Preservation of the pulmonary valve complex in tetralogy of fallot: how small is too small?

BACKGROUND

Surgical repair of congenital lesions associated with right ventricular outflow tract obstruction frequently requires the destruction of pulmonary valve (PV) components including the valve annulus. The resultant pulmonary insufficiency may lead to late functional deterioration of right ventricular performance. Acute right ventricular dysfunction has been associated with poor pulmonary runoff, tricuspid valve regurgitation, and pulmonary hypertension. Preservation of PV competence may prevent both early and late right ventricular failure. However, the recent trend towards earlier repair of tetralogy of Fallot (TOF) may preclude preservation of the PV in favor of a transannular patch. We reviewed our experience with surgical repair of TOF to determine if age and/or body size affected the ability to repair the PV.

METHODS

We reviewed the clinical records of 50 consecutive children who underwent surgical repair of TOF by one surgeon. The latter 27 patients underwent repair with an intention to preserve their pulmonary valve. In total, 28 patients underwent repair with preservation of their pulmonary valve, and form the basis of this study. Serial echocardiographic assessments were performed early (3 to 6 months) and late (12 months) after surgery.

RESULTS

Pulmonary valve preservation was possible in the majority of children (89%) in whom it was intended. Pulmonary valve competence was observed in 68% of children, with only 5 (16%) children demonstrating severe insufficiency at follow-up. Residual right ventricular outflow tract obstruction was present in only 1 child who underwent repair with pulmonary valve preservation at greater than 2 years of age.

CONCLUSIONS

Our data suggest that earlier repair of TOF does not preclude preservation of the pulmonary valve and may indeed facilitate repair. The pulmonary valve remains competent at 12 months, with acceptable gradients, and should participate in somatic growth. Pulmonary valve preservation during repair of TOF may prevent free pulmonary insufficiency, progressive right ventricular dilation, and the need for future prosthetic pulmonary valve replacement.

Surgical treatment of aortic arch hypoplasia in infants and children with biventricular hearts

BACKGROUND

Results of aortic arch reconstruction in the setting of biventricular physiology are well documented in the adult population, however, in children, surgical outcome of this subgroup of patients is less clear.

METHODS

We studied the clinical outcomes of 37 children aged 8 days to 15 years (median 26 months), who underwent aortic arch reconstruction for arch hypoplasia from 1982 to 1997. The children were divided into three groups: Group 1 (20 patients) had isolated aortic arch lesions, Group 2 (13 patients) had associated intra-cardiac pathology yet conserving a biventricular physiology, Group 3 (4 patients) had Williams Syndrome. Previous interventions for coarctation had been performed in 30 patients (81%). Arch repair consisted of a patch aortoplasty in the majority of patients (35 of 37 children).

RESULTS

Operative mortality occurred in 5 children, 4 in Group 2 (31%), 1 in Group 3 (25%) and none in Group 1. Permanent neurological complications occurred in 2 children (5 %). During the follow-up, which ranged from 1 month to 8 years, balloon angioplasty for arch obstruction was required in 1 child. There was one late death, associated with a subsequent intra-cardiac repair.

CONCLUSIONS

Aortic arch surgery in children with isolated arch hypoplasia, is associated with excellent early and late survival in addition to a low reintervention rate. Alternative perfusion and operative strategies must be implemented in infants with associated intra-cardiac anomalies to improve results.

Endovascular stent implantation for the management of postoperative right ventricular outflow tract obstruction: clinical efficacy

OBJECTIVE

Extracardiac conduits between the right ventricle and pulmonary arteries commit patients to multiple reoperations. We reviewed our experience with stent implantation in obstructed conduits.

METHODS

Between 1990 and 1997, stents were implanted across 43 conduits. The median age at procedure was 6 years (0.5-17 years), and the median interval between conduit insertion and stent implantation was 2.4 years (0.3-14 years).

