Prenatal diagnosis, associated findings and postnatal outcome of fetuses with truncus arteriosus communis (TAC).

PURPOSE: To assess the spectrum of associated anomalies, the intrauterine course, postnatal outcome and management of fetuses with truncus arteriosus communis (TAC) METHODS: All cases of TAC diagnosed prenatally over a period of 8 years were retrospectively collected in two tertiary referral centers. All additional prenatal findings were assessed and correlated with the outcome. The accuracy of prenatal diagnosis was assessed. RESULTS: 39 cases of TAC were diagnosed prenatally. Mean gestational age at first diagnosis was 22 weeks (range, 13-38). Two cases were lost follow-up. Correct prenatal diagnosis of TAC was made in 21 of 24 (87.5%) cases and of TAC subtype in 19 of 21 (90.5%) cases. Prenatal diagnosis of TAC was incorrect in three cases: one newborn had aortic atresia with ventricular septal defect postnatally, one had hypoplastic right ventricle with dextro Transposition of the Great Arteries with coartation of the aorta and a third newborn had Tetralogy of Fallot with abnormal origin of the left pulmonary artery arising from the ascending aorta postnatally. These three cases were excluded from further analysis. In 9 of 34 (26.5%) cases, TAC was an isolated finding. 13 (38.2%) fetuses had additional chromosomal anomalies. Among them, microdeletion 22q11.2 was most common with a prevalence of 17.6% in our cohort. Another 3 fetuses were highly suspicious for non-chromosomal genetic syndromes due to their additional extra-cardiac anomalies, but molecular diagnosis could not be provided. Major cardiac and extra-cardiac anomalies occurred in 3 (8.8%) and in 20 (58.8%) cases, respectively. Predominantly, extra-cardiac anomalies occurred in association with chromosomal anomalies. Additionally, severe IUGR occurred in 6 (17.6%) cases. There were 14 terminations of pregnancy (41.2%), 1 (2.9%) intrauterine fetal death, 5 postnatal deaths (14.7%) and 14 (41.2%) infants were alive at last follow-up. Intention-to-treat survival rate was 70%. Mean follow-up among survivors was 42 months (range, 6-104). Postoperative health status among survivors was excellent in 11 (78.6%) infants, but 5 (46.2%) of them needed repeated re-interventions due to recurrent pulmonary artery or conduit stenosis. The other 3 (21.4%) survivors were significantly impaired due to non-cardiac problems. CONCLUSION: TAC is a rare and complex cardiac anomaly that can be diagnosed prenatally with high precision. TAC is frequently associated with chromosomal and extra-cardiac anomalies, leading to a high intrauterine and postnatal loss rate due to terminations and perioperative mortality. Without severe extra-cardiac anomalies, postoperative short- and medium-term health status is excellent, independent of the subtype of TAC, but the prevalence of repeated interventions due to recurrent stenosis is high.

Prenatal diagnosis, associated findings and postnatal outcome of fetuses with truncus arteriosus communis (TAC).

