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Biomedical subjects

H Miyamura

Publications and source records attributed to H Miyamura.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Evaluation of long-term postoperative status and cardiac function in patients with tetralogy of Fallot].

This study was undertaken to clarify the long-term post-operative state of patients with tetralogy of Fallot (TF). Total number of 243 patients with TF who underwent corrective surgery between 1965 and 1984 were investigated by the follow-up study. Cardiac function was evaluated by Holter ECG (for 48 patients), Treadmill exercise tolerance test (for 74 patients), and cardiac catheterization (for 56 patients). Twenty-year's follow-up revealed 13 patients (5.3%) of late deaths, and 10 of them were cardiac deaths. Three patients (1.2%) expired by sudden death. Nineteen female patients experienced 26 deliveries. No patients required artificial abortion due to heart failure during pregnancies. No baby with cardiac anomaly was born by these mothers. Holter ECG showed complex ventricular arrhythmias in 23 patients (48%). The high systolic pressure ratio of right ventricle to aorta, the old age at surgery, and the long elapsed time after surgery, were the three major aggravating factors of complex ventricular arrhythmias after the correction of TF. Treadmill tests disclosed that patients with poor exercise tolerance had low RVEF and high RVEDP, indicating that RV dysfunction limited the exercise capacity in the long-term postoperative state. Among the three methods of RV outflow tract reconstruction, the follow-up data showed that patients with right ventricular patch below pulmonary valve had better event-free rate compared to those with transannular patch or to those with extensive muscle resection without patch enlargement. Cineangiogram revealed that patients with transannular patch had biventricular enlargement, but the cardiac function did not differ among the three RV outflow reconstructive methods. Because 15 years after surgery the event-free rate decreases gradually and the arrhythmia problem becomes prominent, it is concluded that patients with TF should be followed and observed carefully even though they are currently in the healthy state.

Adolescent↗
PubMed1988

Survey of copper granules in liver biopsy specimens from various liver abnormalities other than Wilson's disease and biliary diseases.

Copper granules in hepatocytes were examined by the p-dimethylaminobenzylidene rhodanine method in 965 liver biopsy specimens obtained from patients with various liver abnormalities other than Wilson's disease and biliary diseases. The granules were found in chronic active hepatitis (incidence of positive cases: 17.2%) and alcoholic fibrosis (22%) with lobular disarray and fibrosis, nonbiliary liver cirrhosis (28%), and drug-induced cholestasis (15%). Copper granules were present in the periportal or periseptal hepatocytes where the granules were mainly found in the perinuclear cytoplasm. These intracellular and intralobular distribution patterns of copper granules resembled those of primary biliary cirrhosis. These data suggest that hepatic fibrosis and lobular disarray with fibrosis in these chronic liver disease may lead to distortion or interruption of small biliary branches followed by disturbance of bile flow and deposition of copper granules. Copper stain seems to provide a valuable information for assessment of progression of these chronic liver diseases. Impaired biliary excretion seems important in deposition of copper granules in drug-induced cholestasis.

Biliary Tract Diseases↗
PubMed1988

Electrophysiologic study of patients with ventricular dysrhythmias during long-term follow-up after repair of tetralogy of Fallot.

We performed an electrophysiologic study (EPS) in 8 patients who had received corrective surgery for tetralogy of Fallot. The mean age was 30 years. An average of 15 years had elapsed after corrective surgery. Two patients had episodes of syncope. ECG showed normal sinus rhythm in 7 patients and atrial fibrillation in 1, and all had complete right bundle branch block. All patients had ventricular premature beats of grade 3 or higher of Lown's classification. Overdrive suppression test was performed in 6 patients. Corrected sinus node recovery time (CSNRT) ranged from 230 msec to 510 msec. Wenckebach block of atrioventricular nodal conduction occurred at rates of 130 to 170 bpm during atrial pacing. The H-V interval was prolonged to 60 msec in 1 patient, but was below 55 msec in the others. Programmed stimulation induced ventricular tachycardia (VT) in 3 patients, nonsustained VT in 2 and sustained VT in 1. In 2 of 3 patients, delayed potential or fragmentations were recorded in the outflow tract of the right ventricle. During the follow-up period of 20 months, 2 patients died suddenly. Their CSNRTs and H-V intervals were normal. Ventricular tachyarrhythmia seems to be important as a cause of late sudden death after repair of tetralogy of Fallot.