RESULTS

Mean systolic right ventricular pressures and gradients, respectively, decreased from 71 +/- 18 mm Hg and 48 +/- 19 mm Hg before to 48 +/- 15 mm Hg and 19 +/- 13 mm Hg after stent placement. Mean percentage of predicted valve area for body surface area increased from 26% +/- 12% to 48% +/- 17% after stent placement. Fifteen patients underwent a second transcatheter intervention (dilation or additional stent), and 2 patients, a third, allowing further postponement of surgery in 8 patients. One sudden death occurred 2.8 years after stent placement. Surgical conduit replacement has occurred in 20 patients. Body growth was maintained during follow-up. Freedom from surgical reintervention was 86% at 1 year, 72% at 2 years, and 47% at 4 years. Higher right ventricular pressure and gradient before and after stent placement and lower percentage of predicted valve area for body surface area after stent placement were associated with shorter palliation.

CONCLUSION

Endovascular stent placement across obstructed conduits is a safe and effective palliation that allows for normal body growth.

Minimally invasive surgery with cardioscopy for congenital heart defects

BACKGROUND

Minimally invasive cardiac surgery remains a burgeoning discipline lacking adequate instrumentation and perfusion circuitry, particularly for the pediatric population. Cardioscopy, utilizing first generation imaging equipment with a variety of different angled lenses, provides a unique opportunity to expand the realm for the diagnosis and treatment of congenital heart disease.

METHODS

Sixty-eight children with a mean weight of 23 +/- 11 kg (range 8-62 kg) who underwent repair of atrial septal defects (ASD) using a minimally invasive approach (MINI group) were compared to 25 consecutive children undergoing ASD repair via a full median sternotomy (CONT group). In addition, mini-sternotomy with or without cardioscopy allowed for the diagnosis and treatment of more complex congenital lesions in 24 children.

RESULTS

The mean age in the MINI group was 7 +/- 3 years (range 1-15 years) compared to 4 +/- 4 years in the CONT group (p = 0.009). The mean body surface area of the MINI group (0.8 +/- 0.2 m2; range 0.4-1.6 m2) was larger than the CONT group (mean 0.6 +/- 0.3 m2; range 0.2-1.6 m2; p = 0.04). Ischemic times and cardiopulmonary bypass times were similar in both groups. Postoperative hospital stay was shorter in the MINI group (3 +/- 2 versus 4 +/- 1 days; p = 0.014).

CONCLUSIONS

Minimally invasive cardiac surgery can be performed safely even in small children with congenital heart defects. In addition to improved cosmetic results, these techniques can reduce the utilization of hospital resources. Future advances in cardioscopic technology should permit minimally invasive repair of most complex congenital heart lesions and should obviate the need for full sternotomy in the majority of children undergoing cardiac surgery.

Impact of diaphragmatic paralysis after cardiothoracic surgery in children

OBJECTIVES

We sought to determine the prevalence and clinical impact of diaphragmatic paralysis caused by phrenic nerve injury after cardiothoracic surgery in children.

METHODS

A search of cardiology, radiology, and hospital databases identified 170 episodes of diaphragmatic paralysis after cardiothoracic surgery in 168 children operated on from 1985 to 1997. Medical records were reviewed to determine demographics, details of the operation and postoperative course, diagnostic features and management of diaphragmatic paralysis, and follow-up status.

RESULTS

The prevalence of diaphragmatic paralysis was 1.6% (95% confidence interval 1.4%-1.8%). Median age at operation was 6 months (range <1 day-14.4 years). Median time from the operation to the initial investigation was 5 days (range <1 day-61 days), with 57% of patients receiving mechanical ventilation at diagnosis. Diaphragmatic plication was performed in 40% of the patients at a median interval from the initial investigation of 15 days (range 3 days-11.1 months). Significant independent factors associated with increased postoperative hospital stay were lower patient weight at operation, previous cardiothoracic operations, bilateral diaphragmatic paralysis, increased interval from operation to investigation, mechanical ventilation at the time of investigation, and diaphragmatic plication. Confirmed recovery of diaphragmatic function was noted before hospital discharge in only 15 episodes.

CONCLUSIONS

Diaphragmatic paralysis complicating cardiothoracic surgery continues to occur in the current era, with a significant impact on morbidity. Smaller patients with bilateral hemidiaphragmatic paralysis, requiring mechanical ventilation, may represent a higher risk subgroup to target for increased diagnostic suspicion and more aggressive management; early spontaneous recovery is rare.

Factors associated with outcomes of persistent truncus arteriosus

OBJECTIVES

The purpose of this study was to identify trends and factors associated with outcomes of persistent truncus arteriosus (PTA).

