JAPANESE CIRCULATION JOURNAL
Online ISSN : 1347-4839
Print ISSN : 0047-1828
ISSN-L : 0047-1828
57 巻, 4 号
選択された号の論文の12件中1~12を表示しています
  • MASAHIRO HATTORI, TOSHIKAZU AOKI, KIYOTSUGU SEKIOKA, TOKUJI KONISHI
    1993 年 57 巻 4 号 p. 253-262
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    It is unclear whether aging or hypertension modulates directional contractile function of the left ventricular (LV) wall. We investigated LV midwall shortening and thickening in 35 normal subjects and in 15 patients with mild-to-moderate systemic hypertension (HT) using 2-dimensional echocardiography. The normal subjects were divided into 3 subgroups according to age: 13 subjects be-low 30 years, 12 subjects over 31 and below 59 years, and 10 subjects over 60 years. In normal subjects of all ages, no significant difference was observed between meridional shortening (%Lm=16.3±2.4) and circumferential shortening (%Lc=17.1±4.0), and a significant increase in the short-axis cross-sectional area (CSA) of the LV wall at end-systole was observed (p<0.001). No significant differences with age were found in the measurements, except that %Lc/%Lm was reduced (p<0.05) in the elderly subgroup. In HT, all measured parameters, i.e., %Lm, %Lc, %Lc/%Lm, wall thickening, and the change in CSA, showed no difference from those of normal subjects. We conclude that the shortening of the normal LV midwall is similar in both meridional and circumferential directions, and that aging and mild-to-moderate HT do not significantly affect this characteristic, when echocardiographic measurements are taken at rest at end-diastole and end-systole. This observation may be applied to simulation analyses of basic LV mechanics, such as the finite element method.
  • KENKICHI MIYAHARA, MASAHIRO SONODA, TADASHI KUKIHARA, SHIGERU AMITANI, ...
    1993 年 57 巻 4 号 p. 263-271
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    To investigate the relationships between coronary artery size, left ventricular (LV) mass, and LV stroke work in aortic regurgitation (AR), these values were measured in 19 patients with severe AR. Twenty normal subjects and 15 patients with mitral regurgitation (MR) were used as control groups. The coronary area index, i.e., the coronary cross-sectional area divided by body surface area (BSA), was larger in the AR group than in the control groups in all measured sites except for the peripheral left anterior descending coronary artery (LAD) and right coronary artery (RCA). However, the coronary area index divided by the LV mass was significantly smaller in AR and MR patients than in normal subjects. Furthermore, the coronary area index divided by LV stroke work was smaller in AR patients than in MR patients and normal subjects. These results suggest that the coronary blood flow associated with the increased LV mass and stroke work caused by regurgitation was insufficient in patients with severe AR, especially in the area of the LAD. Therefore, the occurrence of myocardial ischemia in patients with severe AR may involve inadequate enlargement of the coronary artery which perfuses the LV, in addition to factors such as decreased coronary perfusion pressure, increased coronary artery resistance and decreased coronary flow reserve.
  • YOSHIHARU YAMADA, TADASHI ISHIHARA, MASATAKA FUJIWARA, SHIGEMI TAMOTO, ...
    1993 年 57 巻 4 号 p. 272-282
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    Arterial and coronary sinus differences (A-S) of alanine, glutamate, isoleucine, leucine, valine and phenylalanine were measured in 7 control subjects and 12 patients with coronary artery disease (CAD) at rest and during exercise, and in 8 controls and 21 CAD patients at rest and during pacing. Lactate, great cardiac vein flow and oxygen were also measured. However, none of these parameters distinguished CAD from controls. Changes in alanine and glutamate during each load were, for the most part, consistent with previous studies, i.e., a greater release of alanine and uptake of glutamate was observed in the ischemic group. A-S of isoleucine, leucine and valine showed significant positive correlation to that of alanine (r=0.59, r=0.89, r=0.77, respectively, during exercise, and r=0.57, r=0.65, r=0.72, respectively, during pacing). A-S of isoleucine, leucine and valine showed significant positive correlations to each arterial concentration during exercise (r=0.54, r=0.62, r=0.63, respectively), but not during pacing. Although none of the uptakes of the branched chain amino acids (BCAA) were significant, the mean A-S of each BCAA was positive at rest in both controls and CAD, and declined during each load. A-S of leucine was significantly smaller in CAD than in controls during exercise (0.7±7.0 vs 6.8±4.1 pmol/l, p<0.05) and those of leucine and valine were significantly smaller in CAD patients with ischemic electrocardiographic change than in those without electrocardiographic change during pacing (0.1 5.9 vs 6.1 5.5, p<0.05; -3.1 10.1 vs 9.9 ±6.8pmol/l, p<0.01, respectively). These results suggest that BCAA, especially leucine and valine, tend to be taken up by human myocardium physiologically and show characteristic changes under myocardial stress similar to those seen with alanine and glutamate.
