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Biomedical subjects

Y Hayabuchi

Publications and source records attributed to Y Hayabuchi.

At least 37 records · Page 2Linked to original sources

Absence of the inferior vena cava in a patient with omphalocele: two-dimensional echocardiographic and cineangiographic findings.

We report an unusual form of absence of the inferior vena cava (IVC) in a patient with a repaired omphalocele. Two sets of bilateral paravertebral veins served as the channels of systemic venous return from the lower half of the body. These veins were narrower than typical azygos or hemiazygos continuation in the absence of the IVC, with the result that a catheter from the femoral vein could not reach the right atrium (RA). Other associated venous-side anomalies were present, including a chamber between the hepatic vein (HV) and RA, narrowing and angulation at the junction between the HV and the chamber, and a subaortic innominate vein. All these anomalies were demonstrated by two-dimensional and color Doppler echocardiography. The recognition of these venous anomalies is important for cardiac catheterization or IVC cannulation for cardiopulmonary bypass in patients with omphalocele.

Adult↗

Usefulness of QRST isointegral maps for the diagnosis of right ventricular pressure overload in patients with surgically repaired tetralogy of Fallot complicated by right bundle block.

Right ventricular pressure overload was evaluated in 29 patients, 8-12 years old, with surgically repaired tetralogy of Fallot by using body surface QRST isointegral maps. In patients with right ventricular systolic pressure above 50 mmHg, the maxima of the isointegral maps tended to shift toward the lower right-hand region of the map. The maximum value was significantly correlated with right ventricular systolic pressure (r = .58; P < .01). There was a correlation between the right ventricular systolic pressure and the percentage +2SD and percentage +5SD departure areas, which are defined as the area (expressed as a percentage of the total chest area) in which the QRST integral values are greater than the normal mean +2SD or +5SD, respectively (r = .61 and .84, P < .01). The QRST isointegral map can be used to evaluate right ventricular pressure overload in postoperative patients with tetralogy of Fallot complicated by right bundle branch block. The percentage +5SD departure area is the most valuable parameter for the quantitative evaluation of the right ventricular systolic pressure.

Body Surface Potential Mapping↗

Echocardiographic evaluation of the development of aortic valve prolapse in supracristal ventricular septal defect.

UNLABELLED: The development and timing of aortic valve prolapse (AoVP) and aortic regurgitation (AR) was studied by two-dimensional echocardiography in 99 consecutive patients with supracristal ventricular septal defect (VSD). Thirty patients (30%) had aortic valve prolapse (VSD + AoVP group), and 31 patients (31%) had AoVP with AR (VSD + AoVP + AR group). In the VSD + AoVP group, AoVP was detected first by echocardiography at the age of 6.8 +/- 4.2 years (mean +/- SD). In the VSD + AoVP + AR group, the interval from detection of AoVP to the appearance of AR was 3.4 +/- 2.0 years. The configuration of the prolapsed aortic valve was echocardiographically classified into two types: tear-drop type (small) prolapse and box type (large) prolapse. The frequency of tear-drop type prolapse was not significantly different between VSD + AoVP and VSD + AoVP + AR groups (43% versus 32%, respectively), indicating that even minor AoVP can result in AR. Four infants (4%) had AoVP at the ages of 1, 5, 7, and 11 months, respectively. All infants had tear-drop type prolapse. Two infants developed AR by colour flow mapping at the ages of 3 and 11 months, and the interval from prolapse to AR was only 2 and 4 months, respectively. CONCLUSION: Aortic valce involvement can develop under the age of 1 year in supracristal VSD. Regular evaluation by two-dimensional echocardiography with colour flow mapping is important in the follow-up of children with supracristal VSD.

Age of Onset↗

Anomalous inferior vena cava in association with omphalocele: a case report.

We present the case of a 6-year-old boy who had an omphalocele repaired at day 1 of life. He had a secundum atrial septal defect and an anomalous inferior vena cava of a type which has not been previously reported. Cine-MRI was a useful noninvasive tool for diagnosing the anomalous subaortic innominate vein and four immature vessels which make up the venous drainage systems of the lumbar region. The recognition of this malformation is important in planning and executing surgical repair or cardiac catheterization for postoperative patients with omphaloceles.

Child↗

The first report of a patient with interrupted inferior vena cava, multiple post-renal veins and azygos-hemiazygos continuation.

