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T Tedoriya

Publications and source records attributed to T Tedoriya.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Physiological characteristics of arterial graft for coronary artery bypass surgery].

Arterial grafts have been used widely for coronary artery bypass grafting (CABG) because of their excellent long patency. However, some clinical reports suggest that blood flow in arterial grafts may not be adequate compared with aorto-coronary bypass grafting. Pressure in arterial grafts was measured in patients undergoing CABG. The pressure tracing in the ascending aorta (AA) was maintained during diastole. The systolic pressure wave in ITA and GEA was narrow, while the diastolic pressures fell rapidly: the diastolic pressure in GEA was lower than in ITA. The area under the pressure wave was measured in diastole and in systole. Although there was no significant difference in systolic areas, the diastolic area were lower in ITA than in AA, and lower in GEA than in AA and in ITA. These results clarified that arterial grafts which belong to the systolic-dominant systemic circulation have disadvantages over aorto-coronary bypass grafts, in terms of physiological suitabilities to the diastolic-dominant coronary circulation.

Adult↗
PubMed1992

[Diabetes mellitus and coronary artery bypass surgery].

To determine the influence of diabetes mellitus on the results of coronary artery bypass surgery, a review of 163 diabetic patients operated on during 8 years, of whom 146 were receiving no drugs or receiving oral hypoglycemic agents, and 17 were receiving insulin. They were compared with 337 nondiabetic patients operated on over the same period. Higher incidences of hypertension and cerebrovascular disease for the diabetic group were found. The extent of coronary artery disease as judged angiographically was significantly greater in the diabetic group than in the nondiabetic group. Perioperative mortality was similar in the two groups. The incidence of perioperative myocardial infarction, sternotomy complication, neurological complication, and renal insufficiency was equal in the two groups. Early graft patency was comparable in the two groups. Overall 8-year actuarial angina free ratios were 88.5% for the diabetic group, 93.2% for the nondiabetic group. Overall 8-year survival rates were 95.6% for the diabetic group, 98.6% for the nondiabetic group. Results indicate that diabetic patients have quantitatively more coronary artery disease than the non-diabetic patients but have no higher perioperative morbidity and mortality than nondiabetic patients. Long-term results revealed a lower angina free rate in diabetic patients than in nondiabetic patients.

Coronary Artery Bypass↗
PubMed1992

[Coronary artery bypass surgery in patients with familial hypercholesterolemia].

Coronary artery bypass grafting (CABG) was performed in 48 patients with heterozygous familial hypercholesterolemia (FH). Seventy-nine percent of these patients had three-vessel disease or left main trunk disease. The internal thoracic artery was used for grafting in 26 patients and the right gastroepiploic artery was used in 4 patients. Although no patient died during surgery, one died subsequently from graft-versus-host disease. Graft patency at one month after CABG was 95% in vein grafts, 100% in arterial grafts, and 97% overall. Histological study revealed that arterial grafts in patients with FH had similar structures to those in non-FH patients, without evidence of atherosclerosis. All patients were prescribed anti-cholesterol drugs to control serum cholesterol levels, and 4 patients underwent LDL-apheresis because of poor control. Survival rate at 11 years after CABG was 83% without cardiac death. Cardiac event-free rate in 47 surviving patients was 53% at 10 years after CABG in vein bypass group, 93% at 5 years in the arterial graft group, and 58% at 10 years overall. Results of CABG were as good in FH as in non-FH patients, using arterial grafts and anticholesterol therapy.

Adult↗
PubMed1992

[Pressure measurement of coronary artery bypass graft with transducer-tipped catheter].

The pressure of in situ arterial graft was measured with Fiber Optic Transducer-Tipped Pressure Monitoring System (Camino). Internal thoracic artery (ITA) and gastroepiploic artery (GEA) were prepared as in situ grafts, and the pressure at the end of each graft was recorded with ascending aortic pressure (Ao) and electrocardiogram, simultaneously. Although the peak systolic pressures of these grafts were identical, the systolic pressure of ITA and GEA formed narrow contours. While the diastolic pressures of Ao was sustained and high, the diastolic pressures of ITA and GEA showed rapid falling. Therefore, ITA and GEA had the risk of inadequate blood supply. This pressure measurement of in situ arterial graft was an easy and effective method for presumption of the ability of blood supply.

