De Vega tricuspid annuloplasty for tricuspid regurgitation in children.

BACKGROUND: Significant tricuspid valve regurgitation (TR) occurs with other congenital heart defects, typically after repair of right-sided obstructive lesions. Since 1991, we applied the De Vega tricuspid annuloplasty technique for TR in children. METHODS: Forty-one children, aged 5 months to 22.7 years (mean, 9.9 years) underwent 42 De Vega tricuspid annuloplasties for moderate or severe TR during correction of other heart defects. One child had a De Vega during primary ventricular septal defect repair. The remaining patients had prior repair of tetralogy of Fallot or pulmonary atresia, or both (19 patients), double-outlet right ventricle (6 patients), pulmonary stenosis (4 patients), pulmonary atresia and intact ventricular septum (3 patients), complete atrioventricular septal defect (3 patients), and other diagnoses (6 patients). At the time of the De Vega, 37 patients (88%) had pulmonary valve replacement or right ventricular to pulmonary artery conduit replacement. Other procedures included aortic or mitral repair or replacement (6 patients), atrial septal defect and ventricular septal defect closure (5 patients), pulmonary arterioplasty (6 patients), and tracheoplasty (1 patient). RESULTS: There were no deaths at follow-up of 3.4 +/- 2.1 years; 1 child required cardiac transplantation 17 months postoperatively. Early postrepair echocardiography quantified TR as absent or mild (34 patients; 81%), mild-to-moderate (4 patients), moderate (3 patients), and severe (1 patient). The most recent echocardiogram showed moderate TR in 11 patients and severe TR in 2 patients (both with recurrent right ventricular hypertension). One child required tricuspid valve replacement 3 years later and 1 child had redo De Vega at the time of conduit re-replacement. No other child has symptomatic TR, significant tricuspid stenosis, or De Vega-related pacemaker implantation. CONCLUSIONS: The De Vega tricuspid annuloplasty safely provides excellent relief of TR, usually in children undergoing pulmonary valve replacement or conduit replacement. Although echocardiographic TR tends to increase with time (especially with right ventricular hypertension), it rarely requires reintervention or causes symptoms.

Successful biventricular repair after initial Norwood operation for interrupted aortic arch with severe left ventricular outflow tract obstruction.

BACKGROUND: Management of newborns with interrupted aortic arch (IAA) remains challenging. Associated severe left ventricular outflow tract obstruction (LVOTO) have often led to increased mortality with neonatal biventricular repair. We review our experience with an alternative approach for this complex surgical problem. METHODS: From May 1991 to June 1999, 28 neonates were treated for IAA. Thirteen of 28 neonates (46%) had type B IAA, ventricular septal defect (VSD) and severe LVOTO (Z value -2 to -7; mean -5 +/- 1.7). Mean age was 8 days (3 to 23 days old) with average weight of 3.3 kg (2.4 to 4.2 kg). Eight of 13 (62%) had anomalous right subclavian artery. Ten of 13 (77%) had thymic aplasia and chromosome 22 region qll deletion. All 13 patients were treated initially with a modified Norwood procedure. RESULTS: There were no perioperative deaths. Complications included 2 patients with recurrent arch stenosis treated with balloon dilatation. Two patients had systemic arterial shunt revision. Follow-up ranged from 2 to 99 months old (mean 39 months). There were 2 late deaths unrelated to any operation. Nine of 12 patients had a second stage palliation consisting of a bidirectional Glenn shunt. Six patients went on to have biventricular repairs (3 Ross-Konno, 2 Rastelli, 1 VSD closure with LVOT resection). One patient had a modified Fontan operation and 5 patients are awaiting potential biventricular repair. CONCLUSIONS: Children with IAA and severe LVOTO may be managed by initial Norwood palliation with an excellent outcome likely. This initial "univentricular" approach has enabled eventual successful biventricular repair despite severe LVOTO.

Reverse subclavian flap repair of hypoplastic transverse aorta in infancy.

