Abstract: An implantable medical device operates with an algorithm that promotes intrinsic conduction and reduces ventricular pacing. The IMD monitors the occurrence of necessary ventricular pacing and takes certain actions based upon whether this occurrence has been relatively high or relatively low. When noise is detected, asynchronous pacing is provided when the occurrence is relatively high and is not provided when relatively low. When atrial threshold testing is performed, the incidence will determine which methodology is utilized.

Abstract: A vascular prosthesis is constructed from a well-defined pore structure to allow uninterrupted ingrowth of connective tissue into a wall of the prosthesis. Several different methods can be used to produce the prosthesis, including a vacuum impregnation technique, a paste molding technique, a paste extrusion technique, a dip coating technique, and a melt extrusion technique. Furthermore, mechanical properties of the prosthesis are matched with mechanical properties of the host vessel, thereby overcoming problems of compliance mismatch.

Abstract: An impedance monitor for discerning edema through evaluation of respiratory rate. Preferred embodiment includes edema monitor and trigger to initiate diagnostic reporting or corrective action when activated. Recording of Long Term Average and Short Term Average values for secondary edema measure based on DC signal level are described as are methods and apparatus for removing unwanted recurring noise.

Abstract: In using electrogram signals to determine physiologic conditions like ischemia, the bad cardiac cycle information due to noise, axis shifts in the cardiac electrical axis, and the like must be removed if the electrogram signal can be made to be a good indicator. If this is accomplished through the adaptive filtering techniques shown here, the signal can be used to drive a closed loop therapy system responsive to those physiologic conditions discernible from good cardiac cycle electrocardiogram signals.

Abstract: A medical electrical lead having an elongated insulative sheath carrying an elongated electrical conductor therein and having a drug-dispensing electrode assembly coupled to a distal end of the elongated conductor. The electrode assembly takes the form of a conductive electrode member having a distal electrode portion exposed exterior to the elongated sheath and a shank portion extending proximally from the distal portion and coupled to the elongated conductor. A drug release device is mounted around the shank proximal to the distal portion of the electrode member and the electrode member is provided with at least one bore extending from a surface of the release device to a surface of the distal portion of the electrode member.

Abstract: The lead configuration enhances the sensing characteristics of the lead and provides for stable location of the electrodes in the coronary sinus. The J-shaped bend in the distal portion of the lead body spaces the distal tip of the lead body less than about 0.9 inches laterally from the portion of the lead body that is proximal to the bend. The tip of the lead body is provided with a pacing/sensing electrode and the curved portion of the J-shaped bend carries an elongated coil electrode that serves as an indifferent electrode for pacing and sensing. For left atrial pacing, the lead tip electrode is located adjacent the wall of the coronary sinus closest to the left atrium, and the indifferent electrode is located adjacent the opposite wall of the coronary sinus, closer to the left ventricle.

Abstract: A process for producing a medical electrode. A coil of conductive metal is slid over a tubular insulative substrate. The spaces between individual turns of the coil are backfilled with an insulative plastic. The backfilled plastic is thereafter etched away from and off of the exterior of the metal coil by means of a gas plasma.

Abstract: An endocardial defibrillation electrode system as provided, including a coronary sinus lead, a ventricular lead, and a subcutaneous plate. The coronary sinus lead includes an elongated electrode adapted for location in the coronary sinus, extending into the great vein, and termination in the vicinity of the left atrial appendage. The right ventricular eletrode may be located either in the right ventricular apex, or may extend from the right ventricular apex to the vicinity of the tricuspid valve. This subcutaneous electrode preferably is a large surface electrode, adapted for implant in the vicinity of the heart. A variety of defibrillation pulse regimes are disclosed, optimized for use with the defibrillation electrode system, and with subgroupings of the disclosed electrodes.