Characterizing the recurrence of atrial arrhythmia following macro-reentrant atrial tachycardia ablation in adult patients with repaired tetralogy of Fallot.

Background: The recurrence of arrhythmia following catheter ablation of macro-reentrant atrial tachycardia (MRAT) in repaired tetralogy of Fallot (rTOF) is poorly understood.

Objective: To better describe the incidence, mechanisms, and predictors of recurrent atrial arrhythmia following MRAT ablation in rTOF.

Methods: Patients with rTOF ≥18 years of age who underwent radiofrequency ablation for MRAT (typical/cavotricuspid isthmus-dependent atrial flutter, incisional/scar-mediated MRAT, upper and lower-loop reentry, or left atrial MRAT) at Duke University Hospital from 1996 to 2023 were identified.

Causes TRPV4-Mediated Autosomal Recessive Arrhythmogenic Cardiomyopathy.

Background: Arrhythmogenic cardiomyopathy (ACM) is one of the leading causes of sudden cardiac death in children, young adults, and athletes and is characterized by the fibro-fatty replacement of the myocardium, predominantly of the right ventricle. Sixty percent of patients with ACM have a known genetic cause, but for the remainder, the pathogenesis is unknown. This lack of mechanistic understanding has slowed the development of disease-modifying therapies, and children with ACM have a high degree of morbidity and mortality.

Development of right ventricular electromechanical dyssynchrony following surgical repair of tetralogy of Fallot in infants.

Background: In adolescents and adults with tetralogy of Fallot (TOF), right ventricle (RV) electromechanical dyssynchrony (EMD) due to right bundle branch block (RBBB) is associated with reduced exercise capacity and RV dysfunction. While the development of RBBB following surgical repair of tetralogy of Fallot (rTOF) is a frequent sequela, it is not known whether EMD is present in every patient immediately following rTOF. The specific timing of the onset of RBBB following rTOF therefore provides an opportunity to assess whether acute RBBB is associated with the simultaneous acquisition of EMD.

Utility of Cardiac Magnetic Resonance Imaging in Predicting Atrial Arrhythmias in Repaired Tetralogy of Fallot.

Arrhythmias are the leading cause of morbidity and mortality in repaired tetralogy of Fallot (TOF), and over 20% of these patients will develop a sustained atrial arrhythmia during their lifetimes. Cardiac magnetic resonance imaging (cMRI) is frequently performed in TOF, although its ability to identify patients at risk of atrial arrhythmias is uncertain. Adult TOF patients (n = 175) with no history of atrial arrhythmia who underwent cMRI between 2003 and 2020 at a single tertiary care center were identified.

Exercise Capacity and Predictors of Performance After Fontan: Results from the Pediatric Heart Network Fontan 3 Study.

Impaired exercise following Fontan is a surrogate of morbidity. Single-center longitudinal data exist, but there is a lack of contemporary multi-center data. Ramp cycle ergometry was re-performed in consented participants who had originally participated in the Pediatric Heart Network's Fontan cross-sectional study.

A Minimally Invasive Approach for Placing Sew-On Epicardial Leads in the Child.

Traditionally, pacing leads are placed transvenously, although smaller pediatric patients who require permanent pacemakers may benefit from delaying tranvenous lead placement until they are larger. Alternative, minimally invasive atrioventricular pacing options have not previously existed for this patient population, leaving many of these children with large sternotomies or thoracotomies. Using three port sites and an adjustable shaft dual-needle suturing device, we placed a steroid-eluting, sew-on epicardial lead on the right atrium of a 9-year-old patient.

Life-Threatening Event Risk in Children With Wolff-Parkinson-White Syndrome: A Multicenter International Study.

Objectives: This study sought to characterize risk in children with Wolff-Parkinson-White (WPW) syndrome by comparing those who had experienced a life-threatening event (LTE) with a control population.

Background: Children with WPW syndrome are at risk of sudden death.

Methods: This retrospective multicenter pediatric study identified 912 subjects ≤21 years of age with WPW syndrome, using electrophysiology (EPS) studies.

Premature ventricular contraction-induced cardiomyopathy in children.

Background: Adults with high premature ventricular contraction burden can develop left ventricular dilation, dysfunction, and strain, consistent with a cardiomyopathy, which is reversible with radiofrequency ablation of the premature ventricular contractions. Evidence in children with similar ectopy burden is limited. We performed a single-centre retrospective review to examine the prevalence of premature ventricular contraction-induced cardiomyopathy, natural history of ventricular ectopy, and progression to ventricular tachycardia in children with frequent premature ventricular contractions.

Hyperpolarized helium-3 MR imaging of pulmonary function.

Recent advances in HP MR imaging contrast agents have led to novel tests of pulmonary function. Many of these tests show promise in the clinical arena.

Determination of regional VA/Q by hyperpolarized 3He MRI.

Alveolar ventilation/perfusion ratio (VA/Q) is a key parameter in functional imaging of the lung. Herein, regional VA/Q was calculated from regional values of alveolar partial pressure of oxygen (PAO2) measured by hyperpolarized 3He gas MRI (HP 3He MRI). Yorkshire pigs (n = 7, mean weight = 25 kg) were paralyzed and maintained under isoflurane anesthesia.

An evaluation of pulmonary atelectasis and its re-expansion: hyperpolarized 3He MRI in the Yorkshire pig.

Rationale And Objectives: Atelectasis, the collapse of small airways, is a significant clinical problem. We use hyperpolarized (HP) 3He magnetic resonance imaging (MRI), or HP 3He MRI, to describe atelectasis in the normal Yorkshire pig, the pig with atelectasis, and the pig with re-expansion of atelectasis. We compare HP 3He MRI findings with depictions of atelectasis by proton MRI.