Síndrome de hipoplasia de corazón izquierdo: experiencia de 10 años de un programa de etapificación quirúrgica / Hypoplastic left heart syndrome: 10 year experience with staged surgical management

Resumen El síndrome de hipoplasia de corazón izquierdo (SHCI) es una cardiopatía congénita con letalidad superior al 95%. La etapificación quirúrgica es la principal vía de tratamiento, y se inicia con la operación de Norwood; la sobrevida a largo plazo de los pacientes tratados es desconocida en nuestro medio. Objetivos 1) Revisar nuestra experiencia en el manejo de todos los pacientes con SHCI evaluados entre enero 2000 y junio 2010. 2) Identificar factores de riesgo de mortalidad quirúrgica. Pacientes y método Estudio retrospectivo de una única institución con una cohorte de pacientes con SHCI. Se revisan antecedentes clínicos, quirúrgicos, y registros de seguimiento. Resultados Se evaluaron 76 pacientes con SHCI; 9/76 tenían comunicación interauricular (CIA) restrictiva, y 8/76, aorta ascendente de < 2 mm; 65/76 fueron tratados: 77% tuvieron operación de Norwood con conducto entre ventrículo derecho y ramas pulmonares como fuente de flujo pulmonar, 17% Norwood con shunt de Blalock-Taussig, y 6% otra cirugía. La mortalidad en la primera etapa quirúrgica fue del 23%, y en operación de Norwood, del 21,3%. En el período 2000-2005 la mortalidad en la primera etapa quirúrgica fue del 36%, y entre 2005-2010, del 15% (p = 0,05). La sobrevida global fue del 64% a un año y del 57% a 5 años. Por análisis multivariado fueron factores de riesgo para mortalidad la presencia de aorta ascendente diminuta y CIA restrictiva. Conclusiones Nuestros resultados inmediatos y a largo plazo en la etapificación quirúrgica de SHCI son similares a la experiencia de grandes centros. Hay una mejoría en mortalidad operatoria en la segunda mitad de la serie. Se identifican factores de riesgo de mortalidad.

Abstract Hypoplastic left heart syndrome (HLHS) is a lethal congenital heart disease in 95% of non-treated patients. Surgical staging is the main form of treatment, consisting of a 3-stage approach, beginning with the Norwood operation. Long term survival of treated patients is unknown in our country. Objectives 1) To review our experience in the management of all patients seen with HLHS between January 2000 and June 2012. 2) Identify risk factors for mortality. Patients and method Retrospective analysis of a single institution experience with a cohort of patients with HLHS. Clinical, surgical, and follow-up records were reviewed. Results Of the 76 patients with HLHS, 9 had a restrictive atrial septal defect (ASD), and 8 had an ascending aorta ≤ 2 mm. Of the 65 out of 76 patients that were treated, 77% had a Norwood operation with pulmonary blood flow supplied by a right ventricle to pulmonary artery conduit, 17% had a Norwood with a Blalock-Taussig shunt, and 6% other surgical procedure. Surgical mortality at the first stage was 23%, and for Norwood operation 21.3%. For the period between 2000-2005, surgical mortality at the first stage was 36%, and between 2005-2010, 15% (P = .05). Actuarial survival was 64% at one year, and 57% at 5 years. Using a multivariate analysis, a restrictive ASD and a diminutive aorta were high risk factors for mortality. Conclusions Our immediate and long term outcome for staged surgical management of HLHS is similar to that reported by large centres. There is an improvement in surgical mortality in the second half of our experience. Risk factors for mortality are also identified.

[Hypoplastic left heart syndrome: 10 year experience with staged surgical management]. / Síndrome de hipoplasia de corazón izquierdo: experiencia de 10 años de un programa de etapificación quirúrgica.

