First Real-Life Data on the Diving Response in Healthy Children.

Swimming and diving are popular recreational activities, representing an effective option in maintaining and improving cardiovascular fitness in healthy people. To date, only little is known about the cardiovascular adaption to submersion in children. This study was conducted to improve an understanding thereof. We used a stepwise apnea protocol with apnea at rest, apnea with facial immersion, and at last apnea during whole body submersion. Continuous measurement of heart rate, oxygen saturation, and peripheral resistance index was done. Physiologic data and analysis of influencing factors on heart rate, oxygen saturation, and peripheral vascular tone response are reported. The current study presents the first data of physiologic diving response in children. Data showed that facial or whole body submersion leads to a major drop in heart rate, and increase of peripheral resistance, while the oxygen saturation seems to be unaffected by static apnea in most children, with apnea times of up to 75 s without change in oxygen saturation.

"Quality of life" analysis in the long-term follow-up after "Fontan" palliation for CHDs-a single-centre experience.

BACKGROUND: Complex CHDs are life threatening, and surgical treatment is needed for survival. Fontan palliation led to a significant increase in survival rates during the last decades. Consequently, quality of life became more essential. While a reduced quality of life compared to healthy children has been reported, detailed knowledge about individual quality of life and particular areas is lacking. Furthermore, the effect of different risk factors on quality of life is only rarely evaluated. METHOD AND RESULTS: Database of the department for pediatric cardiology, Heart Center Leipzig, was screened for children after total cavopulmonary connection palliation. n = 39 patients were included in the study, the outcome after total cavopulmonary connection was analysed in detail and quality of life data were collected and analysed using the standardised questionnaire "Pediatric quality of life inventory", version 4.0. We compared the total health score of our patients to the mean score of healthy children in the literature. The mean follow-up time was 6.4 ± 3.2 years, the overall survival was 100% after maximal follow-up time of 11.1 years. We could not find any age or gender dependence, nor an influence of age at total cavopulmonary connection on the later quality of life. Yet, patients with three-staged surgery exhibited a worse quality of life than patients with two-staged palliation. Late complications might influence quality of life, but patient number is too small, to find universal results. CONCLUSION: The total cavopulmonary connection palliation affects physical and psychological quality of life as well as cardiac health independently from age and gender. More patients and longer observation should be examined to confirm the results.

Coherent mapping of atrial tachycardias in patients with congenital heart disease.

AIMS: Coherent mapping (CM) uses a new algorithm to identify critical conduction isthmuses of atrial tachycardias (ATs). We analysed our experience of ablation of AT in patients with congenital heart disease (CHD) with this new technology. METHODS AND RESULTS: All patients with CHD who had CM of AT using the high-density mapping PENTARAY™ catheter and three-dimensional electroanatomic mapping system Carto3 between June 2019 and June 2021 were included retrospectively (n = 27). As a control group, 27 patients with CHD and mapping of AT without CM between March 2016 and June 2019 were included. In total, 54 ablation procedures were performed in 42 patients [median age 35 (interquartile range, IQR 30-48) years] and 64 ATs were induced and mapped (thereof 50 AT intraatrial re-entrant tachycardia and 14 AT ectopic AT). The median procedure duration was 180 (120-214) min and median fluoroscopy time was 10 (5.2-14) min. Acute success was 100% (27/27) in the Coherence group and 74% (20/27) in the non-Coherence group (P = 0.01). During follow-up [median 26 (12-45) months], AT recurred in 28/54 patients, thereof 15 patients needed a re-ablation procedure. Log-rank test showed no difference in recurrence rate between the two groups (P = 0.29). Three minor complications occurred (5.5%). CONCLUSION: Mapping of AT in patients with CHD using the PENTARAY™ mapping catheter and the CM algorithm led to excellent acute success. All ATs were possible to map and no complications related to the PENTARAY™ mapping catheter were observed. Thus, the use of the CM algorithm represents a promising tool in patients with CHD and complex AT.

The SIDECAR project: S-IcD registry in European paediatriC and young Adult patients with congenital heaRt defects.

