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Biomedical subjects

K Momma

Publications and source records attributed to K Momma.

At least 199 records · Page 11Linked to original sources

Maximal hemodynamic response after the Fontan procedure: Doppler evaluation during the treadmill test.

After undergoing the Fontan procedure for congenital heart disease, 16 young patients performed a maximal treadmill test according to the Bruce protocol. The peak velocity of the blood flow in the ascending aorta, stroke index, and cardiac index were measured by continuous-wave Doppler echocardiography at rest and at each stage of the test. The results were compared with those from 18 normal children. The body surface area was similar in the two groups. The endurance time was 37% shorter in the Fontan group than in the control group. From the beginning of exercise until the sixth minute, the increase in stroke index was lower in the Fontan group (NS). After that point, the stroke index was maintained at a high level in the control group but decreased toward its original level in the Fontan group. The response of cardiac index to exercise in the two groups was comparable until the sixth minute, after which the Fontan group failed to maintain an ascending curve. All the hemodynamic values were significantly higher in the control group at maximal exercise; at this point the cardiac index had increased 79% in the Fontan group and 170% in the control group. The subnormal response of the stroke volume at submaximal exercise and the subsequent decrease at maximal exercise following the Fontan procedure are important hemodynamic findings.

Adolescent↗

Pulmonary hypertension in patients with complete transposition of the great arteries: midterm results after surgery.

Postoperative results of surgical repair of complete transposition of the great arteries (TGA) with pulmonary hypertension (PH) in 19 patients in whom mean pulmonary arterial pressure was >50 mmHg or the pulmonary/systemic arterial pressure ratio was >0.8 were examined. TGA with intact ventricular septum was diagnosed in 10 patients and TGA with ventricular septal defect in 9. At the time of corrective surgery (arterial switch 10, atrial switch 9), patients ranged in age from 7 months to 14 years (mean 2.4 years). Seventeen patients (89%) survived with New York Heart Association functional class I. Seven patients in whom calculated pulmonary vascular resistance was 10-20 U m2 after surgery survived with subsequent regression of PH. Residual PH was diagnosed in 36% of survivors. Two patients in whom pulmonary vascular resistance was 26 and 36 U m2, respectively, died after surgery. In patients with TGA, severe PH was not necessarily fatal and was potentially reversible after successful surgery.

Adolescent↗

Supravalvular aortic stenosis, pulmonary artery stenosis, and coronary artery stenosis in twins.

Supravalvular aortic stenosis (SVAS) is rare in twins. We report monozygotic twins, both of whom had SVAS, coronary ostial stenosis, and peripheral pulmonary arterial stenosis, but no other phenotypic features of Williams syndrome. One of the twins died suddenly, but the SVAS and the right and left coronary ostial stenoses were enlarged successfully at operation in the other twin.

Aortic Valve Stenosis↗

Aortic arch anomalies associated with chromosome 22q11 deletion (CATCH 22).

Chromosome 22q11 deletion or CATCH 22 is associated with DiGeorge syndrome, conotruncal anomaly face syndrome, and velocardiofacial syndrome. Associated congenital heart diseases include tetralogy of Fallot, truncus arteriosus, and ventricular septal defect. Associated anomalies of the aortic arch, aortic branches, ductus arteriosus, and pulmonary arteries are more frequent in patients with the deletion than in those without the deletion. Associated anomalies include right aortic arch, cervical aorta, aberrant origin or isolation of the subclavian artery, the absence of the ductus arteriosus, major aortopulmonary collateral arteries, isolation of the left pulmonary artery, and vascular ring formed by the right aortic arch, retroesophageal aortic arch, and left descending aorta.

Aorta, Thoracic↗

Prediction of postoperative left ventricular pump function in congenital mitral regurgitation.