UNLABELLED: Hypoplastic left heart syndrome (HLHS) is a lethal congenital heart disease in 95% of non-treated patients. Surgical staging is the main form of treatment, consisting of a 3-stage approach, beginning with the Norwood operation. Long term survival of treated patients is unknown in our country. OBJECTIVES: 1) To review our experience in the management of all patients seen with HLHS between January 2000 and June 2012. 2) Identify risk factors for mortality. PATIENTS AND METHOD: Retrospective analysis of a single institution experience with a cohort of patients with HLHS. Clinical, surgical, and follow-up records were reviewed. RESULTS: Of the 76 patients with HLHS, 9 had a restrictive atrial septal defect (ASD), and 8 had an ascending aorta ≤2mm. Of the 65 out of 76 patients that were treated, 77% had a Norwood operation with pulmonary blood flow supplied by a right ventricle to pulmonary artery conduit, 17% had a Norwood with a Blalock-Taussig shunt, and 6% other surgical procedure. Surgical mortality at the first stage was 23%, and for Norwood operation 21.3%. For the period between 2000-2005, surgical mortality at the first stage was 36%, and between 2005-2010, 15% (P=.05). Actuarial survival was 64% at one year, and 57% at 5years. Using a multivariate analysis, a restrictive ASD and a diminutive aorta were high risk factors for mortality. CONCLUSIONS: Our immediate and long term outcome for staged surgical management of HLHS is similar to that reported by large centres. There is an improvement in surgical mortality in the second half of our experience. Risk factors for mortality are also identified.

Use of the amplatzer vascular plug II device to occlude different types of patent ductus arteriosus in pediatric patients.

INTRODUCTION: Transcatheter patent ductus arteriosus (PDA) closure is difficult in small patients in part due to the diverse PDA morphology. We describe a multicenter pediatric experience using the Amplatzer Vascular Plug II device (AVP II) to occlude PDA. METHODS: All patients undergoing transcatheter closure of PDA with AVP II from April 2008 until May 2012 were included. Clinical, angiographic, and echocardiographic data were collected. RESULTS: One hundred and seventy-seven procedures were performed. Median age was 14 months (2-180) with median weight 9.7 kg (4.7-68). The morphological PDA classification was Type A in 66 (37.1%), Type C in 27 (15.3%), Type D in 17 (9.6%), and Type E in 67 (37.9%). The median minimum PDA diameter was 2.6 mm (1.2-7.7 mm). The implanted device sizes were: 4 mm in 17 patients (9.6%), 6 mm in 81 (45.8%), 8 mm in 56 (31.6%), 10 mm in 18 (10.2%), and 12 mm in 5 (2.8%). The implanted device was mean of 2.6 + 0.7 times the ductus narrowest diameter and mean of 1 + 0.5 times the ductus largest diameter. Complications included: one severe left pulmonary artery stenosis and one device embolization. No aortic obstruction occurred. Closure was complete in the 175 remaining patients. CONCLUSIONS: The AVP II is an effective and safe device for PDA closure. It is particularly useful when dealing with nontypical PDA shapes and in small infants where it eliminated the risk of device-related aortic obstruction. The AVPII is an addition to the PDA device closure armamentarium in pediatric patients.

Atenolol versus propranolol for the treatment of infantile hemangiomas: a randomized controlled study.

BACKGROUND: Infantile hemangiomas have a dramatic response to propranolol, a nonselective beta-blocker. However, this treatment is not risk-free and many patients are excluded because of respiratory comorbidities. Atenolol is a cardioselective beta-blocker that may have fewer adverse events. OBJECTIVE: We sought to evaluate the effectiveness of atenolol against propranolol in a noninferiority trial. METHODS: In all, 23 patients met the inclusion criteria and were randomized to receive either atenolol or propranolol. Thirteen patients were treated with atenolol and 10 with propranolol. Follow-up was made at baseline, 2 weeks, 4 weeks, and then monthly for 6 months. RESULTS: Patients treated with atenolol had a complete response of 53.8% and 60% with propranolol, respectively. These results were nonsignificant (P = .68). Relevant adverse events were not reported. LIMITATIONS: The reduced number of patients could have influenced our results. CONCLUSION: Atenolol appears to be as effective as propranolol. We did not find significant differences between these results or any adverse events.

