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

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.

Transesophageal echocardiography detects thrombus formation not identified by transthoracic echocardiography after the Fontan operation

Transesophageal echocardiography demonstrated six instances of venous thrombus formation in the inferior vena cava, right atrium and caval-pulmonary anastomosis region in four children after a modified Fontan operation. Transthoracic surface echocardiography failed to identify these thrombi in five of the six cases because of the posterior location of the thrombus or imaging interference from surgical hardware. These thrombotic episodes occurred 2 days to 5 years after the Fontan operation in children 25 to 168 months of age. Clinical features of compromised cardiac performance with cyanosis or inadequate perfusion were present during four of the six episodes. In two patients, thrombi occurred around transvenous permanent atrial pacing leads. Therapy to eliminate thrombus included surgery (two cases), anticoagulation with warfarin (three cases) and streptokinase thrombolysis (one case). Disappearance of the thrombus was confirmed by transesophageal study in three of the four cases with follow-up echocardiography. Transesophageal echocardiographic demonstration of atrial and pulmonary thrombi that could not be seen by transthoracic imaging suggests that these thrombi occur with greater frequency in patients who have undergone the Fontan operation than was previously suspected.

Prognostic features of children with idiopathic dilated cardiomyopathy

The presenting features and long-term outcome of 39 children (median age 6.5 months, range 1 day to 16 years) with idiopathic dilated cardiomyopathy (IDC) were reviewed to help determine the appropriate management of these patients. Four outcome groups were identified: those who died, improved, had IDC resolved or received transplants. Presenting clinical features of age, sex, race, congestive heart failure, cardiomegaly, and degree of systolic ventricular dysfunction did not predict final outcome. Left ventricular hypertrophy on the electrocardiogram was seen significantly more often in children who improved than in those who died or in whom IDC resolved (p = 0.002). A rhythm disturbance was also seen more often in those who died than in those who survived (p = 0.025). Of 36 patients treated medically, 12 (33%) died, 15 (42%) improved and 9 (25%) resolved. Eighteen of 26 (69%) patients presenting at age less than or equal to 2 years survived, whereas 6 of 10 patients greater than 2 years survived. There were no differences based on age at presentation, in the time to death or time of follow-up. Three patients received orthotopic heart transplants, 1 of whom died from graft failure. Thus, no clinical feature including age at presentation consistently predicts ultimate outcome in children with IDC.

Comparison of intraoperative transesophageal echocardiography to epicardial imaging in children undergoing ventricular septal defect repair

Intraoperative transesophageal echocardiography was compared with epicardial echocardiography after ventricular septal defect repair. This comparison was made in 18 children aged 7 to 137 months (median, 32 months), weighing 6.3 to 49.1 kg (median, 10.8 kg) from November 1989 to January 1991. Ventricular septal defect types were perimembranous (six), malalignment (seven), supracristal (three), midmuscular (one), and inlet (one). Eight children had isolated ventricular septal defects, four had tetralogy of Fallot, three had double outlet right ventricle, two had double chambered right ventricle, and one had pulmonary stenosis. Patch interrogation was complete in 17 of 18 transesophageal echocardiography and 16 of 18 epicardial echocardiography studies. Inability to fully interrogate the ventricular septal defect patch by epicardial echocardiography occurred in two children as a result of anterior ventricular septal defect location, limited epicardial exposure, and surgical hardware interference. Incomplete transesophageal echocardiography patch interrogation occurred in the child with the midmuscular ventricular septal defect. Seven residual ventricular septal defects were documented by color flow Doppler in six patients. Five of seven residual defects were demonstrated by both real-time transesophageal echocardiography and epicardial echocardiography imaging. Transesophageal echocardiography and epicardial echocardiography missed 1 and 7 defects, respectively. The missed defects were different with each technique and were confirmed by postoperative surface echocardiography. No residual defects of sufficient size to require reoperation were found as determined by combination color flow jet analysis and intraoperative oximetry (no pulmonary to systemic flow ratio was greater than 1.50). Patches caused two-dimensional and Doppler signal masking, but this was not limiting because all residual defects were found at the margins of the ventricular septal defect patch.(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial necrosis in a newborn after long-term maternal subcutaneous terbutaline infusion for suppression of preterm labor

We report a case of myocardial necrosis in a newborn after treatment of the mother with long-term subcutaneous terbutaline. No such serious side effects in the fetus have previously been reported. We speculate that this myocardial damage was due to beta-sympathomimetic therapy.

