Abstract Introduction: Arrhythmic mitral valve prolapse is a rare yet potentially fatal syndrome. Recently, high-risk markers for malignant arrhythmias have been identified in adults with mitral valve prolapse, and a risk stratification scheme has been proposed. Little is known about the prevalence of arrhythmic mitral valve prolapse, the characteristics of the syndrome, and risk markers in children and young adults. Methods: A database of a high-volume, tertiary congenital heart defects department was searched to identify all patients with MVP between 2018 and 2025 (8 years). Patients’ characteristics, including arrhythmic risk factors, AMVP diagnosis, and last survival, were noted. Results: Of 12,955 hospitalised patients, 52 were diagnosed with mitral valve prolapse (0.4%; median age 14y [IQR 6], 35% male). Arrhythmic mitral valve prolapse was diagnosed in 13 patients (25% of the mitral valve prolapse cohort). Phenotypic risk factors were highly prevalent (88.5%), but in the crosstab analysis, only an enlarged left atrium was associated with high-risk arrhythmic events (p = 0.0432). Furthermore, patients with arrhythmic events were significantly older (median 16y) than those without (median 13y; p = 0.019). One patient (2.7%, with concomitant LQTS2) presented with unstable ventricular tachycardia and received an ICD. During a median follow-up of 3 years (IQR 1–4.5), all 52 patients were alive. Conclusions: One in 250 patients admitted to a tertiary invasive paediatric cardiology department has mitral valve prolapse. Among those with mitral valve prolapse, 1 in 4 presents with arrhythmic mitral valve prolapse. Although risk factors are common, outcomes among young arrhythmic mitral valve prolapse patients appear good. Overlapping with primary electrical disease may flag a worse prognosis. Identification of new risk factors for children is warranted.

The ryanodine receptor 2 gene mutation associated with catecholaminergic polymorphic ventricular tachycardia is one of the aetiologies of cardiac syncope and has the risk of sudden cardiac death. This study reported two novel ryanodine receptor 2 gene variants. We described two 9-year-old girls with recurrent syncope during exercise or stress presenting two novel ryanodine receptor 2 gene variants (c.6938T>G/p. Val2313Gly and c.12263A>C/p. His4088Pro) associated with catecholaminergic polymorphic ventricular tachycardia through a comprehensive review of medical history, examination findings and genetic testing. Propranolol was used for treatment, and the two patients didn't experience episodes of syncope during follow-up for 6 months. Besides, literature associated with catecholaminergic polymorphic ventricular tachycardia and ryanodine receptor 2 mutations was reviewed. Recurrent syncope during exertion or stress should be focused on catecholaminergic polymorphic ventricular tachycardia caused by ryanodine receptor 2 gene mutations. The genetic testing is a crucial tool in confirming the mutation of catecholaminergic polymorphic ventricular tachycardia. Early recognition of this disease, timely diagnosis of ryanodine receptor 2 gene mutations, and administration of appropriate pharmacological agents or ICD implantation are critical to ensure favourable clinical outcomes.

To evaluate left ventricular geometry, haemodynamic load, and inflammatory markers with multisystem inflammatory syndrome in children. This retrospective study included paediatric patients with a prior diagnosis of multisystem inflammatory syndrome in children who underwent follow-up echocardiography, ambulatory blood pressure monitoring, and laboratory assessments. Thirty patients (mean age 12.9 ± 5.0 years; 18 boys) were evaluated, including eight (26.7%) who had required an ICU stay during the acute phase. The median interval since the diagnosis of multisystem inflammatory syndrome in children was 48 months (interquartile range 47-50). Body mass index was positively correlated with left ventricular end-diastolic diameter (r = 0.577, p = 0.001), left ventricular end-systolic diameter (r = 0.522, p = 0.002), interventricular septal thickness (r = 0.565, p = 0.001), posterior wall thickness (r = 0.610, p < 0.001), and left ventricular mass (r = 0.594, p = 0.001). Body mass index z-score correlated with interleukin-6 (r = 0.415, p = 0.023), while lymphocyte count correlated inversely with left ventricular end-diastolic diameter (r = -0.559, p = 0.001) and left ventricular mass (r = -0.631, p < 0.001). Multivariate analysis identified lymphocyte count as the only independent predictor of left ventricular end-diastolic diameter [β = -0.492, 95% confidence interval = -0.589 to -0.078, p = 0.013]. Four years after multisystem inflammatory syndrome in children, ventricular enlargement appears to reflect physiological scaling rather than persistent hypertrophy, supporting the need for continued long-term surveillance in this population.

