A prospective, multicentre, randomized, double-blind study designed to evaluate the safety and efficacy of the SonR system.


RESPOND-CRT is an International, multicenter, randomized (2:1), prospective, non-inferiority study.1


  • LVEF ≤ 35%
  • QRS ≥ 120 ms in LBBB or QRS ≥ 150 ms in non-LBBB
  • NYHA III or IV
  • Without permanent AF


  • 125 sites in Europe, USA, Australia
  • Jan 2012 – Oct 2014
  • Long term follow up ongoing (2 years)

Primary Efficacy Endpoint

Non-inferiority on the proportion of responders, based on a clinical composite of criteria (10% non-inferiority margin), at 12 months

Primary Safety Endpoint

Freedom from acute (0-3 months) and chronic (3-12 months) SonRtip lead complications

Secondary Endpoints

  • All-cause death or HF hospitalization
  • Worsened patients
  • Subgroups analysis on the primary efficacy endpoint


  • 1. Brugada J, Brachmann J, Delnoy PP et al. Automatic optimization of cardiac resynchronization therapy using SonR-rationale and design of the Clinical trial of the SonRtip lead and Automatic AV-VV optimization Algorithm in the Paradym RF SonR CRT-D (RESPOND CRT) trial. Am Heart J , 2014 ; Vol 167 (4):429-435

Hear from the experts

Where do we stand after two decades of trying to find the right CRT optimization strategy? Experts discuss the results of the RESPOND-CRT trial and the implications for clinical practice.

Watch the videos
Watch the videos

The Respond-CRT System

SonR technology is available exclusively in LivaNova devices. Learn more about the Platinium SonR family of CRT-D devices.

Learn more
Learn more
Use of cookies

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.

OK, I agree
OK, I agree

This site is intended for healthcare professionals outside the United States of America. By continuing to use this site you are confirming that that you are a healthcare professional based outside the USA.

Contact Us

Request brochure

To request a brochure or any other materials on RESPOND-CRT, SonR or Platinium, please fill in your details below:

Send form
Send form

Access full results

I would like to receive*:

Send form
Send form

Arrange presentation

To arrange a presentation of the RESPOND-CRT results by a LivaNova representative, please fill in your details below:

Send form
Send form