  • YOSHINARI ISAKA, OSAMU IIJI, KEIICHI ASHIDA, MASATOSHI IMAIZUMI
    1993 年 57 巻 4 号 p. 283-290
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    We studied the relationship between cortical grey matter flow (CBF) and age, cerebrovascular risk factors and the severity of subcortical hypersignals (HS, hyperintensity score in MRI) in 47 asymptomatic subjects with cerebrovascular risk factors. Multiple regression analysis revealed that HS was most strongly related to CBF, and that hematocrit, age and evidence of ischemic change detected in the electrocardiogram also appeared to be independent determinants of CBF. Both the severity and location of hypersignals were correlated with CBF. The most significant negative correlation observed was that between CBF and HS in the basal ganglia-thalamic region, where the degree of signal abnormality was modest. Decreased CBF in asymptomatic subjects with cerebrovascular risk factors may be related to (1) microcirculatory disturbance associated with elevated hematocrit and an increase in the number of risk factors, and (2) functional suppression of cerebral cortex due to the neuronal disconnection associated with subcortical lesions. In addition, impaired cerebral circulation may be related to MRI signal abnormalities.
  • KAZUHIRO HASHIMOTO, YUZURU NAKAMURA, MICHIHIKO MATSUI, KAZUHIKO SUZUKI ...
    1993 年 57 巻 4 号 p. 291-298
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    The pulmonary blood flow in 84 patients with left to right cardiac shunts was preoperatively and postoperatively examined by scintigram with macroaggregates of &amp;l;t99m>Tc-labeled human serum albumin. Lung biopsy was also performed in 28 patients. The regional pulmonary blood flow distribution curves obtained from perpendicular scintillation to the long axis of the right lung in the supine position were classified into 4 patterns (normal and types I to 3). The normal pattern displayed uniform distribution, however type I demonstrated a lack of upper corner in the curve. Type 2 showed 2 peaks (a lower peak in the upper and a higher peak in the lower part of the lung) with a dip between them. Finally only I peak in the lower part of the lung was manifest in type 3. The right Upper/Lower lung count ratio, R(U/L), expressed as the mean±standard deviation in each curve type was 0.82±0.12 (n=23), 0.71±0.11 (n=28), 0.6±0.08 (n=17) and 0.58±0.18 (n=16), respectively. The count ratios from the 3 abnormal types were statistically significant compared to the normal curve type (p<0.01). In addition, the type I and 2 curves were significant compared to type 3 (p<0.05-0.01). In patients under 3 years of age, lower R (U/L) count ratio expressed more severe pulmonary hypertension. Negative correlations were observed with the peak pulmonary/peak systemic pressure ratio, Pp/Ps, (r=-0.66, p<0.01) and with the pulmonary vascular resistance index, PVRI, (r=-0.45, p<0.01). However, these correlations disappeared in patients above age 3. The postoperative alteration of the curve type depended on the preoperative severity and was considered useful for follow-up. Seventy-five percent of type I patients changed to normal after I year. However, the more severe type 2 and 3 patients only demonstrated recovery to normal in 43% and 10% of the cases, respectively.
  • KOUICHI TAKEDA, KOICHI KONO, KOUICHI TAMANO, MASAKI TAKAHASHI, YASUYUK ...
    1993 年 57 巻 4 号 p. 299-311
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    Using an active cross-bridge model proposed by the authors, it has been established theoretically that cross-bridge activation rate (Ka) of the left ventricular myocardium, which might correspond to the rate of binding of Ca2+ with troponin C, is approximately expressed as a simple formula: Ka=3/electromechanical systole (sec-1), although no definitive biological proof has yet been provided for the equation. One hundred eighteen patients without significant cardiac disease and 6 patients who had atrioventricular block with a permanent pacemaker were evaluated to determine the Ka value of the normal human left ventricular myocardium (test 1), and to examine the effect of changes in heart rate (test 2) as well as afterloading (test 3) or dobutamine infusion (test 4) on Ka. The pacing rate was increased from 50 to 110 beats/min at 20-beat increments in test 2. Arterial pressure was elevated by angiotensin 11 infusion in test 3, and 7 subjects received a continuous dobutamine infusion in test 4. The Ka value was found to be related to heart rate, to be increased by dobutamine infusion, and to be decreased by myocardial lengthening due to afterloading. Dependence of Ka on heart rate appeared to result from changes in myocardial length. The Ka value corrected for heart rate (Kac) had an average variation of only 4.6%, and was unrelated to age or myocardial length in individual subjects. Thus, the Kac value of normal human left ventricular myocardium appears to be nearly constant between individuals but to be increased by catecholamine infusion or myocardial shortening.
