Early and late outcomes of surgical repair of double-chambered right ventricle: a single-centre experience.

OBJECTIVE: Double-chambered right ventricle is characterised by division of the outlet portion of the right ventricle by hypertrophy of the septoparietal trabeculations into two parts. We aim to report our experiences regarding the presenting symptoms of double-chambered right ventricle, long-term prognosis, including the recurrence rate and incidence of arrhythmias after surgery. METHODS: We retrospectively investigated 89 consecutive patients who were diagnosed to have double-chambered right ventricle and underwent a surgical intervention from 1995 to 2016. The data obtained by echocardiography, cardiac catheterisation, and surgical findings as well as post-operative follow-up, surgical approaches, post-operative morbidity, mortality, and cardiac events were evaluated. RESULTS: Median age at the time of diagnosis was 2 months and mean age at the time of operation was 5.3 years. Concomitant cardiac anomalies were as follows: perimembranous ventricular septal defect (78 patients), atrial septal defect (9 patients), discrete subaortic membrane (32 patients), right aortic arch (3 patients), aortic valve prolapse and/or mild aortic regurgitation (14 patients), and left superior caval vein (2 patients). The mean follow-up period was 4.86 ± 4.6 years. In these patients, mean systolic pressure gradient in the right ventricle by echocardiography before, immediately, and long-term after surgical intervention was 66.3, 11.8, and 10.4 mmHg, respectively. There were no deaths during the long-term follow-up period. Surgical reinterventions were performed for residual ventricular septal defect (2), residual pulmonary stenosis (1), and severe tricuspid insufficiency (1). CONCLUSION: The surgical outcomes and prognosis of double-chambered right ventricle are favourable, recurrence and fatal arrhythmias are unlikely in long-term follow-up.

Magnetic resonance tagging for diagnosis of focal hypertrophic cardiomyopathy in a child.

Magnetic resonance imaging has become an important diagnostic tool in the differential diagnosis of lesions for evaluation of cardiovascular disorders. In magnetic resonance tagging (MRt), tissue elements are magnetically labeled so that their positions can be tracked as a function of time. Thus, MRt evaluates heart wall motion both qualitatively and quantitatively. We present herein the case of a 12-year-old boy who had chest pain, dyspnea on effort and murmur. On cardiac computed tomography, there was focal thickening of the left ventricular posterior wall, similar to a mass. MRt indicated active displacement and deformation of the tags at the level of the hypertrophic myocardium during systole, as with normal myocardium. Thus, the tagged images supported the diagnosis of focal hypertrophic cardiomyopathy (HCM). In view of these results, MRt should be considered as a useful technique for differentiating between a mass-like focal lesion such as neoplasm and HCM.

Multiple giant aneurysms and stenoses of the coronary and systemic arteries in an infant with kawasaki disease at the early stage of convalescent period.

Myocardial infarction and systemic arterial aneurysms are rarely seen during the course of the Kawasaki disease (KD). Herein, we report the case of a 4-month-old Turkish infant who was diagnosed with KD on the 17th day of the illness. On admission, echocardiogram showed multiple coronary arterial aneurysms (CAAs) and massive pericardial effusion. He was given intravenous immunoglobulin, aspirin and anticoagulant drugs. However, the aneurysms progressed to "super giant" CAAs, multiple huge coronary arterial thromboses developed recurrently and caused myocardial ischemia. Furthermore, the conventional angiography revealed multiple giant aneurysms and stenoses in the subclavian, celiac, and iliac arteries, besides CAAs.

Oral budesonide as a therapy for protein-losing enteropathy in children after the Fontan operation.

