Search PubMed⌕ Search

Biomedical subjects

M Shigenobu

Publications and source records attributed to M Shigenobu.

At least 19 recordsLinked to original sources
PubMed1992

Indications and timing of surgery for cholelithiasis associated with valvular heart disease.

Twenty patients with cholelithiasis associated with valvular heart disease were studied to assess the need and the optimal time for cholecystectomy. Twelve patients (11 symptomatic and 1 asymptomatic patients) underwent cholecystectomy. The remaining patients were asymptomatic. The levels of the total bilirubin in 9 patients, and of LDH in 15, were higher than normal. In most of the patients, the serum transaminase levels were higher than normal, but in few cases, the levels were higher than 200 IU/l. These abnormal values, however, were not consistently observed in these patients. No clear association between the type and form of valvular heart disease was demonstrated. The type of prostheses used for valve replacement in these patients were ball, tilting disc and leaflet. No significant differences in efficacy were observed among different types of prostheses. The incidence of silent stones is high in patients with valvular heart disease and heart surgery often causes deterioration in patients with cholelithiasis. The recovery of the patients who underwent cholecystectomy before valve replacement were better than those who underwent cholecystectomy after heart surgery. In conclusion, therefore, patients showing any abnormal results in liver function tests should be assessed in detail by abdominal echography and should receive surgical treatment of biliary tract before heart surgery if necessary.

Cholelithiasis↗
PubMed1992

Long-term results of surgery for mitral regurgitation due to mitral valve prolapse: a comparison of valve replacement and annuloplasty.

Patients with mitral regurgitation (MR) due to mitral valve prolapse operated at the Second Department of Surgery, Okayama University Medical School, between 1976 and 1986 were divided into two groups. The first consisted of 20 patients who had mitral valve replacement (MVR) and the second 15 patients who had mitral annuloplasty (MAP). Long-term results of surgery, cardiac function, hemodynamic status, and surgical findings were compared between the two groups. Before surgery, there were no significant differences in patient's clinical status and cardiac function between the two groups. However, after surgery statistically significant differences emerged between the two groups in ejection fraction (EF), cardiac index (CI) and mean circumferential fiber shortening velocity (mVcf). Left ventricular pumping function and myocardial contractile force tended to decrease after surgery in the MVR group and to remain unchanged or even increase in the MAP group indicating that valve preservation procedures should be selected as often as possible for the patients involved in mitral valve prolapse.

Adolescent↗
PubMed1992

Factors influencing the efficacy of DeVega's annuloplasty for secondary tricuspid regurgitation.

DeVega's annuloplasty was performed on 41 patients with tricuspid regurgitation (TR) associated with combined valvular disease and results were assessed based on Doppler echocardiographic findings in an attempt to examine the applicability of this surgical technique. TR was quantitatively evaluated via Doppler echocardiography before and after surgery. Clinical symptoms, cardiac function, and surgical results were assessed, and the severity of left ventricular myocardial degeneration was determined using electron microscopy. There were no differences in the following factors between the TR recurrence and TR improvement groups: previous heart surgery, number of involved valves, presence or absence of a giant left atrium, preoperative New York Heart Association (NYHA) functional class, and type of prosthetic valve (Björk-Shiley vs. St. Jude Medical). We found no differences between these two groups in TR severity and tricuspid annulus diameter measured during surgery. Severity of myocardial degeneration was closely associated with the recurrence of TR. Clinically, most had diminished cardiac function before surgery. DeVega's technique appears to be remarkably effective in patients with well-preserved myocardium because no TR recurrence was detected even in examinations with the most accurate Doppler echocardiography. However, such long-term effectiveness of DeVega's technique cannot be expected in patients with degenerated myocardium.

Adult↗
PubMed1992

Effect of left atrial plication for the giant left atrium on left ventricular function.

Left atrial plication (LAP) following Kawazoe's method was performed on eight patients with mitral valve stenosis associated with a giant left atrium. To investigate the effect of LAP particularly on left ventricular function, the preoperative and postoperative left ventricular function in these patients were compared. The data were also compared to that of the non-left atrial plication (non-LAP) group with left atrial dimension of 60 mm or over. In the LAP group, there were significant differences between preoperative and postoperative data in the following parameters; New York Heart Association (NYHA) class, cardiothoracic ratio, mean pulmonary arterial pressure (PAP), left ventricular end-diastolic pressure (LVEDP), left atrial dimension, stroke volume index, ejection fraction and cardiac index. On the contrary, in the non-LAP group, there were significant differences between preoperative and post-operative data in the following two factors; NYHA class and PAP. The size of the left atrium in the non-LAP group remained unchanged over the course of long-term follow-up. Despite severe clinical symptoms and severely reduced cardiac function of the patients in the LAP group, cardiac function in all patients improved satisfactorily. This suggests that left atrial plication has a considerably beneficial effect on left ventricular function, and therefore, may be recommended for patients with a giant left atrium.

