World's only contractility sensor for automatic CRT optimization

SonR™ measures real-time LV contractilty1 to optimize AV & VV delays.

The Respond CRT systemTM

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


The SonRTM sensor

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.




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.

Related products:

PlatiniumTM 4LV SonRTMCRT-D; SonRtipTM

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.

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