Pitfalls and limitations in the assessment of the HV interval in a Transcatheter Aortic Valve Replacement population. A prospective analysis

Abstract Funding Acknowledgements Type of funding sources: None. Introduction identification of patients with new-onset conduction disturbances at risk of AV-block remains a major unmet challenge in Transcatheter Aortic Valve Replacement (TAVR). His-Ventricular interval (HVI) measurement has been proposed in patients at risk. However, the HVI assessment is often overlooked, performed as a single assessment without active mapping, and even single-catheter assessment is sometimes performed. Purpose To systematically evaluate HVI measurements in a post TAVR population, in search of methodological pitfalls as related to outcomes Methods Consecutive patients who underwent HVI assessment post-TAVR between June 2014 and December 2021. HV interval was classified as normal (<55), intermediate (55-70) and abnormal (>70 ms). Incremental atrial pacing was performed whenever possible. All tracings were reviewed by two blinded operators. Pitfalls in the assessment of atrioventricular conduction were categorized into types 1 to 5, as reported in Table 1. In sinus rhythm, only proximal HVI were considered defined as the concomitant recording of a near-field atrial signal. Results 90 cases were analyzed; median age 81 years1 [76 – 86] years; 37 (41%) male. The median HV interval was 54 [50 – 65] ms. An abnormal HV interval, exceeding the 55 and 70ms cut-off values, was found in 41 (45.9%) and 13 (14.8%) patients, respectively. At least one pitfall was found in 15 patients (16%). Short-term AV block occurred in 3 patients in sinus rhythm in whom no incremental pacing was performed, and in 2 patients with AF despite normal or borderline HVI in both groups. Conclusions Pitfalls in the assessment of the HVI are often observed after TAVR. Identification of infra- and especially intra-His disorders requires careful mapping and must be an active process on behalf of the operator. Our results call into question the value of the HV assessment using a single catheter or in patients with atrial fibrillation, considering the value of incremental atrial pacing and the inherent limitations in AF to assess the most proximal His or intraHis block.