An implantable medical device is disclosed. A housing includes a hollow body forming a first electrode on an outer surface with end caps affixed to opposite ends, one end cap forming a second electrode. A microcontroller circuit is provided and includes a microcontroller operable under program instructions stored within a non-volatile memory device. An analog front end is interfaced to the electrodes to sense electrocardiographic signals. A transceiver circuit is operable to wirelessly communicate with an external data device. The program instructions define instructions to continuously sample the electrocardiographic signals into the non-volatile memory device and to offload the non-volatile memory device to the external data device. A receiving coil and a charging circuit are operable to charge an onboard power source for the microcontroller circuit.