Arteries↗
PubMed1992

Exercise response assessed by continuous monitoring of ventricular function in patients with coronary bypass operations.

The response of left ventricular function during exercise and recovery after exercise was assessed in 35 patients with coronary artery bypass grafting before and after the operation by means of a continuous ventricular function monitor, which records serial beat-to-beat radionuclide data and calculates left ventricular ejection fractions every 20 seconds. The mean ejection fraction decreased with graded bicycle exercise from 48% +/- 9% to 41% +/- 11% (p less than 0.001) before operation but increased with exercise from 50% +/- 9% to 55% +/- 11% (p less than 0.001) after operation. Cardiac response was divided into four types with respect to the profiles of the ejection fractions during exercise. Type A continued to increase; type B initially increased but then decreased in late exercise stages; type C did not change significantly; type D continued to decrease. Most patients had type C or D responses before operation but type A after operation. Seven patients with occluded grafts or ungrafted coronary arteries had type B or D responses. Three patients with complete revascularization, including an internal thoracic artery and saphenous vein grafts, had type B responses. Three patients with extensive infarction and poor left ventricular function showed type C. In the early recovery period after exercise, most patients had an "overshoot" elevation of ejection fraction. The mean value increased from 59% +/- 10% before operation to 64% +/- 11% after operation (p less than 0.01). The recovery time after exercise was reduced from 2.8 minutes before operation to 1.8 minutes after operation (p less than 0.001). The continuous ventricular function monitor elucidated changes in left ventricular function both during exercise and recovery after exercise, as well as unmasking abnormalities in left ventricular function after coronary bypass operation.

Coronary Artery Bypass↗
PubMed1991

Silent left ventricular dysfunction during exercise after coronary artery bypass surgery.

Serial changes in left ventricular function during exercise were assessed by radionuclide continuous ventricular function monitoring in 80 patients undergoing coronary artery bypass surgery before and after operation. This monitor records serial beat by beat radionuclide and electrocardiographic data and calculates the left ventricular ejection fraction every 20s. The profiles of ejection fractions during graded bicycle exercise were divided into 4 types. In type A, the ejection fraction continued to increase. In type B, the ejection fraction initially increased but decreased in late exercise. In type C, the ejection fraction did not change. In type D, the ejection fraction continued to decrease. Type A is considered to be the normal response to exercise and types B, C and, D are considered to be abnormal responses. Before operation, 8 patients showed type A, 21 type B, 13 type C, and 38 type D. After operation, 53 patients showed type A, 16 type B, 8 type C, and 3 type D. The mean ejection fraction decreased with exercise from 53% +/- 11% to 47% +/- 11% before surgery, but increased with exercise from 55% +/- 10% to 64% +/- 14% after surgery. During postoperative exercise, no patient developed chest pain but 19 patients showed a decrease in the ejection fraction in early or late exercise. A decrease in the ejection fraction is an earlier indicator of myocardial ischaemia than angina or electrocardiographic changes. Silent left ventricular dysfunction during postoperative exercise was considered to reflect myocardial ischaemia resulting from occluded grafts, ungrafted coronary arteries, or inadequate perfusion by arterial grafts. The radionuclide continuous ventricular function monitor can detect silent left ventricular dysfunction after coronary artery bypass surgery.

Adult↗
PubMed1991

Ventricular assistance by right free wall dynamic cardiomyoplasty following acute right heart failure in canines.

The efficacy of right ventricular assistance provided by electrically conditioned skeletal muscle was studied in 17 canines. The right ventricular free wall was made ischemic and akinetic by ligating all coronary branches supplying it. The latter procedure led to deterioration of hemodynamic parameters. After that, 14 canines were divided into two groups: group 1 (n = 8) was observed without cardiomyoplasty for 2 hours; group 2 (n = 6) underwent right ventricular dynamic cardiomyoplasty with the conditioned left latissimus dorsi. The deterioration in hemodynamic parameters in group 1 showed no further significant change during the period of observation. In group 2, right ventricular function was augmented by cardiomyoplasty, as shown by a significant increase in right ventricular and pulmonary artery pressures. In addition, decreased CVP suggested improved right ventricle (RV) filling. Right ventricular function curves obtained by volume loading in a further group of three canines, group 3, also demonstrated improved right ventricular function. Thus right ventricular dynamic cardiomyoplasty appears to contribute significantly to right ventricular function in a model of acute right heart failure.

