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Biomedical subjects

K Hirosawa

Publications and source records attributed to K Hirosawa.

At least 109 records · Page 6Linked to original sources
PubMed1985

Prognosis of dilated cardiomyopathy. An integrated analysis including endomyocardial biopsy findings.

A long-term prognostic study of up to 15 years of dilated cardiomyopathy (DCM) was carried out in 65 cases. The 5-year survival rate after the onset of subjective symptoms was 40%, and the 10-year survival rate 22%. To evaluate the prognostic factor of DCM, the cardiothoracic ratio (CTR), ECG, hemodynamics, and histopathological contractility failure index (HCFI), which we constructed through right ventricular endomyocardial biopsy, were compared. Patients having malignant arrhythmias, such as short runs or multifocal ventricular premature beats with mild impaired cardiac status, mild cardiomegaly, and low HCFI, were more prone to sudden death. In patients with progressively deteriorating cardiac status, refractory cardiomegaly, supraventricular arrhythmias, left axis deviation, prolongation of QRS interval, low voltage, and high HCFI, the cause of death is more likely to be refractory heart failure.

Adult↗
PubMed1985

A case with bronchogenic cyst diagnosed by reconstruction CT prior to surgery which showed cardiac abnormalities.

A case report of a patient with bronchogenic cyst who presented with cardiogenic symptoms was described. The precise diagnosis was finally made after completing various diagnostic procedures which included reconstruction computed tomography. The patient, a 30-year-old man, was admitted to our hospital because of palpitation, chest pain and fever of three weeks duration. An electrocardiogram (ECG) revealed evidence suggestive of left atrial overloading and frequent atrial premature beats. A chest roentgenogram showed an abnormal shadow behind the right upper portion of the heart and a cross-sectional echocardiogram revealed abnormal echoes with ill-defined margins in the left atrium. Computed tomography (CT) revealed the presence of the left atrial tumor but left atriography suggested that it was extracardiac and compressing the left atrium. Reconstruction CT was therefore performed and the cyst was diagnosed as being in a subcarinal position. A mobile calcified mass was also demonstrated by the CT. An operation was performed and a cyst, 6 X 3 cm, was removed almost completely and a histopathological diagnosis of bronchogenic cyst was made. In this particular case, ECG abnormalities which suggest atrial damage and the diagnostic usefulness of reconstruction CT are stressed.

Adult↗
PubMed1985

Recent trends in cardiac sarcoidosis research in Japan.

Our recent survey of the Japanese literature, actual case experience, and previous studies revealed the following results. Fifty-three cases were reported in which the main cause of death in sarcoidosis was congestive heart failure (11 of 17 cases, 64.7%) and not sudden death as was previously believed. ECG analysis revealed that third degree AV block, bundle branch block, and ventricular arrhythmias were the most frequent findings indicating the presence of cardiac sarcoidosis. It was recognized that in the Japanese population fatal myocardial sarcoidosis or clinical diagnosed cardiac sarcoidosis occurred most frequently in females over the age of 40 years. It is suggested that myocardial changes progress independently of granulomatous changes. This is due to the detection of a high incidence of basal lamina layering of myocardial capillaries (14 of 18 cases, 77.8%) and is considered to play a significant role in the progression of this disease. Radionuclide studies showed that thallium scintigraphy or technetium ventriculography were positive in those cases where ECG abnormalities are prominent, indicating the presence of myocardial disease. Previous therapeutic studies of cardiac sarcoidosis have shown a decrease in the incidence of sudden death; death due to congestive heart failure occurred more frequently despite pacemaker implantation. Control of congestive heart failure is thus regarded as the most important aspect of improved treatment and prognosis.

Adolescent↗
PubMed1985

A comparative ultrastructural study on the nature of interstitial cell constituents in idiopathic myocarditis and myocardial infarction.

