Japanese Heart Journal
Online ISSN : 1348-673X
Print ISSN : 0021-4868
ISSN-L : 0021-4868
Volume 32, Issue 2
Displaying 1-14 of 14 articles from this issue
  • Iwao KUWAJIMA, Yasuko SUZUKI, Satoshi HOSHINO, Tatsuo SHIMOZAWA, Akiko ...
    1991 Volume 32 Issue 2 Pages 157-166
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    In order to evaluate the effects of aging on cardiopulmonary receptor function in hypertensive patients, hemodynamic responses after unloading were studied in middle aged and older hypertensive patients.
    Twenty-one hypertensive patients were divided into 2 groups according to age. The younger group consisted of 9 patients less than 65 years old (mean age: 57.2 years) and the older group contained 12 patients more than 65 years old (77.2 years). Following 10min rest, deactivation of cardiopulmonary receptors was obtained by reducing central venous pressure through the application of graded negative pressures of -10, -20, and -40mmHg to the lower body. Blood pressure, pulse rate, and forearm blood flow were measured at baseline and at each level of negative pressure. Furthermore, plasma norepinephrine and plasma renin activity levels were measured at baseline and at -40mmHg. Forearm blood flow was measured by venous occlusive plethysmography using a Silastic strain gauge applied around the forearm. Forearm peripheral vascular resistance was calculated by dividing the mean arterial pressure by the forearm blood flow.
    Baseline mean blood pressure, pulse rate, and peripheral vascular resistance were similar in both age groups. Following lower body negative pressure (LBNP), mean blood pressure and pulse rate did not change, suggesting the selective deactivation of cardiopulmonary receptors. The increase in peripheral vascular resistance at LBNP of -40mmHg in the older group (20.0±6.2) was significantly lower than that in the younger group (15.5±8.9, p<0.05). Furthermore, the increase in peripheral vascular resistance after LBNP was inversely related to age (Y=-0.32X+38.8, r=-0.43, p<0.05). Increases in plasma norepinephrine and plasma renin activity in the older group were not different from those in the younger group.
    It is concluded that the sensitivity of cardiopulmonary baroreceptor function in hypertensive patients deteriorates with increasing age.
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  • Susumu NIIMURA
    1991 Volume 32 Issue 2 Pages 167-180
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Forty-one patients with essential hypertension were classified as saltsensitive (SS) or non-salt-sensitive (NSS) from the changes in mean blood pressure (MBP) with alterations in sodium intake from 35mmol (lowsodium) to 250mmol/day (high-sodium). Whereas there was no difference in plasma levels of atrial natriuretic factor (ANF) on a normalsodium diet (120mmol) between the 2 groups, the degree of increase in the plasma ANF level between the low- and high-sodium intake was significantly greater in NSS than in SS (p<0.001). In addition, the urinary sodium excretion on a high-sodium diet was smaller in SS than in NSS. There was a significant positive correlation between the plasma ANF and MBP after the high-sodium intake in both SS (r=0.67, p<0.01) and NSS (r=0.60, p<0.01); however, the relation of plasma ANF to MBP shifted apparently to a lower level in SS compared with NSS. These findings not only indicate that there exists a hyporesponsiveness of ANF release by the heart of SS patients in response to high-sodium loading, but also imply that such a response contributes to blood pressure-elevating mechanisms due to sodium loading in this type of human hypertension.
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  • Yoshiko MARUNO, Shigehiro KATAYAMA, Munemichi INABA, Akira ITABASHI, J ...
    1991 Volume 32 Issue 2 Pages 181-188
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    With the advent of long-acting or slow-release antihypertensive drugs, we should be aware of a fall in nighttime blood pressure (BP) as well as daytime blood pressure. In the present study, casual BPs at the physician's office as well as ambulatory BP was recorded every hour throughout 24 hours with a noninvasive automated BP monitoring device in 24 essential hypertensives treated with slow-release nifedipine. Administration of slow-release nifedipine (20-40mg, b.i.d.) decreased not only casual BPs but also ambulatory mean BP during the whole day or daytime (6 am to 10 pm). Slow-release nifedipine at 10mg in the morning did not affect casual BPs at the office. However, mean BP obtained by ambulatory BP monitoring during the daytime was significantly attenuated.In addition, a profound fall in mean BP amounting to more than 20mmHg during the night in some of the patients was observed during treatment with slow-release nifedipine not only at 20-40mg (b.i.d.) but also at 10mg once a day.
