World's only contractility sensor for automatic CRT optimization
SonR™ measures real-time LV contractilty1 to optimize AV & VV delays.

Healthcare Professionals Cardiac Rhythm Management Pacemakers SonR™


SonRTM CRT-D + SonRtipTM Atrial Lead

The Respond CRT system is a unique combination of a cardiac contractility sensor with an advanced AV & VV delays optimization algorithm.

  • SonRTM measures real-time LV contractilty1 to optimize AV & VV delays
  • Provides weekly automatic optimization at rest & exercise
  • 35% Risk reduction in heart failure hospitalization2
Click here to download the infographic


The SonRTM sensor consists of a micro-accelerometer embedded in the tip of the SonRtipTM atrial lead.

The sensor picks up cardiac muscle vibrations that reflect the heart sounds.3

SonRTM signal amplitude is a surrogate for cardiac contractility and correlates with LV dP/dt max.1

SonRTM AV & VV Optimization Algorithm

SonRTM measures real-time LV contractilty4 allowing for automatic optimization of AV & VV delays at rest and during exercise. This allows for the therapy to be continuously adapted to the individual needs of each patient.

20201009 Hospital campaign brief webpage


SonRTM optimization is as effective as echo-guided optimization.

The RESPOND-CRTTM trial successfully met its primary endpoint demonstrating that automatic AV & VV optimization using the SonRTM contractility sensor is safe and as effective as Echo-guided AV & VV optimization.

75% of clinical responders in the SonRTM group versus 70% in the control group (p<0.001).

SonRtipTM Lead proven to be safe.

The SonRtipTM lead was proven to be safe, with only 1% of patients reporting lead dislodgement and 0.1% of patients reporting lead fracture.

35% risk reduction in heart failure hospitalization.

The RESPOND-CRTTM landmark trial revealed that sensor-based CRT optimization with SonRTM is associated with a 35% reduced risk in heart failure hospitalization.

Visit the RESPOND-CRTTM website for more information

This feature is not available for sale or distribution in the USA. For further information on product availability, please contact your local representative.

click here to download the Respond CRT results
Graph SONR 1


1. Bordachar P, et al. Contributions of a hemodynamic sensor embedded in an atrial lead in a porcine model. J Cardiovasc Electrophysiol. 2011;22:579-83.

2. Brugada, J, et al. Contractility sensor-guided optimization of cardiac resynchronization therapy: results from the RESPOND-CRT trial. Euro Heart J 2016;38:730–38.

3. Tassin A, et al. Relationship between amplitude and timing of heart sounds and endocardial acceleration. Pacing Clin Electrophysiol. 2009;32(Suppl. 1):S101–104.

4. Rickards AF, et al. An implantable intracardiac accelerometer for monitoring myocardial contractility. The Multicenter PEA Study Group. Pacing Clin Electrophysiol. 1996;19:2066–71.