In order to observe the characteristics of interstitial cellular proliferation in cases with myocarditis of possible viral origin, a systematic ultrastructural analysis of the cell components in the interstitium was made employing endomyocardial biopsy at the acute (0-10 days after onset), subacute (11-25 days), and convalescent stages (26-167 days) of the disease in ten cases. For comparison, myocardial specimens from cases with myocardial infarction were taken from early autopsy cases or from tissue obtained during surgery. The dominant interstitial cells observed in the acute stage of myocarditis were fibroblasts (38.3% +/- 17.5%, mean +/- SD), macrophages (23.3% +/- 12.1%), and lymphocytes (18.0% +/- 18.1%); at the convalescent stage, fibrocytes (44.6% +/- 20.2%) and fibroblasts (22.5% +/- 8.0%) were commonly seen. In myocardial infarction, the dominant cells were macrophages (35.0% +/- 16.0%) and neutrophils (26.0% +/- 13.9%) at the acute stage, and lymphocytes (30.0% +/- 17.8%), plasma cells (27.1% +/- 20.0%), and macrophages (26.4% +/- 11.4%) at the late stage. Thus, some differences between the two diseases could be recognized.

Acute Disease↗
PubMed1985

A clinicopathologic study on a cause of idiopathic cardiomyopathy and arrhythmia and conduction disturbance employing endomyocardial biopsy.

A comparative study of right ventricular histopathologic findings and clinical profiles in 174 cases with hypertrophic cardiomyopathy (HCM), 145 cases with dilated cardiomyopathy (DCM), and 241 cases with idiopathic arrhythmia and/or conduction disturbance with significant myocardial pathology [Electric disturbance type of cardiomyopathy (ECM)], totaling 560 cases, was made in order to clarify the role of viral myocarditis in these conditions. Postmyocarditis change (PMC) was defined by assessing serial biopsy findings in nine cases with acute myocarditis. The PMC was observed in three cases with HCM (1.7%), 22 with DCM (15%), and 21 with ECM (8.7%). The incidence of PMC was significantly higher in DCM and ECM than in HCM (P less than 0.001). The typical pattern of onset of acute myocarditis, i.e., high fever, upper respiratory infection, and gastrointestinal symptoms preceding cardiac symptoms within 10 days, was recognized in one case with HCM, eight with DCM, and 6 of 123 cases with ECM. The incidence was higher in DCM and ECM than in HCM (P less than 0.05). Of 46 cases with PMC, 12 (26%) showed this pattern, on the other hand only 3 of 377 cases (0.8%) without PMC did so (P less than 0.0001). Familial occurrence was not found in any of the 46 cases with PMC but was found in 38 of the 377 cases without PMC (P less than 0.01). This study indicates that viral myocarditis may often be the causative agent of idiopathic cardiomyopathy, especially DCM and ECM. It is also noticed that familial occurrence of the cases with PMC was never seen.

Acute Disease↗
PubMed1985

Hemodynamic studies and response to a combined therapy of nitroglycerin ointment and dopamine in patients with acute myocarditis.

Left ventricular performance was assessed in ten patients with acute myocarditis during the acute stage (within the first 3 days after the onset of cardiac symptoms) and during the convalescent phase (3-5 weeks later). In nine, the diagnosis was confirmed by endomyocardial biopsy during the acute stage, when left ventricular function was markedly reduced, i.e., cardiac index 1.53 +/- 0.33 l/min/m2 (mean +/- SD), left ventricular stroke work index 14.1 +/- 3.9 g/beat/m2, pulmonary capillary pressure 25.9 +/- 4.3 mm Hg, and systemic vascular resistance 27.9 +/- 9.4 R units. During convalescence, seven patients improved clinically with normal cardiac function and in three it remained impaired. Cardiovascular response to nitroglycerin ointment in three patients and a combination of dopamine and nitroglycerin ointment in five were compared. Nitroglycerin ointment reduced pulmonary capillary pressure by an average of 28.5% (P less than 0.05) and systemic vascular resistance by 26.8%, while the cardiac index increased by 34.1% (P less than 0.05) and left ventricular stroke work index by 30.3% (P less than 0.01). The combined therapy was more effective, with a reduction of pulmonary capillary pressure by 30.4% (P less than 0.05) and systemic vascular resistance by 27.5% (P less than 0.05), accompanying an increase in cardiac index by 53.5% (P less than 0.005) and left ventricular stroke work index by 63.5% (P less than 0.01), with little change in the double products. This study suggests that serial hemodynamic monitoring accurately evaluates cardiac function, selection of appropriate therapy, and the hemodynamic effects of treatment in patients with acute myocarditis.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1985

Hemodynamic and clinical effects of a new inotropic agent TA-064 in patients with refractory heart failure due to cardiomyopathy with special reference to dose-response effects.

