Title:
Electrocardiographic QRS duration reflects right ventricular remodeling in patients undergoing corrective surgery for isolated tricuspid regurgitation: a comparative study with cardiac magnetic resonance imaging.

Abstract:
The role of electrocardiogram (ECG) is unclear for the longitudinal follow-up of patients who undergo corrective surgery for isolated severe tricuspid regurgitation (TR).
This study sought to investigate the usefulness of changes in QRS duration of ECG after TR surgery in predicting right ventricular (RV) reverse remodeling as determined by cardiac magnetic resonance imaging (CMR).
We enrolled 30 consecutive TR patients (27 women, aged 57.8 ± 9.6 years) who had undergone prior left-sided valve surgery. A computer-assisted analysis was performed for objective calculation of QRS duration before and after surgery.
At a median CMR follow-up of 27.5 months postsurgery, QRS duration was cut by 14.6%, from 110.4 ± 14.6 msec to 96.9 ± 11.9 msec (P < 0.001), while CMR showed a decrease in RV end-diastolic volume index (RV-EDVI) from 179.5 ± 59.7 to 119.1 ± 30.4 mL/m(2) (P < 0.001). QRS duration correlated significantly with RV-EDVI and RV end-systolic volume index (r = 0.65, P < 0.001 and r = 0.53, P < 0.001, respectively), and a percent change in QRS duration was significantly correlated with a percent change in RV-EDVI (r = 0.40, P = 0.03). When significant RV reverse remodeling was defined as a reduction in RV-EDVI ≥20% following TR surgery, the sensitivity and specificity for significant RV reverse remodeling were 75% and 78%, respectively, with a 9% reduction in QRS duration (P = 0.01, area underneath the receiver operator curve [AUC] = 0.81).
The extent of changes in postoperative QRS duration can be used as a useful, inexpensive, and simple index reflecting the occurrence of significant RV reverse remodeling in patients undergoing corrective TR surgery.