Non-invasive hemodynamic analysis in cardiac resynchronization therapy patients wearing quadripolar left ventricular leads: the importance of pacing electrode selection.

Quadripolar left ventricular (LV) leads offer multiple choices for LV pacing increasing programming flexibility. Aim of this study is to assess the influence of LV pacing vector selection on hemodynamic parameters for patients who underwent cardiac resynchronization therapy (CRT) using quadripolar LV lead chronically evaluated with a non-invasive approach by Nexfin(®) system provided analysis (BMEYE B.V., Amsterdam, The Netherlands).In 16 CRT patients implanted with a quadripolar LV lead (mean follow-up 8,8 ±13,4 months after implantation), we measured Cardiac Output (CO), Mean Blood Pressure (MBP), Total Peripheral Resistance (TPR), LV dP/dt max and Stroke volume (SV) from each one of the ten available bipolar pacing configurations. All the recorded parameters showed marked differences among the ten pacing configurations, but dP/dt max, SV and TPR were those showing the wider range, depending of the selected pacing vector. The average delta for the whole group of subjects between the maximum and minimum hemodynamic values for each pacing configuration were 15.9% for SV, 21.1% for dP/dt max and 20.3% for TPR. Inter-individual analysis of data failed to identify a link between a specific pacing vector and the hemodynamic response.Our study demonstrates that different bipolar pacing configurations, even if arising from a single CS branch, substantially modify the hemodynamic effect of LV pacing in CRT patients. Moreover, the non-invasive hemodynamic analysis suggests the better pacing configuration should be established individually and could represent an important issue in optimizing CRT during follow-up.