BACKGROUND

Although there have been significant improvements, PTA continues to be associated with significant morbidity and mortality.

METHODS

We undertook a review of all consecutive cases of PTA (n = 205) presenting at our institution from 1953 to 1997. Data were collected regarding demographics, anatomy, management (surgical palliation and repair) and outcomes (mortality and reoperation).

RESULTS

Significant trends (p < or = 0.001) related to groups defined by year of birth were as follows: number of cases (1953-1967, n = 13; 1968-1977, n = 42; 1978-1987, n = 69; 1988-1997, n = 81), median age at first assessment (8 months, 42 days, 7 days and 2 days, respectively), proportion who did not have any surgery (58%, 27%, 22% and 11%), proportion who had an initial palliative procedure (25%, 37%, 6% and 2%), proportion who underwent PTA repair (31%, 59%, 72% and 88%), median age at PTA repair (11.2 years, 1.1 years, 1.6 months and 12 days) and proportion dying before hospital discharge after repair (50%, 63%, 56% and 41%). Since 1995, mortality before hospital discharge after repair has further decreased to 2/11 (18%). Increasing time to initial conduit replacement in hospital survivors was significantly related to larger sized conduit at repair (p = 0.02) and use of pulmonary homografts (vs. aortic homografts or xenografts; p = 0.002). Interventional catheterization to address conduit obstructions significantly increased conduit longevity.

CONCLUSIONS

Significant improvements in PTA outcomes are evident with trends toward earlier age at assessment and complete repair.

Equivalent survival following cavopulmonary shunt: with or without the Fontan procedure

OBJECTIVES

In 1992, an analysis of our experience with the cavopulmonary shunt (CPS) demonstrated equivalent long-term survival, with or without subsequent conversion to a Fontan circulation. Before 1992 (era 1) intervention was deferred until mandated by clinical deterioration. Since 1992 (era 2), timing of both CPS and Fontan was compressed in an effort to improve survival. Survival following CPS is analyzed to ascertain whether Fontan confers any survival advantage over no further definitive intervention.

METHODS

From 1962 to 1997 inclusive, 490 patients underwent CPS, excluding those who had a CPS concomitant with a Fontan. In 55 patients the CPS was performed at or after a biventricular repair (BVR), or after a Fontan, and these patients are excluded. The 435 patients remaining followed a surgical protocol which included a subsequent BVR (n = 28), or a subsequent Fontan operation (n = 220), or no further definitive surgery (CPS only, n = 187). Between eras the mean age at surgery decreased for all procedures.

RESULTS

Long-term survival 20 years after a CPS in 435 patients is 56 +/- 5%. Survival at 20 years among the 220 patients who were subsequently converted to a Fontan circulation is 65 +/- 8% compared to 50 +/- 11% for the 187 patients who did not have a Fontan. However, most of their survival difference is because all early deaths after a CPS occurred in the non-Fontan group. Multivariable analysis demonstrated that proceeding to a Fontan did have a small survival advantage which was not evident by univariate analysis. Independent risk factors for death, at any time, are a common atrioventricular valve, or pulmonary artery banding. The era had no effect on survival.

CONCLUSIONS

The single ventricle circulation appears to have a limited durability of, an average, 30-40 years. There is a slight survival advantage in converting patients after a CPS to a Fontan circulation. A marked reduction in age at CPS and at Fontan has, as yet, not improved survival.

Clinical outcomes of acute myocarditis in childhood

OBJECTIVE

To describe clinical outcomes of a paediatric population with histologically confirmed lymphocytic myocarditis.

DESIGN

A retrospective review between November 1984 and February 1998.

SETTING

A major paediatric tertiary care hospital.

PATIENTS

36 patients with histologically confirmed lymphocytic myocarditis.

MAIN OUTCOME MEASURES

Survival, cardiac transplantation, recovery of ventricular function, and persistence of dysrhythmias.

