Evaluation of a modified paediatric early warning score for children with congenital heart disease.

BACKGROUND: Paediatric early warning score systems are used for early detection of clinical deterioration of patients in paediatric wards. Several paediatric early warning scores have been developed, but most of them are not suitable for children with cyanotic CHD who are adapted to lower arterial oxygen saturation. AIM: The present study compared the original paediatric early warning system of the Royal College of Physicians of Ireland with a modification for children with cyanotic CHD. DESIGN: Retrospective single-centre study in a paediatric cardiology intermediate care unit at a German university hospital. RESULTS: The distribution of recorded values showed a significant shift towards higher score values in patients with cyanotic CHD (p < 0.001) using the original score, but not with the modification. An analysis of sensitivity and specificity for the factor "requirement of action" showed an area under the receiver operating characteristic for non-cyanotic patients of 0.908 (95% CI 0.862-0.954). For patients with cyanotic CHD, using the original score, the area under the receiver operating characteristic was reduced to 0.731 (95% CI 0.637-0.824, p = 0.001) compared to 0.862 (95% CI 0.809-0.915, p = 0.207), when the modified score was used. Using the critical threshold of scores ≥ 4 in patients with cyanotic CHD, sensitivity and specificity for the modified score was higher than for the original (sensitivity 78.8 versus 72.7%, specificity 78.2 versus 58.4%). CONCLUSION: The modified score is a uniform scoring system for identifying clinical deterioration, which can be used in children with and without cyanotic CHD.

Low serum 25-hydroxyvitamin D levels and secondary hyperparathyroidism in Fontan patients.

BACKGROUND: Limited data exist on the vitamin D status in Fontan patients. We determined the prevalence and potential risk factors of vitamin D deficiency in this patient subset. Methods and results Data were collected from 27 Fontan patients (55.6% male, mean age 8.1±5.3 years). Protein-losing enteropathy was diagnosed in six patients (22.2%). Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D level of <20 ng/ml. The neutrophil-to-lymphocyte ratio, a marker of systemic inflammation, was calculated. Associations between laboratory measurements and patient characteristics were explored. Mean serum 25-hydroxyvitamin D level was 14.1±10.4 ng/ml. Vitamin D deficiency was found in 19/27 patients (70.3%). Only skin type was associated with vitamin D deficiency (p=0.04). Hyperparathyroidism was present in 5/21 (23.8%) patients, and was more prevalent in patients with protein-losing enteropathy (p<0.001). Parathyroid hormone levels correlated with parameters of systemic inflammation (neutrophil-to-lymphocyte ratio: r=0.484, p=0.026; relative lymphocyte count: r=-0.635, p=0.002). Vitamin D supplementation significantly increased serum 25-hydroxyvitamin D levels (p<0.0001), and was accompanied by a reduction in parathyroid hormone concentrations (p=0.032). CONCLUSIONS: A high prevalence of vitamin D deficiency was found among Fontan patients, independent of age, time after Fontan procedure, ventricular morphology, and presence of protein-losing enteropathy. A potentially important link between parathyroid hormone levels and systemic inflammation is suggested.

Stenting of Native Right Ventricular Outflow Tract Obstructions in Symptomatic Infants.

OBJECTIVE: To assess feasibility, safety and effectiveness of right ventricular outflow tract (RVOT) stenting in symptomatic young infants. METHODS: Multicentre evaluation of 35 patients intended to undergo RVOT stenting in 11 pediatric cardiac centres from 2009 to August 2011. RESULTS: Median age and weight at the time of first stent implantation were 8 weeks and 3.3 kg, with 40% of patients <3 kg. A total of 19 patients had suffered from hypoxemic spells, 8 patients were ventilated, 6 on inotropic support and 5 on prostaglandin infusion. Severe concomitant malformations were present in 11 patients, and acute infections in 2. Stenting of the RVOT was successfully performed in 33 patients, improving oxygen saturation from a median of 77 to 90% 2 days after intervention. Besides the 2 patients in whom RVOT stenting was not successful for technical reasons, there were no procedural complications. In 17 of 33 patients, 1-3 reinterventions were performed during follow-up, less than half of those were reinterventions in the RVOT. A total of 27 patients have undergone successful surgical repair 4-162 (median 19.5) weeks after initial RVOT stent implantation, 2 patients are still waiting. There were no perioperative deaths. CONCLUSIONS: Stenting of the RVOT provides a safe and effective management strategy for initial palliation in symptomatic young infants, including those patients not suitable or at higher risk for surgical therapy.

