Investigator-initiated, prospective, multicentre registry, whose objectives are: 1/ to evaluate the incidence of conduction defects and the need of pacemaker implantation post-procedure, at discharge, at 30 days and at 1 year post Myval transcatheter heart valve deployment, and 2/ To evaluate the factors determining in-hospital and late (at 30 days and 1 year) conduction defects post Myval transcatheter heart valve.

Patients with Severe Aortic stenosis undergoing TAVR using Myval Transcatheter Heart Valve that meet all inclusion criteria and any exclusion criteria will be able to participate in this study if they sign the informed consent. Electrocardiogram, echocardiogram and computed tomography will be performed to patients at different time points (Baseline, post-procedure, discharge, 30 days and 1 year post procedure) and their parameters will be added into a dedicated REDCAP database.

Study Design: Investigator-initiated, prospective, multicentre registry. Study Phase: Phase IV.

Study Objectives:

1. To evaluate the incidence of conduction defects and the need of pacemaker implantation post-procedure, at discharge, at 30 days and at 1 year post Myval transcatheter heart valve deployment.
2. To evaluate the factors determining in-hospital and late (at 30 days and 1 year) conduction defects post Myval transcatheter heart valve.

Description of the study protocol:

• Patients meeting the inclusion and exclusion criteria will be enrolled after taking informed consent. The baseline data and electrocardiogram (ECG), echocardiogram and computed tomography parameters will be added into a dedicated REDCAP database.
• TAVR will be performed as per the standard procedure using Myval Transcatheter Heart Valve.
• The ECG parameters post procedure, at discharge, at 30 days and at 1 year post-procedure will be noted using the REDCAP database.
• Based on these ECG parameters, analysis will be done to look for mean variations of PR and QRS segments, atrio-ventricular block, bundle branch block or need for pacemaker from baseline to post-procedure, at discharge, at 30 days and at 1 year post procedure.
• Echocardiogram parameters at 30 days (optional) and at 1 year post procedure will be noted using the REDCAP database.
• Statistical analysis will be done using IBM SPSS Statistics and R software.

Study duration:

• Inclusion stage: Patients will be recruited during the index procedure; if the patient meets all the inclusion criteria and any exclusion criteria and accepts to participate. ECG, echocardiogram and computed tomography will be done at baseline and the relevant information will be entered into the electronic database.
• In-hospital stage: Postprocedural and predischarge ECGs will be obtained and all the required clinical information will be gathered before discharge.
• Follow up stage: Clinical follow-up will be performed at 30 days and at 1 year post procedure, and the required ECG parameters will be obtained. At the 30-day follow-up, echocardiographic variables will be collected if the centers are available to perform echocardiograms or if an echocardiogram has been performed to the patients for other reasons within the determined period. In the 1-year follow-up, echocardiographic variables collected by clinical practice will be recorded.

Inclusion Criteria:

• Adult patients (over 18 years of age)
• Patients with Severe Aortic stenosis undergoing TAVR using Myval Transcatheter Heart Valve.

Exclusion Criteria:

• Patients with pre-existing permanent pacemaker.
• Patients unable or unwilling to follow up for pre and post procedure clinical assessments and investigations.

All patients with of Severe Aortic stenosis undergoing TAVR using Myval Transcatheter Heart Valve who meet all inclusion criteria and any exclusion criteria in 32 centers in Spain.