When Should an EP Study Be Performed Before Transcatheter Pulmonary Valve Replacement?

All articles of this category (opens in new window) Background: Patients with repaired tetralogy of Fallot (rTOF) or pulmonary atresia with ventricular septal defect (PA/VSD) have a time-dependent increased risk of ventricular tachycardia (VT). However, clear indications warranting an EP study prior to transcatheter pulmonary valve replacement (tPVR) are under active debate. Here, we present the case of a patient who presented with nonsustained VT in the 24-hour Holter ECG before Venus-P-Valve implantation. Methods: A 35-year-old patient with repaired PA/VSD and a 29 mm homograft in pulmonary position presented to our department with reduced exercise tolerance and moderate-to-severe pulmonary regurgitation (PR). QRS duration was 175 ms. A 24 Holter ECG revealed a nonsustained VT. Echocardiography and MRI demonstrated a moderate-to-severe reduction in function of the right ventricle (RV; 31%) and left ventricle (LV; 48%), a severe PR (42%), RV dilatation (end-diastolic volume of 157.6 mL/m 2 ), and a hypoplastic left pulmonary artery (LPA) after stenting. Results: Due to the presence of several risk factors for sudden cardiac death (broad QRS complex, nonsustained VT, and reduced biventricular function), the patient underwent an EP study and programmed ventricular stimulation with subsequent strategic ablation of Isthmus III (Zeppenfeld). Soon after, he was hospitalized with a hemodynamically relevant VT originating from the RV outflow tract (RVOT) and underwent a second EP study. In this study, ablation of the focal VT originating from the RVOT failed. Furthermore, a focal VT originating from the RV-lateral free wall was induced and successfully ablated. Additionally, reablation of the distal Isthmus III was necessary. In a subsequent third (control) EP study, no VT from the RVOT was inducible. After interdisciplinary discussion, we proceeded with tPVR. Initially, serial balloon dilatation (BD) of the LPA stent was performed with a 16 mm Atlas balloon, followed by uncomplicated implantation of a 32/25 Venus-P-Valve. The Venus-P-Valve was implanted in a supra-annular position to avoid interference with the RVOT. Shortly after, the patient underwent implantation of an ICD shortly after the tPVR. At discharge, he already reported an increased exercise tolerance. Conclusion: The indication for an EP study should be carefully evaluated before tPVR, and implementation of risk stratification scores may help. Aiming for supra-annular implantation of PVR is preferable, if feasible. In case of preexisting stents in the PAs, BD of the stent should be performed prior to implantation of transcatheter valves. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany