Subcutaneous Implantable cardioverter-defibrillators (SubQ ICDs) are disclosed that are entirely implantable subcutaneously with minimal surgical intrusion into the body of the patient and provide distributed cardioversion-defibrillation sense and stimulation electrodes for delivery of cardioversion-defibrillation shock and pacing therapies across the heart when necessary. The SubQ ICD is implemented with other implantable and external medical devices and communicates to provide drugs and therapy in a coordinated and synergistic manner.