Impact of Intraventricular Electrical Activation in Resynchronization Therapy (CARTO-CRT)

Comprehensive study, prospective, monocentric and cohort study.

Biventricular pacing is an effective therapy to improve end stage heart failure patients, however up to 30% of patients are unresponsive to this therapy. Among others, optimization of Left Ventricle (LV) pacing site location is critical to optimize response to Cardiac Resynchronization Therapy (CRT). Whether a better comprehension of baseline LV electrical activation can help to determine optimal LV lead location remains to be investigated.

After informed consent patients are included in the sudy. Day 1: CRT device is implanted under general anesthesia in a conventional fashion. The coronary sinus leads will be implanted guided by the acute hemodynamic response (+(dP/dt)max) using a RADI guide wire. After device implantation, a steerable mapping catheter will be inserted in the LV cavity to build a tridimensional activation map of the LV. This map will be obtained with and without CRT. From these maps different parameters describing LV activation will be measured and compared between patients with and without CRT. Quantitative parameters: Global LV activation time (LVATG) (primary outcome); septal activation time (LVTAS); Global intra-LV dispersion time and Qualitative parameters: presence of intraLV line of block, area of late activation. Day 5±2: A non-invasive map of the LV will be recorded with the CardioInsight ® system with and without CRT. The same parameters will be measured and compared with those obtained with invasive mapping. A 3 and 6 months follow-up visit including clinical, biological evaluation (NYHA status, 6-min walking test, BNP) of the patients will be performed with an additional transthoracic echocardiography at 6 months.