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Biomedical subjects

K Tabayashi

Publications and source records attributed to K Tabayashi.

At least 199 records · Page 11Linked to original sources
PubMed1987

Biochemical and hemodynamic changes in the hypertrophied dog heart subjected to chronic protein-calorie malnutrition.

Biochemical and hemodynamic changes were assessed in 13 dogs subjected to sub-coronary valvular aortic stenosis and chronic protein-calorie malnutrition (PCM). Red blood cell, hemoglobin, serum albumin, free fatty acids, blood glucose, cholinesterase and blood amino acid levels were measured. The dynamic geometry of the left ventricle (LV) was assessed with chronically implanted sonomicrometric piezoelectric crystals. Cardiac function was evaluated by mean velocity of circumferential fiber shortening (mean VcF) and the relationship between LV end-systolic pressure (LVESP) or LV wall stress (LVWst) and LV end-systolic diameter (LVESD). The following results were obtained: A decrease in body weight and increases in free fatty acids and 3-Methylhistidine were observed following long-term PCM. Mean VcF was not depressed in dogs subjected to PCM. The relationship between LVESP or LVWst and LVESD shifted downward and to the right after PCM, indicating reduced myocardial contractility. These findings suggest that the left ventricle in hypertrophied dog hearts subjected to PCM retains normal pump function, despite a low state in the myocardium.

Animals↗
PubMed1986

Intermediate term results of isolated mitral valve replacement with glutaraldehyde-preserved porcine xenograft valve: clinical and hemodynamic comparison between Hancock valve and Angell-Shiley valve.

Clinical and hemodynamic assessments were carried out for 30 cases, who underwent isolated mitral valve replacement with glutaraldehyde-preserved porcine xenograft valve. The cases were divided into two groups, according to the types of prostheses. Group H comprised 23 cases with Hancock 342 valve and group AS, 7 cases with Angell-Shiley valve. Mean (S.D.) follow-up periods were 4.0 +/- 0.7 in group H and 4.6 +/- 0.6 years in group AS. Incidence of valvular malfunction was 3.3 in group H and 9.3% per patient-year in group AS. Cumulative survival and event-free rates were calculated by actuarial method, which revealed 91 and 83% in group H and 70 and 71% in group AS at 6 years after operation. Hemodynamic assessments were carried out in 20 cases, in which complete data at rest and during exercise were obtained. Valvular function deteriorated during exercise in both groups. Parameters showing valvular function in group AS were worse than those in group H. It is concluded from this study that intermediate late results are satisfactory in group H, incidence of valvular malfunction is high in children and in group AS, thromboembolisms are seen even in cases with recourse to anticoagulant, xenograft valves are stenotic especially in high flow state and valvular function of AS valve is inferior to H valve.

Adolescent↗
PubMed1986

Regional myocardial protection by retrograde coronary sinus infusion of cardioplegic solution.

Antegrade administration of a cardioplegic solution in the presence of a coronary artery stenosis may lead to the heterogeneous distribution of the agent and poor myocardial cooling distal to a vessel stenosis. To determine the effects of retrograde coronary sinus infusion of cardioplegic solution, coronary stenosis was created in the canine preparation by occluding the left circumflex artery (LCx) during cardioplegic arrest. Left ventricular global and regional function (assessed by sonomicrometry and solid-state micrometers) were studied after 60 min of ischemic arrest. Three groups (all n = 7) were studied: group I (control), cardioplegic solution infused via the aortic root without LCx occlusion; group II, same as group I except with LCx occlusion; group III, retrograde coronary sinus infusion of cardioplegic solution with LCx occlusion. Heart rate was controlled by atrial pacing. Statistically significant differences in global function between the three groups were seen at low filling pressures but were not seen during volume challenge. However, the recovery ratio of regional function in the LCx area at a left atrial pressure of 5 mm Hg in group II was 77.2% (% shortening) and 48.5% (segment work), which was significantly less (p less than .01) than recovery in group I (111.7% and 75.9%) and group III (108.3% and 81.5%). These differences persisted during volume loading, to a mean left atrial pressure of 15 mm Hg. Regional compliance in group II was also significantly (p less than .01) depressed after cardioplegic arrest but was well preserved in groups I and III.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Long-term follow-up of patients who have undergone valve replacements for acquired valvular disease: a clinical and hemodynamic study.

