The purpose of the study is to collect data from the two implanted sensors simultaneously to the surface ECG and echocardiographic measurements of electromechanical parameters, in CRT patients.

The SATURN study is a prospective, interventional, open-label, non-randomized, single-arm, acute, multicenter feasibility study.

The purpose of the study is to collect data from the two implanted sensors simultaneously to the surface ECG and echocardiographic measurements of electromechanical parameters.

The data collected will be analysed in order to explore the relevance of timings and morphological features derived from those signals in comparison with timings determined on echocardiography and electrocardiograms (ECG) in various configurations of atrioventricular (AV) and inter-ventricular (VV) delays.

A maximum of 35 subjects, implanted with a CRT-D device, will be enrolled, at approximately 6 sites in France. Each patient will participate to this study only during an echocardiographic procedure, whose duration is estimated in approximately 1.5 hour.

Inclusion Criteria:

• Patient with class I or II indication for implantation of a CRT-D device according to current ESC guidelines
• Patient newly implanted with a MicroPort CRM Platinium CRT-D SonR or Platinium CRT-D device within 2 months before the Investigational Procedure
• Patient in sinus rhythm with a preserved atrio-ventricular conduction, and PR interval=220 +/- 30 ms on surface ECG
• Patient has reviewed, signed and dated the study informed consent form

Exclusion Criteria:

• Patient with permanent or persistent atrial fibrillation or atrial flutter
• Patient presenting with a permanent or frequent paroxysmal high degree atrio-ventricular block
• Device upgrade or replacement
• Minor patient (i.e. under 18 years of age), or patient under guardianship or kept in detention
• Patient unavailable for the scheduled Investigational Procedure, not able to understand the purpose of this study or refusing to cooperate