BACKGROUND AND AIM: Protein-losing enteropathy is a rare complication of the Fontan palliation surgery. Budesonide is an effective treatment option for protein-losing enteropathy. We reviewed our retrospective experience in four patients who were treated with oral budesonide. METHODS: Four patients with refractory protein-losing enteropathy after the Fontan operation were started on oral budesonide 9 mg/daily. After achieving normal serum albumin the dose was tapered to 3 mg. Response to oral budesonide, side effects, and serum albumin levels before the treatment and at first, fourth, and ninth months of the budesonide course were recorded. Efficacy was measured based on serum albumin levels and clinical symptoms. RESULTS: Mean pretherapy albumin was 2.25 g/dL (range 1.7 to 2.5 g/dL) and nine months after therapy it was 4.15 g/dL (range 3.9 to 4.4 g/dL) (p < 0.05). All patients had at least a transient improvement in serum albumin levels and clinical findings. Systemic side effects included cushingoid features and oral moniliasis. All patients had improvement in side effects after tapering budesonide to 3 mg. The treatment was terminated in one case as soon as serum albumin level exceeded 3 g/dL. One death occurred from respiratory arrest six months after budesonide discontinuation. CONCLUSION: Budesonide can be used to treat protein-losing enteropathy in selected patients with cardiac diseases.

Transposition of the great arteries and cor triatriatum: a rare combination.

In this case report, we present a 5-month-old girl diagnosed with a unique combination of transposition of the great arteries and cor triatriatum sinistra. A 1-day-old female patient presented to our hospital with cyanosis since the early neonatal period. We confirmed transposition of the great arteries by echocardiography. The patient underwent arterial switch operation on day 8 and was discharged on day 35. After 5 months of the operation, the patient had a lower respiratory tract infection and was unable to gain weight. Echocardiography revealed mild neopulmonary regurgitation, minimal neoaortic regurgitation, and pulmonary arterial hypertension. In addition, a fibrous membrane was also seen dividing the left atrium. The patient was diagnosed with cor triatriatum and underwent successful resection of the membrane.

Use of oral budesonide in the management of protein-losing enteropathy due to restrictive cardiomyopathy.

A 7-year-old male patient who had abdominal swelling and eyelid oedema was diagnosed with restrictive cardiomyopathy. His serum albumin level was 2.3 g/dl. Protein-losing enteropathy due to restrictive cardiomyopathy was diagnosed and oral budesonide was started. His serum albumin level began to rise and ascites and peripheric oedema disappeared. The patient underwent a successful cardiac transplantation and budesonide was stopped. After the heart transplantation, the albumin level decreased to 2.3 g/dl, and therefore it was restarted. When the serum albumin level increased, the budesonide dose was tapered and stopped in 1 month. Budesonide may be an effective drug in patients with protein-losing enteropathy due to heart failure.

The Roberts syndrome: a case report of an infant with valvular aortic stenosis and mutation in ESCO2.

Roberts syndrome, which is inherited as an autosomal recessive group of disorders, is a rare syndrome characterized with symmetrical extremity defects, craniofacial abnormalities, and prenatal and postnatal growth retardation. Here, we present a case of Roberts Syndrome brought to the clinic with diarrhoea and multiple abnormalities, that had tetra phocomelia, growth and developmental retardation, abnormality of complete cleft lip-palate accompanied with Aortic stenosis and PDA, and in which cytogenetic analysis identified premature centromere separation. Mutation analysis of ESCO2 revealed a splice site mutation [c.1131+1G>A] in intron 6 in homozygous status in the patient and heterozygous status in the parents. Our case is the first Robert- Syndrome with valvular aortic stenosis in the literature, to the best of our knowledge.

Embolization of pulmonary sequestration with Onyx: an unusual application.

We report a baby with intralobar pulmonary sequestration who was successfully treated with a new embolization agent, Onyx. A 1.5-month-old female infant was admitted to our hospital with sweating and fatigue. Telecardiography showed cardiomegaly, dextrocardia, and increased pulmonary vascular markings. In thoracic computerized tomography, pulmonary sequestration, right pulmonary hypoplasia, and large collateral arteries were seen. The collateral arteries were originating from the celiac trunk and aorta. Echocardiography revealed enlargement of the left atrium and ventricle and left ventricle systolic dysfunction. Angiography revealed a large feeding artery and three branches originating from the aorta and another feeding artery originating from the celiac trunk. We performed embolization of the feeding arteries and their branches, with coils and Onyx. The procedure was performed without complications, and all feeding arteries were completely occluded. The infant started to gain weight. One year later, the infant's body weight had increased and she had no respiratory problems or signs of congestive heart failure. In this case report, we suggest that embolization with Onyx is a reliable alternative method to surgery for infants with pulmonary sequestration. With future studies, pulmonary sequestration embolization with Onyx may become an acceptable and easy treatment option in pediatric patients.

