Apparatus and method for controlling multiple sensitivities in arrhythmia control system including post therapy packing delay

An apparatus for administering electrotherapy to the heart comprising:

• a detector responsive to an electrical signal from the heart, said detector providing an output signal in response to said electrical signal;
• sensitivity control means connected to said detector for controlling the sensitivity of said detector to said electrical signal, said sensitivity control means controlling said sensitivity to a first sensitivity level at a first time;
• tachyarrhythmia detection means for receiving said output signal from said detector set at said first sensitivity level to determine if a tachyarrhythmia is sensed at said first time;
• tachyarrhythmia confirmation means for receiving said output signal from said detector set at said first sensitivity level to confirm the presence of said tachyarrhythmia at a second time after said first time;
• tachyarrhythmia therapy means for delivering tachyarrhythmia therapy to the heart if said tachyarrhythmia confirmation means confirms the presence of tachyarrhythmia at said second time;
• said sensitivity control means controlling said sensitivity of said detector to a second sensitivity level if a tachyarrhythmia is not sensed by said detector at said second time, said second sensitivity level being higher than said first sensitivity level;
• and
• said tachyarrhythmia therapy means delivering tachyarrhythmia therapy if said detector, at said second sensitivity level, detects tachyarrhythmia.