Cardiogoniometry can predict positive response to cardiac resynchronization therapy - A proof of concept study

According to American Heart Association guidelines, QRS duration and morphology are used to select patients for cardiac resynchronization therapy (CRT). But still there are some patients who are not responding to this device. We investigated whether the Cardiogoniometry (CGM) as a three-dimensional vectorcardiogram method can improve patient selection.

Echocardiography and CGM were performed for 25 consecutive patients with Left bundle branch morphology who were candidate for CRT implantation and were in sinus rhythm. Patients re-evaluated by echocardiography after 6 months post CRT implantation.

The mean age of the patients was 63 ± 13 years and 17 (68%) were males. The mean LVEF was 19.4 ± 7.4% and 24.2 ± 11.5% before and after CRT implantation respectively. Median of the duration of the R loop before the R maximum demonstrated a negative correlation with the increase in LVEF, (r = -0.36, P = 0.07) and mean of maximal spatial velocity of the T-loop for all measured showed a positive correlation (r = 0.39, p = 0.04). Other parameters didn't show any significant differences.

Three-dimensional vectorcardiogram parameters can be helpful to predict the CRT response. Shorter duration of the R loop before the maximum R and smaller R loop area are predictors for responder patients.