Cerebral oximetry monitoring in the management of severe hypoxaemia associated with transposition of the great arteries with balloon atrial septostomy. / Monitorización de la oximetría cerebral en el manejo de la hipoxemia severa asociada a la transposición de grandes arterias mediante atrioseptostomía con balón.

Transposition of the great arteries (D-TGA) is one of the most common congenital heart diseases requiring neonatal surgical intervention. In the desperately ill neonate with TGA and the resultant hypoxaemia, acidemia, and congestive heart failure, improvement is often obtained with balloon atrial septostomy (BAS). Current methods employed to evaluate oxygen delivery and tissue consumption are frequently nonspecific. Near infrared spectroscopy (NIRS) allows a continuous non-invasive measurement of tissue oxygenation which reflects perfusion status in real time. Because little is known about the direct effect of BAS on the neonatal brain and on cerebral oxygenation, we measured the effectiveness of BAS in two patients with D-TGA using NIRS before and after BAS. We concluded BAS improves cerebral oxygen saturation in neonates with D-TGA.

[Congenital stenosis of pulmonary veins: long-term efficacy after intraluminal dilatation]. / Estenosis congénita de venas pulmonares: eficacia a largo plazo tras dilatación intraluminal.

We present a 7-month-old infant diagnosed with congenital pulmonary vein stenosis. Cardiac catheterization showed two sequential stenoses of the superior left pulmonary vein and balloon angioplasty was performed. The gradient decreased from 20 to 4 mmHg and pulmonary artery pressure from 75/35 mmHg to 44/28 mmHg. The diameter of the stenoses increased from 2 and 3.5 mm, respectively, to 6 mm. Fourteen years after the procedure the patient is asymptomatic with normal cardiac examination.

[Recurrent syncope due to late paroxysmal atrioventricular block after Senning repair]. / Síncope recurrente por bloqueo auriculoventricular paroxístico tardío tras operación de Senning.

A 14-year old male with d-transposition of the large arteries and Senning repair should have presented four syncopal episodes with spontaneous recovery the year prior to admission is reported. Following conventional diagnostic procedures, including electrophysiologic study, no abnormalities were detected. Therefore, an insertable Holter was implanted, and two months later the patient presented a syncopal episode secondary to 15 second paroxysmal atrioventricular block. A dual chamber pacemaker was implantated and nine months later the patient remains syncope-free.

[Reversibility of myocardiopathy induced by incessant supraventricular tachycardia in children after radiofrequency ablation]. / Reversibilidad de la miocardiopatía inducida por taquicardia supraventricular incesante en niños tras ablación con radiofrecuencia.

BACKGROUND: The so called tachycardia-induced cardiomyopathy may develop as a complication of persistent abnormal high rates. It is especially common in patients who have either a permanent form of junctional reciprocating tachycardia or an ectopic atrial tachycardia. Radiofrequency catheter ablation has become established as an effective and safe treatment to eliminate both arrhythmias. METHODS AND RESULTS: Four children aged from 3 months to 8 years, who had incessant tachyarrhythmias and left ventricular dysfunction (shortening fraction of mean +/- SD, 21.7 +/- 1.2%) underwent radiofrequency catheter ablation. The youngest patient had permanent junctional reciprocating tachycardia caused by a left posteroseptal pathway. She was presented with severe heart failure that did not improve with digoxin and amiodarone. The other patients had palpitations and exercise intolerance. Two of them had an ectopic atrial tachycardia caused by a single atrial focus localized in the left atrial appendage apex and the orifice of the right atrial appendage respectively. The other patient had the permanent form of junctional reciprocating tachycardia caused by a right posteroseptal pathway. All four patients underwent one successful ablation. The average procedure mean time was 3.7 hours with an fluoroscopy time of 44 minutes. There were no complications. Subsequently shortening fraction improved progressively. After a mean follow-up of 21.7 months all patients are asymptomatic without medical treatment. CONCLUSIONS: Radiofrequency catheter ablation is the therapy of choice in children with either the permanent form of junctional reciprocating tachycardia or ectopic atrial tachycardia refractory to medical treatment. The tachycardia-induced cardiomyopathy is reversible after the elimination of the arrhythmia. The presence of tachycardia-induced cardiomyopathy is an indication for radiofrequency ablation even in small infants.