The first case of a patient with interrupted inferior vena cava, four post-renal veins and an azygoshemiazygos continuation is presented. The complicated anomalies were omphalocele and atrial septal defect. Cine-magnetic resonance imaging and cardiac catheterization showed an anomalous retroaortic left innominate vein, azygos-hemiazygos continuation in the prerenal portion, arch formed renal vein in the renal portion and four embryonic vessels in the post-renal portion. Combination of these anomalies in the major venous system suggested that the inferior vena cava had failed to form and that the bilateral embryonic venous system, postcardinal and supracardinal veins, persisted to be the systemic venous channels.

Abnormalities, Multiple↗

Signal-averaged electrocardiographic late potentials in children with complete heart block.

The purpose of this study was to examine signal-averaged electrocardiographic (SA-ECG) late potentials to predict ventricular arrhythmias during intrinsic cardiac rhythm and during ventricular pacing in children with complete heart block (CHB). Recordings of SA-ECG were obtained from eight patients (aged 3-18 years) with documented CHB. The etiology of CHB was congenital in four cases and acquired in four cases. Six of these patients underwent permanent pacemaker implantation. Comparisons of the SA-ECG were made before and during ventricular pacing. Abnormalities of SA-ECG during intrinsic cardiac rhythm were noted in four patients, all of whom were older than 14 years. Although there was no significant difference in SA-ECG parameters between patients with congenital CHB and acquired CHB, abnormal SA-ECG was noted in one of four patients with congenital CHB and in three of four patients with acquired CHB. Two patients without permanent pacemaker implantation had normal SA-ECG, but four of six patients with permanent pacemaker implantation had abnormal SA-ECG. Three of the four patients had abnormal SA-ECG during ventricular pacing, but the abnormal SA-ECG in one patient had normalized during ventricular pacing. It is important to record SA-ECG before and during ventricular pacing to detect late potentials in patients with CHB. It may be useful to record SA-ECG while changing the pacing site to find ideal sites for electrode implantation for the potential prevention of ventricular arrhythmias.

Action Potentials↗

Post-transfusion chronic hepatitis C in children.

Two hundred and twenty-six patients who received blood products for open-heart surgery in childhood were screened by a second-generation enzyme-linked immunosorbent assay and with surrogate markers for hepatitis C virus (HCV) infection, such as alanine aminotransferase (ALT). Twenty-two (14%) of the 161 recipients who received blood products before 1989 and none of the subjects who had received blood products after 1990 (the year that the blood bank began to screen for HCV antibody) were HCV seropositive. Virologic and histologic studies showed that 10 (45%) of 24 seropositive patients had persistent hepatitis C virus infection, many with ongoing hepatitis. The remaining 12 seropositive patients with absent HCV RNA had normal ALT levels, indicating resolved hepatitis C infection. Enrolment in screening is important to detect chronic hepatitis C in children who received blood products prior to screening of blood donors for HCV antibody.

Acute Disease↗

Serologic, virologic, and histologic characteristics of chronic phase hepatitis C virus disease in children infected by transfusion.

OBJECTIVE: We studied the time course of hepatic dysfunction, seropositivity to hepatitis C virus (HCV) antibodies, viremia, and histologic evidence of hepatic injury to evaluate the course of HCV infection in children infected by blood transfusion. PATIENTS AND METHODS: Twenty-nine patients (ages 4 to 18 years) who underwent open-heart surgeries for congenital heart disease were grouped into three categories based on alterations in serum alanine aminotransferase (ALT) levels: Group A, acute infection; Group B, subacute infection; and Group C, chronic infection. RESULTS: In Group C, all 13 patients had detectable HCV RNA in serum. In contrast, all patients in Group A had no detectable HCV RNA: In Group B, one of nine patients had detectable HCV RNA and two of four patients examined had persistent chronic hepatitis by histologic criteria. Antibodies directed against C100-3 antigen or core-antigen were more useful than second-generation HCV antibody assays in determining the relationship between viremia and immunologic response. Infection with HCV genotype II and the presence of higher HCV RNA copy numbers were associated with histologic evidence of hepatic damage. CONCLUSION: An abnormal ALT value is frequently associated with viremia, and biochemically resolved acute infection reflects clearance of HCV. However, a normal ALT does not always reflect an absence of hepatocyte damage and HCV replication in patients with subacute disease. The measures outlined in this study are useful indicators of disease activity during the chronic

Acute Disease↗

Abnormal signal-averaged electrocardiogram in patients with Duchenne muscular dystrophy: comparison of time and frequency domain analyses from the signal-averaged electrocardiogram.

