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Biomedical subjects

M Suwa

Publications and source records attributed to M Suwa.

At least 109 records · Page 6Linked to original sources
PubMed1986

Histological findings of the right and left ventricular myocardium and clinical follow up in idiopathic ventricular tachycardia.

In order to evaluate the etiology of so-called idiopathic ventricular tachycardia, endomyocardial biopsies were performed in four patients with electrocardiographically documented recurrent and sustained ventricular tachycardia. During the episodes of ventricular tachycardia, standard ECG showed a QRS pattern of right bundle branch block with left axis deviation in two patients and left bundle branch block in two patients. The episodes were associated with palpitation, dyspnea and hypotension in all cases. No organic heart disease was detected by physical examination, chest X-ray films, echocardiograms, left ventriculograms or coronary cineangiograms. His bundle electrograms showed blocks at various sites in the atrioventricular conduction system. The biopsy specimens revealed nonspecific myocardial degeneration in the right and left ventricles. These findings suggest mild but wide-spread myocardial damage in both the working myocardium and the conduction system. The clinical course of these patients appeared benign according to follow-up data of one to nine years' duration. None developed overt clinical signs of dilated, hypertrophic or restrictive cardiomyopathy.

Adult↗
PubMed1986

Cardiovascular effects of a new inotropic agent, denopamine (TA-064); with reference to it's effects on cardiac hemodynamics and metabolism.

A new inotropic agent, denopamine (TA-064) was shown to have a strong positive inotropic effect. Its effect on cardiac hemodynamics and metabolism was evaluated by using wall stress and direct measurement of myocardial oxygen consumption. With plasma concentration of denopamine (21-29 ng/ml on average), attainable by one single oral dose (10 mg), the positive inotropic effect was evident by the significant increase in peak (+)dp/dt (+15% increase from control), and shortening velocity of the left ventricle (+39%), when heart rate or blood pressure was not altered significantly. End diastolic stress and end systolic stress of the left ventricle, defined as indices of preload and afterload, respectively, were reduced significantly. The reduction of preload (-51%) was the result of improved left ventricular filling, and the reduction of afterload (-23%) was due to the increased contractility. Neither coronary sinus blood flow not aortocoronary AV O2 defference was changed. Consequently, myocardial oxygen consumption remained unaltered. When the dose is chosen properly, denopamine is able to exert salutary effects in patients with severe heart failure.

Administration, Oral↗
PubMed1985

Electron-microscopic and immunohistochemical studies on endomyocardial biopsies from a patient with eosinophilic endomyocardial disease.

Light- and electron-microscopic studies and immunohistochemical procedures were carried out on blood eosinophils and left ventricular endomyocardial biopsies from a 68-year-old man with an eosinophilia of 8.2 X 10(9)/l and congestive cardiac failure due to eosinophilic endomyocardial disease. Some blood eosinophils were vacuolated and degranulated, and reversal of the normal staining pattern of eosinophil granules was seen by means of electron microscopy. The biopsies showed degenerative changes in the cardiac myocytes, with interstitial fibrosis and infiltration by numerous eosinophils, mast cells, and macrophages. Eosinophils infiltrating the myocardium showed a decrease in the number of granules, many of which were indistinct or contained dissolving crystalloids, which occasionally were seen to be discharged onto the surface of adjacent cardiac myocytes. Immunohistochemical studies of the endomyocardial biopsies with a monoclonal antibody, which is specific for activated eosinophils and binds to the secreted forms of eosinophil cationic protein (ECP) and eosinophil protein-X (EP-X), demonstrated that the lesions contained numerous activated eosinophils and secreted ECP and EP-X. These findings support the concept that in eosinophilic endomyocardial disease, activated eosinophils infiltrate and degranulate in the myocardium, releasing eosinophil cationic proteins which then damage adjacent myocardial cells.

Aged↗
PubMed1985

Factors discriminating survivors and nonsurvivors in alcoholic heart disease.