Tratamiento endovascular de la coartación aórtica nativa y recurrente en pacientes mayores de 4 años: resultados y complicaciones / Endovascular repair of native and recurrent aortic coarctation in patients older than 4 years of age

Objetivos: Reportar nuestra experiencia en el tratamiento endovascular de la Coartación Aórtica (CoAo). Métodos: Se revisaron los registros clínicos de los pacientes mayores de 4 años intervenidos por una CoAo nativa o recoartación en el Hospital Clínico de la Universidad Católica entre los años 2007 y 2012. Se realizaron estadísticas descriptivas y se utilizó el test de Wilcoxon signed rank, con una p <0,05. Resultados: En ese período se realizaron 27 intervenciones en pacientes con CoAo. El promedio de edad fue 20.6 años (5 - 64); 8 (30 por ciento) eran mujeres y 8 (30 por ciento) menores de 14 años. Quince pacientes (55 por ciento) tenían una cardiopatía congénita asociada, de los cuales 9 (33 por ciento) tenían válvula aórtica bicúspide, 3 (11 por ciento) una comunicación interventricular (CIV) y 3 coexistencia de ambas entidades (11 por ciento). Nueve (33 por ciento) pacientes eran hipertensos. En 20 (74 por ciento) pacientes la intervención fue sobre una coartación aórtica nativa y en 7 (26 por ciento) sobre una recoartación (2 con cirugía previa y 5 con angioplas-tia anterior). Se implantó un stent en 23 (85 por ciento) pacientes y se utilizó sólo balón en 4 (15 por ciento). En 26 pacientes (96 por ciento) se logró una reducción del gradiente a menos de 20 mmHg (gradiente pre 32 vs gradiente post 6 mmHg, p<0,01). Hubo complicaciones del sitio de punción en 3 pacientes (2 hematomas y 1 disección focal en el origen de la arteria ilíaca externa) y complicaciones mayores en 2 pacientes (disección aórtica tipo B) que requirieron tratamiento intervencional (uno percutáneo y uno quirúrgico). No hubo mortalidad en nuestra serie. Conclusiones: La intervención endovascular es una opción de tratamiento efectiva para la CoAo.

Aim: There is an increasing interest in the endovascular therapy of both native and recurrent aortic coarcta-tion (Aco). In this article we report the results of endo-vascular treatment of ACo in children and adults at our institution, from 2007 to 2012. Method and Results: The clinical, angiographic and hemodynamic data of all patients submitted to endovascular repair of ACo at the Endovascular Therapy Center of the Catholic University Hospital were reviewed. Children under 4 years of age were excluded. A total of 27 subjects were included. Mean age was 20.6 years (range 5-64); 30 per cent were females and 30 per cent were under 14 years of age. 15 patients had associated congenital defects: bicuspid aortic valve ( 9), VSD (3), or both VSD and bicuspid aortic valve (3). Hypertension was present in 33 per cent of patients. 74 per cent had endovas-cular repair of a native Aco and 26 per cent of a re-coarctation (2 of them post surgical treatment and 5 post endovas-cular repair). 85 per cent of cases had stent implantation. Repair resulted in a significant (p<0.01) decrease in aortic pressure gradient (mean 32 vs 6 mmHg). There was no mortality associated to the procedure. Two patients developed aortic dissection post procedure, successfully treated by surgery or endovascular repair. There were no instances of stent migration. Conclusion: Endovascular repair is an effective means of correcting Aco. Potential complications need careful technique and monitoring during the procedure.

Resultados inmediatos y alejados del switch arterial en pacientes condextrotransposición de grandes arterias: experiencia de 20 años / Early and late results of the switch operation for d-transposition of the great vessels. clinical experience in 108 patients operated on between 1992 and 2012