Stent therapy for acute and chronic obstructions in extracardiac Fontan conduits.

We describe transcatheter therapy for early onset occlusion or stenoses of extracardiac conduits in three children who had undergone Fontan completion. Successful stent implantation was associated with complete resolution of symptoms.

Coarctation of the aorta and vein of Galen malformation - treatment considerations in a severely compromised patient.

A vein of Galen malformation - a rare cause of cardiac insufficiency in neonates - is sometimes associated with coarctation of the aorta, two diseases requiring urgent therapy in the neonatal period. We report on a term neonate in whom we first palliated the coarctation by stent implantation, providing time to treat the vein of Galen malformation by endovascular embolisation. Following this, the coarctation was surgically repaired and the stent was explanted.

Device closure of ventricular septal defects by hybrid procedures: a multicenter retrospective study.

OBJECTIVE: This study reports on the feasibility, efficacy, and outcome of hybrid procedures to close ventricular septal defects (VSD), reflecting the experience of 11 centers in Germany, Austria, and Switzerland. BACKGROUND: Beating heart closure of VSD has attracted interest in small infants, complex anomalies and postinfarction scenarios where patients are at high risk during surgery. Perventricular or intraoperative device placement allows access to the lesions where percutaneous delivery is limited. METHODS: Between December 2001 and April 2009, placement of Amplatzer septal occluders was attempted in 26 patients. The defects were located in the perimembranous (n = 5) and muscular septum (n = 21). In 20 patients, a perventricular approach was used, and, in six, the occluders were placed under direct visualization being part of a complex heart surgery. RESULTS: In 23 of 26 procedures, device placement was successful (88.5%). The mean defect size was 7.8 mm (range, 3.5-20). The occluder types were perimembranous VSD occluder (n = 4), muscular VSD occluder (n = 20), postinfarct VSD occluder (n = 1), and ASD occluder (n = 1) with a ratio device/defect of 0.9-2.4 (median 1.15). Device removal was necessary in three due to arrhythmia, malpositioning, and additional defects. Pericardial effusion occurred once. In the remaining 22 patients, there were no procedure or device-related complications. During mean follow up of 1.4 years (range, 1 day-3.9 years), a residual shunt that was more than trivial was observed in one patient out of 21 successful procedures. CONCLUSIONS: Perventricular and intraoperative device closure of VSD is as effective as a surgical patch and averts the increased morbidity of conventional surgical repair in a subgroup of high-risk patients.

Ablation strategies in a patient with Belhassen tachycardia.

UNLABELLED: The verapamil-sensitive Belhassen tachycardia is a ventricular reentrant tachycardia, involving left-sided Purkinje fibers and abnormal Purkinje or myocardial tissue. Ablation is feasible, targeting a diastolic fascicular potential in the apical left ventricle. CASE REPORT: We report on a 13-year-old girl with left posterior fascicular ventricular tachycardia. Tachycardia stopped during ablation, targeting a left-sided distal fascicular potential, and afterward, there was no tachycardia inducible, but it reoccurred 2 weeks later. During a second procedure, we transected the left posterior fascicle by a line, also with early success. After a further recurrence, we ablated a longer proximal segment of the left posterior fascicle including its most proximal electrograms. After this ablation, there was no further recurrence. CONCLUSION: In refractory patients, proximal ablation of the posterior fascicle might be indicated.

Extended applications of the Amplatzer vascular plug IV in infants.

