Abstract: Methods and apparatus are provided for storing intracardiac electrogram (IEGM) and other cardiac data in an implantable cardiac device. When a physician wishes to create a cardiac data record containing the IEGM and other cardiac data, the physician directs the cardiac device to store the data on demand. A number of cardiac data records can be stored. Data records may also be stored after a delay period following a predetermined cardiac event. When the implantable cardiac device detects the predetermined cardiac event, the delay period begins. At the expiration of the delay period, the implantable cardiac device stores a cardiac data record. Cardiac data records can also be stored according to a predetermined schedule.

Abstract: A programmable pacemaker that allows both noninvasive electrophysiological ("EP") testing for atrial tachycardias and ventricular pacing support, by allowing operation in the atrial channel to be decoupled from operation in the ventricular is provided. Many patients require EP testing to evaluate a predisposition to tachycardias. Many of these patients also have dual-chamber pacemakers for cardiac support. These systems can be noninvasively coupled to a external programmer enabling the already implanted system to serve as an in vivo EP laboratory. When performing noninvasive atrial EP testing with current dual-chamber pacemakers, the device must first be programmed to a single-chamber triggered mode. The present system allows the pacemaker to maintain ventricular pacing during EP testing.