Acute Disease↗
PubMed1991

Ex vivo performance of muscle powered cardiac assist device: potential for right ventricular support.

The present study addressed the filling sensitivity and power output of the TOYOBO VAD (TVAD) and Utah soft artificial ventricle (USAV) to evaluate these pumps as a muscle powered cardiac assist device (MCAD). Two pumps were assembled with three different types of driving chambers placed underneath the latissimus dorsi (LD) muscle: the soft spindle (SS) type, elastic spindle (ES) type and bellows (B) type. The USAV required a filling time of greater than 1000 msec at any preload with any driving chamber, although the TVAD allowed this only with the ES-type chamber assembly. In an ex vivo mock study, the ES- and SS-type chamber assembly demonstrated a maximum stroke volume (SV) of 7.7 mL (39% stroke) by the USAV and 12 mL (17% stroke) by the TVAD at an afterload below 20 mmHg. On the other hand, the B-type chamber increased SV according to afterload in both pumps, resulting in a maximum SV of 25 mL (36% stroke) by the TVAD and 7.6 mL (38% stroke) by the USAV at a 30 mmHg afterload. The maximum stroke work (SW) achieved was 1.3 x 10(6) erg by the TVAD and 0.5 x 10(6) erg by the USAV, which exceeds that of the canine right ventricle. In conclusion, the ES-type chamber provided best pump filling and the B-type chamber best pump ejection, but back pressure at the chamber diaphragm determined performance efficiency. An active filling mechanism for the driving chamber will be necessary to offset the low preload requirements of a VAD, and provide the maximum power output necessary for right ventricular support.

Back↗
PubMed1991

[Transesophageal echocardiography during coronary bypass surgery].

The early diagnosis of intraoperative myocardial ischemia is important because such ischemia can lead to myocardial infarction. Clinical effectiveness of transesophageal echocardiography (TEE) was evaluated for detecting intraoperative myocardial ischemia and for observing the recovery of cardial motion at the end of cardiopulmonary bypass (CPB) in 20 patients who had undergone CABG. After endotracheal intubation, the TEE transducer was introduced into the esophagus to obtain a short axis cross-sectional view of the left ventricle at the level of the papillary muscles. Global LV function was assessed by measuring end-diastolic and end-systolic areas, which were calculated automatically, and the fractional area change (FAC). Regional endocardial wall motion was also analyzed by subdivision into four anatomical segments. The mean FACs were 48% after intubation, 47% after skin incision and 48% after sternotomy. Thereafter it increased significantly to 59% 30 minutes after CPB and 56% at the end of the operation. Thus, global LV function was improved significantly by revascularization. TEE could detect myocardial ischemia more sensitively than ECG. In 9 patients, FAC decreased significantly and new regional wall motion abnormality (RWMA) appeared around the time of sternotomy, but no ECG changes were detected. In another 7 patients, new RWMAs were detected without either a decrease in the FAC or ECG changes. It was found that myocardial ischemia took place more frequently before the initiation of CPB than expected. The recovery of left ventricular wall motion from cardioplegic arrest was able to be monitored visually during the period of weaning from CPB and the TEE could facilitated prompt and exact judgement of weaning from CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[The use of Doty's extended aortoplasty in binovular twins with congenital supravalvular aortic stenosis].

Binovular twins with congenital supravalvular aortic stenosis underwent Doty's extended aortoplasty. Neither twins displayed signs of Williams syndrome. Peak systolic pressure gradients of 65 and 70 mmHg, respectively, were measured across the stenotic portion at the ascending aortae. After surgery, the pressure gradients were reduced to 15 and 20 mmHg, respectively, at the aortic valves. No new aortic regurgitation was observed postoperatively. It is important that the ascending aorta, including the stenotic part, is symmetrically incised into the noncoronary and the right coronary sinus of Valsalva. The fibrous ring should be removed as completely as possible. Doty's extended aortoplasty is a safe and effective procedure for supravalvular aortic stenosis.

