Circumferential ablation devices and methods

An apparatus for delivering pulsed electric fields comprising:

• an elongate body;
• an expandable member at a distal end region of the elongate body;
• a first electrode assembly comprising a first plurality of wire loops, each wire loop of the first plurality of wire loops forms a petal having a first active region, wherein the first active regions of each of the first plurality of wire loops are arranged around the expandable member and extend around all or at least a portion of a circumference of the expandable member;
• and
• a second electrode assembly comprising a second plurality of wire loops, each wire loop of the second plurality of wire loops forms a petal having a second active region, wherein the second active regions of each of the second plurality of wire loops are arranged around the expandable member and extend around all or at least a portion of a circumference of the expandable member,
• wherein the first electrode assembly is laterally offset from the second electrode assembly along a length of the expandable member, and wherein the first electrode assembly and the second electrode assembly are configured to expand radially outward when the expandable member is expanded.