An implantable medical device for use in a patient management system, said medical device comprising: a sensor capable of measuring a body characteristic and generating a data signal describing the measurement; a processor configured to analyze the data signal and configured to identify one or more significant events that warrant attention for the well-being of a patient; a first communications unit comprising a first wireless transmitter/receiver (35, 36) capable of establishing a first communications link with a host computer using an external local transmitter/receiver unit, when said first wireless transmitter/receiver unit is within a short-range telemetry communication range of said local transmitter/receiver unit, to deliver at least notification of the one or more significant events to said host computer using said first communications link; a second communications unit comprising a second wireless transmitter/receiver unit capable of establishing a second communications link with said host computer over a pervasive wireless communications network to deliver at least notification of the one or more significant events to said host computer over said second communications link; and an antenna (13; 100; 110) operatively connected to both the first and second communications unit, so that the first and second communications units share the same antenna, characterized in that the implantable medical device includes: a primary battery and a secondary battery, wherein the secondary battery is configured to power the communications over the pervasive wireless network and the primary battery configured to support other components of the implantable medical device including the short-range telemetry communications capabilities. a sensor capable of measuring a body characteristic and generating a data signal describing the measurement; a processor configured to analyze the data signal and configured to identify one or more significant events that warrant attention for the well-being of a patient; a first communications unit comprising a first wireless transmitter/receiver (35, 36) capable of establishing a first communications link with a host computer using an external local transmitter/receiver unit, when said first wireless transmitter/receiver unit is within a short-range telemetry communication range of said local transmitter/receiver unit, to deliver at least notification of the one or more significant events to said host computer using said first communications link; a second communications unit comprising a second wireless transmitter/receiver unit capable of establishing a second communications link with said host computer over a pervasive wireless communications network to deliver at least notification of the one or more significant events to said host computer over said second communications link; and an antenna (13; 100; 110) operatively connected to both the first and second communications unit, so that the first and second communications units share the same antenna, characterized in that the implantable medical device includes: a primary battery and a secondary battery, wherein the secondary battery is configured to power the communications over the pervasive wireless network and the primary battery configured to support other components of the implantable medical device including the short-range telemetry communications capabilities. a primary battery and a secondary battery, wherein the secondary battery is configured to power the communications over the pervasive wireless network and the primary battery configured to support other components of the implantable medical device including the short-range telemetry communications capabilities.