OBJECTIVE: A variety of devices are available for transcatheter closure of unwanted shunts. We describe our experience with the use of the Amplatzer vascular plug IV in a consecutive series of infants. METHODS: A total of eight consecutive infants - all born preterm at gestational ages ranging from 24 to 35 weeks - undergoing transcatheter closure of unwanted shunts - persistently patent arterial duct in five patients, an aorta to right atrium fistula in one, multiple aortopulmonary collateral vessels in one, and an azygos vein to left atrium connection in one - are described. Their age, from birth, ranged between 3 and 11 months, and weight between 2.6 and 11.3 kilograms. All devices were delivered using percutaneous arterial or venous vascular access via a large lumen (0.038 inch) 4-French delivery catheter. RESULTS: All lesions could be successfully occluded using one or more devices. Device diameters ranged between 4 and 8 millimetres, and exceeded the minimum diameter of the target vessel by 1 to 2 millimetres. Successful occlusion was confirmed either directly at angiography or on follow-up echocardiography. Of the infants who were mechanically ventilated prior to the procedure, three could be successfully weaned following closure of the shunt. There were no procedure-related complications. CONCLUSIONS: The new vascular plug IV is cheap and efficacious in closing a variety of shunts in young infants, and warrants further extended clinical application.

Dilated cardiomyopathy in children with ventricular preexcitation: the location of the accessory pathway is predictive of this association.

BACKGROUND: Ventricular preexcitation may be associated with dilated cardiomyopathy, even in the absence of recurrent and incessant tachycardia. METHODS: This report describes the clinical and electrophysiologic characteristics of 10 consecutive children (6 males), with median age of 8 years (range, 1-17 years), who presented with dilated cardiomyopathy and overt ventricular preexcitation on the 12-lead electrocardiogram. Incessant tachycardia as the cause of dilated cardiomyopathy could be excluded. Coronary angiography, right ventricular endomyocardial biopsy (4/10 patients), and metabolic and microbiologic screening were nondiagnostic. RESULTS: The electrocardiograms suggested right-sided pathways in all patients. A right-sided accessory pathway was demonstrated in 8 patients during invasive electrophysiologic study (superoparaseptal, n = 5; septal, n = 2; fasciculoventricular, n = 1). All pathways were successfully ablated (radiofrequency ablation in 7, cryoablation in 1). Two patients had spontaneous loss of ventricular preexcitation during follow-up. Left ventricular (LV) function completely recovered after a loss of preexcitation in all patients. CONCLUSIONS: Right-sided accessory pathways with overt ventricular preexcitation and LV dyssynchrony may cause dilated cardiomyopathy. An association between such pathways and dilated cardiomyopathy is suggested by the rapid normalization of ventricular function and reverse LV remodeling after a loss of ventricular preexcitation.

Atrioventricular block following implantation of a stent in the oval fossa.

A neonate weighing 2.8 kilograms underwent the staged hybrid procedure for palliation of hypoplastic left heart syndrome. Within 6 hours following placement of a stent to retain patency of the interatrial communication, the infant developed second degree atrioventricular block, which resolved within 24 hours. Four days later, the patient developed complete atrioventricular dissociation. Removal of the stent was followed by recovery of atrioventricular conduction.

Documented narrow QRS tachycardia not inducible during electrophysiology study: should we modify the AV node or not.

Ablation therapy is the widely accepted definitive therapy for atrioventricular reentry tachycardia. Noninducibility of the tachycardia is the targeted end point of the procedure. We report on 21 patients with documented narrow QRS tachycardia, in whom the clinical tachycardia could not be induced during the electrophysiologic study. After exclusion of an accessory pathway, we could treat them by slow pathway ablation, either with radiofrequency energy or with cryoenergy, successfully.

Stenting the Fontan pathway in paediatric patients with obstructed extracardiac conduits.

