Evaluation of right ventricular contraction by myocardial strain in children using a two-dimensional tissue tracking method.

Two-dimensional tissue tracking makes it possible to detect myocardial strain in any direction. Consequently, this method is applicable for evaluation of myocardial dyssynchrony. This study enrolled 22 healthy volunteers (11 boys and 11 girls) ages 1.6 to 10.8 years (mean, 6.8 years). Echocardiography (subxiphoid right anterior oblique view) of the right ventricle was examined. Three tracking points were put on the right ventricle, and time-strain curves of the inflow tract (strain at the inlet) and the outflow tract (strain at the outlet) as well as time-strain curve of the pulmonary annulus diameter were made. The strain at the inlet was larger than the strain at the outlet (0.31 vs 0.15; p = 0.0003). The time to peak negative strain at the inlet was longer than at the outlet (0.48 vs 0.42 s; p = 0.001). The diameter of the pulmonary annulus shortened in systole, and the time to peak negative strain of the pulmonary annulus was longer than that of the outlet (0.48 vs 0.42; p = 0.001). There was no significant difference in the times between the pulmonary annulus and the inlet (0.48 vs 0.48; p = 0.78). Two-dimensional tissue tracking allows assessment for quantification of myocardial performance and timing of the right ventricle.

[Staged surgical palliations for hypoplastic left heart syndrome with poor preoperative conditions].

A 2.8 kg-female newborn diagnosed as hypoplastic left heart syndrome was transferred to our hospital after resuscitation against systemic circulatory failure due to closure of the ductus arteriosus. Her systemic circulation was stabilized after alprostadil (lipo-PGE1) and inotorpic agent infusion along with mechanical ventilation support. On admission, signs of a pulmonary high-flow and low systemic perfusion were evident. Impaired coagulation aspect was gradually noted. Because a surgical palliation with cardiopulmonary bypass was considered to be at high-risk, a bilateral pulmonary artery banding was indicated. Through a median sternotomy, the right and left pulmonary arteries were individually banded. The patient was continued on the same ventilation strategy. Cardiac, hepatic and renal dysfunctions were improved over next few days and the patient weaned from ventilatory support. She underwent combined Norwood stage I and II repair at 4 months of age with weight of 4.8 kg. Postoperative course has been uneventful and the patient is now followed up in preparation for Fontan operation.

[Comparison of right ventricular function between prevention and enlargement of pulmonary valve annulus after repair of tetralogy of Fallot; mid-term results].

Total of 41 patients with tetralogy of Fallot (TOF) who underwent intracardiac repair from 1993 to 1998 were divided into 2 groups: preservation (n = 14) or enlargement (n = 27) of the pulmonary valve annulus. The procedure was decided on the Z value of the annular size: above or under -2 SD of the standard value. Although postoperative right ventricular (RV) diastolic volume (RVEDV) and cardiothoracic ratio (CTR) were larger than the preservation group and pulmonary regurgitation (PR) existed in the enlargement group, RV pressure was decreased and central venous pressure (CVP) was low and RV contraction was preserved. The exercise capacity was also good and no significant arrhythmia was recognized. Our mid-term results showed that appropriate enlargement of the pulmonary valve annulus preserved good RV function in patients with TOF.

Clinical course of fetal congenital atrioventricular block in the Japanese population: a multicentre experience.

OBJECTIVES: To elucidate the prenatal and postnatal course of fetal congenital atrioventricular block (CAVB) during the past decade in the Japanese population. DESIGN: Retrospective multicentre study. All fetuses with CAVB in 10 Japanese institutions in the period from January 1990 to August 2001 were included. PATIENTS: Of the 48 fetuses with CAVB, 17 had a congenital heart defect (CHD) (14 with left atrial isomerism) and 31 had a structurally normal heart (22 with positive maternal autoantibodies). Gestational age at diagnosis was 15 to 38 (median 26) weeks. RESULTS: Of the 17 fetuses with a CHD, three were aborted, one died before birth, and eight died after birth (three in the neonatal period and five after the neonatal period). Of the 31 fetuses without a CHD, two died before birth and two died after birth. CHD (p = 0.005) and the presence of fetal hydrops (p = 0.05) were significant risk factors for death. However, fetal ventricular and atrial heart rates, gestational age at delivery, and birth weight were not related to death. Transplacental medication of sympathomimetics increased the fetal heart rate in five of eight fetuses treated. Dexamethasone did not improve the degree of heart block in any of the six fetuses treated. Postnatally, pacemakers were implanted in 30 of 40 babies. Four fetuses with maternal autoantibodies had decreased cardiac function. CONCLUSIONS: CHD and fetal hydrops are risk factors for prenatal and postnatal death. The fetal ventricular rate of 55 beats/min did not appear to be a threshold value by which to predict fetal hydrops. Patients with CAVB should be subjected to close long term follow up to check for the need for pacemaker implantation or for late onset cardiac dysfunction.