RESULTS

Freedom from death or cardiac transplantation was 86% at one month and 79% after two years. Five deaths occurred within 72 hours of admission, and one late death at 1.9 years. Extracorporeal membrane oxygenation support was used in four patients, and three patients underwent heart replacement. 34 patients were treated with intravenous corticosteroids. In the survivor/non-cardiac transplantation group (n = 29), the median follow up was 19 months (range 1.2-131.6 months), and the median period for recovery of a left ventricular ejection fraction to > 55% was 2.8 months (range 0-28 months). The mean (SD) final left ventricular ejection and shortening fractions were 66 (9)% and 34 (8)%, respectively. Two patients had residual ventricular dysfunction. No patient required antiarrhythmic treatment. All survivors reported no cardiac symptoms or restrictions in physical activity.

CONCLUSIONS

Our experience documents good outcomes in paediatric patients presenting with acute heart failure secondary to acute lymphocytic myocarditis treated with immunosuppression. Excellent survival and recovery of ventricular function, with the absence of significant arrhythmias, continued cardiac medications, or restrictions in physical activity were the normal outcomes.

Stent implantation to create interatrial communications in patients with complex congenital heart disease

A restrictive interatrial communication can complicate the management of complex congenital heart disease. The purpose of this report is to present a new technique to achieve a patent and reliable interatrial communication by using an endovascular stent. A stent was successfully implanted across a fenestrated extracardiac conduit in two patients with low cardiac output after Fontan operations and across the interatrial septum in a patient with double inlet left ventricle and severe left atrioventricular stenosis. The procedures were uncomplicated and all patients showed immediate hemodynamic improvement. Cathet. Cardiovasc. Intervent. 47:310-313, 1999.

'You didn't see them, but now you do!': use of balloon occlusion angiography in the identification of systemic venous anomalies before and after cavopulmonary procedures

We describe the importance of angiographic identification of collateral venous channels by balloon occlusion venography after bidirectional cavopulmonary connections. Use of the balloon occlusion technique is essential for identification of these vessels, as they can easily be missed by standard venous angiography, with possible clinical consequences for postoperative management.

Atrioventricular discordance: results of repair in 127 patients

OBJECTIVE

The conventional management of patients with atrioventricular discordance is directed at associated lesions, taking advantage of physiologic "correction"; however, the morphologic right ventricle and tricuspid valve support the systemic circulation. Questions surrounding survival using this approach led us to analyze our institutional results.

METHODS

All patients with atrioventricular discordance undergoing biventricular repair were analyzed (n = 127, 1959-1997), excluding those with functionally univentricular hearts. The ventriculoarterial connection associated with atrioventricular discordance varied and was most commonly discordant (87%), but occasionally concordant (6%), double-outlet right ventricle (6%), or double-outlet left ventricle (1%). At initial presentation, the most common lesions associated with atrioventricular discordance were ventricular septal defect (86%), pulmonary stenosis (64%), tricuspid regurgitation (28%), and atrioventricular block (12%). Nine patients underwent a double switch procedure to create ventriculoarterial concordance and the remainder were managed conventionally without correcting discordant connections.

RESULTS

Operative mortality was 6% and did not vary by associated lesion. Twenty years after repair, survival was 48%. Within 20 years, 56% of patients required reoperation, usually for atrioventricular valve incompetence (n = 16), pulmonary stenosis (n = 16), or both (n = 3). Pacemakers were required in 50 patients, 4 before repair, 40 within 2 months of repair, and 6 remotely after repair. In early follow-up, the double switch procedure (n = 9) had equivalent mortality and a high pacemaker requirement for atrioventricular block.

CONCLUSIONS

Analysis of conventional management of atrioventricular discordance revealed cumulative increases in mortality, systemic atrioventricular valve (tricuspid) replacement, complete atrioventricular block, and incidence of reoperation. Alternative management should be examined.

Direct neonatal ventriculo-arterial connections (REV): early results and future implications

BACKGROUND

Is the time-honored supposition correct that insertion of a competent prosthetic conduit or homograft is necessary to achieve right ventricular (RV) to pulmonary artery continuity in neonates? A direct ventriculo-arterial connection, or réparation à l'étage ventriculaire (REV), has been successfully used to achieve RV to pulmonary artery continuity in neonates without mortality or major morbidity. Acute RV function is preserved even in the face of free pulmonary insufficiency, but scrupulous preservation of pulmonary artery patency (unobstructed pathway) must be achieved.

METHODS

We retrospectively reviewed the cases of 6 neonates who underwent direct ventriculo-arterial connection to achieve RV to pulmonary artery continuity during open heart procedures in the last 3 years.

