Abstract: A cardiac rhythm management system includes a lead assembly for intracardiac mapping, pacing, and drug delivery. The lead assembly includes an implantable endocardial lead having a proximal end for connection to an implantable cardiac rhythm management device and a distal end for disposal in an intracardiac region. The lead includes a pacing-sensing electrode and a drug delivery device, both located at or near the distal end. A lumen is within and extends throughout the lead, with an opening at or near the proximal end and another opening at or near the distal end. The lumen provides for access to the intracardiac region by a steerable stylet and a hollow needle, one at a time. The steerable stylet allows for electrophysiological mapping of the intracardiac region. The hollow needle allows for delivery of chemical, biochemical, and/or biological substance to the intracardiac region.

Abstract: A method and system for delivering anti-tachycardia pacing is disclosed. A cardiac rhythm management device, such as an implantable pacemaker having anti-tachycardia pacing capability, delivers anti-tachycardia pacing therapy in accordance with an anti-tachycardia pacing protocol upon detection of a terminable arrhythmia. The anti-tachycardia pacing is delivered as a burst of one or more pacing pulses at a specified coupling interval after a sensed ventricular polarization. By sensing if an evoked potential occurs, the device can determine whether or not the anti-tachycardia pacing burst has captured the ventricle and can adjust the coupling interval and/or other parameters accordingly.

Abstract: An implantable system for the defibrillation of the atria of a patient's heart comprises (a) a first catheter configured for insertion into the right atrium of the heart; a first atrial defibrillation electrode carried by the first catheter and positioned to stimulate Bachmann's bundle, or positioned at the atrial septum of the heart (i.e., an atrial septum electrode); (b) a second atrial defibrillation electrode which together with the first atrial defibrillation electrode provides a pair of atrial defibrillation electrodes that are configured for orientation in or about the patient's heart to effect atrial defibrillation, and (c) a pulse generator operatively associated with the pair of atrial defibrillation electrodes for delivering a first atrial defibrillation pulse to the heart of the patient. The second electrode may be configured for positioning through the coronary sinus ostium and in the coronary sinus or a vein on the surface of the left ventricle, such as the great vein.