PURPOSE: To assess the spectrum of associated anomalies, the intrauterine course, postnatal outcome and management of fetuses with truncus arteriosus communis (TAC) METHODS: All cases of TAC diagnosed prenatally over a period of 8 years were retrospectively collected in two tertiary referral centers. All additional prenatal findings were assessed and correlated with the outcome. The accuracy of prenatal diagnosis was assessed. RESULTS: Thirty nine cases of TAC were diagnosed prenatally. Mean gestational age at first diagnosis was 22 weeks (range 13-38). Two cases were lost follow-up. Correct prenatal diagnosis of TAC was made in 87.5% and of TAC subtype in 90.5%. Prenatal diagnosis was incorrect in three cases: one newborn had aortic atresia with ventricular septal defect (VSD) postnatally, one had hypo-plastic right ventricle with dextro transposition of the great arteries (d-TGA) with coarctation of the aorta and a third newborn had tetralogy of fallot (TOF) with abnormal origin of the left pulmonary artery arising from the ascending aorta postnatally. These 3 cases were excluded from further analysis. In 26.5% of cases, TAC was an isolated finding. 38.2% of fetuses had additional chromosomal anomalies. Among them, microdeletion 22q11.2 was most common with a prevalence of 17.6% in our cohort. Another 3 fetuses were highly suspicious for non-chromosomal genetic syndromes due to their additional extra-cardiac anomalies, but molecular diagnosis could not be provided. Major cardiac and extra-cardiac anomalies occurred in between 8.8% and 58.8%, respectively. Predominantly, extra-cardiac anomalies occurred in association with chromosomal anomalies. Additionally, severe IUGR occurred in 17.6%. There were 14 terminations of pregnancy (41.2%), 1 (2.9%) intrauterine fetal death, 5 postnatal deaths (14.7%) and 14 (41.2%) infants were alive at last follow-up. Intention-to-treat survival rate was 70%. Mean follow-up among survivors was 42 months (range 6-104). Postoperative health status among survivors was excellent in 78.6%, but 46.2% needed repeated re-interventions due to recurrent pulmonary artery or conduit stenosis. The other 21.4% of survivors were significantly impaired due to non-cardiac problems. CONCLUSION: Truncus arteriosus communis is a rare and complex cardiac anomaly that can be diagnosed prenatally with high precision. TAC is frequently associated with chromosomal and extra-cardiac anomalies, leading to a high intrauterine and postnatal loss rate due to terminations and perioperative mortality. Without severe extra-cardiac anomalies, postoperative health status is excellent, independent of the subtype of TAC, but the prevalence of repeated interventions due to recurrent stenosis is high.

Exercise during pregnancy and its impact on mothers and offspring in humans and mice.

Exercise during pregnancy has beneficial effects on maternal and offspring's health in humans and mice. The underlying mechanisms remain unclear. This comparative study aimed to determine the long-term effects of an exercise program on metabolism, weight gain, body composition and changes in hormones [insulin, leptin, brain-derived neurotrophic factor (BDNF)]. Pregnant women (n=34) and mouse dams (n=44) were subjected to an exercise program compared with matched controls (period I). Follow-up in the offspring was performed over 6 months in humans, corresponding to postnatal day (P) 21 in mice (period II). Half of the mouse offspring was challenged with a high-fat diet (HFD) for 6 weeks between P70 and P112 (period III). In period I, exercise during pregnancy led to 6% lower fat content, 40% lower leptin levels and an increase of 50% BDNF levels in humans compared with controls, which was not observed in mice. After period II in humans and mice, offspring body weight did not differ from that of the controls. Further differences were observed in period III. Offspring of exercising mouse dams had significantly lower fat mass and leptin levels compared with controls. In addition, at P112, BDNF levels in offspring were significantly higher from exercising mothers while this effect was completely blunted by HFD feeding. In this study, we found comparable effects on maternal and offspring's weight gain in humans and mice but different effects in insulin, leptin and BDNF. The long-term potential protective effects of exercise on biomarkers should be examined in human studies.

[Hypothermia-induced ECG changes: characteristic, but not specific]. / Hypothermieinduzierte EKG-Veränderungen: charakteristisch, aber nicht spezifisch.

Hypothermia-induced J­ or so-called Osborn waves can be detected under therapeutic hypothermia in approximately 20-40% of cases. The occurrence of J­waves in the context of the targeted temperature management after cardiopulmonary resuscitation is characteristic, but not pathognomonic for hypothermia. An electrocardiographic diagnosis under hypothermia after cardiac arrest should always be done with caution due to the various hypothermia-associated electromechanical changes of the myocardium.

Prenatal diagnosis of absent pulmonary valve syndrome from first trimester onwards: novel insights into pathophysiology, associated conditions and outcome.