Aorta↗
PubMed1991

[Assessment of coronary bypass surgery by continuous ventricular function monitoring].

The sequential change of left ventricular function during exercise and recovery after exercise was assessed in 50 patients who had undergone coronary bypass surgery before and after the operation by means of continuous ventricular function monitoring system (VEST). Cardiac response was divided into 4 types with respect to the profiles of the left ventricular ejection fraction during exercise. Type A continued to increase; type B initially increased but decreased in severe exercise stages; type C did not change during exercise; type D continued to decrease. Most patients showed type C or D before surgery but showed type A after surgery. 9 patients with occluded grafts or ungrafted coronary arteries showed type B, C or D. Two patients with extended infarction and poor left ventricular function showed type C after surgery. In recovery period after exercise, the ejection fraction showed an overshoot. The mean ratio of peak ejection fraction during recovery to ejection fraction at rest increased from +62 +/- 12% before operation to +68 +/- 16% after operation (p less than 0.05). The recovery time after exercise was decreased from 195 sec before operation to 98 sec after operation (p less than 0.01). VEST revealed response of left ventricular function during exercise and recovery after exercise as far as detail abnormalities.

Adult↗
PubMed1991

[Cardiac function during exercise in patients with coronary bypass surgery assessed by continuous ventricular function monitoring].

The response of left ventricular function during exercise and recovery after exercise was assessed in 52 patients with coronary artery bypass surgery by means of a radionuclide continuous ventricular function monitor. This system consists of 2 radionuclide detectors, recorder and a computer. After the equilibration of 20 mCi technetium 99m-labeled autologaous red blood cells into the intravascular space, the beat by beat radionuclide data were summed for 20-sec intervals to measure left ventricular ejection fraction (EF). Before surgery, the mean EF decreased with exercise from 51 +/- 9% to 45 +/- 11% (p less than 0.001). Cardiac response was divided into 4 types according to the profiles of the EFs during exercise. In 6 patients, EF continued to increase until maximal exercise (type A). In 10 patients, EF initially increased and then decreased in late exercise stages (type B). In 9 patients, EF did not change significantly during exercise (type C). In 27 patients, EF decreased throughout exercise (type D). After surgery, the mean EF increased with exercise from 53 +/- 10% to 60 +/- 13% (p less than 0.001). Thirty-five patients showed type A, 9 type B, 5 type C, and 3 type D. Two type D and 5 type B patients had occluded grafts or ungrafted coronary arteries. Four patients with complete revascularization including an internal thoracic artery and saphenous vein grafts showed type B. Three patients with extensive infarction and poor left ventricular function showed type C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[A successful case report of mediastinitis after coronary bypass surgery treated with total excision of the sternum and omental transposition].

A 61-year-old male case, who was complicated with mediastinitis after coronary bypass surgery with left internal mammary artery, was reported. He was treated with open packing of gauze saturated with povidone iodine solution for 17 days, and thereafter pedicle transposition of great omentum with total excision of the sternum as a second procedure, was performed. His postoperative course was uneventful without any respiratory complication. From this experience, we concluded that omentum was very effective strategy in management of mediastinal infection following cardiac surgery.

Coronary Artery Bypass↗
PubMed1990

[Surgical treatment of ischemic heart disease combined with hypothyroidism].

Treatment for patients with ischemic heart disease and hypothyroidism contains many difficulties, such as a dilemma that thyroid hormone to hypothyroid patients may worsen angina. The purpose of this study is to propose an appropriate control of thyroid function in these patients before coronary artery bypass grafting (CABG), and to clarify the change of thyroid function during postoperative period. Because of progressive angina pectoris, five hypothyroidism patients underwent CABG. Preoperatively, minimal dose of L-Thyroxine (0-75 micrograms, daily) was administered orally to keep thyroid function at slightly low level before CABG. Ten consecutive CABG patients with normal thyroid function were selected as control group. Between both groups, there was no significant difference in age, coronary artery disease, and the number of bypass grafts. Serum T4, free-T4, T3, free-T3, and TSH were measured at 1st, 2nd, 3rd, and 7th P.O.D. In control group, pituitary-thyroid function was suppressed transiently. In hypothyroid group, T4 revealed no change and was kept at slightly low level during observed period. There was no significant difference in postoperative hemodynamics between both groups. Postoperatively all of hypothyroid patients got free from angina and received an adequate thyroid hormone replacement therapy without complications. It is concluded that CABG for patients with angina and hypothyroidism can be performed safely by keeping preoperative thyroid function at slightly low level.

