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

Figure 1. Receiver-operating characteristic curve of R-wave amplitude in electrocardiogram (ECG) lead V1 for predicting the occurrence of CAVB requiring PPI in patients exhibiting LBBB after TAVR. Abbreviations: AUC = area under the curve; CAVB = complete atrioventricular block; LBBB = left bundle branch block; PPI = permanent pacemaker implantation; TAVR = transcatheter aortic valve replacement.

Figure 2. A 89-year-old woman with severe aortic stenosis and a significant obstruction of the left anterior descending artery requiring stent implantation. (A) Baseline electrocardiogram (ECG) before TAVR. The QRS is narrow (duration 94 ms), and the PR interval is normal (124 ms). R-wave in V1 is small (0.02 mV). (B) Twenty-four hours after TAVR, there is a LBBB (QRS duration 120 ms) associated with a prolongation of PR interval at 195 ms. R-wave in V1 is 0.0 mV. (C) Forty-four hours after TAVR, CAVB is documented with a ventricular escape rhythm of 50/min having a duration of 132 ms and a morphology of RBBB and right axis deviation suggesting an origin close to the left anterior fascicle. The patient received a permanent pacemaker.

Figure 3. A 73-year-old woman with severe aortic stenosis. (A) Baseline ECG before TAVR showing narrow QRS duration (89 ms) with R-V1 amplitude of 0.17 mV. (B) After TAVI, LBBB occurred with a resulting decrease of R-V1 to 0.03 mV. This patient did not develop a high-degree AV block despite the marked increase of PR by 66 ms during LBBB. Note a partial interatrial block (P duration >120 ms after TAVR).6

Figure 4. A 76-year-old woman with severe aortic stenosis. (A) Baseline electrocardiogram (ECG) before TAVR showing R-V1 amplitude of 0.22 mV; (B) After TAVR, LBBB is present with a marked decrease of R-V1 amplitude (0 mV). This patient did not develop high-degree AVB.