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Biomedical subjects

M Hiroe

Publications and source records attributed to M Hiroe.

At least 163 records · Page 9Linked to original sources

[Long-term follow-up study of I-131 therapy for Graves' disease--index associated with late-onset hypothyroidism].

We have studied the follow-up of thyroid function in the patients with late-onset hypothyroidism and euthyroidism after I-131 therapy of hyperthyroidism. Thirty three patients who did not need the thyroid treatment until ten years after I-131 therapy were classified as euthyroid group. And eleven patients who needed the thyroid supplement of thyroid hormone for late-onset hypothyroidism were classified as hypothyroid group. Patients in both groups who required only a single dose of I-131 for successful treatment of hyperthyroidism had similar age, gland size, 24 hour I-131 uptake, pretreatment serum T3 uptake level and T4 concentration, and I-131 treatment dose. Subclinical hypothyroidism occurred in 28.6% of euthyroid group and 66.7% of hypothyroid group four months after I-131 therapy. The levels of T3 were recovered to higher than normal range at 6 months in euthyroid group, while the levels of T3 were kept within the normal range in the seventy percent of hypothyroid group. Patients who were still lower in the level of T3 uptake than normal range at 6 months had a higher incidence of late-onset hypothyroidism. Our observation showed no significant difference in the course of follow-up studies after I-131 therapy between the patients with late-onset hypothyroidism and euthyroidism.

Adult↗

Long-term prognosis of Kawasaki disease patients with coronary artery obstruction.

The prognosis of coronary artery obstruction was studied in patients with Kawasaki disease. Between May 1973 and December 1987, coronary artery obstruction was diagnosed by coronary angiography in 30 patients (21 males, 9 females), of whom, only 8 (26.7%) had clinical symptoms. One patient died after 9 years of illness. Two complained of frequent chest pain, which disappeared after bypass surgery in one case and spontaneously in the other. Five had symptomatic myocardial infarction. Myocardial ischemia was diagnosed in 31.8% by treadmill stress testing, but was well demonstrated in 85.7% by thallium-201 myocardial tomography. Frequent ventricular premature beats, Wenckebach-type atrioventricular block, and ST-segment depression accompanied by chest pain were recognized by 24-h Holter monitoring. In the past, the methods used to determine the prognosis of Kawasaki disease patients with coronary artery obstruction were not adequate. However, the examinations used in this study revealed an improved ability to determine the prognosis in this disease. Myocardial tomography, in particular, provided a more accurate evaluation of myocardial damage. Ventricular arrhythmias seem to be a serious problem in these patients. Therefore, careful observation using these tests, especially myocardial tomography and Holter monitoring, should be done even if the patients are free of symptoms.

Adolescent↗

Detection of coronary artery stenosis in children with Kawasaki disease. Usefulness of pharmacologic stress 201Tl myocardial tomography.

This study determined the feasibility and accuracy of quantitative 201Tl myocardial single-photon emission computed tomography (SPECT) after dipyridamole infusion to detect coronary obstructive lesions in children with Kawasaki disease. 201Tl distribution after dipyridamole infusion was measured in 23 normal children, and with these normal values, quantitative analysis of SPECT was performed in 49 patients. Thirty-four patients had coronary stenosis 90% or greater on angiograms. Side effects resulting from systemic vasodilation were observed in about 70%. Angina pectoris and ischemic ST changes were observed only in patients with coronary stenosis. These symptoms disappeared after aminophylline infusion. Results of visual and quantitative analysis of SPECT were compared. SPECT data were shown on two-dimensional polar maps, and the extent and severity scores were calculated. The sensitivity of SPECT for detection of overall coronary stenosis was 91% (visual analysis) and 88% (quantitative analysis). The specificity of SPECT was 60% visually and 93% quantitatively. The sensitivity of quantitative analysis to detect individual coronary stenosis was similar to that of visual analysis. However, the specificity of visual analysis to detect individual coronary artery stenosis was significantly less than that of quantitative analysis. From these data, we conclude that quantitative analysis of myocardial SPECT after dipyridamole infusion is a safe and accurate diagnostic method for identifying coronary stenosis in children with Kawasaki disease.

Adolescent↗

Detecting abnormalities in left ventricular function during exercise by respiratory measurement.

