Systematic Electrophysiological Study Prior to Pulmonary Valve Replacement in Tetralogy of Fallot: A Prospective Multicenter Study

Abstract

BACKGROUND: Ventricular arrhythmias and sudden death are recognized complications in tetralogy of Fallot. Electrophysiological studies (EPS) before pulmonary valve replacement (PVR), the most common reintervention in tetralogy of Fallot, could potentially inform therapy to improve arrhythmic outcomes. METHODS: A prospective multicenter study was conducted to systematically assess EPS with programmed ventricular stimulation in patients with tetralogy of Fallot referred for PVR from January 2020 to December 2021. A standardized stimulation protocol was used across all centers. RESULTS: A total of 120 patients were enrolled, mean age 39.2±14.5 years, 53.3% males. Sustained ventricular tachycardia was induced in 27 (22.5%) patients. When identifiable, the critical isthmus most commonly implicated (ie, in 90.0%) was between the ventricular septal defect patch and pulmonary annulus. Factors independently associated with inducible ventricular tachycardia were history of atrial arrhythmia (OR, 8.56 [95% CI, 2.43–34.73]) and pulmonary annulus diameter >26 mm (OR, 5.05 [95% CI, 1.47–21.69]). The EPS led to a substantial change in management in 23 (19.2%) cases: 18 (15.0%) had catheter ablation, 3 (2.5%) surgical cryoablation during PVR, and 9 (7.5%) defibrillator implantation. Repeat EPS 5.1 (4.8–6.2) months after PVR was negative in 8 of 9 (88.9%) patients. No patient experienced a sustained ventricular arrhythmia during 13 (6.1–20.1) months of follow-up. CONCLUSIONS: Systematically performing programmed ventricular stimulation in patients with tetralogy of Fallot referred for PVR yields a high rate of inducible ventricular tachycardia and carries the potential to alter management. It remains to be determined whether a standardized treatment approach based on the results of EPS will translate into improved outcomes. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04205461

Automated isochronal late activation mapping for substrate characterization in patients with repaired tetralogy of Fallot

“…The rationale for such approach is the presence of risk factors for the development of VTs in the rTF population programmed to PVR and the fact that the pulmonary prosthesis may cover parts of the infundibular septum and could interfere with later attempts to transect the isthmus by RF ablation. 3 , 21 …”

Tetralogy of Fallot: A Long Journey but Getting Closer to Perfection

“…Once again, neither QRS duration nor ventricular dilatation were significant factors in predicting arrhythmia and sudden death. 16 In the linked report by Waldmann et al, 17 an EPS resulted in a change in management in 19.2% of the study population. A change in management included ablation (endocardial or epicardial) or ICD implantation.…”

Before it is too late: pre-emptive ablation strategies in tetralogy of Fallot

“…This reported prevalence of 50% for inducible VT in pre-PVR patients is on the higher end but remains consistent with previous findings reporting 22–50% prevalence ranges for inducible VT in pre-PVR patients. 10 , 11 These data highlight the importance of comprehensive risk assessment in the repaired TOF population.…”

“…This finding is consistent with prior studies that have identified isthmus 3 as the most commonly implicated isthmus for re-entry VT in repaired TOF. 10 , 11 This observation adds a layer of complexity to the management of repaired TOF patients and raises questions about how to address the impact of PVR on these critical VT substrates.…”