A new hydroxybenzyl alcohol derivative TA-064 exerts a positive inotropic action in experimental preparations. To assess the acute effects in man, we made a cardiac catheterization study of the hemodynamic responses to TA-064 (20 mg and/or 40 mg given orally) in eleven patients with refractory heart failure due to cardiomyopathy (nine patients with dilated cardiomyopathy and one with amyloidosis). All patients were already receiving full digitalis and diuretics therapy. The following statistically significant (P less than 0.05-0.01) effects were noted: Upon administration of 20 mg of the drug, the cardiac index (CI) increased from a mean +/- 1 SD of 1.6 +/- 0.4 to 2.1 +/- 0.6 l/min/m2; pulmonary capillary wedge pressure (PCW) fell from 25 +/- 5 to 21 +/- 5 mm Hg; right atrial pressure (RA) fell from 12 +/- 3 to 10 +/- 4 mm Hg. In contrast, when 40 mg TA-064 were administered orally, the CI increased from 1.7 +/- 0.4 to 2.4 +/- 0.9 l/min/m2; PCW fell from 25 +/- 8 to 20 +/- 6 mm Hg; pulmonary arterial mean pressure fell from 35 +/- 11 to 29 +/- 9 mm Hg. Neither systemic arterial mean pressure nor heart rate increased. No toxicity was observed. The plasma concentration of TA-064 increased dose-dependently and reached a peak value 0.5-1.5 h after oral administration. Plasma catecholamine levels revealed no significant changes before and after use of the drug; therefore, the mechanism of action may not have been mediated by catecholamine.

Adult↗
PubMed1985

Long follow-up study in patients with prior myocarditis by radionuclide methods.

Ten patients with previous myocarditis were evaluated to determine cardiac conditions by T1-201 myocardial perfusion imaging and stress radionuclide ventriculography during the follow-up of 18-102 (average 56) months; the results were compared with those from ten sex- and age-matched controls. Exercise capacity by supine bicycle ergometer was reduced in patients with myocarditis. Their resting left ventricular ejection fraction (LVEF) was 57.5% +/- 3.9%, similar to that of controls. LVEF response to stress in myocarditis was abnormal with an increment of end-systolic volume, while in the controls LVEF increased significantly during stress. Seven of the eight patients with an abnormal ejection fraction response had constant T1-201 perfusion defects. This study indicates that latent left ventricular dysfunction is present in patients with prior myocarditis and that nuclear study is useful for long-term follow-up.

Adult↗
PubMed1985

Clinical spectrum and endomyocardial biopsy findings in eosinophilic heart disease.

Fourteen cases of heart disease with hypereosinophilia were analyzed employing conventional cardiologic methods, including echocardiography, cardiac catheterization, and endomyocardial biopsy. The cases were divided into four types: Acute carditic (endocarditis, myocarditis, pericarditis; five cases); ventricular dilation (three cases); restrictive (three cases); electric disturbance (three cases). Biopsy revealed significant changes in all cases. In one case of the ventricular dilation type, endomyocardial fibrosis with myocardial degeneration was seen, and in another case mural thrombus formation was shown to be present. In three cases of the restrictive type, endomyocardial fibrosis (EMF) was observed. In two cases of the electric disturbance type, minor right ventricular myocardial degeneration was observed. In two of the three cases of the carditic type and in three of eight cases in other categories, postmyocarditic changes were observed. The course of the disease compared with the type of disorder revealed a short course in the carditic type and a longer course, ranging from 2 to 24 years, with one exception, in the other types. It is also confirmed that the various histopathologic changes can be related to particular clinical presentations. We have shown that the basic changes in eosinophilic heart disease are not restricted to the endomyocardium and that they occur in various parts of the heart causing more widespread manifestations. The more comprehensive term "eosinophilic heart disease" is a preferable description.

Adolescent↗
PubMed1985

On the interstitial fibrotic changes in acute and convalescent myocarditis obtained by serial endomyocardial biopsy.