[The radiofrequency catheter ablation of intranodal reentry tachycardia in children and adolescents]. / Ablación con catéter mediante radiofrecuencia de la taquicardia por reentrada intranodal en niños y adolescentes.

INTRODUCTION: Radiofrequency catheter ablation of slow pathway is the primary nonpharmacological treatment for the atrioventricular node reentrant tachycardia at present. OBJECTIVES: To evaluate the results and long term follow-up of the catheter and radiofrequency modification of the AV node in the treatment of the atrioventricular node reentrant tachycardia in children and adolescents in our center. METHODS AND RESULTS: In a series of fifteen patients, 7 men and 8 women, with a mean age of 8.7 +/- 5.5 years (range, from 4 to 18) with atrioventricular node reentrant tachycardia underwent radiofrequency catheter ablation. Six patients had been treated previously with 1.4 +/- 1.1 antiarrhythmic drugs and nine had not received treatment. In all patients slow-pathway atrioventricular node ablation guided by an anatomic stepwise approach was attempted. In 14 out of 15 patients slow pathway was successfully ablated; and in one patient with a previously failed slow-pathway ablation, a fast-pathway ablation was performed. Tachycardia recurred in one patient, and slow pathway was ablated in a second procedure. After successful slow pathway ablation in 14 patients, the shortest cycle length in which the AV conduction was maintained at 1:1, was increased from 271.3 +/- 22.6 to 316.7 +/- 30.1 ms (p < 0.001), while the AH and HV intervals and shortest cycle length of 1:1 VA conduction remained unchanged. In the patient who had fast pathway ablation the AH interval was increased from 65 to 130 ms, and retrograde VA conduction was lost. Noninducibility of the tachycardia was achieved in all patients without significant complications. During a mean follow-up of 18.8 +/- 11.4 months (median of 16), all patients are symptom-free without medication. CONCLUSIONS: Radiofrequency catheter ablation is a successful and safe therapeutic alternative in the treatment of atrioventricular node reentrant tachycardia in children and adolescents.

[Catheter ablation of accessory pathways in infants and children weighing less than 10 kg]. / Ablación con catéter de vías accesorias en lactantes y niños de peso inferior a 10 kg.

INTRODUCTION: Low weight is considered an independent risk factor for the appearance of complications in radiofrequency catheter ablation of accessory pathways in children. OBJECTIVES: The purpose of this study was to evaluate the results and long term follow-up of radiofrequency catheter ablation in eight infants and small children of accessory pathways of less than 10 kg in weight. METHODS AND RESULTS: There were 3 boys and 5 girls with a mean age of 6.3 +/- 5 months (range, 2.5 to 17) and an average weight of 6.2 +/- 1.9 kg (range, 3.5 to 9). The eight patients underwent a single successful ablation procedure. Five left free wall pathways were ablated by transseptal approach, two right posteroseptal pathways were ablated from the inferior vena cava and a left posteroseptal was approached from the inferior vena cava into the coronary sinus. A deflectable 5F bipolar electrode catheter with a 3 mm tip was used in the first five patients and a deflectable 5F tetrapolar catheter with a 4 mm tip and temperature monitoring using closed loop control in the 3 remaining patients. An abrupt increment in impedance due to the development of a coagulum was observed in 2 procedures. One patient developed an acute ischemic complication during ablation of a left lateral accessory pathway by transseptal approach. This patient had mild pericardial effusion after the procedure. Moderate pericardial effusion was also noted in another patient after radiofrequency ablation that resolved itself spontaneously. In the remainder of the procedures there were not complications. After a mean follow-up of 32.3 +/- 22.1 months (median 42) all patients are asymptomatic without antiarrhythmic treatment. CONCLUSIONS: a) radiofrequency catheter ablation can be performed successfully in infants and small children weighing less than 10 kg, and b) echocardiography must be performed inmediately after the procedure in infants to investigate pericardial effusion.