    These results suggest that we have to take into consideration the possibility that long-acting hypotensive agents may cause a great fall in nighttime BP during sleep, especially in the elderly.
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  • Makio TANI
    1991 Volume 32 Issue 2 Pages 189-201
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Increasing evidence in recent years suggests an important role of the central renin-angiotensin system in cardiovascular regulation. Although angiotensin-converting enzyme (ACE) is a pivotal element in this system, little is known about the enzyme in human brain. Thus, the regional distribution and biochemical properties of ACE were investigated in human brain. The highest activity was found in the hypothalamus (1.23±0.22units/mg protein), followed by the caudate nucleus (1.06±0.23), substantia nigra (0.97±0.20), medulla oblongata (0.59±0.17), cerebral cortex (0.30±0.07), and cerebellum (0.08±0.02). A high activity was also detected in the pituitary (0.66±0.12). This enzyme activity was almost completely (70-90%) suppressed by a specific antibody raised against pure human kidney ACE, indicating that the majority of the activity measured is due to true ACE.
    The molecular weight of the enzyme was 290, 000 on gel-exclusion chromatography, 152, 000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and 158, 000 by an immunoprecipitation technique coupled with SDS-PAGE. The optimum pH was 8.0-8.5. The enzyme activity was elevated by increasing concentrations of NaCl, indicating a chloride ion dependency of the enzyme. Most of the enzyme (>80%) was bound to concanavalin A, suggesting the presence of carbohydrate residues.
    These findings provide evidence for the presence of specific ACE in discrete areas of human brain and suggest that angiotensin II could be generated locally in these structures to exert cardiovascular effects in humans.
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  • Relation between Ventricular Depolarization and Repolarization in Normal Subjects
    Takehiko SHIBATA, Isao KUBOTA, Kozue IKEDA, Michiyasu YAMAKI, Kanji HA ...
    1991 Volume 32 Issue 2 Pages 203-213
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    To examine the relation between ventricular depolarization and repolarization, body surface isopotential maps at the end of the QRS complex were studied in 32 normal subjects using a signal-averaged body surface mapping system. The number of beats averaged was 96-154 (mean 126.2). In this study, there were 8 types of isopotential map patterns at the end of the QRS complex. Mean±SD of QRS duration, appearance time of repolarization, and disappearance time of depolarization were 82.0±8.7msec, 71.8±10.5 msec, and 79.7±9.4msec, respectively. Time duration of overlapping depolarization and repolarization was 8.6±6.4msec. The early repolarization was widely distributed on the left anterior chest and the upper sternal region. These results demonstrated the difference between the appearance time of repolarization and the disappearance time of depolarization for each lead. We concluded that it is difficult to evaluate ECG waves in the terminal portion of the QRS complex with the dipolar theory only.
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  • Alpay ÇELIKER, Ali OTO, Sencan ÖZME, Aydin KARAMEHMETOGLU, ...
    1991 Volume 32 Issue 2 Pages 215-225
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Eighteen children (10 females, 8 males; age range 5.5 to 17 years, median: 10 years) who suffered from recurrent syncope, drug refractory supraventricular tachycardia and atrioventricular block or bradycardia were evaluated by cardiac electrophysiologic study between August 1988-April 1990. During the study, basal intervals were measured and the conduction system and sinus node functions were investigated. In some patients the mechanism of the tachycardia was investigated and drugelectrophysiologic studies also performed.
    Two of 6 cases with recurrent syncope had positive electrophysiologic findings and adequate treatment resolved the symptoms. The others have been followed. The mechanism of the tachycardia was determined in 5 cases with drug refractory supraventricular tachycardia and drugelectrophysiologic studies were done in all of them. The site of block was determined in 7 patients with atrioventricular block and pacemaker implantation was done in 5 patients.