Eighteen patients with dilated cardiomyopathy and a history of excessive ethanol intake were monitored for 3-98 months (mean 23 months). Six patients died (mean age 43.7 +/- 9.2 years) and 12 patients survived (mean age 48.8 +/- 9.5 years). Of the echocardiographic findings taken during heart failure, only the relative wall thickness to the internal dimension of the left ventricle (t/r ratio) differed significantly (survivors 0.33 +/- 0.77 vs. nonsurvivors 0.25 +/- 0.04, P less than 0.05). Of the hemodynamic data obtained after treatment of heart failure, left ventricular end-diastolic pressure differed significantly (survivors 6 +/- 2 vs. nonsurvivors 12 +/- 4 mmHg, P less than 0.001). The two groups could not be differentiated by ejection fraction, cardiac output, end-diastolic or end-systolic volumes, or semi-quantitative analysis of histologic findings obtained by right ventricular endomyocardial biopsy (light microscopy). Only two of six nonsurvivors (33%) succeeded in abstaining from alcohol, while eight of twelve survivors (67%) became teetotalers (P less than 0.05). Total abstinence from alcohol seems to be essential but was not necessarily followed by recovery in the most severe cases. Thus, the absence of adequate hypertrophy and high left ventricular filling pressure may predict the prognosis in alcoholic heart disease.

Adult↗
PubMed1985

[Intraoperative visualization of coronary arteries using two-dimensional echocardiography].

We attempted intraoperative ultrasonic visualization of the coronary arteries of animal models and of patients who underwent coronary artery bypass surgery. Ultrasonic visualization of coronary vessels using a high frequency wide band micro-transducer (3.5-9.0 MHz) was first attempted in three open-chest dogs. The coronary arteries were well visualized from the epicardium with and without contrast perfusion, and the experimentally-occluded portion was well imaged. Subsequently, this technique was clinically applied in two patients undergoing cardiac surgery for valvular and congenital heart diseases, and in nine patients undergoing coronary artery bypass surgery. Gas-sterilized probes were placed directly over the cardiac surface. Ultrasonic imaging of the coronary artery was performed to detect the coronary arteries beneath the fat tissue; image the lesions in coronary vessels, especially those not visualized by angiography; determine the site of bypass grafting and evaluate the graft-ability to the distal branch (the latter was poorly visualized via collateral circulation or not visualized angiographically because of total occlusion at a proximal site); and observe the effects of bypass grafting and intraoperative angioplasty of coronary arteries after these procedures. This ultrasonic technique was found to be useful for the intraoperative evaluation of coronary vessels for coronary artery bypass surgery.

Animals↗
PubMed1984

Improvement in left ventricular diastolic function during intravenous and oral diltiazem therapy in patients with hypertrophic cardiomyopathy: an echocardiographic study.

M-mode echocardiography was used to evaluate the acute effect of intravenously administered diltiazem, 10 mg, and the chronic effects of oral diltiazem, 180 mg/day, and propranolol, 60 to 120 mg/day, administered for 2 weeks on left ventricular (LV) systolic and diastolic function in 13 patients with hypertrophic cardiomyopathy. Intravenous injection of diltiazem reduced isovolumic relaxation time from 114 +/- 26 to 99 +/- 21 ms (p less than 0.01) and the time to peak rate of LV dimensional lengthening from 166 +/- 17 to 133 +/- 10 ms (p less than 0.01), without significant changes of LV dimensions or fractional shortening. No significant changes were observed in LV dimensions or fractional shortening, but a significant increase in peak rate of LV dimensional lengthening (from 4.1 +/- 1.5 to 4.8 +/- 1.6/s, p less than 0.05) and a reduction in isovolumic relaxation time (from 105 +/- 26 to 77 +/- 23 ms, p less than 0.01) and the time to peak rate of LV dimensional lengthening (from 156 +/- 23 to 124 +/- 20 ms, p less than 0.01) occurred during the oral administration of diltiazem. In contrast, propranolol caused no significant changes in these values. Thus, diltiazem improves LV relaxation and diastolic filling without altering LV systolic function in patients with hypertrophic cardiomyopathy.

