20 years of arterial switch operation for simple TGA.

BACKGROUND: Arterial switch operation became the golden treatment for simple transposition of the great arteries (sTGA). We describe our experience with the arterial switch operation regarding long-term outcome and the need for re-intervention. Nevertheless, supravalvular pulmonary stenosis (SPS) remains a concern in the long run. We assess the evolution of SPS over time and evaluate the effect of technical modifications on SPS during our experience. METHODS: We performed a retrospective study on 133 patients operated with ASO for TGA between October 1991 and November 2009. Last report method was used. We reviewed our pediatric cardiology and cardiac surgery database to examine the echocardiographic data and electrocardiograms. A mean follow-up of 9.2 years (+/- 5.83 SD) was reached. RESULTS: One (0.8%) patient deceased postoperatively due to cardiogenic shock. The overall actuarial freedom from reoperation (open and percutaneous) was 88.1%, 78.5% and 76.9% at 1, 5 and 10 years. SPS needed to be treated in 17 patients. Valve regurgitation at final investigation was maximal moderate in 5 patients for the aortic valve, 10 for pulmonary valve and 3 in tricuspid valve. CONCLUSIONS: ASO shows excellent long-term results in sTGA with a very low morbidity and mortality and is therefore the procedure of choice. Re-intervention rate is determined by SPS. Since the extensive mobilization of the pulmonary arteries and the creation of a longer neo-pulmonary root, reduction in SPS was seen with no re-interventions in the second half of the group. To obtain a final comparison with the atrial switch operation, a longer Follow-up is necessary.

Infective endocarditis in patients after percutaneous pulmonary valve implantation with the stent-mounted bovine jugular vein valve: Clinical experience and evaluation of the modified Duke criteria.

AIMS: Percutaneous pulmonary valve implantation (PPVI) has proven good hemodynamic results. As infective endocarditis (IE) remains a potential complication with limited available clinical data, we reviewed our patient records to improve future strategies of IE prevention, diagnosis and treatment. METHODS: Medical records of all patients diagnosed with Melody® valve IE according to the modified Duke criteria were retrospectively analyzed in three Belgian tertiary centers. RESULTS: 23 IE episodes in 22 out of 240 patients were identified (incidence 2.4% / patient year) with a clear male predominance (86%). Median age at IE was 17.9 years (range 8.2-45.9 years) and median time from PPVI to IE was 2.4 years (range 0.7-8 years). Streptococcal species caused 10 infections (43%), followed by Staphylococcus aureus (n = 5, 22%). In 13/23 IE episodes a possible entry-point was identified (57%). IE was classified as definite in 15 (65%) and as possible in 8 (35%) cases due to limitations of imaging. Echocardiography visualized vegetations in only 10 patients. PET-CT showed positive FDG signals in 5/7 patients (71%) and intracardiac echocardiography a vegetation in 1/1 patient (100%). Eleven cases (48%) had a hemodynamically relevant pulmonary stenosis at IE presentation. Nine early and 6 late percutaneous or surgical re-interventions were performed. No IE related deaths occurred. CONCLUSIONS: IE after Melody® valve PPVI is associated with a relevant need of re-interventions. Communication to patients and physicians about risk factors is essential in prevention. The modified Duke criteria underperformed in diagnosing definite IE, but inclusion of new imaging modalities might improve diagnostic performance.

Transapical left ventricular access for difficult to reach interventional targets in the left heart.

OBJECTIVE: Interventional targets may be virtually "excluded" due to vascular access problems or complex previous surgical procedures. This study reviews our experience using transapical ventricular puncture to gain direct access to the systemic ventricle. PATIENTS: Patient 1 (74 years, 2 previous sternotomies), patient 2 (66 years, 5 previous sternotomies), and patient 5 (69 years, 3 previous sternotomies) with prosthetic valves had paravalvular mitral valve leaks. Patient 3 (6.3 years, 2 previous sternotomies) with an extracardiac Fontan conduit, had a significant residual leak after two previous surgical attempts of patch closure of a severely regurgitant right atrioventricular valve. Patient 4 (10 months) had failure of standard ablation of the posteroseptal region of the mitral valve with persistent life-threatening episodes of ventricular tachycardia. METHODS: Procedures were performed under general anesthesia. Entry site was percutaneous in three patients and in two (and one conversion) a mini-thoracotomy was used. Sheaths were placed (6 F) using standard Seldinger technique, followed by the procedure as required. Direct surgical closure of the puncture site was done in 4 patients and in patient 3, a percutaneous vascular occlusion device was used. RESULTS: Easy and immediate access was obtained in all patients. The paravalvular leaks were crossed within seconds and completely closed with Amplatzer occluders. In patient 3 the valve was crossed using a Brokenbrough needle and a 12-mm Amplatzer device was placed in the patch leak. Patient 4 was successfully ablated using a 7-F irrigated catheter endo- and epicardially. Complications were in the percutaneous puncture group: in one patient a coronary artery was punctured and in one a hemothorax developed. CONCLUSION: Direct left ventricular puncture offers a very useful alternative access site in selected patients to reach "inaccessible" targets for certain percutaneous interventions in patients where standard approaches may be impossible or difficult.