Aged↗
PubMed1990

Evaluation of postoperative flow capacity of internal mammary artery.

The internal mammary artery has been advocated for use in coronary artery bypass grafting because of its excellent long-term patency. We compared the flow capacities of internal mammary artery and saphenous vein grafts under exercise conditions by means of radionuclide angiocardiography. Fifty-two patients were divided according to the type of bypass graft done to the left anterior descending artery: group 1 comprised 27 patients with the internal mammary artery graft, and group 2 included 25 patients with the saphenous vein graft. Saphenous vein grafts were placed into the right and circumflex systems. Before the operation, global and regional ejection fractions decreased similarly in both groups with exercise. After the operation, the global ejection fraction measured in groups 1 and 2 increased significantly from 54% +/- 2% to 57% +/- 2% and from 54% +/- 1% to 60% +/- 2%, respectively, the anteroseptal ejection fraction from 29% +/- 1% to 32% +/- 2% and from 29% +/- 1% to 35% +/- 1%, respectively, and the apical ejection fraction from 75% +/- 3% to 82% +/- 2% and from 77% +/- 2% to 86% +/- 2%, respectively. There were no differences in exercise-induced increases in the global and regional ejection fractions between groups 1 and 2. Six patients in group 1 had exercise-induced wall motion abnormalities at the anteroseptal and/or apical segments. In contrast, patients in group 2 had no exercise-induced wall motion abnormalities at these segments (p less than 0.05, group 1 versus group 2). Results of this study show that internal mammary artery grafts respond to the increased blood flow demand of exercise in essentially the same way as saphenous vein grafts. However, there seems to be a slightly greater potential for inadequate flow in patients with the internal mammary artery graft, as evidenced by the small group of patients with exercise-induced wall motion abnormalities.

Coronary Artery Bypass↗
PubMed1989

[Pulmonary embolectomy for a patient of chronic pulmonary embolism].

Chronic pulmonary embolism is resistant to medicinal treatment. This is a report of the successful operation for chronic pulmonary embolism. A 29-year-old man suffered from dyspnea attack twice half a year in spite of intensive anticoagulant therapy. Cardiac catheterization showed pulmonary hypertension of 72/25 mmHg, mean 42 mmHg. Pulmonary angiogram demonstrated emboli in the right pulmonary artery and pulmonary perfusion scintigram revealed large perfusion defect in the right lung. The patient underwent pulmonary embolectomy after the total cardiopulmonary bypass. After surgery, blood gas showed an increased PaO2 from 65 to 77 mmHg. Pulmonary artery pressure decreased to 39/12 mmHg, mean 23 mmHg. Pulmonary arteriogram showed increased pulmonary vascular beds and pulmonary scintigram showed an increased perfusion in the right lung. The patient has been free from symptom and a half year after surgery.

Adult↗
PubMed1989

[Mitral regurgitation due to anomalous attachment of chordae tendineae to the left atrial wall].

A 47-year-old female admitted to our hospital with exertional dyspnea and cerebral thromboembolism. There was no history of rheumatic fever. The chest roentgenogram showed marked cardiomegaly with pulmonary congestion. Ultrasound cardiogram showed mitral valve incompetence and abnormal echo shadow in the left atrium. Left ventriculogram revealed grade 3 mitral regurgitation. At operation, a 5-cm anomalous chordae tendineae was attached to the left atrial wall through the mitral orifice. The mitral valve showed thickening of the leaflets and fusion of the posterior commissure. The mitral valve was replaced with a mechanical prosthesis. The patient has been doing well after her surgery.

Chordae Tendineae↗