BACKGROUND: Management of hypoplastic aortic arch associated with coarctation in infancy can be challenging. Reverse subclavian flap aortoplasty plus coarctation resection offers simplicity without needing foreign material or cardiopulmonary bypass. METHODS: Since 1988, 46 of 162 infants less than 3 months undergoing coarctation repair had hypoplastic arch enlargement with reverse subclavian flap aortoplasty. Median age was 11 days; mean weight was 3.2 kg. Thirty-seven patients (80%) had associated cardiac defects including single or multiple ventricular septal defects (14 infants), transposition of the great arteries (7), aortic or mitral stenosis (5), and complete atrioventricular septal defect (5 infants). Twenty-eight patients had pulmonary artery banding; 2 had an arterial switch operation through a separate median sternotomy. RESULTS: There were two hospital deaths: one 4 months postoperatively in a patient requiring a Norwood procedure the next day for underestimated left ventricular hypoplasia; the other of sepsis more than 1 month postoperatively. On follow-up from 1 to 129 months (mean, 38 months), there were five recurrent obstructions: three at the coarctation site treated with balloon dilatation and two at the arch site. Twenty-six children had their heart defects corrected with 29 subsequent operations including an arterial switch operation for transposition of the great arteries/ ventricular septal defect (3 infants), relief of aortic or mitral stenosis +/- ventricular septal defect closure (5), multiple ventricular septal defect closure (3), a bidirectional Glenn (2), complete atrioventricular septal defect (2), and anomalous left coronary with ventricular septal defect repair (1 infant). Four children await debanding and ventricular septal defect closure or Glenn anastomosis. There have been two late deaths (overall survival, 91%). CONCLUSIONS: Reverse subclavian flap aortoplasty is excellent for relief of arch hypoplasia and coarctation in infants with low recurrence rates and acceptable operative and intermediate survival.

Three-dimensional echocardiographic measurement of right ventricular volume in children with congenital heart disease validated by magnetic resonance imaging.

Measurement of right ventricular volume and function by two-dimensional echocardiography is unreliable because of the asymmetric shape of the right ventricle. The purpose of this study was to validate the accuracy of transthoracic three-dimensional echocardiography in assessing right ventricular volumes in children with congenital heart disease after surgical repair of the defects, by comparison with those measured by magnetic resonance imaging. We examined 13 children after repair of tetralogy of Fallot (10), hypoplastic left heart syndrome (2), or atrial septal defect (1). Each underwent magnetic resonance imaging followed by three-dimensional echocardiography done with a transthoracic 5 MHz, prototype internally rotating omniplane transducer. In both methods, endocardial borders were manually traced and volumetric slices were summated. Close correlation was observed between the two methods (R2 0.91 for end-systolic volumes, 0.90 for end-diastolic volumes, 0.64 for ejection fraction, and 0.92 for interobserver variability). A limits-of-agreement analysis showed no adverse trend between the two methods under values of 100 ml and low variation around the mean values. We conclude that three-dimensional echocardiography measurement of right ventricular volumes correlates closely with magnetic resonance imaging in children with operated congenital heart disease and may allow accurate serial evaluation in these patients.

Serial echocardiographic assessment of left atrioventricular valve function in young children with ventricular inversion.

BACKGROUND: Regurgitation of the morphologic tricuspid valve (mTV) adversely influences the clinical outcome of patients with ventricular inversion. METHODS AND RESULTS: To evaluate the mTV regurgitation (TR), we reviewed serial echocardiograms for 25 children with ventricular inversion, with and without congenital heart surgery. Patient age was from 6 months to 19.0 (median 5.8) years. Follow-up was from 5 months to 15.0 (median 4.1) years. Initial assessment was at a median 65 days of age; only nine (36%) of 25 had TR. At follow-up, 16 (64%) of 25 had TR, with two requiring valve replacement. The mTV was abnormal in 16 (64%) of 25 patients and in 11 (69%) of 16 TR worsened compared with one (11%) of nine patients with "normal" mTVs. Nine (36%) of 25 had Ebstein's anomaly, three of whom had new TR develop. Of 17 patients who underwent cardiac surgery, 10 (59%) had new or increased TR compared with three (37%) of eight nonoperative patients. After intracardiac repairs, eight (73%) of 11 had increased TR develop compared with two (33%) of six patients after extracardiac surgery. CONCLUSIONS: (1) Young patients with ventricular inversion had TR develop during follow-up, without cardiac surgery. (2) Surgical patients with intracardiac repairs had more TR develop than with extracardiac procedures. (3) Anatomic abnormalities of the mTV were associated with an increased risk of TR developing. These data help elucidate the factors that affect the development of TR in patients with ventricular inversion.

Use of miniature biplane transesophageal echocardiography during pediatric atrial catheter interventional procedures.