OBJECTIVES: An unobstructed extracardiac conduit (ECC) is essential for optimal Fontan haemodynamics. We aimed to evaluate the feasibility and results of percutaneous transcatheter stenting of the ECC in paediatric patients with a significant Fontan pathway obstruction. METHODS: Our institutional database was searched to identify all Fontan patients who had a stent placed in their ECC. Medical records, cardiac catheterisation data and echocardiographic investigations were reviewed. Vessel diameters were normalised to account for differences in body surface area. RESULTS: Nineteen Fontan patients (age 6.5±3.2 years; male 78.9%) with a significant stenosis of their Dacron ECC graft were identified. Seven patients presented with protein-losing enteropathy (36.8%). An ECC obstruction was suspected on echocardiography in only 6/19 patients (31.6%). The mean minimum diameter of the ECC was 8.3±2.4 mm. A stenosis of >45% was seen in the majority of patients (n=12, 63.1%). Significant correlations between the severity of the ECC obstruction and Fontan pathway vessel diameters were found (all p<0.05). Stenting was successful in all children. The ECC diameter increased significantly after stenting (p<0.0001). An acute clinical benefit of ECC stenting was observed in 18/19 (94.7%) patients. ECC patency was good during a mean follow-up of 1.8±0.9 years. CONCLUSIONS: The feasibility and acute results of percutaneous transcatheter ECC stenting are promising and may provide a good alternative to postpone surgery to a later age. The mechanisms contributing to the development of ECC stenoses are likely multifactorial.

Wireless Holter transmission in suspected dysrhythmias.

BACKGROUND: In patients with a history of possible dysrhythmias, documentation of an episode is mandatory before any form of treatment is given. Holter recordings with wireless telemetry offer the possibility of continuously recording electrocardiograms for days or even weeks with instantaneous analysis of the data in the physician's office. METHODS: Thirty-seven patients (20 male; median age, 8.4 years; range, 0.1-22 years), were investigated by using a telemetric Holter system (M120, Schiller, Switzerland), that is, intermittent transmission of the electrocardiographic data to a remote server using cell phone frequencies, with a median duration of the recordings of 6.5 days (range 1-42 days). RESULTS: Recording quality was sufficient in all patients. Problems were related to electrode disconnections only, which were adjusted by contacting the patients. Twenty-eight of 37 recordings showed decisive findings. Of the 28 patients, no treatment was indicated in 16 patients, as subjective symptoms did not correlate with dysrhythmias; psychotherapy was indicated in 2 patients; antiarrhythmic medication was initiated or intensified in 5 patients; radiofrequency ablation was successfully performed in 5 patients; and 1 patient received an ICD. In 6 of 9 patients with negative Holter findings, a loop recorder implantation (Medtronic, Minneapolis, Minn) was indicated. In 1 patient, no dysrhythmias were recorded; however, when invasively investigated, ventricular tachycardia was detected and successfully treated by radiofrequency ablation. In 2 patients, no decision has been made to date. CONCLUSIONS: Wireless Holter recordings are useful in detecting dysrhythmias with rare occurrence, are less expensive and less invasive compared with implantable loop recorders, and offer the patient rather wide geographic ranges with sufficient signal quality.

Percutaneous tricuspid valve replacement in childhood.

Percutaneous replacement of the tricuspid valve with a bovine jugular venous valve (melody valve) was successfully undertaken in a 9-year-old boy. The patient had a previous history of bacterial endocarditis of the native tricuspid valve in infancy. Initially, a pericardial patch valve was created, followed by surgical replacement of the valve using a biological tissue valve at 4 years of age. Progressive stenosis and regurgitation of the biological valve, with severe venous congestion and resulting hepatic dysfunction prompted percutaneous valve replacement.

Percutaneous radiofrequency septal reduction for hypertrophic obstructive cardiomyopathy in children.

