Abstract: A lead includes a lead body having an expandable section. A plurality of electrodes are disposed on the expandable section. The expandable section is adapted to expand against an inner surface of a heart so as to position at least one of the plurality of electrodes at or near an SA node of the heart.

Abstract: A method and system for delivering anti-tachycardia pacing (ATP) is disclosed. During delivery of an ATP burst, an implantable cardiac rhythm management device is programmed to sense evoked responses and determine whether or not the ATP burst has entrained the heart by counting the number of successive pacing pulses achieving capture. This information may then be used by the device to adjust the manner in which the ATP therapy is delivered.

Abstract: An implantable medical device senses a plurality of electrograms from substantially different atrial locations, detects regional depolarizations from the electrograms, and analyzes timing relationships among the regional depolarizations. The timing relationships provide a basis for effective therapy control and/or prognosis of certain cardiac disorders. In one embodiment, an atrial activation sequence is mapped to show the order of occurrences of the regional depolarizations during an atrial depolarization for classifying a detected tachyarrhythmia by its origin. In another embodiment, conduction time between two atrial locations is measured for monitoring the development of an abnormal atrial conditions and/or the effect of a therapy.

Abstract: A delivery system and method for delivering a pulmonary artery lead into a pulmonary artery includes a delivery device having an inflatable balloon at a distal end. The device is inserted into the venous system, the balloon is inflated and the device is floated along a blood flow path within the venous system through the heart and into the pulmonary artery. The lead is delivered into the pulmonary artery using the device. In one embodiment, the device is a catheter that facilitates placement of an implantation catheter and/or a guide wire into the pulmonary artery for delivery of the lead. In another embodiment, the lead is mounted over the catheter. In yet another embodiment, the delivery device is formed at the distal end of the lead.

Abstract: A delivery system and method for delivering a right ventricular lead into a right ventricle includes a delivery device having an inflatable balloon at a distal end. The device is inserted into the venous system, the balloon is inflated and the device is floated along a blood flow path within the venous system through the heart and into the pulmonary artery. The lead is delivered into the right ventricle using the device. In one embodiment, the device is a catheter that facilitates placement of a guide wire into the right ventricle for delivery of the lead. The catheter is then removed and the lead is inserted into the right ventricle over the guide wire.

Abstract: A lead includes a lead body and an electrode disposed proximate a distal end of the lead body. A retaining member is disposed proximate the distal end of the lead and adapted to retain the electrode proximate an interatrial septum when the retaining member is located on a left atrial side of the interatrial septum.

Abstract: A method and apparatus for delivering therapy to treat ventricular tachyarrhythmias is described. A ventricular tachyarrhythmia can be classified into tachycardia or fibrillation zones using a rate criterion so that the tachyarrhythmia can be treated with either anti-tachycardia pacing or shock therapy, respectively. Rate stability and morphology criteria are employed to determine if a tachyarrhythmia in the fibrillation zone is actually monomorphic ventricular tachycardia which can be treated with ATP.

Abstract: A method and system for delivering anti-tachycardia pacing (ATP) is disclosed. By comparing the time intervals between senses from both ventricles, the origin of a ventricular tachyarrhythmia may be mapped to one or the other of the ventricles. The arrhythmic ventricle may then be paced with either single-ventricle or biventricular ATP pacing.