  • YUHJI FURUTANI, KENICHI YUKI, HIROATSU YAMADA, MASAFUMI YANO, TAKASHI ...
    1993 年 57 巻 4 号 p. 312-321
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    Left ventricular diastolic filling has been reported to be impaired with advancing age in normal subjects. To investigate the influence of regional ventricular diastolic asynchrony on global ventricular filling as a function of age and to assess the location of asynchronous regions within the left ventricle, radionuclide ventriculography was conducted in 48 normal subjects aged 15 to 73 years. Left ventricular regional filling was assessed by dividing the left ventricular region of interest into 4 quadrants, from which global, septal, apical and lateral time-activity curves and first-derivative curves were derived. Indexes of global left ventricular systolic function at rest did not correlate with age . However, indexes of global early diastolic filling declined significantly with age; peak filling rate normalized to enddiastolic volume (r=-0.42; p<0.01), to stroke volume (r=-0.48; p< 0.001) and to peak ejection rate (r=-0.47; p< 0.001) decreased with advancing age. Global time to peak filling rate also increased with aging (r=0.41; p<0.01). Early diastolic asynchrony was measured as the sum of the absolute values of the time differences from global peak filling rate to that in each of three quad-rants (ΔTPFR). ΔTPFR increased with age (r=0.37; p<0.01). Global peak filling rate normalized to end-diastolic volume (r=-0.40; p<0.01), to stroke volume (r=-0.45; p<0.01) and to peak ejection rate (r=-0.51 p<0.001) decreased significantly with increasing ΔTPFR. Time to peak filling rate of the lateral region occurred first (163±33 ms), followed by the apical (184±38 ms) and finally the septal region (195±35 ms). With regard to the sequence of regional filling, this suggests that a physiologic asynchrony exists in resting condition in normal subjects. Times to peak filling rate in the septal and apical regions were modestly correlated with age (r=0.29; p<0.05, r=0.30; p<0.05 respectively), but that in the lateral region did not show significant correlation with age. This may indicated that the effects of advancing age on the regional filling differ in regions within the left ventricle. These results suggest that aging alters left ventricular early diastolic filling in association with the increase in physiologic asynchrony.
  • KENSUKE SHIOI, YOSHIHISA NAGATA, TAKENORI MASE, TAKAHIKO AOYAMA, SHINJ ...
    1993 年 57 巻 4 号 p. 322-327
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    Although the measurement of serum haptoglobin (S-Hp) is of great use for evaluation of intravascular hemolysis, it is not applicable in patients with mechanical prosthetic valves because S-Hp is virtually absent. We administered haptoglobin preparation to 10 patients with Bjork-Shiley mitral prosthetic valves and 10 patients with the same aortic prosthetic valves. Serum haptoglobin levels were measured periodically afterwards. The maximum haptoglobin levels (Hp (max)), serum, haptoglobin reducing rate ((Hp-ΔHp)/ Δt) and expected haptoglobin disappering time (hours) were obtained from the subsequent samples. The screening studies which were performed at the same time were not predictors of difference in the 2 groups. On the other hand, serum haptoglobin reducing rate and expected haptoglobin disappearing time indicated that hemolysis is higher in patients with an aortic prosthetic valve than with a mitral prosthetic valve. This haptoglobin administration test seems to be useful for the comparative examination of the intravascular hemolysis caused by the difference in the position of the prosthetic valve.
  • OSAMU SUZUKI, TATSUAKI MATSUBARA, MASAAKI KANASHIRO, MASAHIDE NAKAO, R ...
