Abstract: A method for extinguishing a cardiac arrhythmia utilizes destructive interference of the passing of the reentry wave tip of an anatomical reentry through a depolarized region created by a relatively low voltage electric field in such a way as to effectively unpin the anatomical reentry. Preferably, the relatively low voltage electric field is defined by at least one unpinning shock(s) that are lower than an expected lower limit of vulnerability as established, for example, by a defibrillation threshold test. By understanding the physics of the electric field distribution between cardiac cells, the method permits the delivery of an electric field sufficient to unpin the core of the anatomical reentry, whether the precise or estimated location of the reentry is known or unknown and without the risk of inducting ventricular fibrillation. A number of embodiments for performing the method are disclosed.

Abstract: A medical device system for guiding placement of a subcutaneous medical device that includes a strap extending along a length from a proximal end to a distal end, a first flange and a second flange extending along a portion of the length of the strap, a base portion extending along a portion of the length of the strap between the first flange and the second flange, an orientation member extending along the strap to limit a predetermined radius of curvature of the strap, and an indentation extending from the proximal end to the distal end of the strap, the indentation formed by the first flange, the second flange, and the base portion, wherein the first flange and the second flange include curved bottom portions that make contact with and compress a tissue layer to position the tissue layer within the indentation during the placement of the subcutaneous device.

Abstract: A medical device system for advancing a subcutaneous device to a desired implant site that includes a strap extending along a length from a proximal end to a distal end, a first flange and a second flange extending along a portion of the length of the strap, a base portion extending along a portion of the length of the strap between the first flange and the second flange, and an indentation extending from the proximal end to the distal end of the strap, the indentation formed by the first flange, the second flange, and the base portion, wherein the first flange and the second flange include curved bottom portions that make contact with and compress a tissue layer to position the tissue layer within the indentation during the placement of the subcutaneous device.

Abstract: An apparatus and method for delivering an external shock pulse receive pacing pulses generated by a first device and a shock pulse generated by a second device. An output of the apparatus is coupled to patient electrodes and the apparatus controls delivery of the received pacing pulses to the output and delivery of the received shock pulse to the output. A control module, pacing control and shock control included in the apparatus cooperatively control delivery of the received shock pulse to the output at a predetermined delay after one of the received pacing pulses.