Congenital heart defects and postoperative follow-up of patients with Williams syndrome as a single center experience and review of the cases from Türkiye.

BACKGROUND: Cardiovascular system involvement is quite common and the leading cause of morbidity and mortality in patients with Williams syndrome (WS), most of whom need surgery. The present study aimed to provide a detailed evaluation of the features of surgical procedures and outcomes of patients with WS given as single-center experience, and additionally to make a detailed review from Türkiye. MATERIALS AND METHODS: Thirty-five children with WS diagnosed between the years 1992 and 2021 were evaluated retrospectively including cardiovascular data, surgical treatment features, and outcomes. A total of six articles from Türkiye were evaluated. RESULTS: A total of 35 patients with Williams Syndrome (24 male) with a median age of cardiologic diagnosis of 6 months (range, 2 days-6 years) were evaluated. The cardiac defects of the patients with WS were found as supravalvular aortic stenosis (SVAS) (n=30, 85%) and peripheral pulmonary stenosis (PPS) (n=21, 65%). Additional cardiac anomalies were seen in 71% patients. The rate of SVAS and PPS surgery in all patients with WS was 77.1%. The median surgical age of the patients was 2.5 years (range, 7 months-15.5 years). No patients died due to surgery. But one patient died because of ventricular tachycardia due to anesthesia at the beginning of angiography. A total of 138 (63% male) patients with WS were evaluated from the articles published in Türkiye. Of 138 patients, 64.4% had SVAS, 52.1% had PPS, and 39.8% had additional cardiac anomaly. The median follow-up period ranged from 17 months to 18 years, and six (4.3%) patients died in the early postoperative period. CONCLUSION: Cardiovascular system involvement is extremely common and is the leading cause of morbidity and mortality in patients with WS, often requiring surgical intervention. As seen in our study including 35 patients with WS and in publications from Türkiye, SVAS in patients with WS generally requires surgery, especially in the first year of life. PPS, on the other hand, requires surgery less frequently than SVAS, and pulmonary stenosis appears to decrease over time.

Pre- and postoperative levels of serum brain-derived neurotrophic factor in neonates with congenital heart defects.

BACKGROUND: The objectives of this study were to assess the preoperative and postoperative serum brain- derived neurotrophic factor (BDNF) levels in neonates undergoing surgery for congenital heart defects (CHD). Also to explore the relationship between changes in BDNF levels and the impact of perioperative factors including intraoperative body temperature, aortic cross-clamp time, perfusion time, operation time, inotropic score, vasoactive inotropic score and lactate levels. METHODS: Forty-four patients with CHD and 36 healthy neonates were included in the study. Blood samples for serum BDNF levels were collected three times: preoperatively, and at 24 and 72 hours postoperatively from each patient in the operated group. Additionally, samples were collected once from each individual in the non-operated case group and the control group. Serum BDNF levels were analyzed using the Elabscience ELISA (Enzyme-Linked Immunosorbent Assay) commercial kit. Cranial ultrasonography (USG) was performed on all infants with CHD. Following cardiac surgery, patients underwent second and third cranial USG examinations at 24 and 72 hours postoperatively, respectively. RESULTS: Forty-four consecutive patients with CHD were divided into two groups as follows: the operated group (n=30) and the non-operated group (n=14). Although there were no differences in the baseline serum BDNF levels between the case and control groups, the preoperative serum BDNF levels were significantly lower in the patients operated compared to the non-operated patients. The serum BDNF levels at the 24th hour postoperatively were higher than the preoperative levels. However, no significant correlation was found between the serum BDNF levels at 24 and 72 hours postoperatively as well as the cranial USG findings at corresponding times. CONCLUSIONS: Serum BDNF levels were initially lower in neonates with CHD who underwent surgery, but increased during the early postoperative period. These results suggest that serum BDNF levels are influenced by CHD and the postoperative period.

Evaluation of acute kidney injury after surgery for congenital heart disease in neonates: a tertiary hospital experience.

