Simple ECG-based score and clinical parameters to predict right ventricular dilation in patients with repaired tetralogy of fallot.

BACKGROUND

Cardiac magnetic resonance (CMR) is the gold standard for assessing right ventricular (RV) function in repaired tetralogy of Fallot (rTOF), but it is expensive and not always available. ECG is a cost-effective, accessible alternative. This study evaluated ECG parameters, specifically QRS duration (QRSd) and QRS fragmentation (QRSf), to predict RV volumes and function, and developed a new score to guide CMR timing.

METHODS

We retrospectively analysed 147 patients with rTOF with pulmonary regurgitation. ECG, echocardiographic and CMR data were collected. Receiver operating characteristic curves identified optimal cut-offs for predicting RV dysfunction and dilation. Logistic regression was used to determine predictors of RV dysfunction and dilation.

RESULTS

QRSd showed moderate positive correlations with RV end-diastolic (EDVi) and end-systolic (ESVi) volume indices and negative correlations with RV ejection fraction (EF) and global radial strain. QRSf was associated with larger RVESVi and lower RVEF. We propose a simple risk score of age ≤20 years, QRSd≥160 ms, QRSf and transannular patch repair. A score >2.5 out of 5.5 predicted RVEDVi ≥150 mL/m2 with 76.5% sensitivity and 63.6% specificity.

CONCLUSIONS

This study highlights the value of ECG, particularly QRSd≥160 ms and QRSf, in predicting RV dilation in rTOF. The proposed score, based on clinical data and ECG parameters, offers a practical tool for guiding the timing of CMR.