We reported the use of a new miniature biplane TEE probe during pediatric cardiac interventional catheterization procedures. Use of this imaging modality provided significant advantages during dilation of obstructed venous pathways and closure of interatrial defects. Procedural characteristics and specific congenital heart lesion-related advantages were discussed.

Fetal surgical protocols in Yucatan miniature swine.

Thirty-nine Yucatan miniature swine were used in three fetal surgical experimental protocols. They involved antiarrhythmic administration, pacemaker implantation, and in-utero diagnosis of ventricular septal defect by intraoperative echocardiography. Because of problems encountered with surgical protocols in the initial stages, modifications were made to prevent fetal hypothermia and intraoperative mortality. These modifications included environmental temperature support, staple surgical techniques to reduce operative time, and development of fetal catheters designed to facilitate cannulation of small vessels. Postoperative care protocols were intensive and included antibiotics, analgesics, and supportive care designed to reduce discomfort and prevent abortion and sepsis. Thirty-seven of 39 sows survived the surgical procedures; experiments were performed on 117 fetuses. Twenty-two fetuses died either intraoperatively or postoperatively because of complications related to the experimental protocols. Modification of surgical and postsurgical protocols for these projects demonstrates the feasibility of using miniature swine as a model for fetal surgery, when their use was appropriate for anatomic and physiologic reasons.

Diagnosis and management of fetal cardiac tumors: a multicenter experience and review of published reports.

OBJECTIVES: We sought to determine the prevalence and natural history of cardiac tumors in patients referred for fetal echocardiography. BACKGROUND: Cardiac tumors are rare; the prevalence, reported from autopsy studies of patients of all ages, varies from 0.0017% to 0.28%. Despite many case reports, the prevalence and natural history of fetal cardiac tumors are unclear. METHODS: Fourteen thousand fetal echocardiograms recorded over an 8-year period in seven centers were available for retrospective review. Medical records and echocardiograms were studied to determine the reason for referral, family history of tuberous sclerosis, prenatal and postnatal course and tumor description and type. RESULTS: Cardiac tumors were present in 19 pregnancies (0.14%). Gestational age at diagnosis ranged from 21 to 38 weeks. The most common indication for referral was a mass on an obstetric ultrasound study. The tumors were singular in 10 patients and multiple in 9. Tumor size ranged from 0.4 x 0.4 to 3.5 x 4 cm, and the majority of tumors were not hemodynamically significant. There were 17 patients with rhabdomyomas, 1 with a fibroma and 1 with an atrial hemangioma. Tuberous sclerosis complex was diagnosed in 10 patients. Partial or complete tumor regression was seen in eight patients; tumors were unchanged in five; and three required operation. CONCLUSIONS: Fetal cardiac tumors, a rare condition, are often benign. The majority of tumors are rhabdomyomas, but not all fetuses with rhabdomyoma have tuberous sclerosis.

Normal hematology, serology, and serum protein electrophoresis values in fetal Yucatan miniature swine.

We are currently developing fetal models of congenital heart disease in Yucatan miniature swine for pharmacologic, diagnostic, and interventional methods used to treat cardiac arrhythmias and ventricular septal defect. Fifty-four fetuses from 12 pregnant sows were included in this study. Eleven were fetuses between 76 and 88 days of gestation (early gestation fetuses). A second population of 43 fetuses were between 96 and 110 days of gestation (late gestation fetuses). Erythrocyte, leukocyte, serum electrolyte, enzyme, lipid, carbohydrate, and metabolite values were measured. Complete serum protein profiles were also obtained by electrophoresis. Significant differences could be shown between the sows and fetuses and between the early and late gestation fetuses in all of the categories studied, though not for every parameter. This study provides a large normal database for development of Yucatan miniature swine as an animal model in the rapidly expanding field of fetal medicine.

Transesophageal echocardiographic evaluation of cor triatriatum in children.

Four children with cor triatriatum underwent intraoperative transesophageal echocardiography. Two patients had cor triatriatum alone and two had associated complex congenital heart disease. Transesophageal echocardiography provided optimal imaging of these defects and provided unique information that facilitated surgical management in these children.

Left ventricular outflow tract obstruction defined by active three-dimensional echocardiography using rotational transthoracic acquisition.

