Introduction and objectives:

Artificial electrical activation of the heart in patients with permanent right ventricular stimulation is responsible for ventricular dyssynchrony. Synchromax® is an electrocardiogram monitor that allows an instantaneous and noninvasive verification of intraventricular synchrony, making a comparative analysis of the antipode leads DII and V6; cut values for a resulting index are available to diagnose dyssynchrony and define its severity. The present study objective is to measure with Synchromax® the dyssynchrony index generated by right ventricular stimulation in patients with implanted pacemakers, comparing with the index during native rhythm.

Methods:

Between September 2018 and January 2019, 18 patients of both genders with unicameral, bicameral, cardio-defibrillator or resynchronization pacemakers were studied. ECG were registered with Synchromax® in all patients, with native rhythm and under artificial stimulation.

Results

Thirteen out of eighteen patients deteriorated their synchrony (72.2%) due to artificial stimulation, the other five remained with unchanged dyssynchrony index. Seven out of those thirteen cases reached a severe degree of dyssynchrony (53.8%). The ANOVA test confirmed a statistically significant difference between the pre- and post-stimulation (p <0.01); it was also confirmed that the apical implant causes more dyssynchrony than the septal implant (p=0.036).

Conclusion:

Synchromax® allows detection of electrical dyssynchrony induced by right ventricular stimulation. It is suggested that the implants could be guided with this easy to use, reproducible and operator independent technology.