OBJECTIVE: To assess the spectrum of associated anomalies, intrauterine course and outcome in fetuses with absent pulmonary valve syndrome (APVS). METHODS: All cases with a prenatal diagnosis of APVS at two centers over a period of 13 years were analyzed retrospectively. APVS was diagnosed in the presence of rudimentary or dysplastic pulmonary valve leaflets with to-and-fro blood flow in the pulmonary trunk on color and pulsed-wave Doppler ultrasound. Data on demographic characteristics, presence of associated conditions, Doppler studies and pregnancy outcome were reviewed. RESULTS: During the study period, 40 cases of APVS were diagnosed prenatally. Thirty-seven (92.5%) cases were associated with tetralogy of Fallot (TOF) and three (7.5%) had an intact ventricular septum. Patency of the ductus arteriosus (DA) was found in 17/37 (45.9%) TOF cases and in all three cases with an intact ventricular septum. Mean gestational age at diagnosis was 19.7 (range, 12-34) weeks with 10 (25.0%) cases (all with TOF) diagnosed in the first trimester. TOF was an isolated finding in 15 (37.5%) cases. Chromosomal anomalies, cardiac defects and extracardiac anomalies were present in 18 (45.0%), four (10.0%) and three (7.5%) cases, respectively. Among the 40 cases, there were 19 (47.5%) terminations of pregnancy, six (15.0%) intrauterine deaths, four (10.0%) neonatal deaths and 11 (27.5%) survivors. Patency of the DA, reversed flow during atrial contraction in the ductus venosus, umbilical artery or fetal middle cerebral artery, and hydrops/increased nuchal translucency thickness were significantly associated with non-survival. All 10 cases diagnosed in the first trimester had a patent DA and abnormal Doppler parameters, eight had hydrops and/or increased nuchal translucency, six were associated with trisomy 13 or 18 and none survived. CONCLUSION: APVS diagnosed in the first trimester is significantly associated with TOF, patency of the DA, abnormal Doppler parameters, lethal trisomies and intrauterine mortality. Cases of APVS with isolated TOF and agenesis of the DA have a better outcome than those with additional anomalies, with > 80% survival. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

[Pulmonary hypertension in grown-ups with congenital heart disease: Recommendations of the Cologne Consensus Conference 2016]. / Pulmonale Hypertonie bei Erwachsenen mit angeborenen Herzfehlern: Empfehlungen der Kölner Konsensus-Konferenz 2016.

The 2015 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension are also valid for Germany. The guidelines contain detailed recommendations for different forms of PH, and specifically address PH associated with congenital heart disease (CHD). However, the practical implementation of the European Guidelines in Germany requires the consideration of several country-specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to PH in grown-ups with congenital heart disease (GUCH). This article summarizes the results and recommendations of this working group.

[Cryoenergy for the ablation of arrhythmogenic paraseptal substrates in children and adolescents with heart rhythm disorders]. / Kryoenergie zur Ablation arrhythmogener paraseptaler Substrate bei Herzrhythmusstörungen im Kindes- und Jugendalter.

BACKGROUND AND OBJECTIVE: Cryoablation is safe for the ablation of substrates in proximity to the AV node, because the initial lesion is reversible. We report our results of cryoablation in a transregional center for ablation in children and adolescents. PATIENTS AND METHODS: Data on 39 children and adolescents (4 - 18 years of age) who had been treated with cryo energy were analyzed retrospectively. The diagnosis was AV nodal reentry tachycardia (AVNRT; n = 30), para-Hisian accessory pathway (AP; n = 6) and congenital junctional ectopic tachycardia (JET; n = 4). In addition to non-inducibility, the targeted endpoint for AP-ablation was a missing or decremental concentric retrograde conduction, for ablation of AVNRT the endpoint was no slow pathway, no AH jumps and no echo-beats. The median follow-up was 3 years (270 - 1919 days). RESULTS: The targeted endpoint was reached in 35/39 patients (90 %), in four patients (10 %) RF energy had to be applied. A recurrence occurred in 7/35 (20 %) successfully treated patients. Two patients had a pre-excitation again after AP ablation, but no symptoms. Thus, 28/35 patients (80 %) remained asymptomatic after cryoablation, and 26/35 (74 %) are definitively cured, regarding all follow-up data. The subgroup of AVNRT patients does not differ from the entire group. There was no AV block in the cryoablation group. CONCLUSIONS: Cryoablation is very safe and effective for the definitive treatment of arrhythmias in children and adolescents. The price for the high safety is a reduced efficacy and a higher recurrence rate.

Regulation of anion transport across the uterine epithelium of Gallus domesticus.