RESULTS

The 6 neonates had a mean age of 12.3 days (range, 2 days to 6 weeks) and a mean weight of 3.2 kg (range, 2.7 to 3.6 kg) at operation. Two of them had a diagnosis of aortic atresia + ventricular septal defect and successfully achieved an in-series circulation. Two had pulmonary atresia + ventricular septal defect and 2, double-outlet right ventricle + transposition of the great arteries + ventricular septal defect + pulmonary atresia. Follow-up is a mean of 16 months (range, 6 to 22 months). Surgical reintervention was required in 3 neonates and resulted in excellent hemodynamics in 2 of them. In the other patient, who had bilateral long-segment branch pulmonary artery hypoplasia, stents were placed without hemodynamic benefit. All children are currently alive with preserved RV function even in the presence of free pulmonary insufficiency.

CONCLUSIONS

Although the creation of a direct ventriculo-arterial connection has routinely been used for children older than 1 year with satisfactory initial results, its application in neonate is very limited. Why have neonates been denied this viable alternative? Perhaps the answer involves legitimate concerns about the consequent free pulmonary insufficiency and the presumed acute RV diastolic dysfunction.

Interventional cardiac catheterization

Over the past decade, transcatheter interventions have become increasingly important in the treatment of patients with congenital heart lesions. These procedures may be broadly grouped as dilations (e.g., septostomy, valvuloplasty, angioplasty, and endovascular stenting) or as closures (e.g., vascular embolization and device closure of defects). Balloon valvuloplasty has become the treatment of choice for patients in all age groups with simple valvar pulmonic stenosis and, although not curative, seems at least comparable to surgery for congenital aortic stenosis in newborns to young adults. Balloon angioplasty is successfully applied to a wide range of aortic, pulmonary artery, and venous stenoses. Stents are useful in dilating lesions of which the intrinsic elasticity results in vessel recoil after balloon dilation alone. Catheter-delivered coils are used to embolize a wide range of arterial, venous, and prosthetic vascular connections. Although some devices remain investigational, they have been successfully used for closure of many arterial ducts and atrial and ventricular septal defects. In the therapy for patients with complex CHD, best results may be achieved by combining cardiac surgery with interventional catheterization. The cooperation among interventional cardiologists and cardiac surgeons was highlighted in a report of an algorithm to manage patients with tetralogy of Fallot or pulmonary atresia with diminutive pulmonary arteries, involving balloon dilation, coil embolization of collaterals, and intraoperative stent placement. In this setting, well-planned catheterization procedures have an important role in reducing the overall number of procedures that patients may require over a lifetime, with improved outcomes.

Aortic atresia with a ventricular septal defect: modified single-stage neonatal biventricular repair

BACKGROUND

The spectrum of hypoplastic left heart disease is diverse but the surgical repair is strictly dichotomous, culminating in either a univentricular or a biventricular surgical repair. Although aortic atresia with a ventricular septal defect historically has been managed by conversion to a univentricular physiology, a biventricular repair occasionally has been attempted in stages or in conjunction with the implantation of multiple allografts or prosthetic conduits. Our repair strategy recently has evolved to the use of a modified single-stage biventricular repair using only autologous tissues without conduits.

METHODS

Retrospective analysis (1989 to 1997) of neonates with aortic atresia with a ventricular septal defect.

RESULTS

Five neonates underwent repair of aortic atresia with a ventricular septal defect. One died in the hospital. The mean age and weight of the neonates who underwent repair were 7.8 days (range, 2 to 17 days) and 3.2 kg (range, 3 to 3.6 kg), respectively. Three neonates had a univentricular repair and 2 had a modified biventricular repair. The latter two procedures were successful and the patients were discharged from the hospital.

CONCLUSIONS

Long-term results are lacking to attest to this surgical modification's superiority over either the standard multistage univentricular operation or the single-stage biventricular repair using multiple conduits. However, we are optimistic that routine use of this modification will enable a greater percentage of neonates to undergo a biventricular repair without the need for serial conduit revisions or future aortoplasty.

