Heart tissue electrical activity mapping used to guide the placement of devices to intervene in (treat) structural heart disease. In some embodiments, the intervention comprises placement of an implantable device, and/or positioning of a therapeutic device used to remove and/or remodel tissue. In some embodiments, electrical activity mapping is performed along with spatial mapping of a body cavity. In some embodiments, the intervention device position is compared to the measured positions of anatomical structures critical to heart electrical function to assess and/or prevent complications due to the device damaging heart electrical function.
