Patent ID: 7200436

Claim:
An implantable pulse generator, comprising: a signal sensor to sense a first cardiac signal; a blanking window initiator coupled to the signal sensor, the blanking window initiator adapted to identify cardiac events in the first cardiac signal and to start a blanking interval when a cardiac event is identified in the first cardiac signal, the blanking interval including a repeatable noise window blanking interval; a noise detector coupled to the signal sensor and the blanking window initiator, the noise detector adapted to analyze the first cardiac signal to detect noise identified by a predetermined noise frequency range in the first cardiac signal during the repeatable noise window blanking interval, wherein the blanking window initiator is adapted to repeat the repeatable noise window blanking interval when the noise detector detects noise in the first cardiac signal during the repeatable noise window blanking interval; and a pace output circuit, coupled to the one or more electrodes, to deliver pacing pulses including pacing pulses separated by a pacing escape interval, wherein the noise detector is adapted to sum repeated repeatable noise window blanking intervals to give a duration of the repeatable noise window blanking intervals and to issue a first signal to start delivery of asynchronous pacing pulses when the duration of the repeated repeatable noise window blanking intervals is greater than the pacing escape interval.