Adult↗
PubMed1991

Doppler echocardiographic evaluation of Björk-Shiley and St. Jude Medical prostheses in the mitral position.

The left ventricular studies by Doppler echocardiography were performed in 50 patients with a Björk-Shiley (B-S) mitral valve and 50 patients after implantation of a St. Jude Medical (SJM) mitral valve; the effect of valve replacement on the hemodynamic performance at rest and during bicycle exercise was determined from serial echocardiographic data. Twenty-eight patients (56%) of the B-S group and 42 patients (84%) of the SJM group showed a good response to the exercise. There was no significant difference in the effective orifice area at rest among each sizes of the B-S valve. In the SJM valve, on the contrary, the effective valve orifice area increases in parallel to the size of the SJM valve. There was a clear relation between the valve size and pressure gradient. The pressure gradient directly depends on the valve size and the effective orifice area in the SJM valve. High pressure gradient group in both prostheses had a tendency to take negative values of percent increase in stroke volume. Further, there were no cases showing positive values of percent increase in end-diastolic volume among the patients whose pressure gradients were assumed to be more than 10 mmHg at rest. It is suggested that impairment of inflow caused by the artificial valve, prosthetic valve stenosis, is possibly a significant factor causing left ventricular dysfunction, notably a decrease in stroke volume during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Comparison of noninvasive techniques in evaluation of the Björk-Shiley and the St. Jude Medical valve prostheses in mitral position].

Pressure gradients and left ventricular function were assessed by Doppler echocardiography in 50 patients with Björk-Shiley mitral valve and 50 patients with St. Jude Medical valve prosthesis. There was correlation between pressure gradient and valve size, and between effective valve orifice area and valve size for St. Jude Medical valve. These correlations were not found in Björk-Shiley valve. Clinical improvement and cardiac function were quite satisfactory in 20 patients with Björk-Shiley valve and in 32 patients with St. Jude Medical valve whose pressure gradients were less than 10 mmHg. Twenty eight of 50 patients with Björk-Shiley valve and 42 of 50 patients with St. Jude Medical valve showed good response to the exercise test. Eight patients underwent reoperation because of unacceptably high gradient caused by thrombus and pannus formation. The patients who show high pressure gradient across the valve prosthesis should be followed up cautiously.

Cardiac Volume↗
PubMed1990

[Elective prosthetic valve reoperation to relieve unacceptably high gradient].

Pressure gradients of Lillehei-Kaster valve (13 patients), Omniscience valve (26 patients) and Omnicarbon valve (7 patients) in the aortic position were evaluated by Doppler echocardiography. Twenty-three out of 46 patients revealed unacceptably high gradients. Seven prostheses were removed because the valve design that they had high gradients across them. Clinical findings including left ventricular function and symptoms improved after the reoperation. Patients who underwent aortic valve replacement with this series of valve prostheses should be followed up cautiously.

Aortic Valve↗
PubMed1989

Return to work after heart valve replacement.

One hundred patients who underwent heart valve replacement during the years 1977 to 1985 were reviewed an average of 57 months after surgery. The overall rate of reemployment after the operation was 78%. The most important factors influencing the return to work were the employment status before surgery, age at the time of surgery, the number and site of the diseased valve, the preoperative New York Heart Association (NYHA) functional class and the number of times cardiac surgery was performed. These factors were closely related to the optimal timing of heart valve replacement. It was suggested that the rate of return to work and the quality of life would be improved if the heart valve replacement had been performed at an earlier stage of the disease.

Adolescent↗
PubMed1988

Results of surgery for aortic regurgitation due to aortic valve prolapse.

