Heart Failure -> Cardiac Resynchronization Therapy: -> Surgical & Other D-PO05 - Poster Session V (ID 39) Poster

D-PO05-118 - The Different Patterns Of Left Ventricular Activation Seen In Left Bundle Branch Block Using High-density Electroanatomical Mapping (ID 1326)


Background: Modern three-dimensional (3D) electroanatomical mapping systems offer an opportunity to assess left ventricular (LV) activation in greater detail, particularly in conduction disturbances, such as Left Bundle Branch Block (LBBB). Greater understanding of this may be crucial in improving the selection of those who benefit from cardiac resynchronisation therapy (CRT).
Objective: To further understand patterns of LV activation in LBBB using high-density electroanatomical mapping.
Methods: Twelve patients with LBBB (assessed against the American Heart Association criteria) and severe LV systolic impairment underwent full electroanatomical mapping of their LV during intrinsic rhythm. Contact mapping was performed using a 64-electrode mini-basket catheter (IntellaMap Orion, Boston Scientific) and 3D-mapping system (Rhythmia, Boston Scientific). Surface 12-lead electrocardiograms, total LV activation times, earliest and latest activation areas and activation patterns were assessed.
Results: Mapping was performed in 12 patients (8 males, age 69 +/- 11). Earliest activation in the LV was most often in the mid-septum(5/12, 42%), followed by proximal septum (3/12, 25%). Latest LV activation was most commonly seen in the basal lateral wall (5/12, 42%), but for 50% of patients (6/12) this was elsewhere (see table).
Conclusion: Our data suggests that LBBB in patients with severe LV systolic impairment is a heterogenous phenomenon. Further work in characterisation of LBBB patterns using 3D mapping may help both better differentiate those likely to respond to CRT and potentially enable us to target where best to place LV leads based on individual pathology.