There is currently no consensus on the optimal mapping technique for atrioventricular nodal re-entry tachycardia ablation. This, the first of its kind, prospective randomised trial compared procedural characteristics and ablation outcomes between an anatomic approach for atrioventricular nodal re-entry tachycardia ablation and an approach guided by low voltage signals, local activation time, and the propagation wave collision. A randomised, prospective, multi-centre clinical trial was performed at 5 paediatric cardiac centres. 3D mapping was used on all patients. After atrioventricular nodal re-entry tachycardia confirmation, patients were randomly assigned to either an anatomic-based approach or to a 3D mapping technique that assessed for low voltage, activation time, and propagation wave collision to select the initial ablation site. Patient and procedural characteristics were collected with up to a 2-year post-procedure follow-up. In all, 70 patients were randomised: 37 within the voltage-propagation wave approach and 33 in the anatomic approach group. There was no significant difference between patient demographics or follow-up duration between groups. No significant difference was seen between duration of procedure, success rate, complications, or recurrences between techniques. There was a trend toward fewer ablation applications to initial success with the voltage-propagation technique (median of 2 vs 5). Conversely, there were significantly more total lesions placed for the voltage-propagation group. Typical atrioventricular nodal re-entry tachycardia trended towards fewer lesions to success and fewer recurrences than ablations for atypical atrioventricular nodal re-entry tachycardia or jump/echo. Both techniques demonstrated an excellent acute success rate and a low recurrence rate. Voltage-propagation mapping trended toward fewer ablations to initial success and did not prolong the procedure time. This paediatric study suggests that both a traditional anatomical technique and a voltage-propagation technique can provide excellent clinical outcomes, especially for typical atrioventricular nodal re-entry tachycardia.

In endocardial mapping of premature ventricular complexes of intramural or epicardial origin, we must be aware that pure origin and exit do not always coincide. In this study, we describe a case of endocardial mapping for epicardial-side premature ventricular complexes of pure origin using the time difference between bipolar and unipolar potentials.

We describe a rare and severe presentation of deglutition syncope, manifesting as complete heart block, along with newer therapeutic options, including cardioneural ablation and leadless pacing. Our 15-year-old patient presented with frequent syncope with swallowing, along with symptoms of orthostatic intolerance and anxiety. When standard non-pharmacologic and pharmacologic treatments were insufficient, cardioneural ablation resulted in improvement in syncope. Subsequent standard treatment of orthostatic intolerance has significantly improved the quality of life, including allowing her a more normal diet. The option of leadless pacing to prevent bradycardia during episodes of induced heart block has not yet been enacted due to her clinical improvement.

Children born with single-ventricle heart disease face a myriad of medical comorbidities, psychological risks, and quality of life challenges as they age. Parent perspectives on their care from diagnosis through development are critical to understand best ways and times to intervene to promote child and family adjustment to illness. Parents of children with status post-Fontan procedure were recruited to complete an electronic qualitative survey exploring parent perspectives of care. Grounded theory was utilised to analyse the data and identify themes and subthemes. Twenty-four parents completed the survey, describing their experience from diagnosis through the early years of treatment and into childhood and adolescence. Seven core themes were identified: survival and hope, parent stress and support, early stress and development, quality of life, increased independence, connection to the team, and communication. Initially, parents shared early worry regarding survival as they learned more about the condition and underwent surgeries. Later, parents supported their child's development and balanced ongoing hypervigilance with promotion of normalcy in their child's life. Quality of life and behavioural health concerns emerged amongst other medical comorbidities, and parents emphasised the need for both child and parent support in navigating family life with this illness. Parent perspectives highlighted the importance of family-centred, multidisciplinary care models that integrate medical subspeciality and psychosocial services for holistic care of children born with single-ventricle heart disease. Implications for care across development and interventions for children and parents are discussed.

