Regarding the extent of TAVI's indication to patients with intermediary risks, it seems essential to lower its complication. Conduction disturbances after TAVI remains a major complication without any standardized guidelines to help with its treatment.

The primary end-point of this study is to confirm that standard criterion for pacing are reliable in post-TAVI conduction disorders and to analyze the contribution of a systematic electrophysiological study.

In TAVI patients, indications for pacing were persistent high-degree atrioventricular block or bundle branch block appearance associated to HV interval longer than 70ms, 24hours after the procedure. After a two-month follow-up, clinical and ECG evaluation and 24-hour ECG Holter monitoring were realized in patients without pacemaker and compared to data obtained from the devices in pacemaker implanted patients (% of ventricular pacing>1%; presence of more than 1 AVB episode).

A total of 165 consecutive patients who underwent TAVI were prospectively included. Out of the 165 patients included, 157 were sampled: 20 in the high grade persistent AV block, 5 in the persistent bundle branch heart block with HV interval>70ms, 13 with HV interval<70ms, and 119 in the temporary conduction disturbances group. Amongst the 22 patients implanted with PMK following the protocol, only 1 had conduction recovery. On the other hand there were 14 patients who didn’t benefit from a PMK implant but should have. HV interval in the bundle branch block group has an 88% specificity and a 44% sensibility. None of the pacing indication would have been missed if considered at day 3 instead of day 2, independently of HV measurement.

From this experimental protocol it appears that an HV based algorithm has a good specificity but a poor sensibility. Conduction disorders are stable at day 3 and allow to decide if pacing is needed. Besides QRS duration, PR interval might be of interest in predicting risk of AV block after TAVI.