Abstract: An implantable medical device including a sampling scheme to obtain digital representation from analog signals is disclosed. The analog signals represent intracardiac activity. Generally, a detector detects the amplitude of the analog signals and generates first and second difference signals. The first difference signal is generated after detection of significant changes in the analog signal amplitude. The second difference signal is generated upon confirmation of the absence of significant changes in the analog signal amplitude over a predetermined period of time. A frequency selection is implemented to select the sampling frequency based on the first and second difference signal.

Abstract: A system and method are provided for monitoring cardiac wall motion. A cardiac lead is provided with a motion sensor that is responsive to an excitation signal. The motion sensor signal induced by the excitation signal varies in time due to motion caused by myocardial wall motion. The time-varying motion sensor signal is obtained by sensing circuitry and provided to a processor for use in computing a wall motion parameter useful in assessing ventricular function. The processor provides wall motion parameter output for display or storage. Pacing parameters may be optimized according to wall motion parameter measurements obtained during iterative procedures using the lead-mounted motion sensor.

Abstract: In general, the invention is directed to identification of intrinsic ventricular activity occurring within a ventricular signal. In particular, the invention involves the analysis of ventricular signal morphology to determine if the signal contains intrinsic ventricular activity while delivering pacing pulses separated by nearly constant time intervals. Furthermore, the invention specifies an extension of a pacing interval based on whether or not the signal contains intrinsic ventricular activity. In this manner, the pacing interval is only extended when it is likely for intrinsic ventricular activity to occur.

Abstract: Method and device for determining capture status of a heart chamber that receives a pulse from an implantable pulse generator (IPG). Signal processing can be used to improve the reliability of capture detection by transforming the sensed response signal into a set of morphological characteristics. Analysis of selected morphological characteristics serves to distinguish signals indicative of capture from signals indicative of loss of capture.