Fenestration in the Fontan procedure was introduced to improve early postoperative outcomes by reducing systemic venous pressure and augmenting preload to the systemic ventricle. It is believed to decrease pleural drainage, shorten hospital stay, and reduce complications. However, fenestration may result in systemic desaturation and carries a potential risk of paradoxical thromboembolism. The benefits of routine fenestration remain controversial. This study aimed to evaluate whether adding a fenestration influences early postoperative outcomes. Between March 2024 and November 2025, 52 patients underwent Fontan completion at our institution. Forty patients met the inclusion criteria and were prospectively divided into two equal groups: non-fenestrated (Group 1, n = 20) and fenestrated (Group 2, n = 20). Twelve patients were excluded due to a primary Fontan procedure, elevated pulmonary vascular resistance, increased transpulmonary gradient, or significant branch pulmonary artery distortion. Demographic and perioperative parameters, including ventilation duration, inotrope duration, chest drain duration and volume, ICU stay, and total hospital stay, were analysed. Baseline demographic and intraoperative variables were comparable between groups. Duration of mechanical ventilation, ICU stay, total chest drainage, and cardiopulmonary bypass time were similar. Chest drain duration was shorter in the fenestrated group (8.1 ± 4.2 vs. 10.2 ± 5.3 days), but this difference was not statistically significant (p = 0.173). Discharge oxygen saturation was significantly lower in the fenestrated group (88.9 ± 5.6% vs. 93.3 ± 3.5%; p = 0.0072). In the present cohort, fenestration was not associated with a statistically significant improvement in most early perioperative outcomes. Larger studies are needed to define its role.

Children with CHD have demonstrated a rise in obesity, and have unique risks related to comorbidities of obesity, including feeding dysfunction and exercise limitations. The incidence and cause of obesity among patients with surgically corrected CHD are not fully understood. This single-centre, longitudinal, retrospective cohort study identified patients between 2004 and 2020 with surgical correction. Diagnoses were restricted to d-transposition of the great arteries, coarctation of the aorta, or tetralogy of Fallot with surgical repair by 6 months of life without long-term post-operative complications or chromosomal abnormalities. Evaluation of Body Mass Index by survival curve for endpoints of overweight and obesity, as well as descriptive analysis of the population, was performed compared to the expected prevalence in the state of Oregon (13.7%). Cohorts were divided into eras in 5-year increments. Of 240 patients identified, 87 (36.2%) were overweight and 50 (20.8%) obese, findings significantly higher than expected prevalence (p = <0.01) for the same time period in the state of Oregon. Patients with coarctation of the aorta had a higher prevalence than other diagnoses (p = <0.01). Patients in the 2004-2008 cohort had the highest rates of obesity compared to other cohorts (p = <0.01 and p = <0.01, respectively), likely due to a longer observational period. However, the 2014-17 cohort had the highest rate of increase in hazard ratio. Children with surgically corrected CHD demonstrate higher prevalences of obesity compared to the general population. There is variation by diagnosis, with coarctation of the aorta having comparatively higher prevalences of obesity. Several factors may impact this discrepancy, including sports participation restrictions and initial emphasis on weight gain.

Cardiac complications significantly contribute to mortality in Duchenne muscular dystrophy patients. Early detection of cardiac involvement is crucial for optimising therapeutic interventions. This study aimed to evaluate the role of N-terminal pro-brain natriuretic peptide in detecting cardiac involvement, as assessed by real-time three-dimensional (four-dimensional) and three-dimensional speckle-tracking echocardiography in patients with Duchenne muscular dystrophy. This cross-sectional study enrolled individuals under 21 years. Participants underwent clinical evaluation, real-time three-dimensional echocardiography, three-dimensional speckle-tracking echocardiography, and simultaneous measurement of serum N-terminal pro-brain natriuretic peptide levels. Correlation analysis between echocardiographic parameters and N-terminal pro-brain natriuretic peptide was performed. The study comprised 38 Duchenne muscular dystrophy patients with a mean age of 9.40 ± 4.13 years. Moderate significant correlations were observed between N-terminal pro-brain natriuretic peptide and echocardiographic parameters, including basal anterolateral and inferolateral longitudinal strain, apical septal longitudinal strain, and basal anterolateral and inferolateral radial strain (p < 0.05). Subgroup analysis based on N-terminal pro-brain natriuretic peptide (<125 pg/ml vs. ≥125 pg/ml) revealed impaired basal anterolateral longitudinal strain in patients with high N-terminal pro-brain natriuretic peptide. This is the first study that includes N-terminal pro-brain natriuretic peptide in conjunction with real-time three-dimensional echocardiography and three-dimensional speckle-tracking echocardiography for assessing cardiac involvement in Duchenne muscular dystrophy patients. The observed correlations between N-terminal pro-brain natriuretic peptide levels and regional contraction parameters hold promise for its relevance as a biomarker for cardiac dysfunction. Prospective studies with a larger population with a broader range of disease severity are necessary in patients with Duchenne muscular dystrophy.