Homograft insertion for pulmonary regurgitation after repair of tetralogy of fallot improves cardiorespiratory exercise performance.

Surgical repair of tetralogy of Fallot (TOF) with reconstruction of the right ventricular (RV) outflow tract invariably results in pulmonary regurgitation. Chronic pulmonary regurgitation has been associated with RV dysfunction and decreased exercise performance. The present study assessed the influence of pulmonary valve replacement (PVR) for severe pulmonary regurgitation after previous TOF repair on cardiorespiratory exercise performance and RV function. Eighteen patients, between the ages of 8 and 18 years, underwent an exercise test and a cardiac magnetic resonance imaging scan at least 1 year after PVR. The exercise data were compared with those obtained from 24 age-matched normal controls and 27 age-matched patients with repaired TOF and a moderate degree of pulmonary regurgitation. A subgroup of 11 patients had an exercise test performed before and after PVR. Cardiopulmonary exercise performance was evaluated by determination of the ventilatory anaerobic threshold (VAT) and by the steepness of the slope of oxygen uptake versus exercise intensity (SVO2). After PVR there was a significant increase in VAT (86+/-11% before to 106.9+/-14% after, p = 0.03) and in SVO2 (1.71+/-0.47 to 2.3+/-0.39, p = 0.004). In patients examined after PVR, the VAT and SVO2 values were not significantly different from the values in the normal controls (104+/-15% [p>0.05] and 2.03+/-0.77 after PVR vs. 2.42+/-0.68 [p>0.25], respectively). In contrast, patients with repaired TOF and a moderate degree of pulmonary regurgitation had a significantly lower VAT (86+/-11%, p<0.05) and SVO2 (1.8+/-0.74 vs. 2.42+/-0.68, p<0.05) than normal controls. Magnetic resonance imaging studies revealed residual RV dilatation and dysfunction. However, there was no correlation between RV dilatation and RV dysfunction and aerobic exercise capacity. It is concluded that aerobic exercise capacity substantially improves after PVR for severe pulmonary regurgitation after previous TOF repair. Although the right ventricle remains significantly dilated and hypocontractile, there is no relation between RV function and exercise performance.

A recognisable behavioural phenotype associated with terminal deletions of the short arm of chromosome 8.

We report the clinical findings in 5 patients with a terminal deletion of the short arm of chromosome 8. Mild developmental delay was constantly present, in association with microcephaly in 4 of 5 patients. Facial anomalies were mild or absent. A congenital heart defect was present in 3 patients: an atrioventricular septal defect (AVSD) in 2 and an atrial septal defect type II (ASDII) with pulmonary stenosis in one. A highly similar pattern of behavioural difficulties was present in the 3 older children (8-11 years), with outbursts of aggressiveness and destructive behaviour. Follow-up in one patient showed that at the age of 16 years, these behavioural problems had largely disappeared. This observation suggests that in addition to mental retardation, microcephaly, congenital heart defect (typically AVSD), a terminal deletion of chromosome 8p may be associated with a characteristic behavioural phenotype during childhood.

Alagille syndrome (arteriohepatic dysplasia) and del(20)(p11.2)

We report on a boy with Alagille syndrome. Chromosome analysis on a peripheral blood lymphocyte culture showed a de novo deletion of the short arm of chromosome 20 with a 46,XY,del(20)(p11.2) chromosome constitution. This is the second report of a del(20p) in a patient with Alagille syndrome. The possible localisation of this autosomal dominant syndrome on 20p is discussed.

Recurrent involvement of chromosomal region 6q21 in heterotaxy.