[Infectious mitral endocarditis after radiofrequency catheter ablation of a left lateral accessory pathway]. / Endocarditis infecciosa mitral tras ablación con catéter y radiofrecuencia de una vía accesoria lateral izquierda.

A 2-years-old child with Wolff-Parkinson-White syndrome associated with life-threatening symptoms underwent radiofrequency ablation of a left lateral accessory pathway. A deflectable 5F bipolar electrode catheter positioned above the atrioventricular groove by transeptal approach was used for ablation. The catheters were repeatedly used after ethylene oxide sterilisation. Although immediate post-ablation echocardiography demonstrated no complications, the patient was readmitted two days later with fever and a new mitral murmur. Penicillin-susceptible Staphylococcus aureus was isolated and intravenous antibiotics were administered. In the following weeks, the patient developed constrictive pericarditis requiring surgical treatment and acute hemiplegia caused by brain embolism arising from valvular vegetation. At 5 years of follow-up the patient presents residual hemiparesia and grade II/IV mitral insufficiency.

[Double-balloon angioplasty of pulmonary venous drainage obstruction after the Senning procedure in transposition of the great vessels]. / Angioplastia con doble balón de la obstrucción al drenaje venoso pulmonar tras la cirugía de Senning en la transposición de las grandes arterias.

A six and half-year old boy with Senning operation for transposition of the great arteries, showed recurrent atrial flutter and obstruction of the pulmonary venous atrium from the early postoperative period. By Doppler examination a peak gradient of 13 mmHg at the isthmus level was recorded in the pulmonary venous atrium. A successful double-balloon dilatation of stenotic area was performed via a retrograde, transaortic, approach through angioplasty. Six months after the procedure the enlargement of the stenosis persists, and the patient is clinically asymptomatic and arrhythmia-free without medication.

[Radiofrequency catheter ablation in permanent atrioventricular junctional reciprocating tachycardia in children]. / Ablación con catéter mediante radiofrecuencia en la taquicardia incesante recíproca de la unión auriculoventricular en niños.

BACKGROUND: The permanent form of junctional reciprocating tachycardia occurs predominantly in childhood and is frequently refractory to pharmacologic treatment. These patients are at high risk for developing tachycardia-induced cardiomyopathy. Radiofrequency transcatheter ablation appears promising as safe and effective therapy in children. PATIENTS, METHODS AND RESULTS: Six patients ranged in age from 3 months to 20 years who had the permanent form of junctional reciprocating tachycardia underwent radiofrequency catheter ablation. Five patients had been treated with 3.4 +/- 1.1 antiarrhythmic drugs and one patient did not receive treatment before ablation. Three accessory pathways were located in the right posteroseptal area, two in the left posteroseptal area and one in the left posterior free wall. The six patients had seven successful procedures performed including one after tachycardia recurrence in one patient six weeks after the first ablation session. Five ablation procedures were performed with temperature-guided catheter ablation. The temperature reached during successful radiofrequency applications was 55-60 degrees C at a power output from 24 to 47 W. In the other two procedures 25 W were given. No complications were observed. After a mean follow up of 11.6 months all patients are asymptomatic including a 3 months old patient with tachycardia-induced cardiomyopathy. CONCLUSIONS: Radiofrequency transcatheter ablation is an important option of therapy in children with the permanent form of junctional reciprocating tachycardia, including patients with tachycardia-induced cardiomyopathy.

[Aortic balloon valvuloplasty in critical aortic stenosis in the newborn and infants]. / Valvuloplastia aórtica con catéter-balón en la estenosis aórtica crítica del neonato y lactante pequeño.