In adult patients with severe chronic mitral regurgitation, many predictors for estimating postoperative left ventricular systolic function have been proposed. However, none has been defined in children. We analyzed the relationship between such predictors and postoperative left ventricular fractional shortening in children with isolated congenital mitral regurgitation. Eight patients with isolated congenital mitral regurgitation were examined before and after surgery with echocardiography. Fractional shortening, left ventricular end-diastolic and end-systolic dimension indices, and left ventricular end-systolic wall stress/left ventricular end-systolic dimension index in the preoperative status were poorly correlated with postoperative left ventricular fractional shortening. Predictive wall stress, which was calculated from preoperative data of end-diastolic dimension, end-diastolic wall thickness, and diastolic blood pressure, correlated well with postoperative left ventricular fractional shortening (r = -0.90, p = 0.0024). It is important to consider not only myocardial contractility but also postoperative afterload for estimating postoperative left ventricular performance in chronic severe mitral regurgitation.

Adolescent↗

Early esophageal cancer: radiologic estimation of invasion into the muscularis mucosae.

BACKGROUND: Lymph node metastasis in squamous cell carcinoma of the esophagus is rare, and the cancer remains in the lamina propria mucosae. In cases with cancer invading the muscularis mucosae (MM), the incidence of lymph node metastasis is approximately 7%. For endoscopic treatment of mucosal cancer, it is necessary to diagnose cancer invasion into the MM. The aim of this study was to estimate cancer invasion into the MM by esophagography. METHODS: One hundred ten lesions of the slightly depressed type were classified into two groups: in group A, cancer was confined to the lamina propria mucosae; in group B, the cancer invaded the MM or slightly into the submucosa. Radiologic findings of each group were studied. RESULTS: In group A, 69% of 70 lesions showed mild depression and a smooth or undulated surface. Thickened folds were noticed in only 3%. In group B, 83% of 40 lesions showed mild or moderate depression with well-defined granules. Thickened folds were evident in 78%. In the differentiation between groups, the accuracy rates of each finding of moderate depression, well-defined granules, and thickened folds were 85%, 73%, and 90%, respectively. The overall diagnostic accuracy rate was 90%. CONCLUSION: Esophagography is useful for estimation of cancer invasion into the MM and, hence, the decision to apply endoscopic treatment to mucosal cancer.

Case-Control Studies↗

Perinatal adaptation of the cardiovascular system.

The perinatal changes in the cardiovascular system were studied in fetal rats. The changes in the cardiovascular system occurred earlier than in humans. The ductus arteriosus closes in the rat in one and a half hours.

Adaptation, Physiological↗

Attachment of a balloon to a transesophageal echocardiographic transducer for improvement of contact with the esophageal wall.

We attached a water-inflated balloon to a transesophageal probe to improve contact of the transducer with the esophageal wall and used it in 26 patients with congenital heart disease. Balloons for this study were made for use in hemostatic therapy for esophageal varix. The contact of the transducer with the esophageal wall was successfully improved in all the patients, which resulted in improvement of the signal-to-noise ratio in both two-dimensional and Doppler echocardiography. The appropriate filling volume of water was within 5 ml to avoid compression of the left pulmonary vein and to avoid the artifact of multiple reflection.

Adolescent↗

Programmed cell death in the myocardium of arrhythmogenic right ventricular cardiomyopathy in children and adults.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by fibrofatty replacement of the right ventricular myocardium. Recently, the myocardial loss in ARVC has been suggested to be related to apoptosis. However, it is still unknown whether this phenomenon is already established in the myocardium of pediatric cases with this disease. We examined the histopathologic characteristics of the ventricular myocardium in specimens obtained from 10 patients, including 3 children with ARVC, and investigated the occurrence of apoptosis in the myocardium by terminal deoxyribonucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) assay and agarose-gel electrophoresis of DNA. Endomyocardial biopsy specimens from the 10 cases and a necropsy sample from one adult case with ARVC were examined. Histopathologic examination of biopsy specimens from the pediatric cases revealed extensive fibrosis. Typical fatty infiltration was demonstrated in one of the 3 pediatric cases. These findings were similar to those in adult cases; the histopathologic index based on the severity of myocardial damage, including myocyte degeneration and fibrosis, was not significantly different from that in adult cases. TUNEL assay revealed positive reactivity of the myocardial cells. The apoptotic index was 1.4 +/- 0.4% in children and 1.6 +/- 0.5% in adults (difference not statistically significant). Agarose-gel electrophoresis of a DNA extract of the myocardial tissue of the autopsy case revealed DNA fragmentation. Cases with idiopathic ventricular tachycardia and control cases with a cardiac transplant (with no rejection) had minimal histopathologic findings and negative reactivity in the TUNEL assay. These results indicate that myocardial damage is already established in cases diagnosed as ARVC in childhood, and suggest that the myocardial damage is closely related to apoptosis in children, as well as in adults, in this disease.