AIMS: Subcutaneous-implantable cardiac defibrillators (S-ICDs) are used increasingly to prevent sudden cardiac death in young patients. This study was set up to gain insight in the indications for S-ICD, possible complications, and their predictors and follow-up results. METHODS AND RESULTS: A multicentre, observational, retrospective, non-randomized, standard-of-care registry on S-ICD outcome in young patients with congenital heart diseases (CHDs), inherited arrhythmias (IAs), idiopathic ventricular fibrillation (IVF), and cardiomyopathies (CMPs). Anthropometry was registered as well as implantation technique, mid-term device-related complications, and incidence of appropriate/inappropriate shocks (IASs). Data are reported as median (interquartile range) or mean ± standard deviation. Eighty-one patients (47% CMPs, 20% CHD, 21% IVF, and 12% IA), aged 15 (14-17) years, with body mass index (BMI) 21.8 ± 3.8 kg/m2, underwent S-ICD implantation (primary prevention in 59%). This was performed with two-incision technique in 81% and with a subcutaneous pocket in 59%. Shock and conditional zones were programmed at 250 (200-250) and 210 (180-240) b.p.m., respectively. No intraoperative complications occurred. Follow up was 19 (6-35) months: no defibrillation failure occurred, 17% of patients received appropriate shocks, 13% of patients received IAS (supraventricular tachycardias 40%, T-wave oversensing 40%, and non-cardiac oversensing 20%). Reprogramming, proper drug therapy, and surgical revision avoided further IAS. Complications requiring surgical revision occurred in 9% of patients, with higher risks in patients with three-incision procedures [hazard ratio (HR) 4.3, 95% confidence interval (95% CI) 0.5-34, P = 0.038] and BMI < 20 (HR 5.1, 95% CI 1-24, P = 0.031). CONCLUSION: This multicentre European paediatric registry showed good S-ICD efficacy and safety in young patients. Newer implantation techniques and BMI > 20 showed better outcome.

Evaluation of Clinical Course and Maintenance Drug Treatment of Supraventricular Tachycardia in Children During the First Years of Life. A Cohort Study from Eastern Germany.

Supraventricular tachycardia (SVT) is considered the most common cause of arrhythmia in children and infants. Regarding the likelihood of a spontaneous resolution of SVTs during the first years of life, drug treatment aims to bridge the time until children 'grow out' out of the arrhythmia. The choice of antiarrhythmic agents and the planning of maintenance therapy are mainly based on clinical experience and retrospective single- and multi-institutional analyses and databases from all over the world approaching differently to this topic. The current study aimed to evaluate the clinical course, pharmacological treatment strategies, and constellations of risk for recurrences in the management of SVTs in children aged 3 < years. The database of the Heart Center Leipzig, Department of Pediatric cardiology, was searched for pediatric patients aged < 3 years with a clinically documented SVT between 2000 and 2019 that received pharmacologic treatment. Patients with complex congenital heart disease or arrhythmias following cardiac surgery were excluded. 69 patients were included. Pharmacologic treatment, follow-up schedule, recurrences, outcomes, and risk factors for complicated courses are reported. Drug therapy of SVTs in young children remains a controversial topic with heterogeneous treatment and follow-up strategies applied. Risk factors for recurrences and/or stubborn clinical courses are difficult rhythm control with 3 or more antiarrhythmic drugs, ectopic atrial tachycardias, and a first occurrence of the SVT in the fetal period. Prospective studies are needed to sufficiently evaluate optimal treatment strategies.

Accuracy of the Apple Watch single-lead ECG recordings in pre-term neonates.