The clinical significance of an abnormal signal-averaged electrocardiogram (SA-ECG) in time- and frequency-domain analyses was assessed in patients with Duchenne muscular dystrophy (DMD). Twenty-four DMD patients and 20 age-matched healthy volunteers were studied. The SA-ECG was recorded by time-domain signal processing using the vector-magnitude method and frequency-domain signal processing using the fast-Fourier transform. Abnormal SA-ECGs were based on comparison with controls and eight abnormal SA-ECGs were detected among 24 DMD patients, seven by frequency-domain analysis and four by time-domain analysis. The end-diastolic left ventricular volume was larger in the patients with abnormal SA-ECG than in those with normal SA-ECG (136 +/- 32 ml vs. 77 +/- 43 ml, p < 0.01). Compared with patients with normal SA-ECGs, the DMD patients with abnormal SA-ECGs had a lower left ventricular (LV) ejection fraction (54 +/- 6 vs. 61 +/- 8%, p < 0.05), as an index of LV contractility, and less LV posterior wall velocity (46 +/- 9 mm/min vs. 62 +/- 16 mm/min, p < 0.01), as an index of LV relaxation. The sensitivity and specificity of frequency-domain analysis for predicting malignant ventricular arrhythmias was 60 and 85%, respectively, compared with 30 and 92%, respectively, for time-domain analysis. The combination of time- and frequency-domain analyses can facilitate identification of DMD patients with ventricular tachyarrhythmias associated with depression of cardiac performance.

Adolescent↗

Hyperuricaemia in cyanotic congenital heart disease.

This study examines the exacerbating factors of hyperuricaemia in patients with cyanotic congenital heart disease (CCHD). We studied 59 CCHD patients aged 1 month-30 years. The following variables were assessed: serum uric acid levels, red blood cell count, haemoglobin, hematocrit, partial oxygen pressure and arterial oxygen saturation. Uric acid excretion and renal function were also measured in ten patients with serum levels of uric acid greater than 8 mg/dl (hyperuricaemia group). Serum uric acid level correlated significantly with age and severity of polycythaemia. However, it did not correlate with partial oxygen pressure or arterial oxygen saturation. Uric acid excretion was measured in hyperuricaemia group. Urinary uric acid excretion (24 h) was within normal limits in infants but markedly lower in patients over 15 years of age. The aetiology of hyperuricaemia and decreased uric acid fractional excretion and clearance in infants appears to be secondary to diminished excretion of uric acid in concert with uric acid overproduction. Hyperuricaemia in adolescents and adults with CCHD, however, results mainly from age-related impairment of uric acid excretion.

Acetylglucosaminidase↗

Abnormal signal averaged ECG after surgical repair of tetralogy of Fallot--a combined analysis in the time and frequency domain.

PURPOSE: The clinical significance of abnormal signal averaged ECG (SA-ECG) determined by time and frequency domain analyses was assessed in tetralogy of Fallot patients after surgical repair, and the methods of analysis were compared. MATERIALS AND METHODS: SA-ECG was performed in 42 patients (mean age, 9.4 years) after radical surgical repair of tetralogy of Fallot, and in 11 preoperative patients (mean age, 2.6 years). Abnormal SA-ECGs were defined by time domain analysis (vector magnitude method) and frequency domain analysis (fast Fourier transformation). RESULTS: Abnormal SA-ECGs were recognized in 10 postoperative, patients (3 by time domain and 9 by frequency domain, analysis), but in none of the preoperative patients. Three patients with abnormal SA-ECGs had nonsustained ventricular tachycardia, 5 others had premature ventricular contractions, and the remaining 2 had no ventricular tachyarrhythmias documented by 24 h Holter monitoring. Patients with abnormal SA-ECGs more commonly had ST-T segment depression on standard ECG during exercise (8/10 versus 8/32, p < 0.001), a history of resection of a hypertrophic septoparietal muscle band (8/10 versus 2/32, p < 0.001) and histologically documented myocardial fibrosis at radical surgical repair (9/10 versus 5/19, p < 0.002). CONCLUSION: A Combination of time and frequency domain analyses was necessary to detect abnormal SA-ECGs in postoperative patients because of ventricular conduction disturbance. This technique might increase our ability to identify patients at risk of ventricular tachyarrhythmia, or those with underlying myocardial abnormalities.

Adolescent↗

[Frequency domain analysis of signal-averaged electrocardiogram in patients with right bundle branch block following repair of congenital heart disease].