For egg shell production, cations, primarily Ca(2+), and anions, primarily HCO(3)(-), must be secreted across the uterine epithelium. Because alterations of HCO(3)(-) transport influence Ca(2+) secretion, the present study was performed to gain insight into the regulation of anion transport (i.e., chloride and HCO(3)(-) transport) across the egg shell gland of the domestic chicken. To this purpose, unstripped uterus epithelia were mounted in modified Ussing chambers and electrogenic [i.e., short circuit current (I(sc))] and electroneutral anion transport were measured. Stimulating adenylate cyclases by forskolin, thereby enhancing the intracellular cyclic adenosine monophosphate( )(cAMP) concentration, evoked 2 patterns of I(sc) responses. Under HCO(3)(-)-buffered conditions, some of the tissues (3/8) showed an increase of I(sc), whereas in others (5/8) a decrease of I(sc) was observed in the presence of the drug. The I(sc) increase existed in HCO(3)(-) secretion because under HCO(3)(-)-free conditions forskolin stimulated only an I(sc) decrease. In addition, methazolamide, a blocker of carboanhydrases, significantly reduced baseline I(sc). The forskolin-induced decrease of I(sc) presented a Cl(-) absorption. In the absence of HCO(3)(-), forskolin yielded only an I(sc) decrease and the transepithelial flux of (36)Cl(-) was reduced. In the presence of mucosal 5-nitro-2-(3-phenylpropylamino) benzoic acid, a nonselective blocker of chloride channels, forskolin-induced I(sc) decrease was inhibited. In addition to cAMP, the regulatory influence of neurons or prostaglandins on baseline I(sc) and anion transport was investigated. Neither tetrodotoxin, a blocker of neuronal Na(+) conductances, electrical field stimulation, nor indomethacin, a blocker of cyclooxygenases, influenced the baseline I(sc) or anion transport. In summary, these data show effects of forskolin (i.e., cAMP) on anion transport across the egg shell gland of the domestic chicken: HCO(3)(-) secretion (supporting Ca(2+) mineralizing of the egg shell) and Cl(-) absorption. Neurons or prostaglandins did not influence the anion transport.

Stem cells in pediatric heart failure.

Pediatric heart failure could be a target for regenerative therapy. Stem cell-based therapy has the potential to provide functional cardiomyocytes. Whereas adult stem cells have shown no or only minimal therapeutic benefit in adults with no evidence of transdifferentiation, embryonic stem cells can differentiate to any cell type, including cardiomyocytes. However, ethical concerns and immunological problems are associated with embryonic stem cells derived from the inner cell mass of blastocysts. Recently, somatic cells could be reprogrammed to a pluripotent state (i.e. induced pluripotent stem cells) with the help of transcription factors. This technique removes ethical and probably also immunological concerns. Nevertheless extensive experimental research will be necessary before cell replacement strategies become clinically applicable. Because the underlying pathophysiology differs significantly with age, caution is warranted extrapolating data obtained in experimental models of cardiac ischemia and clinical studies in adults to the pediatric population. Pediatric heart failure has a good prognosis if causal therapy is possible. However, some forms of congenital heart disease and especially dilated cardiomyopathy still have limited therapeutic options. Almost half of children with symptomatic cardiomyopathy receive a transplant or die within two years. The authors will review the relevant stem cell sources for cell-based treatments. And, given the differences of the underlying diseases between adult and pediatric patients with heart failure, it is contemplated which condition of pediatric patients with heart failure is most likely to benefit and which cell type would be appropriate.

The diagnostic yield from implantable loop recorders in children and young adults.

BACKGROUND: Syncope and palpitations occur frequently in young patients. Noninvasive diagnostic testing may be inconclusive. AIM: To assess the diagnostic yield of implantable loop recorders in young patients. PATIENTS AND METHODS: Thirty-three young patients underwent implantation of a loop recorder for long-term monitoring of cardiac rhythm, to establish symptom-rhythm correlation. They belonged to one of three subgroups: those with structurally normal heart, normal electrocardiogram at rest, and negative family history (n = 16); patients with structural heart disease and previous surgical repair (n = 11), and patients with proven or suspected primary electrical disease (n = 6). A combination of automatic and patient-activated recordings was used to monitor cardiac rhythm during symptomatic episodes. RESULTS: There were no procedural complications. Diagnostic electrograms could be obtained in all patients. A high degree of symptom-rhythm correlation was established. In 8/33 patients, no recurrence of symptoms was observed either until end of battery life of the device (n = 4) or until last follow-up (n = 2). Specific cardiac therapy was required, based on rhythms recorded by the device in 15 patients (until last follow-up). This consisted of catheter ablation of a tachyarrhythmia (n = 7), pacemaker implantation or upgrade (n = 5) or ICD implantation (n = 5). In the remaining patients (n = 10), recurrence of symptoms was associated with a normal electrocardiogram, and in two of these patients a non-cardiac diagnosis was made. CONCLUSIONS: In selected patients, the implantable loop recorder provides valuable diagnostic information to guide further therapy.