Adolescent↗
PubMed1987

Thrombosed St. Jude Medical valve prosthesis in the right side of the heart in patients with tetralogy of Fallot.

Five patients who previously had had repair of tetralogy of Fallot underwent pulmonary valve replacement with a St. Jude Medical valve prosthesis for progressive right ventricular failure. One also underwent tricuspid valve replacement. Two of the valves subsequently became thrombotic despite anticoagulant therapy. Because of the high incidence of thrombosis, we conclude that the St. Jude Medical valve prosthesis is not a suitable prosthesis in the right side of the heart in patients with tetralogy of Fallot.

Child↗
PubMed1986

Late sustained ventricular tachycardia after complete repair of tetralogy of Fallot--a case report.

A female patient had recurrent sustained ventricular tachycardia (VT) as a late sequela after complete repair of tetralogy of Fallot, and the clinically documented VT could be induced and terminated in a reproducible manner by programmed stimulation. VT was accompanied by fragmented electrical activities when the electrode was positioned at the outflow tract of the right ventricle where myotomy was added on the previous scar. The electrophysiological study revealed that the mechanism of VT was re-entry and that the focus of VT was located at the right ventricular outflow tract.

Adult↗
PubMed1986

Long-term postoperative status of tetralogy of Fallot.

From 1965 to 1984, 279 patients with tetralogy of Fallot underwent corrective surgery at Niigata University Hospital, and 228 patients were closely followed postoperatively. Late deaths occurred in 12 cases (5.3%), and overall event-free rate at 20 years postoperatively was 76.9%. The most common events were heart failure due to residual cardiac anomaly and symptomatic ventricular arrhythmias. Treadmill test by Ellestad protocol was performed on 74 postoperative patients, 49% of whom could not complete the protocol. These patients had higher RVEDP and lower RVEF than completing patients. Holter ECG was done on 48 long-term postoperative patients, 48% of whom showed complex ventricular arrhythmias. The age at operation was older and postoperative elapsed time was longer in patients with complex ventricular arrhythmias. Although most postoperative TF patients are able to enjoy a normal social life, the treadmill test and Holter ECG revealed that many patients had latent RV dysfunction and complex ventricular arrhythmias with or without significant symptoms. Since the number of symptomatic patients increases after 15 years postoperatively, a regular check-up with cautious observation is important for the patients' care.

Arrhythmias, Cardiac↗
PubMed1986

A successful electrical ablation of recurrent sustained ventricular tachycardia in a postoperative case of tetralogy of Fallot.

A 26 year old female patient developed recurrent sustained ventricular tachycardia (VT) after undergoing heart surgery for the third time for chronic pulmonary regurgitation following repair of tetralogy of Fallot. At the last surgery, ventriculotomy was again performed in the outflow tract of the right ventricle. At that time, scar formation and thinning of the cardiac wall were obvious. The surgical result was excellent. Three months later, she lost consciousness. ECG showed VT which was refractory to tolerated doses of antiarrhythmic drugs. Electrophysiologic study showed fragmented activity in the outflow tract of the right ventricle during VT which could be induced and terminated by programmed electrical stimulations. DC energy delivery of 200 Joules to catheter electrodes which recorded local activity 20 msec prior to the onset of the QRS of VT was successful in preventing VT. VT could not be induced by extensive programmed stimulation 1 month later.

Adult↗
PubMed1985

Aortic atresia with Ebstein's and Uhl's anomaly in corrected transposition of the great arteries: clinicopathologic findings.

The common form of aortic atresia is associated with atrioventricular and ventriculoarterial concordant connections, but it has been very rarely found in "discordant connection" in the literature. In a 6-day-old male infant, clinical and postmortem pathologic features of this rare lesion, associated with Ebstein's and Uhl's anomaly in "congenitally corrected transposition" in situs solitus, are described. A possible pathogenesis is suggested for the concomitant presence of aortic atresia and poor-functioning, morphologic right ventricle.

Aortic Valve↗