INTRODUCTION: Balloon valvuloplasty in neonates and small infants with critical aortic stenosis is a palliative procedure. The present report describes the results of the technique in our center. METHODS: From April 1993 to March 1995, six consecutive patients with critical aortic valve stenosis underwent catheter-balloon valvuloplasty. Their ages ranged from 2 to 120 days old (45.5 +/- 47.5 days). Four patients had associated lesions: 2 had coarctation of the aorta, 1 had ischemic dilated cardiomyopathy and 1 had endocardial fibroelastosis. Percutaneous femoral artery access was used in four cases and axillary artery dissection in two. RESULTS: The balloon-annulus diameter ratio was 0.92 +/- 0.12. The peak systolic ejection gradient decreased from 66.1 +/- 26.4 to 38 +/- 15.7 mmHg (p < 0.05) and the left ventricle systolic pressure decreased from 136.3 +/- 26.8 to 115 +/- 22.5 mmHg (p < 0.05). There were no mortalities related to the procedure. Both patients who had aortic coarctation developed aortic regurgitation and died after repairing of the coarctation. The patient with endocardial fibroelastosis died during an attempt to perform the Norwood operation (Stage I) and the other patient with ischemic dilated cardiomyopathy survived after cardiac transplantation. The remaining two patients with isolated aortic valve stenosis are currently asymptomatic. CONCLUSIONS: Catheter-balloon valvuloplasty is an effective procedure in the initial treatment of critical aortic stenosis and may be life saving.

[Incessant ventricular tachycardia and myocardial hamartomas in childhood: long-term remission after surgical treatment]. / Taquicardia ventricular incesante y hamartomas miocárdicos en la infancia: remisión a largo plazo tras resección quirúrgica.

Incessant ventricular tachycardia in children 2 years old or younger is usually caused by a well-localized myocardial lesion that has been termed myocardial hamartoma. Its major clinical manifestation is a rapid and potentially fatal tachyarrhythmia that does not respond to antiarrhythmic drugs. We report a patient who underwent successful surgical excision of the hamartoma and we describe the clinical features, pathologic findings and longterm follow-up.

[Congenital ectopic junctional tachycardia: long-term remission after cryoablation of the bundle of His]. / Taquicardia ectópica congénita de la unión auriculoventricular: remisión a largo plazo tras crioablación del haz de His.

Congenital junctional ectopic tachycardia is an uncommon and potentially fatal arrhythmia that does not usually respond to medical therapy. We report a two month old infant with severe ventricular failure. The diagnosis was confirmed by electrophysiologic study. She underwent endocardial cryoablation of the His bundle during extracorporeal circulation and a ventricle epicardial-lead pacemaker was implanted. Eight years later the patient is still symptom-free without needing medical treatment.

[Coronary ischemia during radiofrequency ablation of left lateral accessory pathway in an infant]. / Isquemia coronaria durante la ablación mediante radiofrecuencia de una vía accesoria lateral izquierda en un lactante.

Acute coronary ischaemic complications are uncommon following catheter ablation of accessory pathways. Only isolated cases have been previously reported in adult patients during ablation of left free-wall accessory pathways by retrograde or anterograde approach. We report a transient ischaemic complication after catheter ablation of a left free wall accessory pathway by transseptal approach in an infant.

[Radiofrequency ablation of idiopathic left ventricular tachycardia in children]. / Ablación con radiofrecuencia de la taquicardia ventricular izquierda idiopática en niños.

INTRODUCTION: Nowadays radiofrequency catheter ablation is an alternative to medical treatment in adult patients with idiopathic left ventricular tachycardia. AIM: To asses indications, results and long term follow-up of using this technique in children. : Radiofrequency catheter ablation was performed in five consecutive patients without structural heart disease, mean age 8.6+/-7.1 years (range, 1.3 to 17) and suffering from resistance to medical treatment left ventricular tachycardia (2.4+/-0.9 antiarrhythmic drugs per patient). Palpitations and syncope were the clinical manifestations in four patients while congestive heart failure in the other one. Six types of tachycardia were identified in the five-patient group. All of them responded to intravenous verapamil. There were 3 incessant tachycardias and the other three were paroxysmal ones. The ablation site was selected using activation mapping during tachycardia and pace-mapping. The Tachycardia cycle length was 275+/-123 ms and showed right bundle branch block with superior axis (left in 4 and right in 2 cases). The ablation target was located in the mid-septal region of the left ventricle in 3 cases, in the apical and inferior septal region in 2 other cases and in the anterior free wall in the other one. Local activation times preceded in 33+/-13 ms at QRS beginning and with a 12/12 agreement pattern in 5 cases and 9/12 in 1, in whom ablation was unsuccessful. At follow-up, the 4 patients with effective ablation have been tachycardia-free for 35.8+/-17 months. CONCLUSIONS: Radiofrequency catheter ablation is a useful method of treatment in children with idiopathic left ventricular tachycardia, including those under two years old.