Transcatheter closure of symptomatic aortopulmonary window in an infant.

An aortopulmonary window is a rare congenital cardiac defect. In the majority of symptomatic neonates and infants, primary surgical repair is the treatment of choice. In selected infants, catheter closure of the defect with a device may be feasible. We report on the successful closure of an AP window in a 12 month old infant, using a 6mm Amplatzer septal occluder. The procedure and follow-up were uneventful.

Transcatheter recanalization of acutely occluded modified systemic to pulmonary artery shunts in infancy.

BACKGROUND: There are few data on successful recanalization of acutely occluded modified aortopulmonary shunts in infants in whom the major component of pulmonary flow is shunt-dependent. PATIENTS AND METHODS: Seven infants (age range 6 days to 7 months) with modified (polytetrafluoroethylene) aortopulmonary shunts (central shunt n = 6, modified Blalock-Taussig shunt n = 1), in whom acute shunt occlusion was documented following surgery (interval from shunt surgery 2-6 days) underwent emergency cardiac catheterization with a view to reopening the shunt. Anterograde right ventricle to pulmonary artery flow was present in three patient; two other had additional aortopulmonary collateral vessels, and intravenous prostaglandin E (PGE1) infusion was restarted in three infants to achieve or maintain ductal patency. All occluded shunts could be crossed with a 4F endhole catheter and various guidewire combinations. Balloon dilation was performed using a balloon with the same nominal diameter as the shunt (5 or 6 mm). RESULTS: All shunts were successfully recanalized. Two infants with recurrent cyanotic episodes underwent stent implantation in the right ventricular outflow tract (RVOT) during the same procedure. One infant required shunt revision 24 h following balloon angioplasty, during which a small clot was evacuated from the distal end of the shunt. An immediate improvement in oxygen saturation could be documented in all patients. In the remaining six infants, shunt patency was confirmed at follow-up, until further definitive repair. One infant died of non-cardiac causes, while awaiting definitive repair. CONCLUSIONS: This small series demonstrates that acutely occluded shunts can be successfully recanalized, and that patency can be maintained until further definitive surgery in the majority of infants.

[Sensorineural loss of hearing in lower registers as the main symptom of Lyme disease]. / Symmetrische Tieftonschwerhörigkeit als Hauptsymptom einer Neuroborreliose.

In a 9-year-old boy with sudden sensorineural loss of hearing in the lower registers in both ears, serology showed elevated levels of antibodies against Borrelia burgdorferi and examination of the CSF revealed a positive antibody index against Borrelia burgdorferi. The boy was treated with antibiotics for 2 weeks. Audiometry performed 4 weeks after treatment was completely normal. Inner ear involvement in Lyme disease has often been discussed. Treating these patients with antibiotics may lead to an improvement in some.

Transhepatic approach for catheter interventions in infants and children with congenital heart disease.

UNLABELLED: We report on our experience with transhepatic access for catheter interventions in six children (age range 2.5 months-9 years). Three had systemic venous anomalies, and one infant a femoral venous occlusion. In two further patients with bradyarrhythmia after a Fontan operation with an intraatrial Gore-Tex tunnel, transhepatic access was chosen to achieve a perpendicular orientation of the transseptal needle to the atrial baffle, allowing puncture of the Gore-Tex membrane. Two of the patients underwent ablation of an accessory pathway; in one an atrial septal defect was closed. A 2.5 month old baby after Norwood I operation, underwent balloon dilation of the pulmonary arteries. Two patients after prior Fontan surgery underwent DDDR pacemaker implantation. The size of the introducer sheath ranged from 4 F up to two 9 F introducers in the same vein for pacemaker insertion. At the end of the procedure, hemostasis was achieved by external compression. RESULTS: Transhepatic access could be established in all six patients (using a mirror image approach in children with left atrial isomerism) and the interventional procedures could be performed as planned. In one patient with implantation of a permanent pacemaker, a subcutaneous hematoma occurred, requiring blood transfusion. CONCLUSION: In selected pediatric patients, transhepatic access for catheter intervention can easily be achieved.