The Paediatric Cardiology Hall of Fame: Richard Desmond Rowe MD, MB, ChB. February 10, 1923 to January 18, 1988

Dick Rowe (Fig.) would be embarrassed by this attention, as he was such a very modest man. Yet it is appropriate that the late Richard Desmond Rowe be included in Cardiology in the Young's Paediatric Cardiology Hall of Fame. As I consider the life and contributions of Dick Rowe, I am at first troubled, indeed saddened, by the realization that more than a decade has passed since his untimely and premature death just weeks before his planned retirement. I have his picture on the mantle of my office. Not a day goes by that I don't look at his countenance, however fleeting, reflecting on my good fortune to have worked with and considered Dick Rowe as mentor, colleague, teacher and friend. This sense of good fortune is shared by virtually all those touched by his warmth and generosity.

Accuracy of surface electrocardiograms for differentiating children with hypertrophic cardiomyopathy from normal children

Most patients with hypertrophic cardiomyopathy have abnormal electrocardiograms. In this study of 37 matched pairs in the pediatric age group, the 12-lead electrocardiogram did not differentiate between affected and normal children reliably enough to allow it to be used as a screening test in the general population.

Tetralogy of Fallot with non-confluent pulmonary arteries and aortopulmonary septal defect

Aortopulmonary septal defect and tetralogy of Fallot is a rare combination. We report a case of tetralogy of Fallot, non-confluent pulmonary arteries with the left arising from the arterial duct, and a large aortopulmonary septal defect diagnosed by echocardiogram and confirmed by cardiac catheterization.

From functional pulmonary atresia to right ventricular restriction. Long term follow up of Uhl's anomaly

We report a 14 year old boy who presented as a neonate with functional pulmonary atresia due to Uhl's disease with emphasis on the later detection of restrictive right ventricular physiology.

Complications associated with pediatric cardiac catheterization

OBJECTIVES

The aim of this study was to determine the relative risks of pediatric diagnostic, interventional and electrophysiologic catheterizations.

BACKGROUND

The role of the pediatric catheterization laboratory has evolved in the last decade as a therapeutic modality, although remaining an important tool for anatomic and hemodynamic diagnosis.

METHODS

A study of 4,952 consecutive pediatric catheterization procedures was undertaken.

RESULTS

Patient ages ranged from 1 day to 20 years (median 2.9 years). One or more complications occurred in 436 studies (8.8%) and were classified as major in 102 and minor in 458, with vascular complications (n=189; 3.8% of procedures) the most common adverse event. Arrhythmic complications (n=24) were the most common major complication. Death occurred in seven cases (0.14%) as a direct complication of the procedure and was more common in infants (n=5). Independent risk factors for complications included a young patient age and undergoing an interventional procedure.

CONCLUSIONS

Complications continue to be associated with pediatric cardiac catheterization. Efforts should be directed to improving equipment for flexibility and size, and finding alternative methods for vascular access. Patient age and interventional studies are risk factors for morbidity and mortality.

Relentless pulmonary vein stenosis after repair of total anomalous pulmonary venous drainage

BACKGROUND

Progressive stenosis of the pulmonary veins after repair of total anomalous pulmonary venous drainage is frequently refractory to surgical therapy.

METHODS

Retrospective review of 170 consecutive patients treated for total anomalous pulmonary venous drainage identified 13 patients with postrepair pulmonary vein stenosis. Preoperative and operative data were analyzed to define the patterns of progression and efficacy of surgical techniques.

RESULTS

Seventeen reoperations were performed in 13 patients. Postrepair pulmonary vein stenosis was most common in the infracardiac and mixed subtypes (p < 0.02). All 4 patients with unilateral stenosis, 2 of whom had progression of stenosis resulting in nearly complete unilateral pulmonary vein occlusion, survived. Six of 9 patients with bilateral disease died (p < 0.05 versus unilateral); 2 of the 3 survivors were repaired with a novel technique creating a sutureless neoatrium without evidence of restenosis at 1.8 years' follow-up. Stenting was uniformly unsuccessful.

CONCLUSIONS

In unilateral stenosis, progression of disease may be survivable with loss of single-lung perfusion. Although bilateral disease is lethal in most cases, creation of a sutureless neoatrium has demonstrated short-term freedom from disease progression.

Surgical management of total anomalous pulmonary venous drainage: impact of coexisting cardiac anomalies

BACKGROUND

Recent reports have cited improving results for surgical management of isolated total anomalous pulmonary venous drainage. Complex cases (with other cardiac anomalies) are less frequently reported and are associated with higher mortality.