[Differences in postoperative course by preoperative left ventricular volume after closure of ventricular septal defect during early infancy].

A total of 38 early infants with ventricular septal defect (VSD) were divided into 2 groups by preoperative LVEDV. The group A (n=14, LVEDV>250% N) showed significantly longer period of intubation, cathecholamine drip, and hospitalization compared with the group B (n=28, LVEDV<250% N). At dischage, both groups showed significant lowered right ventricular (RV) pressure, but LVSF in the group A was significantly lower than that in the group B. The patients with larger left ventricular (LV) volume preoperatively were thought to be potential high-risk groups in cardiac and pulmonary function and their postoperative course was prolonged and recovery of LV function was worse. In such patients, special care is mandatory to do postoperative management and to decide timing of operation.

[Congenital supravalvular aortic stenosis; report of a case].

We experienced a successful surgical case of extended aortoplasty by means of Doty's method (two sinus reconstruction) for congenital supravalvular aortic stenosis (SAS). Case was 12-year-old boy, who had no complaint except heart murmur. The retrograde aortography demonstrated localized stenosis just above the aortic valve, and it was an hour-glass type. The preoperative peak systolic pressure gradient between the left ventricle and ascending aorta was 56 mmHg, which was improved postoperatively. This case showed excellent results. Doty's aortoplasty was favorable method for SAS without deformity of aortic valve and coronary obstruction.

Interventional treatment for fetus and newborn infant with congenital heart disease.

BACKGROUND: Catheter intervention has become popular not only in adult patients but in younger patients with congenital heart disease. The early neonatal catheter interventional treatment has also been attempted in conjunction with the development of prenatal diagnosis of the congenital heart disease. METHOD: Recent articles concerning several severe structural cardiac diseases in newborns, such as critical aortic stenosis, complete transposition of the great arteries, premature constriction of the ductus arteriosus, and pulmonary stenosis or atresia with intact ventricular septum are introduced with consideration. RESULTS: This study investigated our own experiences of early neonatal balloon valvuloplasty in a patient with critical aortic stenosis carried out immediately after the delivery following prenatal diagnosis. A case with prenatal diagnosis of premature constriction of ductus arteriosus which could prevent persistent pulmonary hypertension of the newborn by early delivery at 39 weeks and 1 day of gestation were reported. CONCLUSION: Several cardiac interventional treatments performed in the present time during the perinatal period and some prospects in the near future are described in the discussion.

Fetal diagnosis of common arterial trunk with interrupted aortic arch using color power Doppler angiography.

We successfully visualized the brachiocephalic arteries and aortic arch in a fetus seen at 19 weeks of gestation with a common arterial trunk and interrupted aortic arch by means of color power Doppler angiography, a new diagnostic development of color Doppler echocardiography. Power Doppler imaging is more sensitive to the state of low flow in fetal vessels, thus providing better visualization of fetal vascular structures from an early gestational stage.

[A case of simple coarctation].

We report a successful surgical repair of the simple coarctation of a 80-day-old girl by extended end-to-end aortic arch reconstruction. She was admitted to our hospital at the age of 4 days because of poor pulsation of femoral arteries. The systolic blood pressure gradient between the arm and the leg was 30 mmHg. Echocardiography on admission revealed a simple coarctation and patent foramen ovale, with the mildly impaired left ventricular contraction (left ventricular fractional shortening was 23%). Although aortography demonstrated an isolated interrupted segment at the aortic isthmus with collaterals (type A classification of Celoria-Patton), the tubular connection between the distal arch and the descending aorta, of which intralumen was obstructed with abundant ductal tissues, was found at operation. The obstruction of the lumen of aortic isthmus in our case, which was originally patent, might be caused by ductal closure and present as a simple coarctation.

Unguarded mitral orifice, mirror-imaged atrial arrangement, and discordant atrioventricular connections.

We report two autopsy proven cases of unguarded mitral orifice associated with mirror-imaged atrial arrangement, discordant atrioventricular connections, double outlet right ventricle, pulmonary valvar stenosis or atresia, and atrialisation of the morphologically left ventricle. The morphologically left atrioventricular junction was devoid of valvar leaflets, and there was no tension apparatus within the ventricle. To the best of our knowledge, this is the first description of this rare cardiac malformation.

Banding of the pulmonary trunk in preparation for a Fontan operation.

