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Biomedical subjects

C Ibukiyama

Publications and source records attributed to C Ibukiyama.

At least 55 records · Page 3Linked to original sources

Sudden cardiac death from hypertrophic cardiomyopathy and acute idiopathic (Fiedler's) myocarditis: autopsy report.

A 45-year-old man with a rapidly deteriorating heart condition died suddenly, two hours after admission, after resistance to attempts of cardiac pacing. At autopsy, the heart weighed 600g with asymmetric septal hypertrophy. Histological examination revealed an extensive and diffuse disarray of myocardial fibers in the ventricular septum and in the free wall of both ventricles. Pronounced mononuclear cell infiltrations and interstitial edema were distributed widely in both ventricles. There were few abnormal findings in the other organs. The diagnosis was hypertrophic cardiomyopathy accompanied by Fiedler's myocarditis. Such a case appears to be rare.

Cardiomyopathy, Hypertrophic↗

[Early diagnosis and management of acute pulmonary embolism: clinical evaluation those of 225 cases].

To contribute for making early diagnosis and treatment of acute pulmonary embolism (APE), we investigated on clinical pictures of 225 patients with APE. Common underlying factors were heart disease, prolonged bed rest, post-surgical state, thrombophlebitis, malignant tumor and post-catheterization state in this order. Dyspnea, chest pain, tachycardia and shock were frequently seen as initial symptoms and signs. Blood screening showed leukocytosis, hypoxemia, hypocapnia and elevated serum LDH. Electrocardiographic findings highly demonstrated were ST.T abnormalities, such as T inversion with ST elevation in V1-3, ST depression in V4-6 and sinus tachycardia. Chest X-rays showed diminished pulmonary vascular marking and pulmonary artery dilation. Right ventricular dilatation were frequently seen on 2-dimensional echocardiograms. Pulmonary artery pressure were elevated up to 49/20 (30) mmHg. Twenty-five percent of the patients died, and the recurrence was seen in 4%. Thus, as soon as APE is suspected by above clinical findings, definitive diagnosis should be obtained by the lung perfusion scan and pulmonary arteriography, then oxygen and thrombolytic agents should be given immediately to prevent the fatal outcome.

Acute Disease↗

[Pulse wave velocity, thermography in the diagnosis of arteriosclerosis].

1. Pulse wave velocity (PWV) increased with increasing organic stiffness of the arterial wall mainly caused by arterio-sclerosis and also increasing functional stiffness of the arterial wall mainly caused by elevation of blood pressure. Age related changes in PWV have been recognized in variable countries. The PWV in the ascending aorta calculated by the characteristic impedance (378 +/- 141 cm/sec) was lower than that of conventional measurement in the descending aorta (697 +/- 144 cm/sec). 2. Thermography provide us indirect information of arteriosclerosis through reduction of skin temperature caused by disturbance of blood flow.

Aged↗

[Evaluation of latent cardiac disease in diabetic patients with Tl-201 exercise myocardial scintigram and blood pool scintigram].

To find latent heart disease in diabetic patients, 142 diabetic patients were divided into 4 groups: 1) No hypertension and normal ECG (DM group); 2) Hypertension recognized clinically (HT group); 3) Myocardial damage on ECG (MD group) 4) group associated with the previous 2 (HT + MD group). In all groups Tl-201 exercise myocardial scintigrams and blood pool scintigrams were taken for comparative analysis. Positive rates of SPECT were 27.7% (23/83) in the DM group, 30.0% (9/30) in the HT group, 50.0% (6/12) in MD group, and 70.6% (12/17) in the HT + MD group. The rate in the HT + MD group was significantly higher than in that of the DM and HT groups (p less than 0.001, p less than 0.01). Blood pool scintigrams revealed that in the HT + MD group, as compared with the normal control group, both 1/3 FF and PFR were significantly depressed, in addition to significant TPF prolongation in the former (p less than 0.001, p less than 0.05, p less than 0.05). These findings suggest that in diabetic patients hypertension and myocardial damage would lead to a high incidence of abnormality in SPECT and left ventricular rapid filling dysfunction. This indicate a high incidence of latent cardiac disease which can be recognized in diabetic patients by stress myocardial and blood pool scintigrams.

Adult↗

Effect of sodium intake on the hypotensive effect of calcium antagonists.