The degree of exercise-induced cardiac dysfunction and its relation to the anaerobic threshold were evaluated in 23 patients with chronic heart disease. A symptom-limited exercise test was performed with a cycle ergometer with work rate increased by 1 W every 6 seconds. Left ventricular function, as reflected by ejection fraction, was continuously monitored with a computerized cadmium telluride detector after the intravenous injection of technetium-labeled red blood cells. The anaerobic threshold (mean, 727 +/- 166 ml/min) was determined by the noninvasive measurement of respiratory gas exchange. As work rate rose, the left ventricular ejection fraction increased but reached a peak value at the anaerobic threshold and then fell below resting levels. Ejection fraction at rest, anaerobic threshold, and peak exercise were 41.4 +/- 11.3%, 46.5 +/- 12.0%, and 37.2 +/- 11.0%, respectively. Stroke volume also increased from rest (54.6 +/- 17.0 ml/beat) to the point of the anaerobic threshold (65.0 +/- 21.2 ml/beat) and then decreased at peak exercise (52.4 +/- 18.7 ml/beat). The slope of the plot of cardiac output versus work rate decreased above the anaerobic threshold. The anaerobic threshold occurred at the work rate above which left ventricular function decreased during exercise. Accurate determination of the anaerobic threshold provides an objective, noninvasive measure of the oxygen uptake above which exercise-induced deterioration in left ventricular function occurs in patients with chronic heart disease.

Anaerobic Threshold↗

[New color imaging of [99mTc]-pyrophosphate and [201Tl]-chloride dual isotope single photon emission computed tomography in acute myocarditis].

[99mTc]-pyrophosphate (PYP) and [201Tl]-chloride dual isotope single photon emission computed tomography (SPECT) is now available to detect the site and extent of acute myocardial infarction. In inflammatory myocardial disease, [99mTc]PYP makes hot image on damaged area. We performed dual isotope SPECT of [99mTc]PYP and [201Tl]Cl in two patients with acute myocarditis and severe rhythm disturbance to evaluate the severity of inflammation. Myocardial damage was estimated by [201Tl] perfusion coloring blue and myocardial inflammation was estimated by [99mTc]PYP uptake coloring red. The overlap display of both images made it clear to detect spatial extent of myocardial inflammation. Using this technique, we expect to estimate the severity of myocarditis and to make a decision of therapeutic plan.

Acute Disease↗

Left ventricular characteristics during exercise in patients after Fontan's operation for tricuspid atresia.

Left ventricular function during supine bicycle exercise was studied using multigated blood pool imaging in ten patients with tricuspid atresia after Fontan's operation and in 13 children and adults (control group). The mean age of the patients was 16 years and the mean interval between operation and study was 5 years. The peak work loads that the patients could perform were similar to those in the control group. Work loads and heart rates during radionuclide study in the operated group were also similar to those in the control group. The left ventricular ejection fraction at rest and during exercise in the operated group was less than in the control group, although the net increase during exercise was similar in the two groups. During exercise, left ventricular end-diastolic volume decreased significantly in the operated group. In the control group, this variable did not change significantly. Left ventricular stroke volume increased during exercise in the control group but it did not change significantly in the operated group. These data indicate that in patients after Fontan's operation, left ventricular performance remains low during exercise, which is in part due to diminished left ventricular preload reserve, and this in turn may be caused by reduced reserve of right heart output.

Adolescent↗

Immunohistocytochemical localization of alpha human atrial natriuretic peptide in human atrium obtained from endomyocardial biopsy and cardiac surgery.

To demonstrate the localization of atrial natriuretic peptide (ANP), we were able to apply the indirect and avidin-biotin peroxidase complex (ABC) methods for immunohistocytochemical analysis on sections with routine fixation and embedding for conventional histopathological and ultrastructural examinations. Human right and/or left atrial myocardial specimens were obtained at cardiac surgery (n = 12) or by right atrial endomyocardial biopsy, employing Konno's catheter bioptome (n = 30). In both specimens, ANP-like immunoreactivity was observed mainly around the nuclei and in specific granules in atrial myocytes. These new techniques are, therefore, considered to be useful for clinical analysis employing minute human atrial specimens in various heart diseases.

Atrial Natriuretic Factor↗

ECG findings after myocardial infarction in children after Kawasaki disease.

Standard 12-lead ECGs were evaluated in 17 children with myocardial infarction and 78 children without myocardial infarction after Kawasaki disease; sensitivity and specificity of the ECG infarction criteria were determined. The presence or absence of myocardial infarction was determined from either clinical examination results (coronary angiography, ventriculography, and thallium-201 myocardial imaging) or autopsy findings. Of seven patients with inferior infarction, abnormally deep Q waves in lead II, III, or aVF were observed in six, but the duration was greater than 0.04 second in only one (14%). The sensitivity and specificity of inferior infarction criteria based on Q wave amplitude were 86% and 97%, respectively. Of eight patients with anterior infarction, seven (88%) had abnormally deep and wide (greater than or equal to 0.04 second) Q waves in anterior chest leads. The sensitivity and specificity of the infarction criteria based on the amplitude and duration of the Q wave were 75% and 99%, respectively. Of seven patients with lateral infarction, Q waves were observed in lead I, aVL, or both in four patients, and in all of these patients Q waves were wider than 0.04 second. In two patients with both inferior and anterior infarction, Q waves were observed only in leads II, III, and aVF; in only one patient were the Q waves wider than 0.04 second. Thus deep Q waves in lead II, III, or aVF that are not wider than 0.04 second may indicate inferior infarction in children. Q waves in lead I, aVL, and chest leads associated with anterolateral infarction are in most instances deep and wide.