OBJECTIVES: The aim of this study was to assess the efficacy of radiofrequency catheter ablation (RFCA) in the treatment of hypertrophic obstructive cardiomyopathy in children. BACKGROUND: Hypertrophic obstructive cardiomyopathy is an uncommon cause of left ventricular outflow tract obstruction in children. In symptomatic patients, open heart surgical myectomy has hitherto been the only therapeutic option. METHODS: In 32 children, at a median age of 11.1 (range 2.9 to 17.5) years and weight of 31 (15 to 68) kg, ablation of the hypertrophied septum was performed using a cool-tip ablation catheter via a femoral arterial approach. The median number of lesions was 27 (10 to 63) and fluoroscopic time was 24 (12 to 60) min. RESULTS: The majority of patients demonstrated an immediate decrease in the catheter pullback gradient (mean 78.5 ± 26.2 mm Hg pre-RFCA versus mean 36.1 ± 16.5 mm Hg post-RFCA, p < 0.01) and a further reduction in the Doppler echocardiographic gradient (mean 96.9 ± 27.0 mm Hg pre-RFCA versus 32.7 ± 27.1 mm Hg post-RFCA, p < 0.01) at follow-up. One patient died due to a paradoxical increase in left ventricular outflow tract obstruction, and another had persistent atrioventricular block that required permanent pacing. Six patients required further procedures (surgery, pacing, or further RFCA) during a median follow-up of 48 (3 to 144) months. CONCLUSIONS: The preliminary results of RFCA for septal reduction in children with hypertrophic cardiomyopathy are promising and merit further evaluation.

Safety and results of cryoablation in patients <5 years old and/or <15 kilograms.

Current recommendations discourage elective radiofrequency ablation in patients <5 years old and/or weighing <15 kg, primarily because of the greater complication rate. To describe the current use, complications, and immediate outcomes of cryoablation in this patient population, a multicenter retrospective review of all patients <5 years old and/or weighing <15 kg who were treated with cryoablation for arrhythmia was performed. Eleven centers contributed data for 68 procedures on 61 patients. Of those, 34% were elective and 24% (n = 16) were both cryoablation and radiofrequency ablation. The median age and weight at ablation was 3.5 years (range 8 days to 9.9 years) and 15.2 kg (range 2.3 to 23), respectively. Congenital heart disease was present in 23% of the patients. The immediate success rate of cryoablation alone was 74%. No major complications occurred with cryoablation only; however, 2 of the 16 patients who underwent cryoablation and radiofrequency ablation had major complications. Of the 50 patients receiving cryoablation, 8 (16%) had variable degrees of transient atrioventricular block. The recurrence rate was 20% after cryoablation and 30% after cryoablation plus radiofrequency ablation. In conclusion, cryoablation appears to have a high safety profile in these patients. Compared to older and larger patients, the efficacy of cryoablation in this small, young population was lower and the recurrence rates were higher. Cryoablation's effect on the coronary arteries has not been fully elucidated and requires additional research.

Reopening acutely occluded cavopulmonary connections in infants and children.

Little is known about the outcome of acute thrombotic occlusion of segments of the cavopulmonary connections (CPC) in infants and children with univentricular hearts. Early recognition and aggressive therapy may result in successful salvage of some of these patients. Five consecutive patients (age range 4-8 months) presenting with acute occlusion of a CPC segment underwent emergency cardiac catheterization. After angiographic confirmation, the occluded segment was crossed using an endhole catheter and guidewire combination. Serial balloon dilation and stent implantation (ten stents in total) were undertaken to recanalize the occlusion. The stents used were mounted on balloons ranging in diameter from 6 mm to 8 mm, depending on the size of the native vessel. The sites of occlusion were the left pulmonary artery (n=4), and the left-sided superior caval vein (n=3). All occlusions could be successfully recanalized. In three patients, early reocclusion necessitated either surgery or repeat catheterization and angioplasty. There were two early deaths, due to recurrent thrombotic obstruction confirmed either at autopsy or angiography. The remaining patients are alive and well; the majority of survivors have undergone completion of the Fontan operation. A high index of clinical suspicion combined with aggressive therapy can result in successful recanalization in some infants with acutely occluded CPC segments, with acceptable long-term outcome.