Frequency domain analysis of signal-averaged electrocardiograms (SAECGs) were investigated in 24 patients with right bundle branch block (RBBB) following repair of congenital heart disease, in order to determine the block site of RBBB using a SAECG. The block site of RBBB was first identified by a body surface map; 10 patients had proximal RBBB, 14 had distal RBBB. The peak amplitude, the amplitudes on 20 Hz, 40 Hz, 50 Hz, and 100 Hz in the proximal RBBB patients were significantly (p < 0.01) smaller than in the distal RBBB patients. The areas between 0 to 20 Hz, between 0 to 40 Hz, between 20 to 50 Hz, between 40 to 100 Hz in the proximal RBBB patients were significantly (p < 0.01) smaller than in the distal RBBB patients. In conclusion, frequency domain analysis of SAECG was useful for determining the block site of RBBB following surgical correction.

Adolescent↗

[Signal-averaged electrocardiogram in right bundle branch block patients after surgical repair for congenital heart disease].

Right bundle branch block (RBBB) type was investigated using signal-averaged electrocardiogram (SAECG) in 35 RBBB patients after surgical repair of ventricular septal defect and tetralogy of Fallot. The type of RBBB was first identified by body surface mapping; 12 patients had proximal RBBB, and 23 had peripheral RBBB. The control group consisted of 20 healthy volunteers. The following three findings were seen in most patients with proximal RBBB, and were useful for determining the type of RBBB; a filtered QRS duration equal to or longer than 160 msec, a fragmented signal number equal to or greater than 10 and the whole type of filtered QRS pattern. The sensitivity and specificity of SAECG for proximal RBBB were shown to be high. In conclusion, SAECG was found to be useful for non-invasive determination of RBBB types.

Adolescent↗

[Abnormalities in the signal-averaged electrocardiogram in Ebstein's anomaly].

Abnormalities in the signal-averaged electrocardiogram (SAECG) of patients with Ebstein's anomaly were studied. A SAECG was obtained in 4 patients with Ebstein's anomaly, aged 3 to 25 years. The control groups included 8 patients with atrial septal defect (ASD group), 10 with right bundle branch block (RBBB group), 8 with Wolff-Parkinson-White (WPW) syndrome (WPW group), and 40 normal subjects (Normal group). The SAECG was calculated by the vector-magnitude method using the VCM-3000. The root-mean-square during the initial 20 msec of the filtered QRS (i-RMS) was very small in 2 older patients with Ebstein's anomaly compared to the ASD group, the RBBB group and the Normal group, and was as small as that in the WPW group. This probably was affected by the delta wave associated with Ebstein's anomaly or concealed accessory pathway. The root-mean-square during the terminal 40 msec of the filtered QRS (t-RMS) was small in the patients with Ebstein's anomaly and the RBBB group. Two patients with Ebstein's anomaly had a smaller t-RMS than the RBBB group, suggesting pathological changes of an atrialized right ventricle. In conclusion, SAECG is useful for evaluating patients with Ebstein's anomaly, especially older patients.

Adolescent↗

Assessment of sinus node function in patients with congenital long QT syndrome.

Sinus node function was evaluated in 4 patients with congenital long QT syndrome suffering from recurrent episodes of syncope and ventricular arrhythymias. Three of the 4 patients had bradycardia at rest on a 24-hour ECG. Sinus node function was examined by the atrial overdrive suppression test and the atrial premature stimulation test. Corrected sinus node recovery time (CSNRT) was prolonged in all patients. Total sinoatrial conduction time was also prolonged in 2 of the 4 patients. In all patients with abnormally high values, these values returned to normal after atropine administration, except in one patient. His prolonged CSNRT remained high after atropine administration, indicating abnormal automaticity such as that seen in sick sinus syndrome. These results show that sinus node function in congenital long QT syndrome is often associated with autonomic dysfunction, and sometimes with intrinsic disturbances of sinoatrial conduction.

Adolescent↗

Hyperuricemia in an infant with Taussig-Bing anomaly and interruption of the aortic arch.

Hyperuricemia is commonly recognized in adolescents and adults with cyanotic congenital heart disease. We report a case of a male infant with hyperuricemia, Taussig-Bing anomaly, and interruption of the aortic arch. The patient underwent correction of interrupted aortic arch and pulmonary arterial banding at the age of 7 days. Hyperuricemia appeared when he was 2 months old (max 17.7 mg/dl) and persisted until he underwent a Jatene operation at the age of 10 months. The hyperuricemia improved gradually after the disappearance of hypoxia and polycythemia. The laboratory findings suggest that hyperuricemia can result from uric acid overproduction due to secondary polycythemia, impairment of uric acid excretion by the kidney, or the acceleration of anaerobic metabolism. Allopurinol and benzbromarone together were partially effective treatments for hyperuricemia in this patient with cyanotic congenital heart disease.

Abnormalities, Multiple↗