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Biomedical subjects

M Shigenobu

Publications and source records attributed to M Shigenobu.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Mitral valve replacement following myomectomy for idiopathic hypertrophic subaortic stenosis].

A patient is reported with IHSS where mitral valve replacement was performed 3 years following myomectomy because of a residual pressure gradient of left ventricular outflow tract. After mitral valve replacement, the left ventricular outflow tract obstruction was almost completely relieved not only at rest but also at provocation by isoproterenol. The patient successfully returned to work with no symptoms.

Adult↗
PubMed1989

[Emergency surgery for thrombosed Björk-Shiley mitral valve prosthesis].

A case of a thrombosed Björk-Shiley mitral valve with severe pulmonary edema which developed six years following an initial operation was reported. Doppler echocardiography was one of the most useful tools to evaluate prosthetic mitral valve dysfunction. Peak blood flow velocity was high (2.7 m/sec) compared to the data (1.7 m/sec) obtained six months before the reoperation. Emergency surgery disclosed the thrombosed valve prosthesis which was replaced with a St. Jude Medical valve. The patient recovered successfully with no problems.

Adult↗
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↗