You cannot ablate the Lernaean Hydra: SCN5A mutation in a patient with multifocal ectopic Purkinje-related premature contractions syndrome treated with Flecainide and an implant of a subcutaneous defibrillator—a case report

Background SCN5A mutations may present with different clinical phenotypes such as Brugada syndrome, long QT3 syndrome, sick sinus syndrome, atrial fibrillation, dilated cardiomyopathy, and the least known multifocal ectopic Purkinje-related premature contractions syndrome. Case summary We report a case of a 29-year-old woman with palpitations due to multifocal premature ventricular complexes (PVCs) and a family history of sudden death. The previous electrophysiological study had shown that PVCs arose from Purkinje fibres but catheter ablation was unsuccessful. Cardiac magnetic resonance (CMR) imaging demonstrated non-ischaemic areas of subendocardial fibrosis at multiple left ventricular (LV) segments with concomitant dilatation and mild systolic impairment. Amiodarone suppressed the ectopy but caused hyperthyroidism. Due to recent pregnancy, she received no antiarrhythmics which resulted in PVC burden increase and further deterioration of the ejection fraction (EF). After gestation, amiodarone was reinitiated and switched to flecainide after implantation of a subcutaneous defibrillator as a safety net. At follow-up, LV function had almost normalized. Genetic analysis confirmed an SCN5A mutation. Discussion Multifocal ectopic Purkinje-related premature contractions syndrome is associated with SCN5A mutation which in our case (R222Q) is the most common described. Flecainide can be an appropriate treatment option when ablation is ineffective. Defibrillator—even a subcutaneous type—could be implanted in cases of LV dysfunction or scar. PVCs suppression by flecainide and restoration of EF implies an arrhythmia—induced mechanism of LV impairment.

Abstract 17310: Feasibility of Contralateral Dialysis Access in Patients With Novel Leadless Devices versus Conventional Transvenous Devices

Introduction: Patients with end stage renal disease (ESRD) often progress to hemodialysis (HD), where permanent access such as arteriovenous fistula (AVF) is needed. Due to associated cardiovascular comorbidities, several of these patients also require cardiac implantable electronic devices (CIEDs) for pacing or defibrillation needs. HD vascular access is their lifeline, yet prolonged use is fraught with complications which often necessitate the eventual use of both upper extremities. Conventional CIEDs require placement of leads through subclavian veins which limits the ability to use that extremity for AVF. Novel devices such as subcutaneous defibrillator and leadless pacemakers do not require placement of leads in the upper extremity and may offer an advantage in HD patients to preserve both upper extremities for AVF. Objective: To compare the incidence of successful use of contralateral upper extremity for AVF following HD access failure in patients with novel and conventional devices. Methods: This study included all patients who underwent placement of novel leadless and conventional devices during the last 10 years at the Ohio State University. Incidence of successful use of contralateral upper extremity for AVF following HD access failure was assessed as the primary outcome. Incidence of initial HD access failure was assessed as a secondary outcome. Results: A total of 58 patients with novel devices (subcutaneous defibrillator: 30 and leadless pacemaker: 28) comprised the interventional group, while a total of 25 patients with conventional devices comprised the control group. The primary outcome occurred in 18% of the interventional group and 0% of the control group (p < 0.01). Incidence of initial access failure was 46% in the interventional group and 40% in the control group (p= 0.2). Conclusion: Patients on HD have a high incidence of access failure and often require use of the contralateral upper extremity for AVF. Presence of novel devices provides the option for contralateral access compared to conventional transvenous devices. Where possible and clinically indicated, novel devices should be preferred over conventional transvenous devices in ESRD and HD patients.