INTRODUCTION: Telemedicine gained an increasing use throughout the last years. Lifestyle tools like the Apple watch seem to have an increasing spread even in remote areas and underdeveloped regions. The increasing availability of these tools offers the chance to use the health care functions of these devices to improve provision of professional medical care. First data on the use of the Apple Watch as a remote monitoring device in children have been reported, showing good acceptability and usability of the Apple Watch for symptom monitoring in children. This study aimed to evaluate the accuracy of the Apple Watch iECG in comparison to a standard 12-lead ECG in pre-term babies. METHODS: In this prospective, single-arm study, consecutive preterm neonates hospitalised in Leipzig University Hospital neonatal ICU were eligible. A 12-lead ECG and an iECG using Apple Watch 4 were performed. iECG and 12-lead ECG measurements were performed by a paediatric cardiologist. Cardiac rhythm was classified and amplitudes and timing intervals were analysed for comparability. RESULTS: Fifty preterm neonates, gestational week (23-36 weeks), and body weight (0.65-3.09 kg) were enrolled. Overall good quality and excellent correlation of the Apple Watch generated iECG in comparison to the standard 12-lead ECG could be demonstrated (p < 0.001). When interpreted by a paediatric cardiologist, a correct rhythm classification could be done in 100% of cases. CONCLUSION: The Apple Watch iECG seems to be a valuable tool to record an ECG comparable to lead I of the standard 12-lead ECG even in pre-term neonates. With a widespread availability and excellent connectivity, the Apple Watch iECG function may provide practitioners with a tool to send an iECG for interpretation to a paediatric cardiac specialist.

Open field stress testing: finally an optimal method in young children? Reference values for mobile cardiopulmonary exercise testing in healthy children aged 4-8 years.

INTRODUCTION: Cardiopulmonary exercise testing represents the diagnostic tool for determining cardiopulmonary function. Especially in small children, exercise testing is extremely challenging. To address this problem, field testing has been implemented using small mobile devices. This study aims at using this protocol for developing normal values for cardiopulmonary exercise testing in very young children. MATERIAL AND METHODS: Healthy children aged 4-8 years were recruited. All children were tested according to an outdoor protocol, in which they were instructed to walk, then run slowly, then a little harder and at last run at full speed. Each step lasted for 2 minutes, except the last step, in which the children were instructed to maintain as long as possible. RESULTS: A total of 104 children (64 female/35 male, mean age 6.6 years) performed outdoor cardiopulmonary exercise testing using a mobile device. Almost all tests were completed successfully (95%). Despite a predominance of female study subjects, anthropometric values did not differ between boys and girls. V̇O2peak/kg, respiratory exchange ratio, VT1, heart rate at VT1, and time of exercise were also comparable between sexes. Generally, a tendency of higher maximal oxygen uptake could be observed in older children. CONCLUSION: Open field mobile cardiopulmonary exercise testing represents a novel approach in very young children. In this study, we were able to determine normal values of maximal oxygen uptake and OUES/kg for 4-8-year-old children. The method is easy to achieve and safe.

Use of the Apple Watch iECG in adult congenital heart disease patients.

INTRODUCTION: This study evaluates the accuracy of iECGs in comparison to the gold standard ECG in adult patients with congenital heart disease and recommends the appropriate iECG derivation based on the patient's characteristics. METHODS: In 106 adults (51 female, 55 male) with congenital heart disease, a gold standard 12-lead ECG was recorded, followed by three iECGs with the Apple Watch series 4, which correspond to Einthoven leads I, II, and III. Two experienced and independent cardiologists analyzed the time intervals, amplitudes, and polarities of the ECG parameters as well as the rhythm type and correlated the patient characteristics with the iECG parameters. RESULTS: The iECG parameters of all three iECG leads correlate strongly with those of the gold standard ECG, with exception of the P and T wave durations. We demonstrated that the informative value of the individual iECGs was independent of the patient's characteristics, in particular the heart axis, anatomy, and situs, even if the quality of the Einthoven III-like derivation was partially inadequate. The automatic rhythm analysis of the Apple Watch and the heart rhythm classification of a standard ECG analyzed manually by a cardiologist corresponded in 77%. CONCLUSION: iECG recordings of adults with congenital heart disease provide comparable results with Einthoven recordings I, II, and III of the 12-lead ECG and current data encourage the use of the Apple Watch not only in patients with structurally normal hearts but also in patients with congenital heart disease.

Pediatric catheter ablation at the beginning of the 21st century: results from the European Multicenter Pediatric Catheter Ablation Registry 'EUROPA'.