Intracardiac rhabdomyomas producing symptoms in infancy: the role of radiofrequency catheter ablation.

BACKGROUND: Cardiac rhabdomyomas, although benign, may produce symptoms related to arrhythmia or mechanical obstruction. Surgical excision is the therapy of choice for symptomatic rhabdomyomas in infancy. PATIENTS AND METHODS: Two infants with intracardiac rhabdomyomas producing symptoms underwent radiofrequency catheter ablation of the tumour. In patient 1 the diagnosis of multiple rhabdomyomas associated with recurrent supraventricular tachyarrhythmias and foetal hydrops was made in utero. After birth, several antiarrhythmic agents were administered, without successful suppression of the tachyarrhythmia. At seven months of age, the infant had one large residual tumour on the left atrial aspect of the anterior mitral valve leaflet with associated pre-excitation and re-entrant supraventricular tachyarrhythmia suggestive of a left-sided pathway. Catheter ablation of the accessory pathway was performed via a retrograde femoral arterial approach, targeting the earliest site of ventricular activation. Patient 2 presented as a neonate with multiple rhabdomyomas, one of which, measuring 15 mm × 15 mm, was producing severe mitral valve inflow obstruction resulting in symptoms of heart failure due to a large left-to-right shunt at atrial level and persistent pulmonary hypertension. Via the femoral vein, a 5F ablation catheter was advanced across the atrial septum, and the tumour directly ablated. RESULTS: Echocardiography performed 24 hours later demonstrated alteration in tumour morphology, with the development of a large central echolucent area, followed by progressive tumour shrinkage in both infants. Patient 1 was discharged at 24 hours, and patient 2 at seven days post-ablation, without symptoms. Follow-up at four weeks confirmed further tumour shrinkage. CONCLUSION: Transcatheter tumour ablation may be beneficial in selected infants and children.

Slow pathway ablation in children with documented reentrant supraventricular tachycardia not inducible during invasive electrophysiologic study.

UNLABELLED: Radiofrequency catheter ablation (RFA) has become the procedure of choice for permanent therapy of atrioventricular nodal reentrant tachycardia (AVNRT). This report presents our experience with atrio-ventricular node (AVN) modification in patients with documented narrow complex reentrant SVT, but no evidence for an accessory pathway, and no inducible tachyarrhythmia during invasive electrophysiology (EP) study. METHODS: The study population consists of nine children, age range 6-13 years (median 9) with previously documented SVT who had no tachyarrhythmia inducible during EP study (at baseline and following isoprenaline infusion). Eight of the 9 EP studies were performed under general anesthesia, and one under conscious sedation. An accessory pathway was excluded in all patients by appropriate atrial and ventricular extrastimulus pacing techniques. Eight of the nine patients had dual AV nodal physiology, and one had single AV nodal echo beats. The slow AV nodal pathway was empirically ablated, by applying RF lesions in the right inferoseptal AV groove, achieving catheter tip temperature of 50 degrees C. The appearance of an accelerated junctional rhythm during RF application was deemed to denote a successful application site. AV conduction during RF application was confirmed by incremental atrial pacing. The catheter position, and its relation to the compact AV node was constantly monitored using the LocaLisa navigation system. The end-point was absence of dual AVN physiology, and/or AV nodal echo beats. RESULTS: Successful slow pathway ablation was achieved in all patients. One patient appeared to have two separate slow pathways with different locations and two AH-jumps, which were both successfully ablated. None of the patients had evidence of temporary or permanent AV block at follow-up (median duration 9 months, range 4 to 36 months); none has had recurrence of symptoms or documented tachyarrhythmia. CONCLUSIONS: In children with structurally normal hearts, a previously documented SVT, absence of an accessory pathway and noninducibility of SVT during EP study, empirical slow pathway ablation appears to be justified.