We present a patient with heterotaxy and a de novo, apparently balanced reciprocal translocation with breakpoints at 6q21 and 20p13. Another patient with heterotaxy was previously reported with a de novo balanced translocation involving chromosome band 6q21. The breakpoints in both patients on 6q21 were found to be located in the same chromosomal region spanning maximally 2 Mb. We speculate that the two breakpoints lead to the disruption of the function of a single gene, either directly or through long distance effects. Alternatively, the present observation suggests additional heterogeneity in heterotaxy in humans.

Percutaneous treatment of stenosed major aortopulmonary collaterals with balloon dilatation and stenting: what can be achieved?

BACKGROUND: The natural history of major aortopulmonary collateral arteries (MAPCAs) in patients with pulmonary atresia and ventricular septal defect (PA-VSD) is frequently complicated by progressive stenosis, leading to pulmonary hypoperfusion and debilitating hypoxaemia. OBJECTIVE: To evaluate balloon dilatation and stenting for relief of stenoses and improvement of pulmonary flow in patients with PA-VSD. DESIGN: Retrospective analysis of all patients where dilatation of MAPCA stenoses was attempted. PATIENTS: Twelve patients with stenotic MAPCAs. INTERVENTIONS: Dilatation was attempted in 25 stenoses. Vessels were stented if elastic recoil was noticed (n = 3), in the presence of long segment stenosis (n = 4) or marked tortuosity (n = 1). MAIN OUTCOME MEASURES: Diameter of stenoses before and after dilatation as well as arterial oxygen saturation data. Patients proceeding to surgical therapy. RESULTS: Two stenosed MAPCAs could not be crossed by a catheter. Four lesions were non-dilatable despite the use of high inflation pressures (18 atm). Six stenoses could be completely dilatated using angioplasty only; in five, only partial dilatation was obtained; eight stenoses needed stenting. In the group with partial expansion the mean (SD) diameter increased from 1.7 (0.8) to 3.5 (1.7) mm (p < 0.05); where full dilatation was achieved it increased from 2.1 (0.8) to 4.8 (1.9) mm (p < 0.05); and in the stented group in increased from 2.3 (0.9) to 5.0 (2.5) mm (p < 0.01). Percutaneous arterial oxygen saturation increased from 75(8%) to 82(8)% (p < 0.001). No complications were experienced during the procedures. Repeat dilatation was attempted in six stenoses, but only two procedures were successful. There were two episodes of vasospasm and in one an aneurysm had developed after redilatation. Two patients proceeded to outflow plasty and two subsequently had a unifocalisation procedure. CONCLUSIONS: Pulmonary blood flow can be improved using balloon angioplasty or stents in patients with stenotic MAPCA; however, 17% of the lesions were not dilatable. Procedures are generally safe, but carry a small risk of vasospasm, dissection, occlusion or aneurysm formation.

Cardiac strangulation, a rare complication of epicardial pacemaker leads during growth.

A six year old boy with an epicardial pacing lead since infancy presented with thoracic pain triggered by movement. The pain was thought to be musculoskeletal, but two weeks later he collapsed and died in ventricular fibrillation. Necropsy showed strangulation of the ventricular apex by the epicardial lead.

Self expandable stents for relief of venous baffle obstruction after the Mustard operation.

OBJECTIVE: Obstruction of the venous pathways after Mustard repair for transposition of the great arteries is associated with an increased risk of arrhythmia and sudden death. The purpose of this study was to assess the effectiveness of the largest (tracheal 22 x 40 mm) Wallstents in treating baffle obstructions. DESIGN: Retrospective analysis of patients with stented venous pathways. SUBJECTS: Eleven patients with baffle obstruction after Mustard repair for transposition of the great arteries. INTERVENTIONS: Stenoses were dilated with an 18 or 20 mm balloon. However, recoil was noticed in 11 patients: immediately (n = 7) or on repeat angiography (n = 4). Eighteen stents were implanted (mean (SD)) 18 (3.3) years postoperatively. After dilatation a tracheal Wallstent (11.5 F) was deployed. MAIN OUTCOME MEASURES: Relief of obstruction, haemodynamic improvement. RESULTS: In the inferior vena cava, 10 stents were deployed in seven baffle obstructions with an increase in diameter from 9.8 (2.4) mm to 16.5 (1.4) mm (p < 0.01) and a mean (SD) pressure gradient decrease from 5.1 (3.6) mm Hg to 1.4 (2.0) mm Hg; in the superior vena cava, eight stents were implanted increasing the diameter from 9.1 (3.7) mm to 15.6 (3.8) mm (p < 0.001) with a decrease in mean pressure gradient from 5.1 (2.7) mm Hg to 1.9 (1.5) mm Hg. No complications were experienced during implantation. No anticoagulation was prescribed. During follow up (1.7 (0.6) years; range, 0.9-2.6) no problems were noted; five patients were re-catheterised without change in measurements. There was no evidence of peal formation in any of the stents. CONCLUSION: It is concluded that Wallstents are safe, easy to use, and effective in relieving baffle obstruction. Anticoagulation does not seem necessary.