A rotational data acquisition system was used to create three-dimensional images from thoracic and subxiphoid echocardiographic windows in children with various types of subaortic stenosis. Thirteen patients, ranging in age from 2 days to 17 years, were examined. Subaortic obstruction was caused by a discrete fibrous ridge in six patients, hypertrophic cardiomyopathy in two patients, subaortic tunnel in two patients, and septal malalignment, restrictive VSD, and abnormal suture placement each in one patient. Unique views could be obtained equivalent to surgical or autopsy dissections, and allowed more complete understanding of morphology than conventional imaging techniques.

Right ventricular outflow reconstruction with cryopreserved homografts in pediatric patients: intermediate-term follow-up with serial echocardiographic assessment.

OBJECTIVES: This study was performed to assess by echocardiography the intermediate-term outcome of cryopreserved homografts employed in pulmonary outflow reconstruction in children and to validate the reliability of Doppler echocardiography in their evaluation. BACKGROUND: Cryopreserved homografts have become the most widely used pulmonary conduits. Previous reports have shown the occurrence of homograft regurgitation in the immediate postoperative period and the propensity of regurgitation to progress. Although Doppler echocardiography has been useful in assessing extracardiac valved conduit stenosis, its reliability in assessing a large series of cryopreserved homografts has not been documented. METHODS: Echocardiograms of 41 patients (43 homografts) who underwent operations between December 1986 and October 1992 were retrospectively reviewed. The median age of patients at operation was 37.5 months (range 3 to 333), and the median duration of follow-up was 28.5 months (range 1 to 68). Homograft regurgitation was classified on a scale of 0 to 4+. Pressure gradients across the homografts measured in 23 catheterizations were correlated with corresponding echocardiographic gradients. RESULTS: Regurgitation: Homograft regurgitation occurred in 100% of patients at follow-up. Progression of severity > 2 grades occurred during follow-up in 35% and was associated with operation before age 18 months (p < 0.002) and stenosis progression (p < 0.05) but not with homograft type (aortic or pulmonary). These data predict that 50% of patients operated on before 18 months of age will have severe regurgitation by 15 months postoperatively compared with only 15% operated on after 18 months. Stenosis: At follow-up, 51% of homografts had a stenotic gradient > or = 25 mm Hg predominantly at the distal anastomosis, and stenosis progression was related to young age at operation (< 18 months, p < 0.005) and small conduit size (p < 0.01). Fifty percent of conduits implanted before age 18 months could be predicted to stenose by 21.8 months compared with only 5% of those implanted after age 18 months. The gradient measured from Doppler echocardiography correlated well with the catheterization gradient (r = 0.86). CONCLUSIONS: Cryopreserved homograft dysfunction is frequent and progressive. Young age at operation (< 18 months) predicts more rapid deterioration. Doppler echocardiography is reliable in assessing the systolic gradients across homografts. Serial echocardiographic assessment in the follow-up of these patients accurately characterizes these problems.

Color flow Doppler in the diagnosis of double-chambered right ventricle: a demographic and echocardiographic study.

UNLABELLED: The purpose of this study was to evaluate the demographic and echocardiographic data of patients diagnosed with double-chambered right ventricle and attempt to explain a perceived rise in the incidence. DEFINITION: Double-chambered right ventricle (DCRV) is a division of the right ventricle into two chambers by a hypertrophied muscle bundle. METHODS: The medical records of patients diagnosed with DCRV were reviewed, and demographic, echocardiographic, and catheterization data were tabulated. Annual incidence of DCRV, based on year of birth, was compared to yearly detection rate, based on year of DCRV diagnosis. To evaluate the influence of color flow Doppler on the frequency of diagnosis of DCRV, demographics of patients born prior to September 1986 (when utilization of color Doppler began in our institution) were compared to those born after that date. RESULTS: Despite an unchanged annual incidence of DCRV, yearly detection rate of this lesion rose significantly following the introduction of color flow Doppler to our institution (September 1986). DCRV was diagnosed earlier and was accompanied by earlier catheterization, which also showed lower right ventricular body gradients after September 1986. Associated anomalies, both cardiac and noncardiac, in our population differed from those reported in previous series. CONCLUSION: This study infers that the advent of color flow Doppler significantly enhanced the diagnosis of DCRV in our pediatric patients and led to a perceived rise in incidence.

Computational methods for wide-field reconstruction of transoesophageal echocardiographic images.