    The results emphasized the usefulness of cardiac electrophysiologic study in childhood arrhythmias.
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  • Alpay ÇELIKER, Süheyla ÖZKUTLU, Sema ÖZER, Senca ...
    1991 Volume 32 Issue 2 Pages 227-237
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Endomyocardial biopsy studies in adults have demonstrated the usefulness of this method. It is possible that studies will be more productive in determining the etiology and clinical status in patients with clinically diagnosed myocardial diseases. A prospective study conducted over 16 months included 17 children, aged 14 months to 18 years, with the diagnosis of dilated, restrictive cardiomyopathy and myocarditis. In 16 patients right, and in 1 patient left heart endomyocardial biopsies were performed. The specimens were evaluated by light and electron microscopy. There were no serious complications after the procedure. In 1 of 17 children histology showed no myocardial tissue. Electron microscopy evaluations were currently available in 9 patients. Endomyocardial biopsy findings were found to be diagnostic in 41.2%, helpful in 29.4% and of no help in 29.4% of patients. In conclusion, endomyocardial biopsy technique is highly sensitive in children with myocardial disorders. In future it will be the major diagnostic tool for invasive but safe detection of myocardial disease.
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  • Ken-ichi YOSHIDA, Choei WAKASUGI
    1991 Volume 32 Issue 2 Pages 239-246
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Recently we have shown that actomyosin ATPase activity decreases with age when measured under appropriate conditions (Yoshida K et al, Age 12: 97-102, 1989). Many previous studies, which examined changes in ATPase activity in myosin, actomyosin, or myofibrils under pathological states, ignored the age-related changes. In this study actomyosin was isolated from myocardia of middle-aged subjects (37-49 years old) and examined for ATPase activity under various conditions and protein composition. Proteolysis of myosin and troponin was more frequently observed in ischemic heart disease (IHD) subjects than in non-IHD subjects. The proteolysis was associated with a decrease in Ca2+ sensitivity of Mg2+-ATPase activity and enhanced stimulation of Ca2+-ATPase activity with a sulfhydryl reagent, N-ethylmaleimide. Hypertrophy appeared not to significantly affect ATPase activity.
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  • Tomiyasu KOYAMA, Ming-Yan ZHU, Masataka KINJO, Tsunehisa ARAISO
    1991 Volume 32 Issue 2 Pages 247-253
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    The effects of ischemia combined with reperfusion on the dynamic microstructure of mitochondrial membranes were studied in the hearts of anesthetized open-chest rabbits by means of time-resolved fluorometry. The fluorescence of diphenyl hexatriene (DPH) and its anisotropic decay were used to calculate membrane viscosity, wobbling angle of phospholipids and fluorescence life time. The anterior descending branch of the coronary artery was occluded for 15min and reperfused for 15min. Mitochondria from the area of the left ventricular wall exposed to ischemia-reperfusion and from an unexposed control area were separately isolated in 8 rabbits. For comparison, mitochondria from ventricular wall exposed to ischemia but not to reperfusion were obtained from 5 rabbits. The membrane viscosity increased from 0.44 to 0.49 poise and the wobbling angle of phospholipids tended to decrease from 59 to 56°at 37°C. The amount of peroxidized lipid rose from 1.5 to 4.3nmol/mgprotein as expressed with MDA in the mitochondria exposed to ischemiareperfusion. The fluorescence life time of DPH was slightly longer in the latter than in mitochondria from the control area. None of these parameters was altered in mitochondria exposed only to ischemia. The increase in viscosity observed in mitochondria from the ischemic-reperfused area probably produces a decrease in the diffusion of molecules through mitochondrial membranes. The concurrent tendency of the decrease in wobbling angle of membrane phospholipids suggests a decrease in the size of molecules which can permeate membranes. Limitations in diffusion will affect the metabolic activity of mitochondria and finally, overall cardiac function.
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  • Shingo KAWASAKI, Kazuo TAKEDA, Motoo TANAKA, Hiroshi ITOH, Masahiro HI ...