Objetivos: Comunicar los resultados de la operación de switch arterial en pacientes portadores de dextro Transposición de Grandes Arterias (D-TGA) y evaluar su evolución en el tiempo. Pacientes y Método: Estudio retrospectivo de pacientes sometidos a switch arterial entre mayo de 1992 y noviembre de 2012. Se comparó período 1 (1992 a 2002) con período 2 (2003 a 2012). Se definió D-TGA simple aquella sin lesiones asociadas y D-TGA compleja aquella con asociación de comunicación interventricular o coartación aórtica. Resultados: Un total de 108 pacientes componen la serie, 44 en el período 1 y 64 en el período 2, sin diferencias demográficas y anatómicas entre ambos períodos. Setenta tenían D-TGA simple y 38 D-TGA compleja. La mortalidad operatoria en el período 1 fue 33% versus 8,4 por ciento en el período 2 (p< 0.025); hubo tendencia a mayor mortalidad en pacientes con anatomía coronaria compleja. Se observó una disminución del riesgo relativo de mortalidad de 68,7 por ciento en el período 2. El 28,7 por ciento presentaron complicaciones postoperatorias, sin diferencias entre ambos períodos. Un paciente falleció en forma alejada. La mediana de seguimiento fue de 60 meses y la supervivencia de 84,25 por ciento a 10 y 20 años. Se realizaron 16 re intervenciones, principalmente plastías percutáneas de ramas pulmonares. La mayoría de los pacientes se mantenían asintomáticos. La mortalidad operatoria de los últimos 5 años fue 2,6 por ciento. Conclusiones: La mortalidad operatoria ha disminuido significativamente a lo largo de 20 años; persiste un mayor riesgo en ciertos patrones de anatomía coronaria. La supervivencia alejada y libre de reintervenciones es muy favorable.

Aim: to report the results of the arterial Switch operation in patients with D-transposition of the great vessels (D-TGA) and to evaluate their late course. Patients and Methods: A retrospective review of the clinical data on patients consecutively operated on for D-TGA using the switch procedure. Results obtained in patients operated on between 1992 and 2002 (Period 1) were compared to those obtained in patients undergoing their operation between 2013 and 2012. Patients with D-TGA and no complications were compared to those who had interventricular septal defect or aortic coarctation associated their TGA. Results: 44 patients belonged in Period 1 and 64 in Period 2 (total 108). Demographic and anatomical characteristics were similar in both periods. Simple D-TGA was present in 70 patients and complex D-TGA in 38. Operative mortality was higher in Period 1 compared to Period 2 (33 per cent vs. 8.4 percent, p<0.025). A higher, albeit not statiscally significant mortality was observed in patients with complex as opposed to simple D-TGA. A 68.7 per cent relative reduction mortality risk was observed in Period 2. Complications developed in 28.7 per cent of patients, with no difference between periods. Only 1 patient died during late follow up. Median follow up was 60 months and survival rate was 84.3 percent at 10 y 20 years. Sixteen patients required re-intervention, mainly to perform percutaneous plastic procedures on pulmonary artery branches. Most patients had an asymptomatic course during follow up. Surgical mortality for the last 5 years was 2.6 percent. Conclusion: surgical mortality for the arterial switch operation in patients with D-TGA has significantly decreased along a 20 year period. An increased surgical risk persists for patients with certain forms of coronary artery anomalies. Late survival free of re-intervention was the rule in these patients.

Cardiovascular magnetic resonance findings in a pediatric population with isolated left ventricular non-compaction.

BACKGROUND: Isolated left ventricular non-compaction (LVNC) is an uncommon disorder characterized by the presence of increased trabeculations and deep intertrabecular recesses. In adults, it has been found that ejection fraction (EF) decreases significantly as non-compaction severity increases. In children however, there are a few data describing the relation between anatomical characteristics of LVNC and ventricular function. We aimed to find correlations between morphological features and ventricular performance in children and young adolescents with LVNC using cardiovascular magnetic resonance (CMR). METHODS: 15 children with LVNC (10 males, mean age 9.7 y.o., range 0.6-17 y.o.), underwent a CMR scan. Different morphological measures such as the compacted myocardial mass (CMM), non-compaction (NC) to the compaction (C) distance ratio, compacted myocardial area (CMA) and non-compacted myocardial area (NCMA), distribution of NC, and the assessment of ventricular wall motion abnormalities were performed to investigate correlations with ventricular performance. EF was considered normal over 53%. RESULTS: The distribution of non-compaction in children was similar to published adult data with a predilection for apical, mid-inferior and mid-lateral segments. Five patients had systolic dysfunction with decreased EF. The number of affected segments was the strongest predictor of systolic dysfunction, all five patients had greater than 9 affected segments. Basal segments were less commonly affected but they were affected only in these five severe cases. CONCLUSION: The segmental pattern of involvement of non-compaction in children is similar to that seen in adults. Systolic dysfunction in children is closely related to the number of affected segments.

