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Biomedical subjects

K Hirosawa

Publications and source records attributed to K Hirosawa.

At least 145 records · Page 8Linked to original sources
PubMed1984

Effect of atrial pacing on phase analysis in patients with the Wolff-Parkinson-White syndrome.

Phase analysis of ECG-gated radionuclide ventriculography was performed during sinus rhythm and atrial pacing for 11 patients with the Wolff-Parkinson-White (WPW) syndrome. During sinus rhythm, phase analysis demonstrated abnormal early-emptying segments reflecting preexcitation in six of the 11 patients. In the remaining five patients, the precise site of abnormal early-emptying could not be detected. Atrial pacing increased the degree of pre-excitation, and abnormal early-emptying segments became clear in all patients. Our study demonstrated the utility of atrial pacing in performing phase analysis for patients with the WPW syndrome. Seven patients had abnormal early-emptying segments; four of them with ECG type A, in the left ventricle, and three of them with ECG type B, in the right ventricle. These results were consistent with results of the body surface and electrophysiologic mapping. In patients with posterior septal accessory pathways, phase analysis suggested probable laterality of the accessory pathway.

Adolescent↗
PubMed1983

Some observations on the structure of Suncus liver with special reference to the vitamin A-storing cell.

The structure of the liver of the thick-tailed shrew (Suncus murinus) was studied with special reference to the vitamin A-storing cell. The macroscopic arrangement of hepatic lobes was the same as those of rodents. Connective tissues of Glisson's sheath were not prominent. There were gradual differences in the size and the cytoplasmic contents of hepatocytes among perihepatic, intermediate, and periportal regions. These correspond to the acinar zones 3, 2, and 1 of Rappaport, respectively. The ultrastructural features of the hepatocyte were numerous microvilli, a large mass of glycogen particles (alpha-particles), and well-developed Golgi complexes and lysosomes in the peribiliary region. Cellular elements of the sinusoid were the same as those of rodents. Vitamin A-storing cells were demonstrated by autoradiography of tritiated retinyl acetate administered orally. They were distributed in the perihepatic and intermediate regions. The number of vitamin A-storing cells was much smaller than that in the mouse liver and did not increase after excess vitamin A was given to the animal. Cytological features of the vitamin A-storing cells in Suncus liver were similar to those for other mammalian livers. The scarceness of vitamin A-storing cells and the low amount of vitamin A esters suggest that Suncus does not store much vitamin A in the liver.

Adipose Tissue↗
PubMed1983

Clinical and echocardiographic features of pulmonary valve endocarditis.

We studied the clinical and echocardiographic features of eight patients with infective pulmonary valve endocarditis. In two patients, the vegetation was limited to the pulmonary valve; in the six other patients, infective lesions were also present on the mitral or aortic valves. None of the patients were addicted to narcotics. Seven of the eight patients had underlying congenital heart disease. In six patients the organism responsible for the infective endocarditis was Streptococcus viridans. Two-dimensional echocardiography performed using a wide-angle sector scanner was more useful than M-mode echocardiography for evaluating patients with pulmonary valve endocarditis.

Adolescent↗
PubMed1983

Availability of electrophysiological approach to the selection and assessment of antiarrhythmic drugs for recurrent ventricular tachycardia.

We performed serial electrophysiological-pharmacological studies on 21 patients with recurrent sustained or non-sustained ventricular tachycardia (VT). In 8 of 11 patients with recurrent sustained VT, VT could be induced repeatedly by programmed electrical stimulation and terminated by ventricular burst pacing. In 13 of the 21 patients, repetitive ventricular response (RVR) was successfully induced. In the 8 patients with induced VT, the efficacy of several antiarrhythmic drugs intravenously administered was assessed. Procainamide prevented the initiation of VT in 57%, disopyramide in 50% and mexiletine in 40%. However, lidocaine, propranolol and verapamil could not prevent VT in any of 5, 3 and 6 patients, respectively. Verapamil in combination with quinidine prevented the initiation of VT in one case. Each of disopyramide, propranolol and verapamil increased the VT zone in 2 patients. The drugs belonging to the same group classified by their electrophysiological properties were not interchangeable in 2 patients. Their ability to terminate induced VT did not always correlate with that to prevent its initiation in 2 patients. The effects of specific drugs were rather variable and unpredictable in each patients, and especially those of combination regimens using more than 2 antiarrhythmic drugs were more unpredictable. In all patients, the induced VT was morphologically identical to the spontaneously occurring VT and its rate was ranged within 13% of that of the spontaneously VT. In 10 of 13 patients with RVR, QRS configuration of RVR was not similar to the spontaneously occurring arrhythmia. The pharmacological suppression of RVR as an index for prevention against spontaneous VT remains controversial. This study concludes that the serial electrophysiological-pharmacological study provides a rapid prediction of effectiveness of a particular regimen and combination and a rapid identification of the deleterious effects of certain drugs in patients with recurrent sustained VT.

Adolescent↗
PubMed1983

Surgery in severe rheumatic mitral valve disease--recognition of severity and risk factors.