The utility of transesophageal echocardiography during and after Fontan operations in small children

Transesophageal echocardiography with Doppler examination was performed intraoperatively in 19 children undergoing modified Fontan operations and in 10 patients postoperatively. Comparisons were made with results of intraoperative epicardial imaging (9 patients) and with postoperative transthoracic imaging (10 patients). Transesophageal echocardiography optimally visualized atriopulmonary and cavopulmonary anastomoses. Epicardial echocardiography was successful in only three of nine patients. Intraoperative transesophageal echocardiography showed residua in 8 of 19 studies and led directly to surgical revision or medical therapy. These residua included stenosis of the cavopulmonary anastomosis (1 patient), unsatisfactory atrial fenestration (2 patients), patent ductus arteriosus (1 patient), residual cavoatrial shunting (1 patient), atrial thrombi (1 patient), and poor ventricular function (2 patients). Results of examination in the postoperative intensive care unit showed significant abnormalities in 4 of 10 patients. This study demonstrates that transesophageal echocardiography provides unique anatomic and physiologic information during and after modified Fontan operations in small children and therefore may have significant impact on patient management.

Preoperative prediction of postoperative pulmonary arteriolar resistance after surgical repair of complete atrioventricular canal defect

The natural history of patients with complete atrioventricular canal defect is one of unrelenting development of pulmonary vascular obstructive disease. Corrective surgery, which can be performed with low mortality during infancy, reduces the time that the pulmonary vascular bed is exposed to excessively high pressure and blood flow. In some patients, however, advanced vascular disease may already be established at operation. Surgical intervention in these patients may not prevent the progression of obliterative pulmonary vascular disease and may in time even result in right ventricular failure, since after the corrective operation there is no ventricular septal defect to shunt away the right ventricular pressure overload. This article outlines a numeric method for predicting pulmonary vascular resistance after surgical correction; the method is based on age and hemodynamic data available from preoperative cardiac catheterization. Retrospective analysis of preoperative and postoperative data from 20 patients produced a regression equation in which a linear combination of inverse pulmonary/systemic blood flow ratio and age at operation predicted pulmonary vascular resistance after operation, with a multiple correlation coefficient of 0.85. This newly discovered relationship may provide valuable insight into the probable outcome of surgical intervention in cases in which pulmonary vascular obstructive disease is suspected as significant.

Transesophageal echocardiography for congenital heart disease

Surface echocardiographic imaging of small children is routinely successful in defining anatomical details and Doppler flow patterns with even the most complex congenital cardiac malformations. However, in larger children or adults, imaging is frequently limited. A recent expansion of the role of echocardiography is intraoperative epicardial imaging. Epicardial and postoperative imaging, however, have significant limitations. To avoid some of these limitations, transesophageal echocardiography has increasingly been used in the arena of congenital heart disease. The more recent development of small sized gastroscopic probes has allowed transesophageal echocardiographic assessment of congenital heart disease in children down to newborn size. As detailed studies of individual lesions are reported, it has become clear that the mere presence of a congenital heart defect is not an indication for transesophageal echocardiography in most children if imaging can be accomplished by surface examination. However, transesophageal echocardiography may be indicated for the intraoperative or postoperative assessment of that defect, particularly when repair has been difficult or is known to be associated with significant residual abnormalities. Cardiac structures encountered with horizontal and vertical imaging plane transducers have been described and should be completely familiar to the examining echocardiographer.

Hemi-Fontan operation in surgery for single ventricle: a preliminary report

Mortality after Fontan operation is related to risk factors like ventricular hypertrophy, pulmonary artery deformity, and young age (infancy). Preliminary procedures may improve Fontan results. The hemi-Fontan operation includes atriopulmonary anastomosis and correction of all anatomical risk factors, but an atriopulmonary patch directs superior vena caval flow into both pulmonary arteries and inferior vena caval flow into the ventricle, thus maintaining cardiac output (modified Glenn physiology). We performed 17 hemi-Fontan procedures in 16 patients, 14 primarily (median age, 9 months) and 3 for takedown of a Fontan operation. The 14 primary operations were for hypoplastic left heart syndrome (5), pulmonary atresia with intact ventricular septum (4), and other (5). All patients had multiple risk factors. Extubation was at 18 hours (median), chest tube removal was at 3 days, and hospital discharge was at 8 days postoperatively. Important complications included subglottic stenosis, transient diaphragmatic paralysis, pulmonary artery stenosis and thrombosis requiring reoperation, and transient ventricular fibrillation. One patient required hemi-Fontan takedown, and this patient later (3 months postoperatively) became the only death. Fontan take-downs have had a high mortality rate. In 3 patients who tolerated Fontan operation poorly, converting Fontan to hemi-Fontan abruptly reversed the downhill course. For these patients, the operation was life-saving. Hemi-Fontan operation is safe and well-tolerated, even in infants, provides the advantages of modified Glenn physiology before Fontan operation, and may be especially useful for Fontan takedown after failed Fontan.