METHODS

Retrospective review identified 170 consecutive patients treated for total anomalous pulmonary venous drainage from 1982 to 1996: 44 cases were "complex" (with significant associated cardiac lesions) and 126 cases were "simple."

RESULTS

Operative mortality for simple cases decreased from 26% to 8%, and mortality for complex cases remained constant at 52%. Age, size, and the presence of atrial isomerism were univariate predictors of mortality. Multivariable analysis identified only univentricular hearts and associated cardiac lesions as predictors of operative mortality. Pulmonary artery (n = 16) and arteriopulmonary (n = 7) shunting strategies for complex cases resulted in less than 30% long-term survival.

CONCLUSIONS

Despite improvement in survival for simple cases, management of total anomalous pulmonary venous drainage with single-ventricle hearts or other associated cardiac lesions remains problematic.

Myocardial bridging in children with hypertrophic cardiomyopathy--a risk factor for sudden death

BACKGROUND

Myocardial bridging may cause compression of a coronary artery, and it has been suggested that myocardial ischemia may result. The clinical significance and prognostic value of myocardial bridging of the left anterior descending coronary artery in children with hypertrophic cardiomyopathy are unknown. We sought to determine the prevalence and clinical effects of myocardial bridging in children with hypertrophic cardiomyopathy who underwent cardiac catheterization.

METHODS

Angiograms from 36 children with hypertrophic cardiomyopathy were reviewed to determine whether myocardial bridging was present and, if so, to assess the characteristics of systolic narrowing of the left anterior descending coronary artery caused by myocardial bridging and the duration of residual diastolic compression. We also reviewed clinical data on these patients.

RESULTS

Myocardial bridging was present in 10 (28 percent) of the patients. Compression of the left anterior descending coronary artery persisted for a mean (+/-SD) of 50+/-17 percent of diastole. As compared with patients without bridging, patients with bridging had a greater incidence of chest pain (60 percent vs. 19 percent, P=0.04), cardiac arrest with subsequent resuscitation (50 percent vs. 4 percent, P=0.004), and ventricular tachycardia (80 percent vs. 8 percent, P<0.001). On average, the patients with bridging had a reduction in systolic blood pressure with exercise of 17+/-27 mm Hg, as compared with an elevation of 43+/-31 mm Hg in those without bridging (P<0.001). The patients with bridging also had greater ST-segment depression with exercise (median, 5 vs. 0 mm, P=0.004) and a shorter duration of exercise (mean, 6.6+/-2.4 vs. 9.1+/-1.4 minutes, P=0.008). The degree of dispersion of the QT interval corrected for heart rate on the electrocardiogram was greater in patients with bridging than in those without bridging (104+/-46 vs. 48+/-31 msec, P=0.002). Kaplan-Meier estimates of the proportions of patients who had not died or had cardiac arrest with subsequent resuscitation five years after the diagnosis of hypertrophic cardiomyopathy were 67 percent among patients with bridging and 94 percent among those without bridging (P=0.004).

CONCLUSIONS

Myocardial bridging is associated with a poor outcome in children with hypertrophic cardiomyopathy. Our observations suggest that bridging is associated with myocardial ischemia

Anomalous origin of one pulmonary artery from the ascending aorta: 36 years' experience from one centre

Anomalous origin of one pulmonary artery from the ascending aorta is an uncommon lesion with an uncertain outcome. We reviewed 16 consecutive children (9 males) presenting with this lesion over a 36 year period at a single institution. Median age at presentation was 2 days (range, birth to 3.2 years). The anomalous pulmonary was the right in 12 and the left in 4, all originating from the proximal ascending aorta, with no patient having stenosis at the origin of the anomalous pulmonary artery. Associated cardiac anomalies were noted in 9 patients. No intervention was attempted in 2 patients: one was deemed inoperable due to complex associated lesions and pulmonary vascular obstructive disease, while the other one died before repair. Surgical intervention was attempted in 14 patients, with 3 intraoperative deaths (21%). Of 11 operative survivors, 8 developed pulmonary arterial stenosis graded severe in 2, moderate in 1 and mild in 5. Patients with severe stenosis required surgical angioplasty, 1 after unsuccessful dilation combined with placement of an endovascular stent. One patient with moderate, and one with mild, stenosis underwent successful transcatheter balloon dilation. The remaining 4 patients with mild stenosis remain unchanged during follow-up. One patient had biopsy evidence of pulmonary vascular obstructive disease at 3.3 years of age. There were no late deaths, giving a total mortality of 25% (4/16).