AIMS: Contemporary data from prospective multicentre registries on catheter ablation in pediatric patients are sparse. Aim of the European Pediatric Catheter Ablation Registry EUROPA was to contribute data to fill this gap of knowledge. METHODS AND RESULTS: From July 2012 to June 2017, data on catheter ablation in pediatric patients (≤18 years of age) including a 1-year follow-up from five European pediatric EP centres were collected prospectively. A total of 683 patients (mean age 12.4 ± 3.9 years, mean body weight 50.2 ± 19 kg) were enrolled. Target tachycardia was WPW/atrioventricular-nodal re-entrant tachycardia (AVRT) in 380 (55.7%) patients, AVNRT in 230 (33.8%) patients, ventricular tachycardia (VT) in 24 (3.5) patients, focal atrial tachycardia (FAT) in 20 (2.9%) patients, IART in 14 (2%) patients, and junctional ectopic tachycardia in 3 (0.45) patients. Overall procedural success was 95.6%. Compared with all other substrates, success was significantly lower in FAT patients (80%, n = 16, P = 0.001). Mean procedure duration was 136 ± 67 min and mean fluoroscopy time was 4.9 ± 6.8 min. Major complications occurred in 0.7% of the patients. No persisting AV block requiring permanent pacing was reported. At 1-year follow-up (605/683 patients, 95%), tachycardia recurrence was reported in 7.8% of patients. Recurrence after VT ablation (33%) was significantly higher (P = 0.001) than after ablation of all other substrates. CONCLUSION: The present study proves overall high efficacy and safety of catheter ablation of various tachycardia substrates in pediatric patients. Of note, complication rate was exceptionally low. Long-term success was high except for patients after VT ablation.

Performance of pacemaker leads in alternative lead positions after tricuspid valve replacement.

BACKGROUND: Bradycardic arrhythmias requiring pacemaker (PM) implantation are still common in patients in need of tricuspid valve replacement (TVR). Leaving an existing PM lead in an extravalvular position may represent a helpful alternative in special situations like the implantation of a mechanical TV. This study aimed to examine the short- to mid-term outcome of paravalvular leads concerning lead survival and prosthesis dysfunction in patients after TVR. METHODS: A retrospective case-control study of patients with TVR and ventricular pacing was conducted. Patients from the database of the Leipzig Heart Center were included. Data of the paravalvular lead group (PVG) and coronary sinus lead group (CSG) were compared to a control group with conventional transvalvular leads (TVG). RESULTS: Eighty patients with TVR and cardiac PM (TVG [n = 13], PVG [n = 40], and CSG [n = 27]) were included. The mean follow-up was 2.8 years. The rate of lead revisions (TVG 15.4%, PVG 2.5%, and CSG 7.5%) was lower in PVG but without significance (P = .286). The CSG demonstrated significantly higher pacing thresholds (1.4 V/0.8 ms) than TVG (0.5 V/0.4 ms), P = .004. However, the deterioration of threshold amplitudes during follow-up was similar in CSG (7.4%) and PVG (7.5%) compared with controls (7.7%). Function of TV prosthesis regarding development of stenosis or regurgitation showed a similarity between the groups (regurgitation PVG P = .692, CSG P = 1; stenosis PVG P = .586, CSG P = 0.69). CONCLUSION: Paravalvular positioning of PM leads seems to represent a reasonable alternative to the conventional transvalvular lead positioning concerning the lead and Tricuspid Valve prosthesis's function and durability in selected patients.

Arterial Hypertension in Children.

Pharmacological treatment of arterial hypertension in children is mainly based on individual experience, but there is evidence that blocking the angiotensin system reduces systolic and diastolic blood when compared to placebo, and these drugs are safe to use for a short duration, also in children under 6 years of age. Blocking the angiotensin system either by angiotensin-converting enzyme inhibitors or by antagonizing the angiotensin 1 receptor is effective, but did not display a consistent dose-response relationship with escalating doses, but the effective doses are known. Calcium channel antagonists are effective antihypertensives in children, but the evidence is limited. Based on small-sized studies, beta-blockers modestly reduce systolic blood pressure, but have no significant effect on diastolic blood pressure compared to placebo. They act in combination to antagonize reflex tachycardia induced by vasodilators. The most commonly used antihypertensive agents are safe to use in short-term studies.

Quality of life and psychological co-morbidities in children and adolescents with cardiac pacemakers and implanted defibrillators: a cohort study in Eastern Germany.