[Percutaneous valvotomy in critical neonatal pulmonary stenosis. Results and mid-term follow up]. / Valvulotomía percutánea de la estenosis pulmonar crítica neonatal. Resultados y seguimiento a medio plazo.

INTRODUCTION: Catheter-balloon valvotomy has been proposed as an alternative to surgical valvotomy in the critical pulmonary stenosis in newborns. OBJECTIVES: The present report describes the results, complications and follow-up of this technique at our center. METHODS AND RESULTS: From May 1993 to June 1998, fourteen consecutive patients with critical pulmonary stenosis underwent balloon valvotomy. Their mean ages were 8.7 +/- 5.8 days. Each of them was cyanotic and ten of the fourteen were on prostaglandin E1 therapy and three of them required endotracheal intubation and ventilation. The diameters of balloons were 9.6 +/- 2.1 mm (range, 5 to 12 mm) and the balloon/annulus diameter ratio was 1.3 +/- 0.2 (range, 0.8 to 1.5). By means of this technique, right ventricle systolic pressure decreased from 95.2 +/- 22.4 mmHg to 51 +/- 23.2 mmHg (p < 0.001) and the right ventricle/aortic pressure ratio decreased from 1.5 +/- 0.4 to 0.8 +/- 0.3 (p < 0.001). Surgical valvotomy was performed in two patients (cases 1 and 8) at 5-months and 3 days, respectively, from the balloon valvotomy. One patient (case 4) required a blalock-taussig shunt. Complications included cardiac tamponade in one patient. One patient died seven days after successful valvotomy by extracardiac complications. All eleven patients are currently symptom free 26.6 +/- 17.1 months later (range, 5 to 56) and Doppler residual gradient ranges from 0 to 29 mmHg (11.1 +/- 10.4 mmHg). CONCLUSIONS: Balloon pulmonary valvotomy is an effective and relatively safe technique for treatment of critical pulmonary stenosis in newborns with low index complication and mid-term relief of valvular obstruction.

[Catheter ablation of accessory pathways in patients with congenital cardiopathies]. / Ablación con catéter de vías accesorias en pacientes con cardiopatías congénitas.

The catheter ablation procedure in patients with accessory pathways and congenital heart defects can potentially become complicated because of abnormal anatomy and atypical conduction system. Eight patients ranging in age from 4.5 months to 18 years with accessory pathways and congenital heart defects underwent radiofrequency ablation. The cardiac diseases were diagnosed as Ebstein anomaly (n = 3), cardiac rhabdomyomas (n = 1), double outlet right ventricle (n = 1), endocardial cushion defect, partial form (n = 1), repaired Fallot's tetralogy (n = 1) and interventricular septal defect (n = 1). Six patients had manifest Wolff-Parkinson-White syndrome and 2 had concealed pathways. One patient with Ebstein anomaly had multiple accessory pathways. Radiofrequency ablation was initially successful in eight of the nine accessory pathways (89%). Two procedures were performed in one patient for pathway recurrence. Procedure was unsuccessful in 1 patient with Ebstein anomaly who later had surgical interruption of the accessory pathway. After a mean follow-up of 30.9 +/- 16.4 months, six of the 7 patients in which pathways were successfully ablated are tachycardia-free. One patient had late recurrence of tachycardia and is well controlled by propafenone.

