Patent ID: 8214033
Filing Date: 2012-07-03
Classification: A61N

Abstract:
1. A medical device comprising: a plurality of electrodes configured for placement adjacent cardiac tissue; a sensing circuit configured to sense cardiac electrogram signals through one or more of the electrodes; an arrhythmia detection module configured to process detected cardiac electrogram signals and detect for a cardiac arrhythmia; an AC shocking circuit configured to concurrently deliver first and second alternating current (AC) signals having a frequency difference of about 50 hertz to about 200 hertz to cardiac tissue through one or more of the electrodes, wherein the AC signals are configured such that the concurrent delivery thereof preconditions the cardiac tissue to lower the activation threshold of the cardiac tissue without causing depolarization of the cardiac tissue; a DC shocking circuit configured to deliver a direct current (DC) signal to cardiac tissue through one or more of the electrodes, wherein the DC signal is configured such that delivery thereof depolarizes the cardiac tissue; and a microcontroller configured to, upon detection of a cardiac arrhythmia, cause the AC shocking circuit to deliver multiple cycles of the first and second AC signals, and cause the DC shocking circuit to deliver a DC signal after delivery of the AC signals.