Administration, Oral↗
PubMed1984

Incidence of the coexistence of left ventricular false tendons and premature ventricular contractions in apparently healthy subjects.

The incidence of the coexistence of left ventricular false tendons and premature ventricular contractions (PVCs) was evaluated prospectively. Over 14 months, left ventricular false tendons were found in 71 (6.4%) of 1117 consecutive patients examined echocardiographically. Two types of false tendons were observed: longitudinal, from the ventricular septum to the posteroapical wall (n = 62), and transverse, between the septum and the lateral wall (n = 9). Among 62 patients with PVCs and no underlying heart disease, false tendons were detected in 35 (56%); 28 had unifocal and seven had bifocal PVCs. Episodes of ventricular tachycardia were documented in one of the 28 patients with unifocal PVCs and in one of the seven patients with bifocal PVCs. These PVCs were poorly controlled by antiarrhythmic drugs but easily suppressed by exercise. Left ventricular false tendons were detected in 36 patients on routine echocardiographic examinations performed in the other 1055 subjects, and 10 of these patients were judged to have no underlying heart disease. PVCs were detected in two (20%) of these 10 patients. Although a definite conclusion that left ventricular false tendons are arrhythmogenic cannot be derived from these results, the unexpectedly high incidence of the coexistence suggests that left ventricular false tendons may be an etiologic factor in the development of PVCs, especially the rate-dependent and medically uncontrollable PVCs seen in apparently healthy individuals.

Adolescent↗
PubMed1983

Coxsackie B5 myopericarditis in a young adult--clinical course and endomyocardial biopsy findings.

An 18-year-old student with recent gastrointestinal symptoms was found to have Stokes-Adams syndrome. A transvenous pacemaker was successfully inserted with clinical improvement. Subsequent viral titer studies and serum enzyme changes supported the diagnosis of coxsackie B5 myopericarditis. The first cardiac catheterization and endomyocardial biopsy of the right ventricle were performed on the 14th hospital day; the former revealed no hemodynamic abnormalities, but the latter showed marked necrosis of the myofibers, disarray of the remaining ones, mononuclear cell infiltration and the appearance of fibroblasts with fine collagen fiber proliferation in the interstitium. A second biopsy of both ventricles, carried out on the 46th hospital day, showed no necrosis of the myofibers or inflammatory cell infiltration but increasing collagen fiber proliferation in the interstitium and disarray of the surviving myofibers. These pathological findings suggest the healing process of the myopericarditis. To the best of our knowledge, reports of viral myopericarditis with serial endomyocardial biopsies have been few.

Adolescent↗
PubMed1982

Enteric coated polymyxin B in the treatment of hyperammonemia and endotoxemia in liver cirrhosis.

Effects of enteric coated polymyxin B capsules on hyperammonemia and endotoxemia in liver cirrhosis were investigated. Six million units of polymyxin B were orally administered daily to 21 patients with liver cirrhosis and 3 patients with hepatoma cum liver cirrhosis, whose plasma ammonia was higher than normal limit and/or whose plasma endotoxin was positive, for 5-32 days, and serum polymyxin B concentration (in 5 cases), changes of plasma ammonia level (in 19 cases) and plasma endotoxin (in all cases) were observed. Serum polymyxin B concentration was below the detectable limit (0.5 unit/ml) in all cases observed. In the patients with liver cirrhosis, plasma endotoxin and ammonia levels decreased rapidly after polymyxin B treatment, and the decreases in endotoxin levels were kept throughout the treatment. Twelve patients with liver cirrhosis (10 among them were treated with lactulose) were served as controls. All patients who were treated with lactulose alone showed rapid decrease in plasma ammonia, but the decrease in endotoxin in these patients was slower than that in those treated with polymyxin B. From these results, oral administration of polymyxin B is concluded to be useful in the treatment of hyperammonemia and endotoxemia in liver cirrhosis, as a poorly absorbed antibiotic and as an antiendotoxin agent.