Doppler echocardiographic evaluation of streptokinase lysis of thrombosed right-sided St. Jude Medical valves in patients with congenital heart defects

Four episodes of St. Jude Medical prosthesis leaflet thrombosis were serially evaluated by two-dimensional and Doppler echocardiography during treatment with streptokinase. Three patients aged 4, 11, and 24 years with congenital heart disease had St. Jude Medical valves in pulmonary positions (two cases) for tetralogy of Fallot and in the tricuspid position (one case). The duration of thrombosis was not known in any patient. Leaflet immobility and its resolution were demonstrated by echocardiography and were confirmed fluoroscopically. Continuous wave Doppler echocardiography showed abnormal stenotic gradients in thrombosed valves that were reduced after thrombolysis. These studies demonstrate the utility of two-dimensional and Doppler echocardiography in serial evaluation of prosthetic pulmonary and tricuspid valve thrombosis during thrombolysis.

New approaches to treatment of incessant ventricular tachycardia in the very young

It was assumed that the availability of new antiarrhythmic drugs and new surgical techniques might allow medical or nonexcisional surgical treatment in many young children with incessant ventricular tachycardia. Fourteen infants and young children less than 5 years of age were evaluated and treated for incessant ventricular tachycardia. Medical treatment was pursued up to the use of amiodarone with a type Ib or Ic antiarrhythmic drug unless the patient became hemodynamically unstable. Patients underwent surgery when these drug regimens failed or when moderate congestive heart failure was present. Seven patients were successfully treated medically and seven underwent surgical treatment. Of those treated surgically, five had cryothermic lesions and two had excisions. Five of the surgically treated patients required temporary additional medical treatment. Follow-up ranged from 12 to 53 months (mean 28). Eleven of the 14 patients are currently not taking any antiarrhythmic medication. No patient required a pacemaker, none received anticongestive medications and none died.

Tricuspid atresia: current concepts in diagnosis and treatment

Tricuspid atresia is the third most common cyanotic cardiac malformation, seen in 1 per cent of children with congenital heart disease. Anatomic details in each patient can be elucidated by echocardiography. Surgical treatment initially is palliation, usually with aortopulmonary shunt. Definitive treatment is with a Fontan operation, in which the systemic venous return is connected directly to the pulmonary arterial tree. Long-term results of the corrective procedure have been very good.

Fetal echocardiographic diagnosis of congenital heart disease

The delineation of the structural and functional abnormalities of the fetal heart by echocardiography has led to the emergence of a new and vital subspecialty, that of fetal cardiology. Its practitioners are from disciplines such as genetics, obstetrics, and pediatrics, the common interests of which in the well-being of the unborn child have converged as technologic advances in ultrasound have enabled detailed evaluation and sometimes treatment of fetal hemodynamic abnormalities. Each discipline forms an entry point for the identification and referral of the high-risk patient or fetus with a suspected abnormality. As has been shown obstetric cardiac screening of the general population with ultrasound provides the highest yield of cardiac malformations when suspicious findings are referred to a subspecialist in fetal cardiac sonography. As we study the pathogenesis of congenital defects, it is likely that hitherto unidentified high risk populations will be found. The future holds the possibility of meaningful surgical interventions that may change the dismal outcome of fetuses with certain, now lethal cardiac malformations. Patients with hydrops fetalis due to congenital complete heart block are almost certain to die. Intrauterine cardiac pacing has been attempted and is a potentially life-saving procedure. Patients in whom pulmonary underdevelopment occurs because of the cardiac enlargement associated with some types of pulmonary atresia could potentially benefit from intrauterine surgery such as valvotomy. Serial fetal echocardiographic examination of the developing heart with higher resolution equipment during the first trimester may one day pinpoint the exact moment of teratogenesis and lead to more specific treatments designed to restore normal embryogenesis. Such examinations will, when known to be safe themselves, at the very least significantly advance our knowledge of normal cardiac embryogenesis and pathogenesis.

Real-time, automated, interactive cardiac electrophysiology testing

We describe a new automated interactive system that performs all of the functions required for complete evaluation of the intracardiac conduction system, for inducing, terminating and analyzing tachydysrhythmias, and for locating and characterizing accessory atrioventricular (AV) connections and ectopic foci. In the first year of operation, the system was used to conduct 210 electrophysiology studies. These ranged from simple postoperative evaluation of the conduction system to complete tachycardia studies during pharmacological manipulation of the patient. Patient age at time of catheterization ranged from 6 days to 70 years, with median age of 8 years and 7 months. Advantages accruing from automated electrophysiology testing with this system included great precision and accuracy of timing measurements, flexibility in designing and implementing pacing protocols, and rapid management of induced or spontaneous dysrhythmias. Significant savings of time and labor were achieved by computer generation of reports and graphs as opposed to manual data extraction and plotting. The single most significant advantage is the ability of the system to provide information on a real-time basis, permitting the electrophysiologist to analyze, modify, extend or curtail the procedure.

