The effects of pulmonary valve replacement on QRS duration in repaired tetralogy of Fallot patients with pulmonary regurgitation

Abstract

Introduction: Chronic pulmonary regurgitation (PR) following surgical correction in Tetralogy of Fallot (TOF) leads to right ventricular (RV) dysfunction, arrhythmias and sudden cardiac death (SCD). Pulmonary valve replacement (PVR) decreases PR and improves RV function, but data regarding QRS duration reduction remain scarce.

Methods: All adult TOF patients undergoing transcatheter PVR or surgical PVR from 2010 to 2016 were included. Clinical characteristics and QRS duration were measured and compared to post-intervention QRS duration using an institutional software and manually verified. Significantly wide QRS was defined as QRS >140 ms.

Results: Of 133 PVR patients, 85 had TOF and 27 (21.1%) had QRS > 140 ms (14 transcatheter, 13 surgical) and were included in this analysis. A 6 ms decrease in QRS duration was seen at 3-year follow-up (168.0 ± 3.5 ms vs. 161.8 ± 3.5 ms, p = .04). There was a significant decrease in the median RV size (defined as RV/LV diameter ratio) pre-intervention to 3-year post-intervention: (0.96 vs 0.89, p = .03). The median PR decreased significantly from moderate-severe to mild post-intervention (p < .0001).

Conclusions: Replacement of the pulmonary valve in high risk TOF patients reduces QRS duration at 3 years. Further study is needed to assess whether this QRS duration reduction may identify patients at lower risk of ventricular arrhythmias.

Keywords: Pulmonary valve replacement; QRS duration; Tetralogy of Fallot.