In order to determine the characteristics of the interstitial fibrotic change of the myocardium in cases with viral or idiopathic myocarditis, right ventricular endomyocardial biopsy findings in 9 cases where serial endomyocardial biopsy had been performed at the acute (5-10 days after the onset of the disease), subacute (11-21 days) and convalescent stages (22-167 days) and in 1 case at the acute stage were analyzed. They were then compared with right ventricular endomyocardial biopsy findings from 58 cases with chronic right ventricular overloading and which were of various kinds of congenital and valvular heart diseases. The following results were obtained: Interstitial fibrosis was seen at the acute stage along with an increase in fibroblasts, macrophages and lymphocytes. An analysis of the interstitial changes revealed that, at the acute stage, thin collagenous fibers were prominent as well as interstitial edema and at the convalescent stage, the edema became less prominent and instead, thick collagenous fibers increased. Comparison with the 58 cases with chronic right ventricular overloading revealed that diffuse and/or subendocardial fibrosis and endocardial thickening were more frequent and statistically more significant in cases with myocarditis.

Acute Disease↗
PubMed1985

The usefulness of electrophysiological-pharmacologic studies in the long-term therapy of paroxysmal tachycardias.

In 96 cases of paroxysmal tachycardia, results of chronic pharmacological assessment (CPA) were compared with acute electrophysiological-pharmacologic assessments (EPA) to evaluate the usefulness of EPA. I. Patients with sustained VT (31 cases): Sustained VT and repetitive ventricular response (RVR) could be induced in 61% and 23% respectively. More than one effective drug was found by EPA for 23 of 24 subjects. Of the 22 followed by CPA, the effectiveness of medication was excellent for 14 (64%), moderate for 1, slight for 4, and ineffective for 3 (14%). II. Patients with non-sustained VT (23 cases): RVR could be induced in 52%. Effective medication was identified by EPA for 8 of 10 patients. Of the 7 followed by CPA, the effectiveness of medication was excellent for 2(28.5%) moderate for 2, and ineffective for 3. III. Patients with PSVT (42 cases): PSVT could be induced in 90% of cases. Effective medication was found for all 31 cases which underwent EPA. Of the 23 cases followed by CPA, the chronic efficacy of drugs was excellent for 7 (30%), moderate for 5 (22%), slight for 7 (30%), and noneffective for 4 (18%). Therefore, we conclude that the usefulness of EPA differs according to the type of tachycardia. EPA is most useful in predicting chronic results for patients with sustained VT, especially when the sustained VT is readily reproducible by electrical stimulation. It is less useful for nonsustained VT and PSVT. With nonsustained VT, EPA is limited by difficulty in repeatedly inducing RVR, and by difficulty in predicting the appropriate medication for chronic oral therapy. With PSVT, even though the PSVT can be induced with greater success, EPA is limited by variations in pharmacologic effects over time, which create discrepancies between EPA and CPA.

Administration, Oral↗
PubMed1985

Improved myocardial ischemia and left ventricular function during exercise after successful percutaneous transluminal coronary angioplasty.

Percutaneous transluminal coronary angioplasty (PTCA) was performed in 42 patients with effort angina, 28 (67%) of them underwent successful angioplasty. Treadmill exercise testing, thallium-201 myocardial scintigraphy and radionuclide ventriculography were performed before and after PTCA for evaluation of the improvement of myocardial ischemia and left ventricular function at rest and during exercise. The average exercise duration by treadmill testing in 14 successful cases increased from 14 +/- 4 (mean +/- S.D.) to 16 +/- 2 minutes (p less than 0.05). Sixteen of 28 the patients were studied by thallium-201 myocardial scintigraphy. Before PTCA, regions of decreased thallium-201 uptake after exercise were observed in 12 of the 16 patients. After angioplasty, no distinct defects were recognizable in 9 of the 12 patients, and in the remaining three, a significant decrease in defects was recognized. Fifteen of the 28 patients were studied by radionuclide ventriculography. The mean ejection fraction was 61 +/- 5% at rest and 56 +/- 11% during exercise (N.S.) before PTCA. After angioplasty, the ejection fraction was unchanged at rest (61 +/- 5 to 62 +/- 4%), but increased significantly during exercise (62 +/- 4 to 74 +/- 4%, p less than 0.001). In conclusion, left ventricular function was improved by successful PTCA due to improvement of myocardial ischemia. The long term results require further study.

Adult↗