Administration, Oral↗
PubMed1982

Echocardiographic observations of hemodynamic differences between mitral and aortic regurgitation. Quantitative interpretation of functional state by multivariate statistical analysis.

The hemodynamic differences between chronic mitral (MR: n = 30) and chronic aortic regurgitation (AR: n = 37) at various functional stages were investigated by echocardiography and compared with the findings in healthy subjects (n = 20). The ordinary statistical analysis revealed that in MR myocardial contractility and afterload to the left ventricle (LV) well preserved even at the stage of decompensation, while in AR the contractility deteriorated and the afterload was elevated even at the asymptomatic stage. By the multivariate statistical analysis, the functional differences and characteristics of the 2 diseases were clarified with 2 statistic factors derived from 6 hemodynamic parameters (LV end-diastole and end-systolic dimensions, mean velocity of circumferential fiber shortening, LV mid-systolic stress, LV mass, and left atrial dimension). In the differentiation between the 2 diseases by the multivariate analysis, left ventricular size tended to be smaller, contractility was preserved and loading of the left atrium was increased in MR more than in AR. Furthermore, a quantitative system which could explain the functional state by these echocardiographic parameters was derived from this multivariate analysis. The functional states was found to be strongly affected by LV end-systolic dimension and left atrial dimension. This quantitative method of determining the functional state, along with an accurate assessment of cardiac symptoms, provides a useful guideline for the clinical evaluation of the 2 diseases.

Analysis of Variance↗
PubMed1982

[Midsystolic closure of the aortic valve in hypertrophic nonobstructive cardiomyopathy].

Midsystolic cessation of left ventricular contraction was documented in a patient with hypertrophic nonobstructive cardiomyopathy (HCM) associated with Cushing's syndrome (adrenal adenoma) without history of hypertension. The carotid pulse tracing showed a rapid upstroke with a prominent percussion wave which was rapidly decayed at midsystole followed by a tiny tidal wave. The decay of this percussion wave coincided in timing with midsystolic closure of the aortic valve in the echocardiogram. The left ventricle (LV) was symmetrically hypertrophied (wall thickness = 1.8 cm). The motion of the interventricular septum and LV posterior wall appeared trapezoid, and the contraction of these walls was normal in early-systole followed by the sudden cessation at midsystole till end-systole. Systolic anterior motion of the mitral valve was not observed. Cardiac catheterization revealed no pressure gradient in the LV even after the various provocative maneuvers. The left ventriculogram simultaneously recorded with LV pressure showed that LV ejection was completed at midsystole, when LV pressure fell from 98 to 83 mmHg. Mitral regurgitation was not observed. Midsystolic cessation of left ventricular contraction in this case is thought to be the cause of sudden interruption of forward aortic flow, resulting in a bifid carotid pulse and midsystolic closure of the aortic valve in the echocardiogram.

Adult↗
PubMed1981

Serum glutathione S-transferase in experimental liver damage in rats.

The changes of serum glutathione S-transferase (GST) was observed after carbon tetrachloride (CCl4) administration to Wistar rats. Serum GST activity increased rapidly and reached the peak 24 hours after CCl4 administration, and decreased rapidly thereafter. Centrilobular massive necrosis was already observed at the peak time of serum GST activity. On the other hand, serum glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) activities varied slowly, and the peak time of GOT and GPT activities was 36 hours after CCl4 administration. GST-containing Y fraction obtained from rat liver was injected intravenously to control and nephrectomized rats, and the plasma disappearance of GST activity was observed. The plasma disappearance of GST activity was very rapid in the control rats. When the Y fraction obtained from 1/12 g liver was injected, no statistically significant difference in the plasma GST half lives was observed between the control and nephrectomized rats. Half life of serum GST was significantly shorter in control rats receiving the Y fraction from 1/60 g liver, comparing with that in nephrectomized rats receiving the same amount of Y fraction. From these results, serum GST is concluded to be a precise index of the early stage of hepatic necrosis in the rat, and considerable amount of GST is excreted from the kidneys, but most of the enzyme is metabolized in vivo.

Alanine Transaminase↗