A Guide to the Use of Left Ventricular Analysis with 3D Echo in Dyssynchrony

Data from single-centre studies suggest that echocardiographic parameters of mechanical dyssynchrony may improve patient selection for cardiac resynchronisation therapy (CRT). To our knowledge, the only published multicentre trial that compared 12 echocardiographic methods, the Predictors of response to cardiac resynchronization therapy (PROSPECT) trial, stated that none of the echocardiographic measurements of ventricular dyssynchrony applied in the study were able to distinguish responders from non-responders. Realtime 3D echocardiography is able to measure left ventricular (LV) size, function and dyssynchrony to identify the presence and extension of scar tissue and to evaluate where the site of latest mechanical activation is. After CRT device implantation, it also allows physicians to detect where the first mechanical activation secondary to LV pacing is located. Indeed, it can be useful in interventricular (VV) delay optimisation of the device after the implantation and, in single-centre studies, it was able to predict response to CRT and to identify responders from non-responders. Care must be taken to optimise temporal resolution, but now volume rates of 70–80vps can be easily obtained in the majority of cases. VV optimisation using realtime 3D echocardiography is feasible and intuitive, but time-consuming compared with traditional methods based on Doppler or algorithms. In this article we illustrate our approach to LV analysis with realtime 3D echocardiography in the study of dyssynchrony.