Child↗

An integrated study employing histopathological, immunohistocytochemical and radioimmunoassay analyses of atrial natriuretic peptide in the right and left atria in patients with mitral valve disease.

To clarify the production mechanism of atrial natriuretic peptide (ANP) in right (RA) and left atria (LA) in mitral valve disease, histopathological and immunohistocytochemical analyses were performed and ANP levels were investigated by radioimmunoassay (RIA) in 28 patients. Atrial tissues were obtained during mitral valve replacement. ANP-like immunoreactivity of the myocytes applied by the avidin-biotin peroxidase complex method was observed around the nuclei of the atrial myocytes. Electronmicroscopically, immunoreactivity was observed in atrial specific granules. Light-microscopically determined intensity of the immunoreactivity was classified into 4 grades and the intensity in 100 myocytes was expressed by adding the scores of each myocyte. Mean right atrial pressure was positively correlated with the activity score in RA (r = 0.80). Pulmonary capillary wedge pressure was not correlated with the score in LA. The score in RA was significantly higher than that in LA. The ANP level in RA investigated by RIA was also higher than that in LA. Histopathological findings such as myocyte hypertrophy, degeneration and interstitial fibrosis were more severe in LA than in RA. In conclusion, longstanding atrial overloading, especially in LA, caused severe pathological damage, resulting in a smaller production of ANP. Much more ANP may be produced from RA in long-standing mitral valve disease.

Adult↗

DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy and deafness) syndrome associated with myocardial disease.

A 30 year old man with DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy and deafness) syndrome associated with myocardial disease is reported. Echocardiographic study revealed a marked symmetric left ventricular hypertrophy. Histology of the endomyocardial biopsy specimen from the right ventricle showed severe glycogen deposition in the myocytes. This case may indicate that DIDMOAD syndrome is a hereditary systemic disease affecting multiple organs, including the myocardium.

Adult↗

Endomyocardial biopsy approach to patients with ventricular tachycardia with special reference to arrhythmogenic right ventricular dysplasia.

Right ventricular endomyocardial biopsies were performed in patients with repetitive ventricular tachycardia (VT; 8 patients) or ventricular premature beats (1 patient) which showed left bundle branch block morphology in electrocardiograms. These 9 male patients ranging in age from 21-55 years (mean 37.7 years) revealed enlargement and/or asynergy of the right ventricle in the ventriculogram. Randomly selected biopsied patients with dilated cardiomyopathy (DCM; 18 patients) and chronic right ventricular overloading (14 patients) who did not show the above-described arrhythmias served as controls. A histopathological analysis revealed advanced myocardial interstitial fibrosis associated with an increase in fatty tissue in 8 of the 9 patients (89%). Moreover, advanced hypertrophy of myocytes (grade 2 or more of our criteria), disarrangement of muscle bundles and endocardial thickening were prominent with incidences of 75%, 75% and 78%, respectively. Incidence of all findings was more pronounced in the ARVD group. Suggestiveness of post-myocarditic change in the biopsied specimen was high in 1 patient, showing a lower incidence (12%) than the DCM group (17%). From these results, we can conclude that different etiological factors may be the bases of these pathological changes. We believe that the presence of a large amount of fatty tissue within the myocardial tissue is an important element in the etiology of ventricular arrhythmias as it has also been recognized in patients with non-ARVD idiopathic ventricular tachycardia in our biopsy series.

Adult↗

Prognosis of dilated cardiomyopathy: from a retrospective to a prospective study employing multivariate analysis.

To determine the prognostic factors of dilated cardiomyopathy (DCM), a retrospective long-term investigation of 111 patients seen between 1967 and 1983 was carried out. Fifty-four deaths were divided into 3 subgroups: (1): sudden death (n = 6); (2): sudden death on the basis of heart failure (n = 17); (3): refractory heart failure death (n = 31). Multivariate analysis was employed to ascertain the prognostic score, which was constructed from the grading of the New York Heart Association functional classification, the cardiothoracic ratio, electrocardiographic findings and cardiac function. Individual variables were indicated on the first (I) and second (II) principal component axes. The mean center points for the death modes were as follows: (1): I = -0.4, II = +0.8, (2): I = +0.7, II = +1.1, (3): I = +1.4, II = -0.8. Surviving cases (n = 57) showed I = -0.6, II = +0.1. Forty-one cases examined during 1984-1985 were analyzed to evaluate the prognostic efficacy of this score. Fourteen of 17 cases (82%) located in the refractory heart failure death group died within one year after determination of the prognosis, showing thereby that the prognostic determination by multivariate analysis is effective.

Adult↗