Banding of the pulmonary trunk is an important surgical procedure for patients who have congenital cardiac malformations with unrestricted pulmonary flow. We propose a new concept for determining in such circumstances the most appropriate length of the band used to constrict the pulmonary trunk in preparation for a Fontan operation. We studied 14 patients undergoing banding of the pulmonary trunk and measured the following parameters: diameter of aorta, diameter of pulmonary trunk, length of pulmonary arterial band and maximum flow velocity across the banded segment. We calculated an index from our original parameter based on the formula; length of band/(diameter of aorta diameter of pulmonary trunk). The diameter of aorta was 9.5 +/- 1.4 mm, and that of the pulmonary trunk was 9.6 +/- 2.3 mm. The length of the band was 16.5 +/- 3.4 mm, giving a calculated index of 0.188 +/- 0.038. The maximum flow velocity was 4.02 +/- 0.46 m/s. No correlation was found between the length of the band and body weight, and also no correlation was found between the length of the band and maximum flow velocity. The calculated index had a negative correlation with the maximum velocity of flow across the band (y = -8.13x +/- 5.56, R = 0.74, p < 0.01). We believe that the proposed index is a useful guide in determining the length of a pulmonary band when preparing patients for a Fontan operation.

Analysis of ventricular septal motion by doppler tissue imaging in atrial septal defect and normal heart.

The aortic root and the upper part of the ventricular septum moves anteriorly in early systole, while the lower part moves posteriorly. The hinge of the counterpart motion of the ventricular septum is called pivot point. Using Doppler tissue imaging (DTI), we attempted to clarify the location of the pivot point of the ventricular septum in children with normal heart and with atrial septal defect (ASD), and to investigate the relation between the degree of the downward shift of the pivot point and that of volume overload of the right ventricle in patients with ASD. Study subjects consisted of 20 healthy children and 36 patients with ASD, aged from 1 to 15 years (mean 5.7+/-3.4) in the normal group and 6 months to 12 years (mean 4.4+/-3.2) in the ASD group, respectively. The pivot point was designated as a border of the color signal of DTI of the ventricular septum in early systole. Measurements were then obtained on cross-sectional echocardiography and DTI: septal length in the parasternal long-axis view, distance from aortic valve to pivot point in early systole, diastolic left ventricular internal dimension, and diastolic right ventricular internal dimension. In the normal group, the ratio of distance from aortic valve to pivot point/septal length was 0.13+/-0.049, whereas it was 0.26+/-0.168 in the group with ASD (p <0.001). In the ASD group, the distance from aortic valve to pivot point normalized by body surface area (mm/m2) correlated with the ratio of diastolic right/left ventricular internal dimension and with the ratio of pulmonary to systemic flow (Qp/Qs) (r = 0.63 and 0.50, respectively). The ratio of the distance from aortic valve to pivot point/septal length correlated with the ratio of diastolic right/left ventricular internal dimension and Qp/Qs (r = 0.56 and 0.44, respectively). By DTI, the pivot point was located at the upper 13+/-5% of the total length of the ventricular septum in normal children, and was located at 26+/-17% in patients with ASD (p < 0.001). The degree of this displacement in ASD correlated with that of volume overload of the right ventricle. The paradoxic motion of the ventricular septum shown in the ASD could be explained by this downward shift of the pivot point.

Has fetal echocardiography improved the prognosis of congenital heart disease? Comparison of patients with hypoplastic left heart syndrome with and without prenatal diagnosis.

BACKGROUND: As prenatal diagnosis of congenital heart disease has gained in popularity, the questions of whether prenatal diagnosis of congenital heart disease is beneficial for the patient and whether fetal echocardiography has improved the prognosis of congenital heart disease are arising. METHODS: We compared four patients with prenatally diagnosed hypoplastic left heart syndrome (HLHS) with 10 patients of non-prenatally diagnosed HLHS from the view points of (i) age at transfer to our Children's Hospital; (ii) whether the oxygen was inhaled during perinatal period; (iii) whether prostaglandin E1 was administered in the period of waiting before operation; (iv) whether the patient had ductal shock; (v) timing of operation; and (vi) surgical outcome. RESULTS: The timing of the transfer to our Children's Hospital was earlier in prenatally diagnosed group than in non-diagnosed group. Oxygen was not given to any of the patients in prenatally diagnosed group. In contrast, oxygen inhalation was given in two of 10 patients in the non-prenatally diagnosed group. Prostaglandin E1 was administrated in three of four patients in the prenatally diagnosed group and seven of 10 patients in the non-prenatally diagnosed group. In terms of ductal shock, none of the patients in prenatally diagnosed group had ductal shock. However, four of 10 patients had ductal shock in the non-prenatally diagnosed group. The median age at Norwood operation was 7 days in the prenatally diagnosed group; however, it was 19 days in non-prenatally diagnosed group. Surgical outcomes showed no significant changes between the two groups. CONCLUSIONS: Prenatal diagnosis of HLHS was surely beneficial for preventing ductal shock and for keeping the patients' preoperative condition good.

