Metallic ink compositions for use in capillary-action markers are provided. A subscriber accesses a voice communications menu by accessing a voice services node. Each inverter includes a pair of switches and a resistor for connecting opposite polarity voltage sources to a separate capacitor connected in shunt with gate electrodes of the PFET and NFET. The implantable medical device may receive such a signal by, for example, detecting a ventricular tachyarrhythmia, sensing a pressure that indicates a need for increased cardiac output, or receiving a signal from a patient via a patient activator.