PURPOSE OF THE ARTICLE: Acute kidney injury (AKI) after cardiac surgery in children with congenital heart disease (CHD) is a serious complication closely associated with high morbidity and mortality. Despite numerous studies on AKI in children, most studies have excluded neonates. We sought to characterize AKI associated with cardiac surgery in neonates, determine its incidence, perioperative and postoperative risk factors, and short-term results. MATERIALS AND METHODS: This retrospective study included 177 neonates who were operated on for CHD in our hospital between January 2015 and December 2019. Data of the patients were analyzed according to nKDIGO (neonatal Kidney Disease Improving Global Outcomes) and nRIFLE (neonatal Risk, Injury, Failure, Loss of function, End-stage kidney disease) criteria for evaluating AKI retrospectively. Data of groups with and without AKI were analyzed. RESULTS: The average age of 177 neonates were 8.2 ± 6.1 (1-28) days. Twenty-two (12.4%) neonates had CS-AKI defined according to nKDIGO criteria. Four (2.3%) neonates reached nKDIGO stage I, 1 (0.6%) reached stage II, 17 (9.6%) reached stage III. Thirty-eight (21.5%) neonates had CS-AKI defined according to nRIFLE criteria. Twenty-four (13.6%) neonates reached nRIFLE stage risk(R), 6 (3.4%) reached stage injury(I), 8 (4.5%) reached stage failure (F). The incidence of cardiac surgery-associated acute kidney injury (CS-AKI) in neonates was 12.5% and 21.5% for nKDIGO and nRIFLE, respectively. The percentage difference between nKDIGO and nRIFLE for AKI assessment was due to the criteria for nRIFLE stage risk(R) urine output < 1.5 mL/kg/h for 24 h. In both classifications, the duration of cardiopulmonary bypass, operation, inotropic treatment, and mechanical ventilation, length of intensive care unit (ICU), and hospital stay were significantly higher in the AKI group than those without AKI group (p˂.05). The mortality rate in the groups with AKI was found to be significantly higher (p˂.05) than in the groups without AKI. In Kappa analysis, when two classifications were compared according to AKI stages, a significant agreement was found between nKDIGO and nRIFLE classifications (p˂.05) (Kappa: 0.299). CONCLUSION: AKI and mortality rates were similar between groups according to the nKDIGO and nRIFLE criteria. For early prediction of AKI and adverse outcomes, diagnostic reference intervals might be specified in more detail in neonates undergoing cardiac surgery for CHD.

Neurologic Complications After Pediatric Heart Transplant: A Single-Center Experience.

OBJECTIVES: Neurologic complications that can lead to serious mortality and morbidity in pediatric heart transplant recipients have been reported to range from 23.6% to 45%. In this study, the frequency, time, cause, and characteristics of neurologic complications in pediatric heart transplant recipients were evaluated. MATERIALS AND METHODS: We retrospectively reviewed data of 37 pediatric heart transplant recipients aged <18 years who were seen at our hospital between 2007 and 2017. Medical records were reviewed to identify neurologic complications. Clinical features were compared between pediatric heart transplant patients with and without neurologic complications. RESULTS: The rate of posttransplant neurologic complications in pediatric heart transplant was 27% (10/37). Median age of patients with neurologic complications was 12 years (range, 11-18 years). Median time for neurologic complications was 3 days (range, 2-46 days). Primary diagnoses of these 10 recipients were dilated cardiomyopathy (n = 7) and restrictive cardiomyopathy (n = 3). There were no significant differences between recipients with and without neurologic complications (P > .05).The etiologies of neurologic complications were posterior reversible encephalopathy syndrome in 3 patients (8.1%), stroke in 2 patients (5.4%), peripheral neuropathy in 2 patients (5.4%), hypertensive encephalopathy in 1 patient (2.7%), and drug encephalopathy in 1 patient (2.7%). CONCLUSIONS: Neurologic complications may lead to serious mortality and morbidity in pediatric heart transplant patients. Seizures, posterior reversible encephalopathy syndrome, stroke, peripheral neuropathy, transient ischemic attack, and cerebral infections are the most common neurologic complications, which are seen in the perioperative period in particular. Careful follow-up of pediatric heart transplant patients, with detection and early treatment of neurologic findings, will contribute to lower rates of sequelae. To our knowledge, this is the largest study to show a detailed experience of neurologic complications in pediatric heart transplant patients from a single center in Turkey.