Neonatal pulmonary artery banding does not compromise the short-term function of a Damus-Kaye-Stansel connection.

BACKGROUND: The surgical approach of neonates with a functionally univentricular heart, transposition of the great arteries and excessive pulmonary bloodflow remains a challenge. Pulmonary artery banding remains a valuable option, but may induce ventricular hypertrophy, restriction of the bulboventricular foramen and dysplastic changes of the pulmonary valve. These secondary changes might compromise a later Damus-Kaye-Stansel connection because of pulmonary regurgitation but also a subsequent Fontan repair because of ventricular hypertrophy. The aim of this study is to investigate whether a previous pulmonary artery banding might compromise the function of a Damus-Kaye-Stansel connection. METHODS: Thirteen neonates underwent pulmonary artery banding for functionally univentricular heart, transposition of the great arteries and pulmonary hypertension. Coarctation repair was associated in seven patients. All but one survived the operation. The twelve survivors underwent at a second stage a Damus-Kaye-Stansel connection after a mean interval of 1.1 years. The length of this interval was dictated by the degree of ventricular hypertrophy, the restriction of the bulboventricular foramen and by the degree of cyanosis. The Damus-Kaye-Stansel connection was constructed without any foreign material and with resorbable sutures. Associated procedures were: Glenn/hemi-Fontan (8 pts), Blalock-shunt (2 pts), biventricular correction with a homograft (1 pt), Fontan repair (1 pt). Four patients underwent successfully a Fontan repair at a third stage; seven patients are waiting for such repair. RESULTS: All patients survived the second and third stage of this surgical approach. The mean follow-up after the Damus-Kaye-Stansel connection was 2.5 years. Echocardiography at the last follow-up revealed: PR grade 0 (1 pt), grade 1 (8 pts), and grade 2 (3 pts). All patients - except one patient with a systolic gradient of 24 mmHg - had laminar flow without any gradient in the ascending aorta. All patients, including those who underwent a definitive repair, are doing extremely well. CONCLUSION: This experience demonstrates that a neonatal pulmonary artery banding does not compromise the function neither of a Damus-Kaye-Stansel connection nor a Fontan repair.

Mid-term results of the Ross procedure.

METHODS: Fifty patients underwent a Ross operation between June 1991 and October 1996. Preoperative diagnosis was: congenital aortic valve disease (31 patients), complex left ventricular outflow tract (LVOT) obstruction (11 patients), outgrowth of a small aortic valve prosthesis (five patients) and valve endocarditis (three patients). Half of the interventions were reoperations. All operations were root replacements. A pulmonary homograft was used in 45 patients. An aorticoventriculoplasty was combined with the root replacement in the 16 patients with LVOT obstruction and a too small aortic valve prosthesis. An enlargement or reduction plasty of the ascending aorta was necessary in seven patients. RESULTS: The mean age was 20.9 years (range: 2.5-54 years). The mean follow up was 34.2 +/- 21 months and was 94% complete. Two patients died after 8 days (low cardiac output due to myocardial fibrosis) and 17.4 months (sudden death), respectively, resulting in a survival of 95 +/- 4% at 4 years. Those two deaths occurred in the group of patients undergoing Ross procedure and aorticoventriculoplasty. Two autografts were replaced after respectively 2 days (technical failure) and 44 months (progressive root dilatation) resulting in a reoperation-free incidence of 93 +/- 6% at 4 years. Other postoperative major complications occurred in six patients. All survivors had regular echo-Doppler examination. All autografts except one had a systolic gradient below 10 mmHg at the last examination. Thirty-four autografts had no leak, ten showed grade 1-2 regurgitation. Two patients showed a higher than grade 3 regurgitation: one leak remains stable with normal left ventricular dimensions and function, one autograft was replaced by a mechanical valve. CONCLUSION: This experience demonstrates that the medium-term results of the Ross procedure are excellent even in complex LVOT obstructions.

Homograft valve insertion for pulmonary regurgitation late after valveless repair of right ventricular outflow tract obstruction.

