Patent ID: 7930028

Claim:
An implantable cardiac device comprising a housing; a pulse and shock generator situated within said housing and configured to generate physiologically effective electrical pulses or pace pulses; at least one shock lead, external to said housing, connectable to said pulse generator and implantable into a patient's body to apply said physiologically effective electrical pulses to said patient's body; a monitor to automatically detect a lead condition during a pace pulse selected from said pace pulses applied by said pulse and shock generator via said at least one shock lead as to whether said at least one shock lead is in an implanted state or in an explanted state; wherein said lead condition is detected by said monitor with two voltage measurements associated with said pace pulse to determine a resistance comprising a voltage measurement at a beginning of said pace pulse and a voltage measurement at an end of said pace pulse; and, a control, which due to a detected lead condition, automatically enables said pulse and shock generator when all of said at least one shock lead is in said implanted state and disables said pulse and shock generator when any of said at least one shock lead is in said explanted state.