[Validation of quality of life questionnaire ConQol for Chilean children with congenital heart diseases]. / Validación del cuestionario de calidad de vida ConQol, en niños chilenos portadores de cardiopatías congénitas.

BACKGROUND: ConQoL questionnaire assesses health related quality of life among children with congenital heart diseases. It has a version for children aged 8 to 11 years and another for children aged 12 to 16 years. AIM: To validate ConQol questionnaire for Chilean children with a congenital heart disease. MATERIAL AND METHODS: Using a multicentric cross sectional design, 334 children from four hospitals (54% males), were surveyed. Among them 45% were aged 8 to 11 years and 55%, 12 to 16 years. The study involved three stages: cross cultural adjustment of the original questionnaire, pre-test study, and estimation of its psychometric properties. Content, construct and criterion validity and internal consistency with Cronbach's alpha, were assessed. RESULTS: The version for children aged 8 to 11 years and comprised by three domains (symptoms, activity and relationships), obtained and α ≥ 0.60. In the questionnaire for children aged 12 to 16 years, there is one more domain called coping, which obtained an α of 0.53, that was different to the other three domains that obtained an α > 0.70. The correlation between Health Quality of Life and Perception of Health Quality of Life was statistically significant for both groups. The association between Health Quality of Life and health capability was only significant among children aged 12 to 16 years (p < 0.01). CONCLUSIONS: The adapted ConQol questionnaire matched properly with the original one. The adapted questionnaire is valid and reliable to assess Health Quality of Life among Chilean children with congenital heart diseases.

[Screening for cardiovascular diseases among teenagers that will engage in sport activities]. / Rol de la evaluación preparticipativa en adolescentes, en el diagnóstico de enfermedades cardiovasculares y prevención de muerte súbita.

Promotion of physical activity must be a priority in all modern societies, but there are some persons with medical conditions that can develop serious symptoms associated with sports, that can even be fatal, such as sudden death (SD). Adolescents are the age groups with the higher level of participation in recreation or competitive sports. International studies have demonstrated that approximately 1:250.000 adolescents die during the practice of sports. Of these, 50% had a prodrome 24 hours before the event and 75% had an underlying cardiovascular disease. Therefore, adolescents should be screened for cardiovascular diseases prior to their engagement in sports. This review gives a scientific approach to this issue, usually oversized by mass media. It also analyzes and reports international governmental strategies and practical tools for the clinician that must perform this type of screening.

Cierre percutáneo de orejuela izquierda para prevención de fenómenos embólicos en fibrilación auricular: experiencia preliminar / Percutaneous closure of left atrial appendage with the amplatzer cardiac plug device in patients with atrial fibrillation: preliminary data

Introducción: Dentro de las complicaciones más importantes de la fibrilación auricular (FA) se encuentra el accidente vascular encefálico embólico (AVE), siendo la terapia anticoagulante oral (TACO) la principal herramienta para su prevención. Cerca de un 20 por ciento de los pacientes con FA presentan condiciones clínicas que impiden su uso. Como la orejuela izquierda (01) ha sido identificada como el principal sitio de formación de trombos en la FA no valvular, se ha postulado que su oclusión podría disminuir la incidencia de eventos embólicos en este tipo de pacientes. Con este objetivo se han desarrollado múltiples técnicas, tanto quirúrgicas como dispositivos percutáneos para el cierre de esta estructura. En esta publicación se presenta la experiencia del cierre percutáneo de la 01 en tres pacientes, con el uso del dispositivo Amplatzer Cardiac Plug (ACP). Métodos: Los tres pacientes tenían alto riesgo embólico y contraindicación para uso de TACO. El procedimiento se realizó en el laboratorio de hemodinamia, bajo guía radioscópica y ecocardiográfica, con anestesia general. Resultados: Se logró la oclusión completa de la 01 en todos los pacientes, realizando además el cierre de un foramen oval permeable (FOP) en uno de ellos. Uno de los pacientes presentó derrame pericárdico el cual requirió pericardiocentesis. Los pacientes no presentaron otras complicaciones. Luego de un seguimiento de 6 meses no se han evidenciado eventos embólicos en ninguno de ellos. Conclusión: En esta experiencia preliminar, hemos comprobado la factibilidad de la oclusión de la 01 con el uso del dispositivo Amplatzer Cardiac Plug, en pacientes con FA con alto riesgo embólico y malos candidatos a TACO.