INTRODUCTION: The implantation of a pacemaker or an implantable cardioverter-defibrillator during childhood may reduce quality of life and lead to mental health problems. This study aimed to evaluate potential mental health problems (i.e., depressive and anxiety symptoms) and quality of life in children with cardiac active devices in comparison to healthy peers. METHODS: We analysed data of children with pacemakers or implantable cardioverter-defibrillators aged 6-18 years. Quality of life, depressive and anxiety symptoms were assessed by standardised questionnaires. The results were compared to age-matched reference groups. RESULTS: Children with implantable cardioverter-defibrillator showed significant lower quality of life in comparison to reference group (p = 0.03), but there was no difference in quality of life between children with pacemaker and reference group. There was no significant difference in depressive symptoms between children with a cardiac rhythm device compared to reference group (self-report: p = 0.67; proxy report: p = 0.49). There was no significant difference in anxiety (p = 0.53) and depressive symptoms (p = 0.86) between children with pacemaker and children with implantable cardioverter-defibrillator. CONCLUSIONS: Living with an implantable cardioverter-defibrillator in childhood seems to decrease the patients' quality of life. Although children with pacemaker and implantable cardioverter-defibrillator don't seem to show more depressive and anxiety symptoms in comparison to their healthy peers, there still can be an increased risk for those children to develop mental health problems. Therefore, treating physicians should be aware of potential mental health problems and provide the patients and their families with appropriate therapeutic offers.

Ryanodine receptor mutations presenting as idiopathic ventricular fibrillation: a report on two novel familial compound mutations, c.6224T>C and c.13781A>G, with the clinical presentation of idiopathic ventricular fibrillation.

Idiopathic ventricular fibrillation (IVF) is a rare genetically determined disease causing unexpected cardiac death in otherwise healthy individuals. This study identified two novel, functional heterozygous mutations in the ryanodine receptor 2 (RyR2) gene in a family with IVF. In the presented case all the patients received a thorough diagnostic workup to exclude structural heart disease. Blood was drawn from the patients, and genetic testing was performed including amplification and sequencing of splice locations in two exons of the RyR2 gene. The mutations were detected in five symptomatic family members. The genetic status of the five affected family members remains unclear. No clinically affected patient is without mutation. At this writing, one family member with confirmed mutation is asymptomatic. The differentiation between catecholaminergic polymorphic ventricular tachycardia (CPVT) and IVF remains a difficult issue, mainly based on clinical characteristics and gross genetic classification. In our case, the family history, exercise testing, and epinephrine stress testing do not suggest an association of arrhythmia and adrenergic triggers, which makes CPVT rather unlikely despite the fact that genetic testing showed RyR2 mutations. Currently, knowledge concerning the functional meaning of genetic mutations is growing. Future exploration of these functional aspects might give further impetus to allocation of these patients to a specific diagnosis.

Secundum atrial septal defect with interrupted inferior vena cava and azygos continuation: transfemoral closure in a 3-year old boy.

A secundum atrial septal defect (ASD 2) was closed percutaneously via the transfemoral approach in a 3-year-old boy with interrupted inferior vena cava and azygos continuation. The procedure was guided by transesophageal echocardiography and fluoroscopy using conscious sedation. Successful transhepatic and jugular accesses in similar patients are described. This is the first pediatric report describing a transfemoral closure of a secundum atrial septum defect via azygos continuation.

Odd acoustic window and elongated ventricles: echocardiographic diagnosis of congenital absence of the pericardium.

A 14-year-old boy with a heart murmur was referred to the authors' department because structural heart disease could not be ruled out by standard echocardiographic views. The best apical four-chamber view was obtained with the patient turned to a right lateral decubitus position and the transducer shifted almost to the posterior axillary line. A biplane chest x-ray also showed a counterclockwise heart axis deviation. Magnetic resonance imaging confirmed the suspected congenital absence of the pericardium.

Pharmacologic cardiac resynchronization of a 1-year-old boy with severe left ventricular dysfunction.

