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

Abstract

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. 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. 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. 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. 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. Abbreviations: Dis: Distal His-Ventricle measurement, Prox: Proximal His-Ventricle measurement, RB: His-ventricle measurement over the right bundle. HV interval measurements differ significantly by recording site, with proximal high-density mapping catheter recordings yielding longer intervals and identifying more patients with abnormal conduction than distal recordings. Women exhibit consistently shorter HV intervals than men, across all measurement locations, emphasizing the need for sex-specific reference values in conduction assessment. Standard clinical HV measurements closely reflect distal values, potentially underestimating conduction delay and influencing pacemaker decision-making.