiomyopathy with unusual features was detected by echocardiography and magnetic resonance imaging. There was a single fused apical hypertrophic papillary muscle and akinesia of the left ventricular apical segment. Abnormal left ventricular filling was also detected by Doppler echocardiography.
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