Postero-septal accessory pathways (AP) are a rare cause of intraventricular dyssynchrony and severe LV dysfunction in children. Beside the common treatment with radiofrequency ablation of septal substrates we present the case of a successful pharmacologic resynchronization in a 13/12 years old male toddler with Wolff-Parkinson-White syndrome (WPW) and severe LV dysfunction (left ventricular biplane EF of 31 %) due to intraventricular dyssynchrony with septal to posterior wall motion delay (SPWMD) of 350 ms. Interventricular mechanical delay (IVMD) was 65 ms. Using propafenone, pharmacologic cardiac resynchronization could be achieved. Pharmacologic resynchronization should be considered as safe and effective alternative to catheter ablation in very young children.

A case report: Amplatzer occluder device closure of an iatrogenic ventricular septal defect following radiofrequency ablation.

BACKGROUND: Interventricular septal perforation is an extremely rare complication of radiofrequency ablation (RFA), with an incidence of 1%. The most common mechanism is a 'steam pop', which can be described as 'mini-explosions' of gas bubbles. Data for percutaneous repair of cardiac perforations due to RFA are limited. CASE SUMMARY: A 78-year-old female patient was referred to our department for the treatment of two iatrogenic ventricular septal defects (VSDs) following radiofrequency ablation (RFA) of premature ventricular contractions. One week post-ablation, chest pain and progressive dyspnoea occurred. Transthoracic echocardiography detected a VSD, diameter 10 mm. Hence, iatrogenic, RFA-related myocardial injury was considered the most likely cause of VSD, and the patient was referred to our tertiary care centre for surgical repair. Cardiovascular magnetic resonance (CMR) imaging demonstrated border-zone oedema of the VSD only and confirmed the absence of necrotic tissue boundaries, and the patient was deemed suitable for percutaneous device closure. Laevocardiography identified an additional, smaller muscular defect that cannot be explained by analysing the Carto-Map. Both defects could be successfully closed percutaneously using two Amplatzer VSD occluder devices. DISCUSSION: In conclusion, this case demonstrates a successful percutaneous closure of a VSD resulting from RFA using an Amplatzer septal occluder device. CMR might improve tissue characterization of the VSD borders and support the decision if to opt for interventional or surgical closure.

Influence of a 100-mile ultramarathon on heart rate and heart rate variability.

AIMS: This study aimed to investigate the impact of an ultramarathon (UM) with a distance of 100 miles on heart rate (HR) and heart rate variability (HRV). METHODS: 28 runners (25 men and 3 women) underwent 24-hour Holter ECG monitoring 1 week before the UM, immediately after the UM and after a week of recovery. The influence of age, body mass index (BMI), HR and HRV on the run time and recovery was investigated. RESULTS: A rise in the baseline HR (18.98%) immediately after the run accompanied by a significant drop in the SD of all normal RR intervals (7.12%) 1 week after. Except for the runners' age, BMI, HR and HRV showed no influence on the competition time. Full return of HRV to the athletes' baseline did not occur within 1 week. There were no significant differences between finishers and non-finishers in the analysed parameters. CONCLUSION: The present results show that a 100-mile run leads to an increase in sympathetic activity and thus to an increase in HR and a decrease in HRV. Also, HRV might be a suitable parameter to evaluate the state of recovery after a 100-mile run but does not help to quantify the status of recovery, as the damage to the tendomuscular system primarily characterises this after completing a UM.

Simulation in Neonatal Echocardiography.

There is a growing interest in neonatologists to train in echocardiography. Recommendations for training have been published by medical societies and working groups, but concerns exist on their feasibility in the face of limited resources. Simulators are increasingly used for training in medicine, including echocardiography. They have the potential to help overcome the shortage of training opportunities. We describe the currently available 2 echocardiography simulators designed for neonatology. Both systems are based on real 3-dimensional echocardiographic data and use an electromagnetic tracking system. Although limited data exist proving their effectiveness, deduction from other disciplines support this assumption.

Junctional ectopic tachycardia in neonatal enterovirus myocarditis.

Differential diagnosis is challenging in poor conditioned neonates referred to the emergency room. Infectious disease is common, yet tachycardia should alert the clinician to look for cardiac arrhythmia and comprise. Tachycardia can lead to cardiomyopathy and should warrant further diagnostics for myocarditis, especially in rare or unusual combination of arrhythmias.