Early detection of right atrial dysfunction assessed by MR-feature tracking in patients with arrhythmogenic right...

The importance of right atrial (RA) function assessment in arrhythmogenic right ventricular cardiomyopathy (ARVC) is increasingly being recognized. MR-feature tracking (MR-FT) has emerged as a novel approach for quantifying atrial function. Therefore, we aimed to evaluate whether early RA dysfunction, even without RA dilation, can be identified in patients with ARVC using MR-FT.

Sixty-four patients with ARVC, of whom 47 were non-RA dilated and 17 were RA dilated patients, along with 41 healthy controls were included. RA reservoir, conduit, and booster strain (εs, εe, and εa) and peak positive, early negative, and late negative strain rate (SRs, SRe, and SRa) were measured using MR-FT. Right ventricular (RV) remodeling index was calculated as the ratio of RV to left ventricular end-diastolic volumes.

Patients with ARVC (both RA Dilated and non-RA Dilated group) exhibited significantly lower RA εs, εe, εa, SRs, SRe, and SRa compared to healthy controls. RA dilation patients further reduced these parameters (all P < 0.001). Among RA strain parameters, SRe showed the highest diagnostic value for RV remodeling in patients with ARVC (AUC = 0.799, 95% CI: 0.683-0.915). A strong correlation was observed between RA strain, strain rate, and RA emptying fractions in ARVC patients (P < 0.001). Intra- and inter-observer reproducibility was excellent for RA strain measurements.

Patients with ARVC exhibit impaired RA reservoir, conduit, and booster function even with normal RA volumes. MR-FT may serve as a promising approach for detecting early RA dysfunction in this population.