Ventricular dyssynchrony is a serious heart dysfunction, meaning ineffective timing of ventricle contractions. It usually results in significantly lowered ejection fraction and, furthermore, in increased risk of sudden cardiac death. Ventricular dyssynchrony can be effectively treated by cardiac resynchronization therapy - CRT. Unfortunately, up to 30-40 percent of CRT recipients do not benefit from the therapy. The main reason is unspecific guidelines with significant false positivity for selecting CRT patients. In the past, we proposed new method for more accurate responders/non-responders selection and preliminary results on over 60 CRT patients are very promising. For method completion the verification on large data cohort from international, well established facilities is crucial.