Interpreting sex differences in atrial voltage: low-voltage areas and global atrial voltage

This commentary refers to ‘Sex differences in atrial fibrillation-related atrial remodelling assessed by electroanatomic mapping and biopsy’, by K. Nakashima et al., https://doi.org/10.1093/eurheartj/ehaf768 and the discussion piece ‘Sex differences in atrial fibrillation-related atrial remodelling: the end of the debate?’, by M. Bergonti et al., https://doi.org/10.1093/eurheartj/ehag045. We sincerely thank Dr Bergonti and Dr Conte for their thoughtful interest in our work and their insightful comments regarding sex differences in atrial structural remodelling in patients with non-valvular atrial fibrillation. In this study, we aimed to identify the underlying mechanisms contributing to lower atrial voltages in women. Our data indicate that these sex differences do not primarily reflect more advanced histological atrial remodelling in women, but rather a lower myocardial mass, potentially attributable to inherently smaller cardiomyocyte size in women.1 Consequently, atrial voltages for the same degree of pathological change are consistently lower in women. Considering this fundamental biological difference, we identified sex-specific thresholds of global left atrial voltage (VGLA)—defined as the mean left atrial bipolar voltage—for recurrence prediction, with lower cut-off values in women than in men (4.6 mV vs 3.3 mV, respectively).1 These findings indicate the importance of sex-specific interpretation of atrial voltage mapping data.