Transoesophageal echocardiography imaging is limited by the proximity of the transducer to many cardiovascular structures. The location of the transducer causes these structures to appear near the apex of the backscatter image, and since the angle of the scan cannot exceed 90 degrees, much of the image information appears in a constricted area. We describe a computer-based, wide-field reconstruction technique which pieces together the picture fields from adjacent sector scans to form composite images. This description includes information regarding lessons learned, as well as technical details of the algorithms, in sufficient depth to permit reproduction of the system by interested parties. Significant aspects of wide-field image reconstruction, including computational complexity, image-pair alignment processes, requirements of alignment resolution, and image acquisition techniques, are addressed in depth. We believe that wide-field presentation of echocardiographic backscatter data enhances the utility of the transoesophageal approach, particularly when dealing with posteriorly located cardiovascular lesions.

Randomized trial of oral indomethacin and terbutaline sulfate for the long-term suppression of preterm labor.

OBJECTIVE: Our purpose was to determine the efficacy and safety of long-term oral tocolysis with indomethacin or terbutaline sulfate. STUDY DESIGN: Seventy-one patients at 26 to 32 weeks' gestation admitted for preterm labor were prospectively randomized to receive oral indomethacin or terbutaline sulfate after successful intravenous tocolysis. Patients were monitored weekly for cervical change, maternal side effects, amniotic fluid volume, and constriction of the fetal ductus arteriosus. Patients receiving indomethacin were converted to terbutaline at 34 weeks or with the occurrence of fetal ductal constriction or oligohydramnios. RESULTS: Of 71 patients randomized six were excluded after randomization. Thirty-three patients were randomized to indomethacin and thirty-two to terbutaline. There were no differences in the percentage of patients achieving 34 weeks of gestation. No differences in neonatal outcome were noted. Nine (27%) fetuses receiving indomethacin had constriction of the fetal ductus arteriosus, and 13 (38%) had oligohydramnios. Most patients on terbutaline reported beta-mimetic side effects (53%), but only one required discontinuation of therapy. CONCLUSION: Both indomethacin and terbutaline sulfate are effective tocolytics, but major fetal side effects are common with long-term indomethacin use.

Sonographic assessment of fetal cardiac arrhythmias.

The fetus with an arrhythmia may be at high risk both from the arrhythmia itself and from the condition that provoked it. Incorrect diagnosis and inappropriate or delayed treatment may further compound the hazard. Although echocardiography can specifically identify the arrhythmia, this technique requires very skilled and careful examination by a physician who fully understands how to differentiate optimally between similar-appearing but mechanistically different arrhythmias. Congenital heart disease may also be present and must be evaluated specifically. This report describes ultrasound recording techniques used to diagnose arrhythmias and includes a discussion of M-mode echocardiography, two-dimensional imaging, pulsed Doppler, and color-flow Doppler. It also differentiates specific arrhythmias--premature atrial contractions, ventricular tachycardia, atrial flutter, complete heart block, and supraventricular tachycardia--and presents the optimal diagnostic tools for each.

Echocardiographic and anatomic correlation of ventricular septal defect morphology in newborn Yucatan pigs.

With the use of a Yucatan micropig strain with a high incidence of ventricular septal defects (VSDs), results of two-dimensional and color-flow Doppler echocardiography of VSD morphology in newborn piglets were correlated with autopsy findings. A spectrum of perimembranous, muscular outlet, and doubly committed subarterial VSDs was found. Echocardiography was performed in 29 piglets weighing 1.2 to 4.4 (mean 2.8) kg, studied at age 4 to 18 (mean 8) days. VSD was diagnosed by means of echocardiography in 16 of 29 subjects; morphologic findings included perimembranous defects in 12, muscular outlet in two, and doubly committed subarterial defect in two. At autopsy the presence and location of defects were confirmed in all pigs. No additional defects were found. VSD diameters were 1.0 to 5.0 (mean 3.94) mm on echocardiography and 1.0 to 6.0 (mean 2.84) mm at autopsy. After aortic valve diameter was used as an internal control for tissue shrinkage during fixation, echocardiography/color Doppler imaging tended to overestimate VSD diameter by 21% (0.6 mm). In conclusion, echocardiography/Doppler imaging accurately identified the presence, morphology, and size of even the smallest VSDs in newborn Yucatan micropigs. Echocardiographic classification of VSD morphology in vivo will facilitate future research on specific types of VSDs in this animal model.