    1993 年 57 巻 4 号 p. 328-334
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    The present study was designed to investigate the cardiac impairment during ischemia/reperfusion injury in rats with streptozotocin-induced diabetes vs controls. Male rats were divided into three groups: controls, one-week diabetic rats (1wDM) and four-week diabetic rats (4wDM). In the isolated working heart, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), and maximum positive and negative dP/dt were measured before ischemia and after 20 min of global ischemia followed by 30 min reperfusion. In the pre-ischemic state, hearts of 4wDM showed a significant (p<0.05) depression of the maximum positive and negative dP/dt compared with those of controls and 1wDM. There were no significant differences in LVDP and LVEDP among the three groups. The incidence of reperfusion-induced ventricular fibrillation (VF) was 75% for controls, 15% for 1wDM rats, and 27% for 4wDM rats. In hearts without reperfusion-induced VF, there were no differences in the three groups, between the pre- and post-ischemic values in LVDP, LVEDP, and maximum positive and negative dP/dt. These findings suggest that diabetic hearts exhibit no susceptibility to ischemia/reperfusion in jury.
  • SATORU OTSUJI, NOBUHIKO SHIBATA, HISAO HIROTA, HIROTAKA AKAGAMI, AKIRA ...
    1993 年 57 巻 4 号 p. 335-343
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    We examined the effects of dietary supplementation with eicosapentaenoic acid (EPA) on experimental myocardial infarction in dogs. Twenty-five dogs were fed standard diets, 10 of which were supplemented with EPA-ester (100 mg/kg body weight/day) for 8 weeks, while 15 served as controls. After ingesting EPA for 8 weeks, the ratio of EPA to arachidonic acid (AA) in platelet cell membranes significantly increased (from 0.033 to 0.105; p<0.01). The chemotactic response of neutrophils to leukotriene B4 (LTB4) was reduced in the EPA group (34% reduction at 10-6 M LTB4, p<0.01). Also in the EPA group, the amount of 12-hydroxyeicosatetraenoic acid, one of the chemotactic products of AA in infarcted myocardium, was reduced to 40% (p<0.05). EPA treatment resulted in significant reduction in the ultimate size of the infarcted area. Contractile function of infarcted myocardium was well-preserved in the EPA group. Myeloperoxidase activity, an indication of the infiltration of neutrophils into the infarcted myocardium, was less in the EPA group than in the controls (0.68 ±0.25 U/0.1 gr. vs 1.22±0.55 U/0.1 gr., p<0.05). Therefore, we conclude that dietary supplementation with EPA attenuates ischemic myocardial damage through inhibition of neutrophilic infiltration into the infarcted myocardium.
  • HIDEHARU HAYASHI, HARUO MIYATA, HAJIME TERADA, NAOHISA NODA, HIROSHI S ...
    1993 年 57 巻 4 号 p. 344-352
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    To clarify the role of phospholipase C (PLC) in arrythmias and cell injury during myocardial ischemia/reperfusion, we studied its effects on electrophysiology and [Ca2+]i in guinea pig hearts. After exposure to PLC (1 and 2 U/ml), the action potential durations of right ventricular papillary muscles were decreased. Delayed afterdepolarizations were observed in all of the preparations, and some developed into triggered activities. Developed tension decreased after an initial increase for the first 5 min, while resting tension increased consistently. The effects of PLC (0.02, 0.1, and 0.2 U/ml) on [Ca2+]i of ventricular myocytes were measured using fura-2 fluorescence. The ratio of rod-shaped cells to all cells decreased in a time- and a concentration-dependent manner. Perfusion with 0.1 U/ml PLC elevated [Ca2+]i from 56±5 nM to 245 ±47 nM before cell rounding, and to 1167±172 nM after cell rounding, suggesting that PLC causes Ca2+ overload. In conclusion, activation of PLC may play a role in arrhythmias and cell injury during ischemia/reperfusion. The increase in [Ca2+]i during ischemia/reperfusion may activate phospholipase, which would further increase [Ca2+]i to form a vicious cycle.
  • MASAMI KOSUGE, KAZUO KIMURA, TOSHIYUKI ISHIKAWA, MAKOTO SHIMIZU, HIDEO ...
    1993 年 57 巻 4 号 p. 353-357
    発行日: 1993/04/20
    公開日: 2008/04/14
    ジャーナル フリー
    We report a case of successful transaortic closure of a postinfarction ventricular septal rupture using a Swan-Ganz catheter. The method markedly reduced a left-to-right shunt and the improved hemodynamic condition of the patient, an 81-year-old woman, was maintained for about a week before surgical treatment. Inflation of the balloon with water made the balloon visible via echocardiography and was effective in maintaining inflation and echocardiographic follow-up.
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