Injectable subcutaneous heart device (ISHD) for regulating arrhythmias in a heart of a patient, including a plurality of linked structures, each one of the linked structures being hollow, an interconnecting bus, a biocompatible coating, at least two electrodes and a plurality of sensors, the interconnecting bus for electrically coupling the linked structures and the biocompatible coating for hermetically sealing and electrically insulating the linked structures, one of the linked structures encapsulating a power source, another one of the linked structures encapsulating at least one capacitor and a third one of the linked structures encapsulating electronics, the electrodes and the sensors being respectively placed on an outer surface of the linked structures located at opposite ends of the ISH D, for detecting arrhythmias and providing electrical shocks to the heart, the electrodes and the sensors being electrically coupled with the interconnecting bus and the ISHD being positioned subcutaneously around the heart.