Advances in the treatment of supraventricular tachycardia

Patients with supraventricular tachycardia should be able to lead a perfectly normal life without significant treatment related side effects. Many of these patients have normal hearts and no other significant medical problems. Using the techniques described above, no patient should have significant symptoms from SVT.

Neonatal cardiac arrhythmias and their potential role in sudden infant death syndrome

A broad spectrum of dysrhythmias effects neonates. With modern monitoring techniques, we are detecting more of them. Modern treatment techniques should allow virtually all infants to be treated successfully and to lead normal lives.

Valve prostheses in children: a reassessment of anticoagulation

We have previously published evidence that children with St. Jude Medical prostheses on the left side of the heart may not require anticoagulation. Between March 1979 and September 1986, we followed up 48 patients who had no anticoagulant therapy for up to 7 years after valve replacement, an aggregate of 122 patient-years. The 25 male and 23 female patients ranged in age at implantation from 5 months to 21 years (12 +/- 6 years, mean +/- standard deviation). Five patients (all with complex associated malformation) died in the hospital (10%), and nine died late (22%). None of the early and one of the late deaths was associated with a thrombosed prosthesis. During follow-up, seven thrombotic (one mitral, one aortic) or thromboembolic (two mitral, three aortic) events occurred (5.7 +/- 2.1 per 100 patient-years). Of these seven events, five occurred within the last 14 months of the study. There was no relation of these events to age of patient at implantation, age at the time of even, gender, or site of implantation. Concurrently, we have followed up 340 adult patients with St. Jude Medical prostheses who had warfarin sodium (Coumadin) anticoagulation for 875 patient-years. By the end of this study, the children who did not receive anticoagulants were significantly less free of thrombotic and thromboembolic events than the adults who did receive anticoagulants (p less than 0.01).

Cardiomyopathy with arrhythmias and ectodermal dysplasia: a previously unreported association

Hidrotic ectodermal dysplasia represents a group of congenital or hereditary disorders that involve ectodermal derivatives. It is characterized by partial or complete alopecia, dystrophic nails, and dental abnormalities. Dilated cardiomyopathy has not previously been reported in association with this illness. We report the cases of three children with fatal dilated cardiomyopathy with associated cardiac arrhythmias and ectodermal dysplasia. Laboratory investigations revealed no specific cause for the cardiomyopathy. It is speculated that this association is not simply coincidental.

Double-chambered right ventricle

Thirty (10.8%) of 279 patients undergoing correction of a ventricular septal defect (VSD) from January, 1972, to September, 1986, also had a double-chambered right ventricle (DCRV). Age at operation ranged from 1.3 to 18.8 years (mean, 6.7 +/- 4.5 years [+/- standard deviation]). Seventeen patients were male, and 13 were female. Two-dimensional echocardiography was used after 1978 in the initial evaluation of 20 patients; however, the diagnosis of DCRV was made with the use of subcostal views only since 1984 in 4 of 5 patients. Surgical correction consisted of closure of the VSD and resection of anomalous muscle bundles through a right ventriculotomy (28 patients), and right atriotomy (2 patients). All patients survived and are asymptomatic 4.2 +/- 3.4 years following operation. Six patients have undergone catheterization postoperatively and 8 patients had intraoperative pressure recordings. The mean preoperative ratio of right ventricular to left ventricular pressures was 0.67 +/- 0.22 compared with 0.34 +/- 0.15 postoperatively (p less than .001). In 2 patients, DCRV was not recognized preoperatively or at VSD closure through a right atriotomy, and reoperation was necessary after DCRV was demonstrated at postoperative catheterization. DCRV may occur in approximately 10% of patients undergoing correction of VSD. Careful evaluation of echocardiographic and catheterization data preoperatively and careful evaluation of the anatomy intraoperatively are necessary so that DCRV not be overlooked, especially because most VSDs are now closed through the right atrium. Successful correction of VSD and DCRV is associated with excellent long-term results.

Resolution of dilated cardiomyopathy after surgical ablation of ventricular tachycardia in a child

Sustained tachycardia may be associated with dilated cardiomyopathy that may improve after medical management of the tachycardia. Ventricular tachycardia due to an ectopic focus is uncommon in children and rarely presents as congestive heart failure. This report documents that severe dilated cardiomyopathy in a child was caused by sustained ventricular tachycardia and that, after cryoablation of the tachycardia focus, ventricular function rapidly returned to normal.