[Cases of multiple ventricular septal defects].

We had 4 cases with multiple ventricular septal defects (VSDs) in complexed congenital heart disease. One of four had two separate VSDs detected by two dimensional echocardiography before operation. Second of four had additional infundibular muscular VSD which was detected by echocardiography in the intensive care unit (ICU) after patch closure of a perimembranous VSD. The third case had two additional VSDs of inlet muscular and subaortic septum detected by transesophageal and direct echocardiography during reoperation, beside a subpulmonary VSD which was originally diagnosed before Jatene operation for double outlet right ventricle. The fourth case had multiple trabecular muscular VSDs diagnosed by postoperative angiography soon after Rastelli operation. Since these additional multiple VSDs compromise the postoperative hemodynamics if those are unrecognized, it is indispensable to detect all VSDs before operation, using transthoracic and transesophageal echocardiography.

Absent aortic valve: successful palliation in the neonate.

A successful palliation of a neonate with absent aortic valve in hypoplastic left heart syndrome is reported.

[A case of severe cytomegalovirus infection after the repair of coarctation of aorta].

We report a 2-month-old boy without any immuno-compromised diseases, who suffered from the severe cytomegalovirus (CMV) infection after the subclavian flap aortoplasty and pulmonary artery banding for coarctation complex. He underwent the operation at 2 months old and received 2 units of irradiated packed red blood cells before and after the surgery. His postoperative course was uneventful but the interstitial pneumonitis, until he developed watery diarrhea 10 days after the surgery following hepatitis with the marked hepatomegaly 3 weeks after. Since CMV infection was confirmed as the cause of the pneumonitis, enterocolitis and hepatitis, he was initially treated by gamma-globulin with the high CMV titer at a dose of 200 mg/kg/day for 2 days and ganciclovir at a dose of 10 mg/kg/day for 14 days. Because of the persistent CMV infection, he needed two more treatments of ganciclovir at the same dosage and gamma-globulin once a week for 2 months. He finally recovered from severe CMV infection 5 months after the above treatments. In conclusion, the severe CMV infection can occur by blood transfusion even in the surgical case with normal immune system. If one finds pneumonitis, hepatitis or enterocolitis after any type of surgery with history of blood transfusion, CMV infection should be suspected as the cause of these diseases.

[One-stage repair of interrupted aortic arch with selective cerebral perfusion].

To minimize the neurological compromise after the circulatory arrest, the selective cerebral perfusion could be beneficial. We underwent one-stage repair of the interrupted aortic arch (IAA) with various intracardiac anomalies for the six patients, age ranging from 12 days to 4 months, by using the selective cerebral perfusion. Cardiopulmonary bypass was established by using two-way arterial cannulation supported by the two respective pump systems, one of which utilized the EPTFE graft anastmosed to either the bracheocephalic artery or the right subclavian artery and second of which enrouted through the arterial ductus to the descending aorta. The cerebral perfusion during the circulatory arrest for the aortic arch repair was maintained by the selective perfusion via EPTFE graft with 10 ml/kg/min blood flow. After the completion of the arch repair, the total system perfusion was restarted through the graft and the repair of the intracardiac anomalies was followed. Of six, no operative death or neurological complications related to the operation were found. The clinical neurological evaluation after operation also demonstrated the normal for the age. In conclusion, the selective cerebral perfusion by using the EPTFE graft during the circulatory arrest might decrease the risk of brain damage.

[Two cases of complete atrioventricular canal defect whose pulmonary vascular resistance were over 10 wood unit.m2 before 6 months of age].

We report two cases with complete form of atrioventricular canal defect (CAVCD) accompanied by Down's syndrome whose pulmonary vascular resistance (Rp) were more than 10 Wood unit.m2 at the age of less than 6 months. One child was 3-month-old boy whose Rp was 12 Wood unit.m2. The open lung biopsy at 3 months old showed histopathological change of Heath-Edwards grade I. He underwent intracardiac repair at the age of 4 months. He is doing well at 30 months of postoperative period. Another child was 5-month-old girl whose Rp was 15.5 Wood unit.m2. Histopathological change of lung at 5 months old demonstrated Heath-Edwards grade III. She underwent intracardiac repair at the age of 7 months, 2 months after lung biopsy. However, she died of oversystemic pulmonary hypertension and low output syndrome 7 days after surgery. The postmortem examination revealed that pulmonary vascular obstructive disease progressed during 2 months interval between the lung biopsy and the operation. In conclusion, cardiac catheterization with estimation of Rp should be performed in the cases of CAVCD, especially in those with Down's syndrome, in early infancy. If Rp is more than 10 Wood unit.m2 and lung biopsy indicates the surgical indication, surgical intervention should be done as soon as possible since the pulmonary vascular obstructive disease may progress in a short period.