To clarify the influence of Na balance on the hypotensive effect of calcium antagonists, the changes of blood pressure and humoral factors after a single oral administration of 40 mg nicardipine were evaluated in 15 subjects with essential hypertension under high, normal, and low Na regimens (mean 24 hour urinary Na excretion: 320 +/- 24, 147 +/- 7, 27 +/- 6 mEq, respectively). Nicardipine induced a significant reduction of mean blood pressure and increase in heart rate. The change of mean blood pressure after nicardipine was negatively related to the pretreatment mean blood pressure under the three levels of Na intake (p less than 0.01). The slopes of the correlation lines for high, normal, and low Na regimens were -0.61, -0.69, and -0.52, respectively, without statistical significance. Nicardipine brought about significant increases in plasma renin activity and plasma norepinephrine, but no changes in plasma levels of epinephrine, 6-keto-prostaglandin F1 alpha, thromboxane B2 or serum aldosterone concentration. These results suggest that the magnitude of the untreated blood pressure and thereby the peripheral resistance are major determinants of the blood pressure fall caused by calcium antagonists, and that the failure to increase aldosterone and epinephrine in the face of peripheral vasodilation may be responsible in part for the hypotensive effect of this drug.

6-Ketoprostaglandin F1 alpha↗

[Validity of estimating left ventricular relaxation and filling dynamics by Doppler trans-mitral flow].

To evaluate the validity of estimating left ventricular (LV) diastolic function using the Doppler transmitral flow profile, the relationship of transmitral flow to LV relaxation and LV filling dynamics was observed. A total of 54 subjects, including patients with ischemic heart disease, idiopathic cardiomyopathy, and normal persons were examined. LV filling dynamics were assessed in 20 of them who had no regional wall motion abnormality or irregular LV geometry. Peak velocity of rapid filling (R) and acceleration of rapid filling (AR) at the mitral annular level were measured as indices of transmitral flow during the rapid filling period. LV relaxation was evaluated according to the time constant of LV isovolumic pressure decline (T) using the method of Weiss et al. The correlation coefficient between R and T was -0.27 and that between AR and T was -0.16, indicating lack of correlations. The v-wave of pulmonary wedge pressure (PWPv) was measured as an index for left atrial driving pressure during the rapid LV filling period. Multiple regression analyses of R or AR as dependent variables and T and PWPv as independent variables revealed significant correlations (r = 0.66 and r = 0.59). The peak transit rate (PTR = R/TVI) and atrial transit fraction (ATF = TVIa/TVI) were determined from the time integral of the transmitral flow velocity (TVI = time velocity integral during diastole, TVIa = time velocity integral during the atrial contraction phase). Also, the peak filling rate (PFR) during the rapid filling and atrial filling fraction (AFF) were determined by left ventriculography.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Radionuclide angiography in pulmonary sequestration.

We report a case diagnosed as pulmonary sequestration by radionuclide angiography prior to operation which showed anomalous arteries. Radionuclide angiography clearly revealed the condition of both the pulmonary artery and aorta, and is considered to be extremely useful in the diagnosis of pulmonary sequestration. It will probably be applied to more patients in the future.

Aorta, Thoracic↗

Exercise parameters for the prediction of post-training increase in exercise tolerance in patient with stable angina pectoris.

Twenty cases with effort angina underwent exercise training for a mean follow-up period of 38 weeks. Various parameters were investigated to clarify whether or not such parameters can be used to predict an increase in exercise tolerance of patients with effort angina. The increase of exercise tolerance after training was found to be related to a reduction of the myocardial oxygen demand at a given external work load. The maximal heart rate (max HR) the maximal systolic blood pressure (max SBP) and the maximal rate-pressure product (max RPP) could not predict the post-training increase in exercise tolerance. Before training, the maximal oxygen intake (VO2max) was found to be lower, and the HR/VO2max and the SBP/VO2max were higher in the group (11 patients) which showed a good response to the exercise program (effective group) than those in the group (9 patients) which did not (unchanged group). Before training, the HR/VO2max and the SBP/VO2max in the effective group were also higher than those of 96 healthy adults. On the other hand, the HR/VO2max and the SBP/VO2max in the unchanged group were not different from those of the healthy adults throughout the training. It is useful to compare the values of the HR/VO2max and the SBP/VO2max of patients with effort angina to those of healthy adults for the prediction of post-training increase in exercise tolerance.

Angina Pectoris↗

[Evaluation of left ventricular asynergy by two-dimensional echocardiography: comparison between fixed external axis system and floating axis system].