The clinical, hemodynamic and pathological findings of 13 patients with aortic regurgitation due to aortic valve prolapse caused by advanced myxomatous degeneration were evaluated. Eleven patients showed a favorable outcome with no complications resulting from surgery. One patient died from aortic dissection, and another died suddenly from an unknown cause. Five patients had mitral valve prolapse as a complication. Ten patients (77%) had a long-standing history of hypertension. Twelve patients (92%) were male. None of the patients had the stigmata of Marfan's syndrome. All patients had marked myxomatous degeneration of the aortic valves without any inflammatory changes. Two patients showed microcalcification; 7 demonstrated moderate fibrosis. Five patients showed severe fragility of the cusps which appeared redundant, gelatinous and softened by degenerative changes. Myxomatous degeneration of the aortic valve is not rare, and, in fact, it may be one of the most common pathologic and clinical entities associated with pure aortic insufficiency.

Adult↗
PubMed1988

A case of complete atrioventricular block due to malignant lymphoma.

A case of malignant lymphoma associated with complete heart block in a 30-year-old woman is reported. The patient progressively deteriorated despite temporary pacing and died 24 days after being admitted. Microscopic examination of the heart revealed marked infiltration by lymphoma cells in the atrioventricular node and the bundle of His. A diffuse lymphoma (large cell type, B cell) was diagnosed. This case is considered to be rare, since complete heart block was the first and only manifestation of the malignant lymphoma.

Adult↗
PubMed1988

Improvement of left ventricular function after surgical correction of chronic aortic regurgitation.

Serial left ventricular (LV) echocardiographic studies were performed in 21 patients before and after aortic valve replacement for chronic aortic regurgitation. The effect of valve replacement on LV dimensions, cross-sectional area of the LV muscle and LV function was determined from the echocardiographic data. The relation between degeneration of the myocardium and surgical outcome was also investigated. The average LV end-diastolic dimension decreased from 66.0 +/- 8.3 mm to 46.3 +/- 5.7 mm twelve months postoperatively. The average LV end-systolic dimension also fell from 43.4 +/- 8.1 mm to 31.1 +/- 5.0 mm. The muscle cross-sectional area decreased from 33.1 +/- 5.1 cm2 to 24.5 +/- 4.0 cm2, indicating a decrease in LV mass. The indices of contractility (fractional shortening, ejection fraction and mean velocity of circumferential fibre shortening) had a tendency to decrease one month after surgery, but they subsequently increased to the normal level 12 months after surgery. Nineteen out of 21 patients showed a favorable outcome as to the functional status. The remaining two patients had a large LV dimension and subnormal contractility, and they failed to show a significant reduction in the follow-up period. The muscle score in the two patients was greater than 8 points, which indicated irreversible impairment of the myocardium. Patients with persistent postoperative LV enlargement have a poor prognosis and should be identified so that aggressive medical treatment can be instituted.

Adolescent↗
PubMed1987

Intermittently stuck occluder: case report of an unusual complication with the use of an aortic Omniscience prosthesis.

An occluder which intermittently became stuck in the open position with concomitant aortic regurgitation was encountered in a patient subjected to an aortic valve replacement with a 23 Omniscience prosthetic valve. The patient was intermittently aware of the complete momentary disappearances of the valve sounds, the etiology of which could not be discerned. During fluoroscopic examination, the occluder became stuck for a few cardiac cycles in what appeared to be the fully open position before finally moving. Prosthetic valve malfunction was thus diagnosed. The emergency operation was successful. Operative findings revealed that a thin thrombus had developed in a curtain-like fashion on the left ventricular face of the prosthesis with mild tissue overgrowth along the perimeter of the valve. The Omniscience prosthesis was replaced with a 19-mm St. Jude Medical prosthesis, and the patient's postoperative course has been uneventful.

Adult↗
PubMed1987

Characteristics of chronically paced cardiac functions in the congenital complete atrioventricular block.

Characteristics of morphology, cardiac function, and cardiac reserve at late state were evaluated at rest, by changing the pacing rates, and after exercise in patients with ventricular pacemakers for isolated congenital complete atrioventricular block. Heart size was reduced statistically after pacemaker implantation, and concentric myocardial hypertrophy was observed. Cardiac pump functions at rest seemed fairly well compensated by increased ejection fraction, but the cardiac index was still lower than that of the normal heart. Responses of cardiac function towards the changing rates were considered satisfactory, and those variables had statistic correlations with the pacing rates. After exercise, significant increase of cardiac pump function and also statistic acceleration of myocardial function were observed. This fact proved that cardiac reserve was good, although the increased cardiac output after exercise was still insufficient without an increase in heart rate. More physiological pacing modes would be required as currently recommended.

Adolescent↗