Results of balloon and surgical valvuloplasty in congenital aortic valve stenosis: A 19-year, single-center, retrospective study.

BACKGROUND: This study aims to compare the success, complications, and long-term outcomes of aortic balloon valvuloplasty and surgical aortic valvuloplasty in pediatric patients with congenital aortic valve stenosis. METHODS: Between March 2000 and October 2019, a total of 267 procedures, including 238 balloon valvuloplasties and 29 surgical valvuloplasties, in 198 children (135 males, 63 females; mean age: 57.4±62.6 months; range, 0.03 to 219 months) were retrospectively analyzed. The hospital records, echocardiographic images, catheterization data, angiography images, and operative data were reviewed. RESULTS: Aortic regurgitation was mild in 73 patients before balloon valvuloplasty, and none of the patients had moderate-to-severe aortic regurgitation. Compared to surgical valvuloplasty, the rate of increase in the aortic regurgitation after balloon valvuloplasty was significantly higher (p=0.012). The patients who underwent balloon valvuloplasty did not need reintervention for a mean period of 46±45.6 months, whereas this period was significantly longer in those who underwent surgical valvuloplasty (mean 80.5±53.9 months) (p=0.018). The overall failure rate was 8%. Moderate-to-severe aortic regurgitation was the most important complication developing due to balloon valvuloplasty in the early period (13%). All surgical valvuloplasties were successful. The mean length of hospitalization after balloon valvuloplasty was significantly shorter than surgical valvuloplasty (p=0.026). During follow-up, a total of 168 patients continued their follow-up, and a reinterventional or surgical intervention was not needed in 78 patients (47%). CONCLUSION: Aortic balloon valvuloplasty can be repeated safely and helps to eliminate aortic valve stenosis without needing sternotomy. Surgical valvuloplasty can be successfully performed in patients in whom the expected benefit from aortic balloon valvuloplasty is not achieved.

Aortic balloon valvuloplasty and mid-term results in newborns: a single center experience.

BACKGROUND AND OBJECTIVES: Aortic balloon valvuloplasty (ABV) has become the first-line treatment for critical aortic valve stenosis in infants. We aimed to evaluate the short- and mid-term results of patients who underwent ABV during neonatal period, the factors affecting the success and complications of the procedure. METHODS: We retrospectively examined 65 patients who underwent ABV during the neonatal period between 1998 and 2017. All hospital records including cardiac catheterization reports, echocardiographic information, and angiographic views were reviewed. RESULTS: Forty five (69.2%) of the patients were male and mean follow-up was 6.2 ± 4.9 years (range: 6 months - 19 years). The mean age of the patients at the first ABV was 14.5 ± 10.6 days (range: 1-30 days) and body weight was 3.25 ± 0.6 kg (range: 1.5-4.8 kg). The peak systolic gradient measured during pre-valvuloplasty cardiac catheterization was 73.3 ± 22.7 mmHg (range: 30-142 mmHg), and it decreased to 29.2 ± 12.2 mmHg (range: 5-55 mm Hg) after the procedure. Valvuloplasty was successful in 59 (90.7%) patients. There was no more than mild aortic regurgitation in any patient before valvuloplasty. There was mild aortic regurgitation in 21 patients before the valvuloplasty. In the acute phase after valvuloplasty, 30 patients had mild, 15 had moderate and two had severe aortic regurgitation. There was a significant increase in the degree of aortic regurgitation related to valvuloplasty (p < 0.05). The most important complication of ABV was increased aortic regurgitation (26.2%). Another important complication was femoral artery occlusion; and was detected early after valvuloplasty (61.6%). There was no serious complication or death in the acute phase. CONCLUSIONS: In newborns with valvular aortic stenosis, balloon valvuloplasty has become the first choice in many centers due to its high success rate, low mortality and morbidity, and increased clinical experience. Aortic regurgitation and femoral artery occlusion were the most important complications. Although reintervention for residual or recurrent aortic valve stenosis is common during the first year after valvuloplasty, these patients are able to reach advanced ages without the need for surgical intervention. Surgical valvotomy is a good alternative treatment for a small number of patients in whom valvuloplasty fails.