Embolic Stroke is a major concern in patients with atrial fibrillation. Anticoagulant therapy is the preferred tool to prevent this complication, but some patients have contraindications to anticoagulation. Most of the thrombus originates at the left atrial appendage (LAA), so the closure of LAA could prevent embolization of thrombus. Three patients with high embolic risk and contraindication to anticoagulant therapy were treated at our institution with an occlude device of the LAA (Amplatzer Cardiac Plug). Implantation of the device was successful in all the patients; one had a hem pericardium and underwent pericardiocentesis without further consequences. Patients were discharged without anticoagulants. After 6 months of follow-up, no embolic complications have been reported. In this preliminary experience, we report the feasibility of the closure of LAA with the Amplatzer Cardiac Plug Device.

[New surgical approach to device closure of multiple apical ventricular septal defects]. / Cierre perventricular de la comunicación interventricular múltiple con dispositivo Amplatzer.

We present an alternative technique for closing multiple ventricular septal defects difficult to access during surgery. A guidewire is advanced through the right ventricular free wall and through the main apical defect to the left ventricle, and this approach is used to place an Amplatzer device to occlude the ventricular septal defects. The procedure is performed in the beating heart, under intraoperative transesophageal echocardiographic guidance, and without extracorporeal circulation. It appears to be a simple and reproducible procedure with excellent short-term results.

Cierre perventricular de la comunicación interventricular múltiple con dispositivo Amplatzer / New Surgical Approach to Device Closure of Multiple Apical Ventricular Septal Defects

Se presenta una técnica alternativa para el cierre de la comunicación interventricular de difícil acceso quirúrgico. Con el corazón latiendo y sin necesidad de circulación extracorpórea, se punciona el ventrículo derecho y se avanza una guía de alambre hasta el ventrículo izquierdo a través del defecto apical principal; esto permite colocar un dispositivo Amplatzer que ocluye completamente los defectos. El procedimiento se realiza con visión ecocardiográfica transesofágica, es simple y con excelentes resultados a corto plazo (AU)

We present an alternative technique for closing multiple ventricular septal defects difficult to access during surgery. A guidewire is advanced through the right ventricular free wall and through the main apical defect to the left ventricle, and this approach is used to place an Amplatzer device to occlude the ventricular septal defects. The procedure is performed in the beating heart, under intraoperative transesophageal echocardiographic guidance, and without extracorporeal circulation. It appears to be a simple and reproducible procedure with excellent short-term results (AU)

[Immediate results of palliative surgery for different forms of univentricular heart using the Norwood procedure]. / Cirugía paliativa mediante operación de Norwood en distintas formas de corazón univentricular: resultados quirúrgicos inmediatos.

BACKGROUND: Norwood procedure is used as the first stage in the palliative treatment of the hypoplastic heart syndrome and can be used, with some technical modifications, in other forms of univentricular heart with aortic stenosis or hypoplasia. These patients have a high mortality (50%), derived from the procedure itself and from their abnormal physiological status. AIM: To report our experience with the Norwood procedure. PATIENTS AND METHODS: Retrospective analysis of all patients subjected to the Norwood procedure between February, 2000 and June 2003. RESULTS: Thirteen patients (9 females, age range 5-60 days and median weight of 3.3 kg) were operated. Eight had hypoplastic heart syndrome and five had a single ventricle with aortic arch hypoplasia. The diagnosis was done in utero in eight patients. All technical variations, according to the disposition and anatomy of the great vessels, are described. Cardiac arrest with profound hypothermia was used in all and regional cerebral perfusion was used in nine. Three patients died in the perioperative period and three died in the follow up (two, four and 10 months after the procedure). Gleen and Fontan procedures were completed in five and one patients, respectively. CONCLUSIONS: Our results with the Norwood procedure are similar to other series. There is an important mortality in the immediate operative period and prior to the Glenn procedure.