The postoperative course of 294 patients with rheumatic mitral valve disease, who underwent mitral valve surgery during a period from July, 1978 to June, 1981, was studied by comparing the influences of the following clinical parameters: a low left ventricular ejection fraction (LVEF), a high pulmonary arterial systolic pressure (PASP), a high pulmonary vascular resistance (PVR), tricuspid regurgitation (TR), a high right ventricular end-diastolic pressure (RVEDP) and a giant left atrium (GLA). The patients with a functional capacity of class III or IV according to the New York Heart Association were classified into 3 groups (improved, unimproved and died), and from this data we calculated the improvement ratio and the mortality rate. The improvement ratios were 73% in patients with a low LVEF, 70% with a high PASP, 78% with a high PVR, 66% with TR, 11% with a high RVEDP and 77% with a GLA; the mortality rates were 19, 14, 17, 24, 78 and 19%, respectively. As compared with the case of deteriorated left ventricular performance and pulmonary hypertension, deteriorated right ventricular performance, especially high RVEDP, was accompanied by a comparatively poorer surgical prognosis. It is concluded that mitral valve surgery should be performed during the period in which the right ventricular function is still preserved.

Adolescent↗
PubMed1983

Ventriculographic findings in the convalescent stage in eleven cases with acute myocarditis.

In order to clarify the sequelae of 11 patients who suffered from acute myocarditis of viral origin and were diagnosed by endomyocardial biopsy in the early and the convalescent stage of the disease, left ventriculograms were obtained from 17 to 167 (46.5 +/- 41.2, mean +/- SD) days after the onset of the disease were analyzed. The data were compared with the biopsy findings in the convalescent stage. The mean left ventricular ejection fraction (LVEF) was 57.5 +/- 10.8% and in 3 cases the LVEF was less than 50%. In 2 cases, apparent asyneresis was observed. In all cases coronary arteriographic findings did not show significant stenosis. It is concluded that after viral myocarditis, increase in left ventricular end-diastolic volume, depressed ejection fraction and asyneresis occur in some cases and it can be said that a development from myocarditis to dilated cardiomyopathy occurs.

Acute Disease↗
PubMed1983

[Unstable angina].

Explore the source record for details and available documents.

Angina Pectoris↗
PubMed1983

Seeding of gallbladder carcinoma along the tract after percutaneous transhepatic choledochoscopy.

An implant metastasis developed along the tract after percutaneous transhepatic cholecystoscopy 5 months after initial placement of the catheter into the gallbladder. Percutaneous transhepatic cholecystoscopy is conducted by insertion of choledochofiberscope into the gallbladder through the dilated sinus tract established around a catheter inserted into the gallbladder. The catheter had been placed for total of 15 days. Two days after the removal of the catheter, cholecystectomy supplemented by partial resection of the liver was carried out because of the extent of a gallbladder carcinoma. The choledochofiberscope used was Olympus CHF type 4B, with a thinner flexible part 5.0 mm in diameter. It is not surprising that carcinoma of the biliary tract or pancreas may seed along the tract of a biliary drainage catheter, but only few reports describing such incidence related to percutaneous transhepatic biliary drainage have previously been published. Physicians should be aware of this complication whenever a firm nodule develops at the site of previous entry of a biliary drainage catheter in a patient with malignant obstruction.

Adenocarcinoma↗
PubMed1983

[Hepatic vein blood flow pattern measured by Doppler echocardiography as an evaluation of tricuspid valve insufficiency].

Evaluation of tricuspid regurgitation was attempted by analyzing the blood flow pattern in the hepatic vein using a combined system of a pulsed Doppler technique and two-dimensional echocardiography. The Doppler incident angle to the hepatic vein from the subcostal approach was approximately 0 degrees to 30 degrees, and the Doppler output was easily recognized as a narrow frequency-band pattern on the sound spectrogram. The study population consisted of 60 patients with valvular heart disease and 17 healthy subjects. Inferior vena cava dimension (IVCD), hepatic vein dimension (HVD) and the blood flow pattern in the hepatic vein were compared with the severity (negative, mild, moderate and severe) of tricuspid regurgitation (TR) assessed by right ventriculography and with right atrial and ventricular pressures. The following conclusions were derived from the study: IVCD and HVD in a group of TR severe were significantly larger than those of the other groups. The normal flow pattern of the hepatic vein was biphasic with a systolic flow greater than a diastolic flow. In cases of valvular heart disease with atrial fibrillation, three types of abnormal blood flow patterns were demonstrated; Type 1 had a slower systolic flow than a diastolic flow. Type 2 had no flow signal during systole, and had only a diastolic flow. Type 3 had a reversed systolic flow with several variations. By this hepatic flow patterns, it was possible to differentiate the TR of severe and moderate groups from the TR of mild group, because 81% of the former groups showed a Type 3 of a flow pattern. The Doppler shifts from the base line on the sound spectrogram were well correlated with right atrial pressure and right ventricular end-diastolic pressure (r = -0.72 and -0.64, respectively). The early changes of the hepatic blood flow pattern after operation were due to the improvement of TR by tricuspid annuloplasty, and also seemed to be affected by the postoperative changes of right atrial compliance and contraction.

Adult↗