CONCLUSION

While early diagnosis and repair of anomalous origin of one pulmonary artery from the ascending aorta is necessary, restenosis of the site of repair is common.

Mortality in potential arterial switch candidates with transposition of the great arteries

OBJECTIVES

We reviewed the factors contributing to or causing death before surgery in neonates with d-transposition of the great arteries (TGA) despite anatomy suitable for the arterial switch operation (ASO) to develop strategies to minimize preoperative attrition.

BACKGROUND

Currently the ASO for neonates with TGA carries a low operative mortality. However, there is a paucity of information regarding the patients who die before the ASO. Strategies to ensure survival to operation are of importance to improve overall outcome.

METHODS

We reviewed all neonates with TGA and patent forearm ovale (PFO) < or = 2 mm, a birthweight <2 kg, or who died before surgery, between 1988 and 1996.

RESULTS

We identified 12 out of 295 neonates with TGA (4.1%) with anatomy suitable for the ASO who died prior to surgery. All had TGA/intact ventricular septum (IVS) and presented with a severely restrictive PFO. In 11 of 12 cases the cause of death was attributed to the sequelae of profound hypoxemia from inadequate mixing. Contributing factors were prematurity, 41.7%; severe respiratory distress syndrome, 25%; and persistent pulmonary hypertension of the newborn (PPHN), 16.7%. All patients received prostaglandin E1 (PGE1) infusion. Urgent balloon atrial sepstostomy (BAS) was performed in 66.7% with improved oxygenation. No cases were diagnosed prenatally. In contrast, all patients with a PFO < or = 2 mm who survived to ASO had a significantly better response to PGE1 infusion (p=0.03) than nonsurvivors. The ASO was accomplished without mortality in four of nine with a weight <2 kg.

CONCLUSIONS

Of those neonates admitted with TGA, 4.1% died before surgery. Eleven of 12 (3.7%) died due to consequences of inadequate interatrial mixing despite PGE1 infusion. Earlier diagnosis and BAS are critically important in determining survival. Early ASO may improve survival in patients weighing <2 kg. Prenatal diagnosis with delivery in a high-risk obstetrical unit with facilities for immediate BAS and supportive therapy for pulmonary hypertension and ventricular failure may be necessary to salvage this group of patients.

Primum atrial septal defect in children: early results, risk factors, and freedom from reoperation

BACKGROUND

Repair of primum atrial septal defect in children usually is associated with a low operative mortality, except for a subgroup of children with congestive heart failure. To determine the early mortality and incidence of reoperation in children with primum atrial septal defect, we analyzed retrospectively the results of patients who underwent repair of this defect.

METHODS

Between July 1982 and December 1996, 180 children underwent repair of primum atrial septal defect. The mean age at repair was 4.6 years (median, 3.6 years; range, 1 month to 16.4 years); of the 180 children, 23 were infants less than 1 year of age. Absent or mild symptoms were present in 145 (80%), whereas 34 (20%) of children presented with severe symptoms or congestive heart failure.

RESULTS

Early mortality occurred in 3 (1.6%); 2 were less than 1 year of age. Follow-up ranged from 2 months to 14.5 years (mean, 6 +/- 4.2 years). Actuarial survival is 98% at 10 years with no late deaths. Age less than 1 year is a predictor of death. During follow-up, 17 (9%) of the 180 patients underwent reoperation, 5 of whom were in the infant group. Five underwent reoperation for subaortic obstruction, and 12 for left atrioventricular valve regurgitation of whom 11 were repaired; and 1 required valve replacement. Age and preoperative moderate-to-severe left atrioventricular valve regurgitation were predictors of reoperation.

CONCLUSIONS

Results of the repair of primum atrial septal defect during childhood are favorable. Infants have a higher risk for death and reoperation. Left atrioventricular valve insufficiency and subaortic stenosis are important late complications and can be repaired safely at reoperation.