Coronary artery fistulae and treatment in children.

BACKGROUND AND OBJECTIVES: In this study, we aimed to review the treatment options and long-term problems of patients who were diagnosed with coronary artery fistulae (CAF) in our institution. We also tried to determine the most appropriate time for treatment of this condition. METHOD: From 2000 to 2018, the medical records of 56 patients (33 males and 23 females) who had CAF diagnoses were retrospectively reviewed. RESULTS: The mean age of the patients at the time of diagnosis was 3.9 ± 4.6 years (range, 1 month to 18 years) and the mean duration of the follow-up period was 7.4 ± 4.5 years (range, 1 year to 17.5 years). The right coronary artery (RCA) was the most common origin site for CAF, the left main coronary artery (LMCA) was the second most common origin site whereas the left anterior descending coronary artery (LAD) was the third most common origin site. Catheter angiography showed that right ventricle (RV) was the site of termination for CAF in 23 patients (41.1%) while the CAF drained to the pulmonary artery in 16 patients (28.6%). Transcatheter intervention was performed in ten patients, while CAF were corrected surgically in five patients. Transcatheter intervention was initially attempted in two out of the five surgically-treated patients, but the procedure was unsuccessful. A vascular plug was deployed in six patients, a platinum coil was used in three patients, and a platinum coil with tissue adhesive was placed in one patient using a catheter. Early complications were seen in two patients during transcatheter intervention and in one patient during surgery. There were no instances of death or late complications in patients treated surgically or via transcatheter. CONCLUSIONS: Coronary artery fistulae are usually asymptomatic, and medical therapy with long term follow up is the first line treatment. Fistulae that cause hemodynamically significant shunting, chamber enlargement, or visible symptoms should be closed at an early age. This study shows that transcatheter closure is a safe treatment option for CAF that may be performed with high success. Also, it should be known that surgery may be performed effectively with low rates of complications. Because complications can develop in treated and untreated patients of all ages, follow-up should occur during the patient`s lifetime.

Management of pediatric cardiac transplantation candidates with pulmonary hypertension and high pulmonary vascular resistance.

BACKGROUND AND OBJECTIVES: Right ventricular failure is an important cause of mortality and morbidity after orthotopic heart transplantation (OHT). The right ventricle of the donor may fail to accommodate to the high pulmonary vascular resistance (PVR) of the recipient. Pulmonary hypertension (PH) due to chronic heart failure with PVRi > 4 Wood units.m2, transpulmonary gradient > 15 mmHg adversely affect the outcome of OHT. In this study we aimed to evaluate management strategies in our pediatric cardiac transplantation candidates with PH and high PVR prior to OHT. METHOD: Twenty-six cardiac transplantation candidates (age: 10.2 ± 4.6, 1-17 years) underwent cardiac catheterization for the determination of PVR and pulmonary arterial pressure. They were admitted to the hospital and received 1-3 days of intravenous (IV) vasodilator therapy; 0.5-3 µg/kg/min nitroglyserin and/or 0.5-3 µg/kg/min nitroprusside, 5-15 µg/kg/min dobutamin and/or dopamin to keep systolic blood pressure above 80 mmHg. RESULTS: Thirteen patients had dilated cardiomyopathy (CMP), 11 had restrictive CMP, one had hypertrophic CMP and one had congenital heart disease (CHD). Nineteen of the 26 patients underwent OHT. Mean pulmonary arterial pressure of the patients ranged between 11 and 82 mmHg (30.4 ± 16 mmHg) and PVRi between 0.41-21.4 Wood units.m2 (5.3 ± 5.7). Nine patients had PVRi above 4 Wood units.m < sup > 2 < /sup > . Six of these patients had IV treatment for longer than three days and some received specific anti-PH treatment. Eventually they underwent a pulmonary vasoreactivity test with IV iloprost and six had PVRi < 4 Wood units.m < sup > 2 < /sup > . Five of them underwent OHT. CONCLUSION: Cardiac transplantation candidates with PH and high PVR should be evaluated after conditioning with vasodilator and inotropic treatment. Specific treatment for PH and vasoreactivity testing may help selected patients reenter the transplantation list.