Detection and quantitative estimation of segmental asynergy in the infarcted area has been impeded by the rotation and anterior movement of the heart during systole. In the present communication, we compared the two measurements determined by the floating and fixed external axis systems. The former takes into account of the effect of cardiac movement. Furthermore, we assessed which system is superior by the left ventriculographic and coronary arteriographic analyses. The materials consisted of 24 cases of myocardial infarction. There was no significant difference between the two systems in the estimation of the number of asynergic segments or between echocardiographic and ventriculographic findings. The floating axis system had a tendency to underestimate asynergy, so that the number of hypokinetic segment estimated by the floating system was greater than that by the fixed external axis system. Therefore, the fixed external axis system was superior to the floating axis system in determining the causative coronary artery.

Adult↗

A coordinate axis transformation study of spatial QRS loop in hypertrophic cardiomyopathy.

To obtain an overall view of the QRS loop on vectorcardiograms (VCG) of hypertrophic cardiomyopathy (HCM), the coordinate axis was transformed using the resolver method. The morphological features and planarity of the loop were compared with hypertrophic patterns and hypertensive heart disease (HHD). The subjects in the present study included 30 normal individuals, 40 patients with HCM and 30 with HHD. The HHD group was selected from patients showing left ventricular hypertrophy on VCG similar to that of HCM patients. The HCM group showed significantly greater values than the HHD group in the thickness/length ratio, which represents the planarity of the spatial QRS loop. The above finding suggests that the HCM group had greater deformation in the QRS loop than the HHD group. This may provide a useful indicator for the differential diagnosis of the two diseases.

Adult↗

Experimental study on enzyme distribution and its relation to myocardial ischemic changes following coronary circulatory disturbances.

Coronary artery ligation of canine heart was performed to investigate the relationship between the lactate dehydrogenase (LDH) pattern in myocardium and the distribution of coronary flow, especially in the early stage of ligation and after reperfusion. In the myocardium of normal dogs, the LDH pattern was similar in the left ventricle, the interventricular septum, and the right ventricle; the average LD5:LD4 ratio was 1.1, 1.2, and 1.2, respectively, and consisted mainly of heart type. In the left and right auricles, however, the ratios were 0.3 and 0.2, respectively, lacking heart type. In the left ventricle, LD5:LD4 ratio in the subendocardium was different from that in the subepicardial layer. Blood flow distribution in canine myocardium was investigated by the fluorescent pattern on the cut surface of heart, in which 10% fluorescein sodium was injected into the cavity. By this method the evolution of the ischemic area from the endocardial layer to the epicardial side following coronary artery ligation and the effect of reperfusion on the ischemic area were clarified. Electron microscopic studies indicated that loss of mitochondrial function may account for the irreversibility of myocardial cell alteration. A new method for studying enzyme localization in tissues was introduced for studying LDH isoenzyme distribution in normal and injured myocardium.

Animals↗

[Intravascular ultrasound assessment at the site of balloon angioplasty: comparison with quantitative coronary angiography].

The effect of coronary angioplasty is usually evaluated on the basis of coronary angiography. However, angiographic images taken after angioplasty vary and the angiographic assessment of the therapeutic success of angioplasty is limited by local disruptions and dissections at the site of the dilatation, which are often difficult to detect by angiography. Intravascular ultrasound imaging is a new method for evaluation of coronary dimensions and wall morphology. Quantitative coronary angiographic analysis was compared with intravascular ultrasound assessment after balloon angioplasty in 42 patients. A diagnostic ultrasound imaging catheter was used during percutaneous transluminal coronary angioplasty (PTCA) to image both the lesion and the vessel segment just proximal (reference segment). Correlation between angiographic and ultrasound findings of vessel diameters and areas at reference segments was closer (r = 0.78, 0.66) than at the sites of PTCA (r = 0.54, 0.36). Dilated sites were analyzed in two subgroups segregated by degree of lumen eccentricity. An eccentric vessel lumen, defined as a circular shape factor of less than 0.92, was present at 25 of 42 sites. The correlation between angiographic and ultrasonic cross sectional area was not as close for these eccentric segments (r = 0.37). The difference in luminal areas between eccentric lumens estimated by edge detection and densitometry methods was 0.93 +/- 0.3 mm2, significantly greater than 0.54 +/- 0.31 mm2 in the circular group (p < 0.01). Luminal area after balloon angioplasty is clinically important to confirm by intravascular ultrasound especially in patients with large differences in measured values by quantitative coronary angiography.

Adult↗