[Implantation of stents in Blalock-Taussig shunt in an adult patient with pulmonary atresia and interventricular septal defect]. / Implantación de stents en la fístula de Blalock-Taussig en un adulto con atresia pulmonar y comunicación interventricular.

We present the case of a 26 years-old woman with pulmonary atresia and interventricular septal defect. Classical Blalock-Taussig and Waterston-Cooley shunts were performed in infancy. When she was 14 years old related progressive cyanosis and dyspnea and angiography showed severe stenosis of the Blalock-Taussig. Cardiac catheterization performed 12 years later demonstrated complete obstruction of the shunt. A new surgical palliation was precluded by hemorrhagic complications. Two self-expandable stents were successfully deployed in Blalock-Taussig anastomosis: previously, a balloon-expandable stent was implanted in right pulmonary artery. Oxygen saturation increased from 68% to 89% after stents implantation. Twelve months later clinical and laboratory tests are still improved, and Doppler confirmed patency of the shunt.

[Surgical treatment of Fallot's tetralogy with hyperplasia or agenesis of the conal septum]. / Tratamiento quirúrgico de la tetralogía de Fallot con hipoplasia o agenesia del septo conal.

INTRODUCTION: The clinical evolution, anatomosurgical aspects, and postoperative evolution of a specific group of Fallot's tetralogy with hipoplasic or agenesic of the conal septum (representing a 7% of our Fallot's tetralogy cases) is presented. METHODS: A total of 41 patients surgically corrected in our Service between February 1973 and December 1995 has been retrospectively studied. Ages ranged between 13 months and 13 year. Clinically all cases developed moderate or severe hypoxemia. In 43.9% of cases it was necessary to perform a palliative surgery at an age between 15 days and 4 years. RESULTS: There was no hypoxemics spells. In the ECG we have found a QS in the aVR in 40% of cases. There was 7 deaths (17% of mortality rate). Four cases required reoperation. The clinical evolution, ECG, EKO, and hemodynamics findings are commented. CONCLUSIONS: In this type of Fallot's tetralogy, specifically in those cases with a pulmonary artery ring of normal size, it is necessary to have a good preoperative diagnoses in order to perform a longitudinal ventriculotomy with right ventricular outflow tract enlargement. Also, it is important to be meticulous with the stitches in the closure of the ventricular septal defect with a patch in order to avoid the potential lesion of the aortic valve.

[Thyroid function alterations in children with congenital cardiac disease after catheterization with iodinated contrast agents]. / Alteraciones de la función tiroidea en niños con cardiopatía congénita tras la realización de cateterismo con contrastes yodados.

INTRODUCTION AND OBJECTIVES: Iodinated contrast agents can block thyroid hormone synthesis. The aims of this study were: 1st) to study the incidence of thyroid function disturbances in children with congenital heart disease after cardiac catheterization, 2nd) to analyze the predisposing factors that may lead to the development of hypothyroidism after angiography, and 3rd) to determine the duration of these hypothyroidism states. PATIENTS AND METHODS: From february 1993 to April 1997 thyrotropine (TSH) and free thyroxine (FT4) serum values were analyzed before cardiac catheterization and in the two following weeks, in 99 children under three years of age, with congenital cardiac disease. Those patients who showed any postangiography increase in TSH were further evaluated by weekly measures of serum thyroid hormones and TSH until normal values were obtained or until the initiation of hormonal replacement therapy. The patients' data (age, previous exposure to contrast agents, cardiac disease, associated extracardiac malformations, renal failure, severity of illness, treatment) and the catheterism data (the dose and type of contrast and the fluoroscopy time) were included in the univariant analysis. RESULTS: 10 mUI/ml), that persisted beyond three weeks in six cases. The occurrence of multiple malformation syndromes was the most clearly associated risk factor (p < 0,01) not only in the development of postangiography hypothyroidism but also in longer hormonal dysfunction. CONCLUSIONS: Thyroid function should be tested in every patient with multiple malformation syndrome that undergo angiocardiography with iodinated contrast agents.