[Electrical heart diseases--therapy during childhood and adolescence]. / Elektrische Herzerkrankungen--Behandlung im Kindes- und Jugendalter.

With increasing experience, radiofrequency catheter ablation of tachyarrhythmia substrates has become first choice therapy for children >4 years of age with recurrent tachyarrhythmia. In younger patients, the risks associated with the procedure (typically procedure-related AV block or possible coronary artery damage) have to be weighed against the natural history of the tachyarrhythmia substrate, and the degree of control achieved with pharmacologic agents. Ablation for postoperative arrhythmias is more complicated, and associated with lower success rates and a higher rate of recurrence (of the same or a new tachyarrhythmia) despite acute procedural success. In this setting, catheter ablation has to be considered in conjunction with further surgery or the use of a defibrillator as a backup device to prevent arrhythmia-related sudden death. Also in inherited arrhythmias as in long QT syndrome and Brugada syndrome, implantable defibrillators have to be considered as a possible therapeutic option for patients with a higher risk for sudden cardiac death, irrespective of age.

Radiofrequency catheter septal ablation for hypertrophic obstructive cardiomyopathy in childhood.

Two patients, a 5 year old boy with progressive hypertrophic obstructive cardiomyopathy and increasing symptoms despite appropriate pharmacologic therapy and an 11 year old girl with symptoms of tiredness and peak instantaneous LVOT gradient of 80 and 90 mmHg respectively were considered for radiofrequency catheter septal ablation, to relieve the left ventricular outflow tract obstruction. Via a femoral arterial approach, the His bundle was initially plotted and marked using the LocaLisa navigation system. Subsequently, using a cooled tip catheter a series of lesions was placed in the hypertrophied septum, commencing distally in the ventricle and proceeding towards the aortic valve, taking care to stay away from the His bundle. The procedure was deemed to be completed when the entire extent of the hypertrophied septum had been treated. In the boy the procedure was complicated by two episodes of ventricular fibrillation, requiring DC cardioversion, but without any neurologic sequelae. The peak to peak gradient between left ventricle and aorta was 50 mmHg and 60 mmHg respectively pre-ablation, and remained unchanged immediately after. Both patients were discharged from the hospital 48 hours later. Serial measurement of serum Troponin T and CK-MB isoenzyme confirmed significant myocardial necrosis. Follow-up echocardiography at 7 days and at 6 weeks post-ablation respectively confirmed a beneficial hemodynamic result, with reduction of left ventricular outflow obstruction and relief of symptoms. In young children, in whom alcohol induced septal ablation is not an option, radiofrequency catheter ablation offers an alternative to surgery, with the benefits of repeatability and a lower risk of procedure-related permanent AV block.

Catheter ablation of junctional ectopic tachycardia in children, with preservation of atrioventricular conduction.

BACKGROUND: Idiopathic junctional ectopic tachycardia is a rare arrhythmia in children. Several studies have demonstrated that drug therapy is often ineffective and sometimes the only achieved effect is rate control. Early presentation and frequent recurrence are associated with adverse outcome. PATIENTS AND METHODS: Three consecutive children, aged 9, 7 and 12 years respectively, underwent radiofrequency catheter ablation for junctional ectopic tachycardia, after having failed antiarrhythmic drug therapy. The entire His bundle was plotted out and marked, using the Localisa navigation system. The arrhythmia was readily and repeatedly inducible using intravenous isoprenaline infusion and the site of earliest retrograde conduction during tachycardia could be assessed. Ablations were performed in sinus rhythm, empirically targeting the site of earliest retrograde conduction during tachycardia. RESULTS: This approach was successful in abolishing tachyarrhythmia in the first two patients, in whom the successful ablation site was located superoparaseptally. In the third patient, junctional ectopic tachycardia was inducible, despite abolishing retrograde atrial activation, in a septal location on the tricuspid valve annulus. Further ablations in the superoparaseptal region, closer to the His bundle, were successful in rendering tachyarrhythmia noninducible. Over a median follow-up of 10 months, none of the patients has had recurrence of arrhythmia, despite discontinuing all antiarrhythmic medications. CONCLUSIONS: Radio frequency catheter ablation of junctional ectopic tachycardia is feasible with preservation of atrioventricular conduction.