    1991 Volume 32 Issue 2 Pages 255-262
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    The hypothesis that a functional projection from the locus coeruleus (LC) to the posterior hypothalamus contributes to the development of hypertension in SHR, was tested by measuring norepinephrine (NE) in the posterior hypothalamus by brain dialysis after injections of L-glutamate (L-glu) into LC. L-glu elicited a prolonged elevation of blood pressure in both SHR and WKY. Pressor effects were significantly larger in SHR than in WKY. Extracellular NE in the posterior hypothalamus increased after LC stimulation; NE release was significantly higher in SHR than in WKY. Injections of 6-hydroxydopamine (6-OHDA) into posterior hypothalamus lowered the resting blood pressure and attenuated the pressor responses to L-glu injections into the LC in SHR. These findings suggest that the LC projects functionally to the posterior hypothalamus and that the projection can contribute to the development of hypertension in SHR.
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  • Ilhan PASAOGLU, Metin DEMIRCIN, Süheyla ÖZKUTLU, Ahmet Y&uum ...
    1991 Volume 32 Issue 2 Pages 263-266
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    Cardiac myxomas are extremely rare in infancy. We report a case of right atrial myxoma in a 35-day-old male infant (with cyanosis and convulsions). Echocardiography was carried out and a diagnosis of right atrial myxoma was made. Open heart surgery was performed using cardiopulmonary bypass and a 2.5×3.0cm mass was removed. The patient's postoperative course was uneventful. To our knowledge there is no previously reported case of right atrial myxoma in such a young infant which was operated on successfully.
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  • Junichi EJIMA, Ichirou OHMURA, Yoshikazu KAJI, Yasuo TSUDA, Shozo KANA ...
    1991 Volume 32 Issue 2 Pages 267-272
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    A 16-year-old girl appeared with fever and dyspnea. In her peripheral blood, leukocytes were found to have increased up to 25, 200/mm3, and eosinophils occupied 49% of the leukocyte population. By echocardiography, an abnormal echo layer which appeared to be thrombus was observed over the entire left ventricular endocardium including the posterior leaflet of the mitral valve, and mild mitral valve regurgitation was noted. After treatment, the abnormal echoes were markedly reduced simultaneously with the improvement of subjective symptoms.
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  • Kenji KODAMA, Hiroshi MURATA, Masanobu HIRATSUKA, Sachiko KAKITSUBATA, ...
    1991 Volume 32 Issue 2 Pages 273-279
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    A case of atypical coarctation of the suprarenal aorta with symptoms of acute hypertensive heart failure is reported. A 62-year-old man was admitted because of dyspnea associated with severe hypertension. Chest x ray demonstrated mild pulmonary congestion. Following antihypertensive management, symptoms of congestive heart failure improved. Abdominal computed tomography and digital subtraction angiography undertaken several days later demonstrated a narrowed segment of the suprarenal aorta. Control of hypertension was poor with currently available antihypertensives and a bilateral axillo-femoral bypass operation with artificial grafts was undertaken. Postoperative blood pressure was maintained at a normal level with a small dose of atenolol. The patient had an uneventful hospital course and remains well.
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  • Masaomi CHINUSHI, Masaru YAMAZOE, Yusuke TAMURA, Toshikazu FUNAZAKI, Y ...
    1991 Volume 32 Issue 2 Pages 281-286
    Published: 1991
    Released on J-STAGE: December 09, 2008
    JOURNAL FREE ACCESS
    A 46-year-old Japanese woman, who had been diagnosed as having aortitis syndrome 4 years earlier, was admitted to our hospital in May 1989. The diagnosis of aortitis syndrome was confirmed by intravenous digital subtraction angiography which showed stenotic lesions in each subclavian artery, the left common carotid artery, and the descending aorta. Coronary arteriography revealed diffuse and prominent dilatation of entire coronary artery segments. Moreover, a left ventriculogram showed complete obstruction of the mid-ventricle during systole. Thus, we diagnosed this case as aortitis syndrome complicated by coronary artery ectasia and mid-ventricular obstruction. The causal relations of these findings are discussed.
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