OBJECTIVE: Pulmonary regurgitation after valveless repair of right ventricular outflow tract obstruction (RVOTO) results in progressive right ventricular (RV) dilatation and dysfunction in an increasing number of patients. Since 1989, we have exclusively used cryopreserved homografts to restore pulmonary valve competence in these patients. Our 9-year-experience with pulmonary valve insertion (PVI) in such cases has been reviewed to evaluate the indications for this procedure and its benefits. METHODS: From 1989 to 1998, 49 patients (original diagnosis: tetralogy of Fallot in 42 patients and pulmonary stenosis in seven) aged from 3 to 42 years (mean 18 +/- 9 years) underwent PVI with homografts late (mean 13 +/- 7 years) after valveless repair of RVOTO (transannular patch, n = 38; pulmonary valvulotomy therefore tau chi infundibular patch, n = 11). Preoperatively, all patients had severe pulmonary regurgitation, cardiomegaly, significant to severe RV dilatation and dysfunction, fatigue, reduced exercise tolerance, and were in NYHA class II (n = 43) or III (n = 6). Ten patients had ventricular arrhythmia. RESULTS: There was one early death, due to air embolism, and one late death, due to ventricular arrhythmia. All survivors but one, who subsequently underwent heart transplant, had symptomatic improvement after homograft insertion. The mean RV end-diastolic diameter decreased from 38 +/- 9 to 26 +/- 8 mm (P < 0.01), and cardiothoracic ratio decreased from 0.62 +/- 0.07 to 0.54 +/- 0.04 (P < 0.01). Good late homograft function was the rule, with all the survivors being free of reoperation for valve failure. At a mean follow-up of 42 +/- 28 months, 41 patients (87% of the survivors) were in New York Heart Association (NYHA) class I and six in class II. Within this group three patients are still in treatment for RV failure and five for ventricular arrhythmias. In these patients, the average interval between RVOTO repair and PVI was significantly longer than in the others (18 +/- 7 vs. 12 +/- 6 years, P < 0.01). CONCLUSION: Homograft PVI is safe and provides clinical improvement with a significant reduction in RV volume overload and excellent mid-term results in most patients with severe PR late after RVOTO repair. This procedure should be undertaken early in symptomatic patients, before severe RV failure and ventricular arrhythmias ensue.

Presenting symptoms and clinical features in 130 patients with the velo-cardio-facial syndrome. The Leuven experience.

During the last 5 years, we diagnosed in Leuven 130 patients with a 22q11 deletion. The deletion was familial in 14 out of 110 index patients (12%), which is significantly less compared to previous studies. In 10 patients, the deletion was maternal, in 4 patients paternal. A cardiac defect was the main presenting symptom in 49% of patients. The other patients were ascertained through developmental delay (16%), behavioural disturbances (7%), otorhinolaryngological manifestations (6%), psychiatric manifestations (3%) and mental retardation (2%). In one patient hypocalcemia was the presenting symptom. In another patient the severe immune deficiency led to diagnosis. Most patients presented a wide variety of the classical features of the Velo-Cardio-Facial syndrome. Velopharyngeal incompetence, learning difficulties or mostly mild mental retardation were almost always present, whereas clinical significant hypocalcemia or immune disturbances were rare. Previously un(der)recognised features include polyhydramnios, renal malformations and laryngotracheamalacia or laryngeal stenosis.

Stenting of hypoplastic aortic segments with mild pressure gradients and arterial hypertension.

OBJECTIVE: To determine the safety, feasibility and effectiveness of stent expansion of hypoplastic aortic segments with pressure gradients in patients with arterial hypertension. DESIGN: Non-randomised prospective clinical trial. SETTING: Tertiary referral centre, congenital cardiac unit. PATIENT SELECTION: 20 consecutive patients (median age 14.5 years, range 11.6-38.8 years) with arterial hypertension and a hypoplastic segment of the aorta. Seventeen patients had successful previous arch interventions in a coarctation site. INTERVENTIONS: Stent deployment in hypoplastic arch segments. MAIN OUTCOME MEASURES: Gradient across the aortic arch; complications early and during follow up; residual hypertension. RESULTS: 23 stents were deployed: 13 in the cross and 10 in the isthmus. The mean gradient across the aortic arch decreased from 16 (SD 6) (median 17) to 3 (4) (median 1) mm Hg (p < 0.001). In a few patients a mild gradient persisted just distal to the left carotid artery due to residual orificial narrowing or acute angulation. No complications occurred during or after the procedure. During follow up of 2.2 years (range 0.2-4.8 years) arterial hypertension resolved in 10 patients and 10 required residual drug treatment with better control of blood pressures. CONCLUSIONS: Pressure loss due to residual hypoplastic aortic segments can be treated effectively and safely with stent expansion. Some patients remain mildly hypertensive and require additional drug treatment.

