High-density mapping of his-ventricular intervals: impact of recording site and sex-specific differences.

BACKGROUND: Accurate assessment of the His-ventricular (HV) interval is essential to diagnosing infranodal conduction disease, but the influence of recording site and sex on HV values is not well defined. OBJECTIVE: To evaluate the impact of measurement location and sex on HV interval values using high-density (HD) mapping catheters in patients undergoing atrial fibrillation (AF) ablation. METHODS: We prospectively studied patients in sinus rhythm undergoing AF ablation. HV intervals were measured with a decapolar catheter and a HD mapping catheter at the end of the procedure. HD-based HV intervals were classified as proximal (HVprox), distal (HVdis), and right bundle (HVRB) recordings. Conduction velocities and sex-specific differences were analyzed. RESULTS: A total of 67 patients (mean age 64 ± 10 years, 33%women) were evaluated. The clinical HV interval was 45 ± 9 ms and shorter in women (40 ms vs. 47 ms, p < 0.001). HVprox was longer than HVdis (51 ± 10 ms vs. 46 ± 10 ms, p < 0.001) and HVRB (37 ± 10 ms; p < 0.001). Abnormal HV intervals (> 55 ms) were more often detected using HVprox than HVdis or HVRB. Conduction velocities did not differ by sex and correlated poorly with surface ECG parameters. CONCLUSION: HV interval measurements vary significantly by recording site and sex. Proximal measurements reveal longer HV intervals and detect more conduction delays, while women have systematically shorter HV intervals. Anatomical precision and sex-specific interpretation are important for accurate diagnosis of infranodal conduction delay.