Adolescent↗

Myocardial dysfunction and depressed fatty acid metabolism in patients with cyanotic congenital heart disease.

BACKGROUND: Myocardial contractile dysfunction has been frequently observed in adolescents or adults with cyanotic congenital heart disease. Impaired energy metabolism may be present in such dysfunctional myocardium. METHODS AND RESULTS: To evaluate the findings of myocardial free fatty acid metabolism, and its relations to ventricular wall motion and myocardial perfusion in cyanotic congenital heart disease, we performed a combined study of iodine 123-labeled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) scintigraphy, thallium scintigraphy, and contrast cine-angiography in seven patients with single right or left ventricle. The results showed that wall motion was reduced in 17 of 35 ventricular segments (49%), which were mostly identical in location to decreased BMIPP uptake. The severity of BMIPP uptake deficit correlated positively with the degree of impairment of wall motion. On the other hand, thallium uptake was abnormal only in 5 of 35 segments (14%), and the severity of the perfusion defect did not correlate with the degree of wall motion abnormality. CONCLUSIONS: Contractile dysfunction in cyanotic heart disease was primarily linked to impaired free fatty acid metabolism rather than to myocardial scar as represented by perfusion defect on thallium imaging.

Adolescent↗

Tetralogy of Fallot associated with chromosome 22q11.2 deletion in adolescents and young adults.

PURPOSE: To clarify the clinical profiles of adolescents and young adults with tetralogy and 22q11.2 deletion, which has recently been identified as a cause of tetralogy of Fallot in about 15% of patients. METHODS: Thirty-four patients with 22q11.2 deletion and tetralogy of Fallot, with or without pulmonary atresia, including 15 males and 19 females, with their age ranging from 16 to 35 years (mean = 25) were studied. Main outcome measurements include chromosome deletion identified by fluorescence in situ hybridization (FISH) of peripheral blood lymphocytes, medical states assessed with New York Heart Association classification, social activity assessed with Warnes index, IQ assessed by Wechsler test. RESULTS: Eighteen of 20 patients with tetralogy and pulmonary stenosis had cardiac repair, and their cardiac conditions were good except one. Of 14 patients with tetralogy with pulmonary atresia, 7 had Rastelli type cardiac repair and were doing well, although 4 of them needed re-operation for conduit stenosis. No cardiac repair was done in the other 7 patients with tetralogy, pulmonary atresia and major collateral arteries because their peripheral pulmonary arteries were too small. In 28 of the 34 patients (82%), overall social activity was limited because of extracardiac diseases, including deafness, club feet, mental retardation, and schizophrenia. The IQ in 17 patients was 59 +/- 13 (mean +/- SD): range 41 to 79. In two patients, repeated IQ study showed a decrease. Four patients developed schizophrenia. CONCLUSION: Tetralogy with 22q11 deletion can be repaired surgically except in those patients with pulmonary atresia, major collateral arteries, and small peripheral pulmonary arteries. However, most of the adult patients show an inability to function in social life in contrast to most patients with tetralogy but without the deletion, who have a normal social life. Extracardiac diseases, including deafness, club feet, mental retardation, and schizophrenia were major handicaps limiting full social activities in postoperative adolescents and young adults with 22q11.2 deletion and tetralogy.

Adolescent↗