Thirty-three cases, comprizing 5 of mitral regurgitation (MR), 11 of mitral stenosis (MS), 11 of aortic regurgitation (AR) and 6 of AR and mitral steno-regurgitation (MSR), underwent both preoperative and postoperative heart catheterization in association with a muscle exercise test. Comparisons were made between preoperative and postoperative clinical symptoms, hemodynamics and cardiac functions. The following results were obtained: 1) Improvements in clinical symptoms and hemodynamics at rest were observed in all but two patients. 2) Abnormalities in hemodynamics were obtained after the muscle exercise test, even in cases exhibiting normal hemodynamics at rest. 3) An increase in pulmonary artery mean pressure was noted in MR and MS groups after the muscle exercise test. 4) The cardiac function index values in both the MR and MS groups showed lower levels than those in both the AR and AR + MSR groups. 5) The presence of atrial fibrillation and extent of myocardial fibrosis were related to improvements in postoperative cardiac functions.

Adult↗
PubMed1982

[Transthoracic catheterization under monitoring by ultrasono-cardiotomography and its clinical usefulness].

When serious postoperative complications such as mechanical malfunction of the implanted valve occur in patients with multiple valvular replacements, it is very urgent to evaluate the function of the valve and heart and to establish an accurate diagnosis as to the damaged prosthetic valve, while giving intensive life-saving bed-side care. Under such circumstances, transvascular heart catheterization necessary for obtaining hemodynamic data or for angiocardiography can not be applied because it is almost impossible for a catheter to pass through a prosthetic valve without potential danger. Then, the present authors have introduced a method of cardiac catheterization by a direct transthoracic route during which cardiac structures are monitored by ultrasono-cardiotomography. This method is called "transthoracic catheterization monitored by ultrasono-cardiotomography," and was applied to cases of double (aortic and mitral) valve replacements. The immobile adhesive area in the vicinity the right ventricular wall is detected from the longitudinal or horizontal cross-section pictures, through which a polyethylene catheter with stylet was introduced from the subxiphoid region and was advanced toward the left ventricle. After introduction of the catheter into the right ventricle, the catheter tip was advanced to the midportion of the ventricular septum, which was selected to avoid the penetration of the tricuspid valve and coronary arteries. Then, the catheter was passed into the left ventricle on the ultrasonic scanning plane along the direction of the short axis of the heart. After placing the catheter into the left ventricle, a small amount of contrast material was injected to confirm the precise positioning of the catheter tip in the left ventricle. Thus, the hemodynamic measurement and angiocardiograpy were performed easily. By utilizing contrast cardiotomography, valvular function was evaluated easily without any side effects as in case of angiocardiography. Furthermore, ultrasono-cardiotomography was sensitive in detecting cardiac tamponade if appeared during direct heart catheterization, making immediate treatment possible. Thus, transthoracic catheterization monitored by ultrasono-cardiotomography was useful for the evaluation of the function of the prosthetic valve, especially in cases with double valve prostheses.

Adult↗
PubMed1981

Division of patent ductus arteriosus by "isthmus taping method".

"Isthmus taping method" as the safe and simple technique for division of patent ductus arteriosus (PDA), along with surgical and follow-up results were reported. 175 patients with PDA and without other cardiac anomalies were operated by this technique. Most of the patients were operated by junior surgeons as a first step in cardiac surgery. The left chest was entered through posterolateral thoracotomy in the third or fourth intercostal space. Tapes were placed around the isthmus of aorta and PDA. Intercostal arteries were not divided. PDA was divided in-between Potts' clamps. Pulmonary and aortic stumps of the PDA were closed with two rows of continuous over and over suture. Of the 175, one patient (0.6%) with pulmonary hypertension died of postoperative respiratory failure. No surgical hazards of bleeding were noted. No deaths were noted among 131 patients without pulmonary hypertension. Follow-up results in 174 patients up to 14 years were excellent.

Adolescent↗