Multi-site atrial electrostimulation

An apparatus, comprising:

• a first wireless electrostimulation electrode assembly comprising:
• an electrostimulation circuit;
• a wireless receiver configured to receive wireless energy and configured to provide at least some of the received wireless energy to the electrostimulation circuit;
• a first expandable support mechanically coupled to the electrostimulation circuit and the wireless receiver and configured to support the first wireless electrostimulation electrode assembly at least partially using a ring formed by an annulus of a mitral valve of the heart;
• and
• wherein the electrostimulation circuit is configured to deliver at least some of the received wireless energy as an electrostimulation to the heart;
• wherein the first wireless electrostimulation electrode assembly is configured to be intravascularly delivered to an implant location within a chamber of the heart at the annulus of the mitral valve of the heart;
• and
• wherein the first wireless electrostimulation electrode assembly is configured to fit entirely within the heart.