Wireless treatment of arrhythmias. At least some of the example embodiments are methods including: charging a capacitor of a first microchip device abutting heart tissue, the charging by harvesting ambient energy; charging a capacitor of a second microchip device abutting the heart tissue, the charging of the capacitor of the second microchip device by harvesting ambient energy; sending a command wirelessly from a communication device outside the rib cage to the microchip devices; applying electrical energy to the heart tissue by the first microchip device responsive to the command, the electrical energy applied from the capacitor of the first microchip device; and applying electrical energy to the heart tissue by the second microchip device responsive to the command to the second microchip device, the electrical energy applied from the capacitor of the second microchip device.