The R-wave amplitude in V1 on baseline electrocardiogram correlates with the occurrence of high-degree atrioventricular block following left bundle branch block after transcatheter aortic valve replacement.

AIMS: Several procedural and electrocardiogram (ECG) parameters have been associated with the occurrence of high-degree atrioventricular block (AVB) requiring permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement (TAVR). We hereunder sought to assess if the baseline R-wave amplitude in V1 ECG lead of patients with normal QRS duration undergoing TAVR is associated with a higher patient's risk for developing high-degree AVB following left bundle branch block (LBBB).

METHODS AND RESULTS: In this retrospective single-centre study in 720 consecutive patients who underwent TAVR, 141 (19.6%) patients with normal QRS duration developed a new LBBB after TAVR. The 24 (17%) patients who underwent PPI for reasons other than high-degree AVB were excluded from further analysis. In the remaining 117 study patients, 14 (12%) developed high-degree AVB requiring PPI (Group 1) while the remaining 103 (88%) patients did not (Group 2). There were no significant differences in baseline demographic or procedural characteristics nor in PR interval, QRS duration, and QRS axis between these two groups. The incidence of left anterior hemiblock was higher in Group 1 (3 of 14, 21.4%) than that in Group 2 (9 of 103, 8.7%), but the difference was not statistically significant (P = 0.156). The R-wave amplitude in V1 was smaller in Group 1 than that in Group 2 (0.029 ± 0.04 mV vs. 0.11 ± 0.14 mV, P = 0.0316). In the receiver-operating characteristics analysis, the cutoff for R-wave amplitude pre-TAVR was 0.03 mV, area under the curve = 0.7219 (P = 0.0002).

CONCLUSION: The R-wave amplitude in lead V1 during baseline ECG in patients with normal QRS duration may predict the occurrence of high-degree AVB following new LBBB after TAVR.