Transesophageal electrophysiologic study to determine the inducibility after successful ablation of supraventricular tachycardia in children.

BACKGROUND: Radiofrequency ablation has become first-line therapy for supraventricular tachycardia in all age groups, but there has been a concern regarding the long-term effectiveness of the procedure in children. This study aimed to determine the inducibility after successful ablation of supraventricular tachycardia in children; assessment was performed using a transesophageal electrophysiologic study. RESULTS: A total of 63 patients who had been treated successfully for supraventricular tachycardia with radiofrequency ablation were included in the study. A transesophageal electrophysiologic study was performed 2 months after radiofrequency ablation. Tachycardia was induced in nine of 34 symptomatic and five of 29 asymptomatic patients by a transesophageal electrophysiologic study. Ten patients had recurrence of the same type of supraventricular tachycardia seen previously, and two had a new type of arrhythmia during a transesophageal electrophysiologic study. Tachycardia inducibility rate was 16% in all patients, 22.8% in patients with atrioventricular reentrant tachycardia, and 8% in patients with atrioventricular nodal reentrant tachycardia. CONCLUSION: Radiofrequency ablation is a safe and effective method to manage children with supraventricular tachycardia, but patients must be observed for recurrence and new arrhythmias. Sustained tachycardia may also be induced in asymptomatic patients. A transesophageal electrophysiologic study is effective and safe for follow-up of radiofrequency ablation for assessment, diagnosis, and treatment of patients.

Clinical experiences of patients with catecholaminergic polymorphic ventricular tachycardia.

Catecholaminergic polymorphic ventricular tachycardia is a rare entity that can occur in children without cardiac disease and with a normal QT interval. It may cause syncope, convulsions, and sudden death during physical activity or emotional distress. We report the clinical features, treatment, and follow-up of 16 children with this diagnosis, emphasizing the potentially fatal nature of the disease.The mean age of patients at the onset of symptoms and at the time of diagnosis was 7.8 plus or minus 2.5 years, and 10.6 plus or minus 3.5 years, respectively. Syncope was the main complaint in 11, and 7 were treated as erroneously as having epilepsy. Diagnosis was confirmed by exercise and/or infusion of isoproterenol. Once the diagnosis was made, we started propranolol in all patients, and added verapamil if ventricular tachycardia was still inducible on a treadmill exercise test. An intracardiac defibrillator was implanted in 4 patients. Of the 16 patients, 4 died suddenly, giving a rate of mortality of 25%. In 2 of those dying suddenly, there was evidence of poor compliance to the recommended treatment. Another 2 patients had been resuscitated because of sudden cardiac arrest.Catecholaminergic polymorphic ventricular tachycardia must be considered in the differential diagnosis of syncope in children without heart disease but with a normal QT interval. Medical treatment with propranolol and verapamil may decrease the incidence of arrhythmia. Implantation of intracardiac defibrillators should be considered in those resistant to drug therapy. Delay in diagnosis, and inadequate treatment, can result in sudden cardiac death.

Clinical importance of transesophageal electrophysiologic study in the management of supraventricular tachycardia in children.

Transesophageal electrophysiologic study (TEEPS) is a semi-invasive method widely used for evaluation of symptoms related to arrhythmia. In this study, we aimed to determine the accuracy of TEEPS in the diagnosis and differentiation of mechanisms of supraventricular tachycardias (SVTs) by comparing results of transesophageal and intracardiac electrophysiologic studies. We performed TEEPS and a subsequent radiofrequency ablation (RFA) procedure in 76 patients. Indications of TEEPS were risk assessment for Wolff-Parkinson-White syndrome in 32 patients and diagnosis and differentiation of tachycardia mechanisms in 44 patients. The procedure was well tolerated in all patients. Positive predictive value of TEEPS in our study was 91% for differentiation of SVT mechanisms. The results suggest that TEEPS is safe, useful and effective in the evaluation of symptoms related to arrhythmia, in differentiation of mechanisms of SVTs, and finally in defining the treatment options of SVT. The technique also provides an opportunity for risk assessment and deciding the treatment modality in Wolff-Parkinson-White patients.