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Biomedical subjects

H Oku

Publications and source records attributed to H Oku.

At least 217 records · Page 12Linked to original sources
PubMed1981

[Clinical usefulness of RI angiography using amplitude image and phase image by Fourier analysis for the detection of anteroseptal myocardial infarction (author's transl)].

In 19 patients with anteroseptal myocardial infarction, the wall motion of interventricular septum was analyzed by RI angiography using the amplitude image and the phase image. Both images were obtained from ECG gated blood pool data by Fourier analysis. Namely, from the first harmonic in the Fourier series, the heart motion was detected as the amplitude and phase of time-activity curve in each pixel. The distribution of the amplitudes and phases were displayed in color scale, and then both the amplitude and phase images were acquired. Those images allowed us visualization of the ischemic area, even if the scar was parallel to the detector. Moreover, we were able to assess the wall motion of the entire interventricular septum and to distinguish hypokinetic region and dyskinetic region from the hypokinetic region with shift of phase estimated by conventional method. Abnormal region detected by those images closely corresponded with the region of decreased radioisotope concentration in thallium-201 myocardial scintigram.

Adult↗
PubMed1981

[Evaluation of myocardial infarction by ECG gated cardiac computed tomography (author's transl)].

ECG gated cardiac computed tomography (cardiac (T) was performed in 9 cases with old myocardial infarction. Seven of these had anterio-septal infarction, one had inferior wall infarction and the remaining one had posterior wall infarction. All were investigated by left ventriculography and coronary arteriography. Cardiac CT was performed after intravenous administration of contrast medium usually given as a bolus injection. The infarcted myocardium was thin and showed abnormal wall motion in cardiac CT, but the motion did not always coincide with left ventricular cineangiographic findings. In 3 cases, mural thrombi at the left ventricular apex were observed by cardiac CT, and in 2 of which the thrombi were confirmed by left ventriculography. In 2 cases, cardiac CT showed stasis of contrast medium and aneurysmal formation in the left ventricular cavity and the aneurysms were confirmed by left ventriculography. Sequential 8 mm thick non-ECG gated cardiac CT scans from the cardiac apex to the base were performed in 7 cases with anterio-septal infarction, and the infarcted area were observed in the anterior interventricular septum in 6 cases. We concluded that cardiac CT was a useful noninvasive method to detect abnormal wall motion, abnormally thin wall, mural thrombus and left ventricular aneurysm in old myocardial infarction.

Adult↗
PubMed1979

Presystolic pulmonary valve opening in constrictive pericarditis.

Right heart pressure tracings were studied in 5 cases with constrictive pericarditis. The pressure of the A-wave in the right atrium of these cases was higher than the pulmonary arterial diastolic pressure. In addition, a presystolic wave appeared in the pulmonary arterial and the right ventricular pressure tracings, in coincidence with atrial systole. The pressure of this presystolic wave was similar to that of the right atrial A-wave. This suggests that the pulmonary valve opens following atrial systole, and then the blood flows into the pulmonary artery in the presystolic phase in patients with constrictive pericarditis. In 2 cases, pulmonary valve echograms were recorded. The a-dip in these 2 cases was as deep as 8.4 mm and 9.6 mm (1.8-4.1 mm with a mean of 2.80 mm for normal men), and its duration was prolonged to 0.17 sec and 0.18 sec (0.10-0.13 sec with a mean of 0.115 sec for normal men). In conclusion, such a deep and prolonged a-dip on pulmonary valve echogram is presumably a sign of presystolic pulmonary valve opening.

Adult↗
PubMed1978

Insulin secretion after oral calcium load.

Oral glucose tolerance test with 50 g glucose was carried out with and without simultaneous oral administration of 3 g calcium lactate. Blood sugar and serum immunoreactive insulin (IRI) were measured before and 30, 60, 90 and 120 min after glucose load in 11 diabetics and 11 non-diabetics. Similar oral glucose tolerance test was performed with and without intravenous administration of 10 ml 8.5% calcium gluconate in 6 diabetics and 6 non-diabetics. Maximum serum level after glucose load (Max IRI), maximum rise of serum IRI following glucose load (Max delta IRI), maximum delta IRI/delta BS following oralglu cose load (Max delta IRI/delta BS), the area surrounded by the delta IRI curve and the abscissa (sigma delta IRI) and the area surrounded by the delta IRI/delta BS curve and the abscissa (sigma delta IRI/delta BS) significantly increased in diabetics but not in non-diabetics after oral calcium load, whereas intravenous calcium load failed to influence any of these values. Oral calcium load thus appears to augment glucose-induced insulin secretion only in diabetics, suggesting some abnormality in the mechanism of insulin secretion with reference to calcium in diabetes mellitus.

Administration, Oral↗
PubMed1976

Operative indication for corrective surgery in cases of complete transposition of the great arteries associated with large ventricular septal defect.

Among 23 patients with complete transposition of the great arteries (TGA) and large ventricular septal defect (VSD) who underwent corrective surgery, there were nine deaths (39 per cent). Since 1972, improvement in operative techniques, linked with increasing experience in postoperative care, has reduced the hospital mortality rate to 29 per cent (five deaths in 17 patients). Only one of these 23 patients had pulmonary artery banding prior to definitive repair. Analysis of the preoperative hemodynamic data suggests that complete surgical repair is not indicated for patients who have TGA and large VSD, without significant pulmonary stensosis, when the pulmonary arteriolar resistance is greater than 2,500 dynes-sec.-cm.-5 or the effective pulmonary flow index is less than 1.2 L. per minute per square meter of body surface area.

Cardiac Surgical Procedures↗