New ultrasound methods to quantify regional myocardial function in children with heart disease.

From a temporally resolved radio-frequency data set, a series of new developing indices of regional myocardial deformation can be measured. These may be important new data sets to quantify regional radial and long axis function of the left or right ventricle in children with acquired or congenital heart disease. Using color Doppler methodology unidimensional regional myocardial strain rates (SR) and natural strain (e) can now be calculated from local myocardial velocity data sets. Normal regional velocity, SR, and e values have already been determined in older children and should form the database for studies into acquired or congenital heart disease in this age group. Neonatal and infant values have yet to be determined. This article will present preliminary data on the potential clinical value of ultrasonic regional SR and e imaging in children and will discuss the close interrelation of these new regional function parameters with an alternative approach to quantification: the measurement of local cyclical changes in integrated backscatter levels.

Tumour-induced rickets: a case report and review of the literature.

UNLABELLED: Hypophosphataemic rickets was diagnosed in a 6-year-old boy with a negative family history. After 16 years of medical treatment he developed a malignant sarcoma of the right distal thigh. Removal of the tumour by high amputation of the leg resulted in disappearance of the phosphate leak. In spite of surgery and chemotherapy, the patient died due to extensive lung metastases. Retrospective analysis of the initial X-ray films showed a benign lesion on the lateral side of the right distal femur. This lesion is believed to be at the origin of the rickets. This is the first paediatric case reported with malignant degeneration of a benign tumour causing rickets. CONCLUSION: Patients with the classical hallmarks of X-linked, familial hypophosphataemic rickets but no affected family members should have a careful periodic search for a tumour, even years after onset of the disorder.

Oxygen uptake versus exercise intensity: a new concept in assessing cardiovascular exercise function in patients with congenital heart disease.

OBJECTIVE: To assess the relation between exercise intensity and oxygen uptake during graded exercise in paediatric patients who underwent surgical repair of congenital heart disease, and to compare it with conventional measures of aerobic exercise function. DESIGN: Cross sectional study. Exercise testing was performed on a treadmill and gas exchange was measured on a breath by breath basis. PATIENTS: 29 patients who underwent an atrial switch operation for transposition of the great arteries (TGA) (mean (SD) age at testing 10.3 (2.5) years) and 30 patients who underwent total repair of tetralogy of Fallot (TF) (age 12.1 (3.3) years) performed graded exercise testing. Exercise responses were compared with data obtained in 24 normal controls (age 11.4 (2.6) years). RESULTS: The slope of oxygen uptake versus exercise intensity averaged 1.50 (0. 64) ml O(2)/min(2)/kg in the patients with TGA and 1.68 (0.75) ml O(2)/min(2)/kg after TF repair, both lower (p < 0.005) than in normal controls (2.42 (0.68) ml O(2)/min(2)/kg). The lower slope of oxygen uptake was correlated with a subnormal value for ventilatory anaerobic threshold, which averaged 78.0 (13.3)% of normal in TGA and 85.1 (10.6)% in TF. This was associated with a steeper slope (p = 0.001) of carbon dioxide output versus oxygen uptake above the ventilatory anaerobic threshold in TGA (1.26 (0.20)) and TF (1.20 (0. 18)) compared with the normal controls (1.05 (0.13)), and also a steeper slope of ventilation versus carbon dioxide in TGA (47.0 (15. 4)) and TF (41.5 (13.7)) than in the controls (30.3 (8.5)). CONCLUSIONS: Calculation of the steepness of the slope of oxygen uptake versus exercise intensity is a valid measurement of oxygen flow to the exercising tissues, which may be limited in congenital heart disease.

Prenatal diagnosis of a terminal short arm deletion of chromosome 8 in a fetus with an atrioventricular septal defect.

We report the prenatal diagnosis at 30 weeks of gestation of a del(8)(p21.3-->pter) in a growth-retarded fetus with an unbalanced atrioventricular septal defect (AVSD) and a hypoplastic right ventricle. This observation further confirms the association of AVSD with terminal deletions of chromosome 8p. Terminal deletions of chromosome 8p are more frequent than previously thought, but small terminal deletions can easily be overlooked. This observation illustrates that when an AVSD is diagnosed prenatally, special attention should be paid to distal chromosome 8p.