[Effects of tilt test and beta-adrenergic stimulation on the QT interval in normal children and pediatric patients with unexplained syncope]. / Efectos de la prueba de la mesa basculante y de la estimulación betaadrenérgica sobre el intervalo QT en niños sanos y en pacientes pediátricos con síncope de etiología no precisada.

In normal children, any procedure that increases heart rate, such as the tilt test, may shorten the QT interval. The effect of the tilt test on QT interval in children with syncope remains unknown. We analyzed the response of RR and QT intervals during a tilt test in 3 groups of children: 28 healthy children (group 1), 26 with syncope of unknown etiology and negative tilt test results (group 2), and 17 with vasovagal syncope (group 3). During the tilt test, RR and QT intervals were significantly shortened in groups 1 and 2. In group 3, RR interval was lengthened during syncope whereas the QT interval remained constant. QT interval lengthening during the tilt test is not a characteristic finding in normal children or in children with vasovagal syncope.

Efectos de la prueba de la mesa basculante y de la estimulación betaadrenérgica sobre el intervalo QT en niños sanos y en pacientes pediátricos con síncope de etiología no precisada / Effects of tilt test and beta-adrenergic stimulation on the QT interval in normal children and pediatric patients with unexplained syncope

En niños normales, las maniobras que aumentan la frecuencia cardíaca acortan el intervalo QT. La prueba de la mesa basculante aumenta la frecuencia cardíaca y debería acortar el intervalo QT en niños sanos. Se desconoce el efecto de esta prueba en niños con síncope. Se analizó el comportamiento de los intervalos RR y QT durante la prueba de la mesa basculante con isoproterenol en 3 grupos de niños: 28 sanos (grupo 1), 26 con síncope de etiología no precisada y prueba de la mesa basculante negativa (grupo 2) y 17 con síncope vasovagal (grupo 3).Durante la prueba, los intervalos RR y QT se acortaron significativamente en los grupos 1 y 2. En el grupo 3, el intervalo RR se prolongó en el momento del síncope y el intervalo QT se mantuvo constante. La prolongación del intervalo QT durante la prueba de la mesa basculante no es una característica de niños normales ni con síncope vasovagal (AU)

[Fontan procedure: early and mid-term results with total cavopulmonary anastomosis]. / Operación de Fontan: resultados inmediatos y a mediano plazo con anastomosis cavopulmonar total.

BACKGROUND: During the last five years, 65 patients with univentricular heart have been treated surgically in our institution, according to a protocol of staged operations that have been previously reported. AIM: To evaluate the early and mid-term outcome of those patients that have completed their staging protocol by means of a Fontan procedure. PATIENTS AND METHODS: Between April 1996 and June 2001, 23 patients (age 16 to 223 months) underwent a Fontan procedure, 15 with an intracardiac lateral tunnel technique and 8 with an extracardiac conduit. A retrospective review of their clinical, surgical, echocardiographic, angiographic and hemodynamic data was performed, trying to identify risk factors for both mortality and functional capacity (FC). Follow up was complete in all survivors. RESULTS: Three patients died early after surgery (13.04%). Excessive pulmonary blood flow was a risk factor for early death (p = 0.03). One patient died at 14 months. Follow up was 29.9 months (1-63). For those who survived the operation, five years survival was 93.3%. The majority of patients are in FC I or II, with no related risk factors. CONCLUSIONS: Our current results are comparable with those of larger series. Patients reach good FC and mid-term survival, irrespective of type of single ventricle or the surgical strategy.

Ecocardiografía fetal I: fundamentos / Fetal echocardiography I: fundamentals

Se plantean los fundamentos de la ecocardiografía fetal; explicando la identificación detallada del corazón fetal y la visualización por ecografía de los grandes vasos. Se destaca la importancia del diagnóstico prenatal de las malformaciones cardíacas congénitas fetales