An extra-cardiovascular implantable cardioverter defibrillator senses R-waves from a first cardiac electrical signal by a first sensing channel and stores a time segment of a second cardiac electrical signal in response to each sensed R-wave. The ICD determines intervals between successively sensed R-waves and, in response to at least a predetermined number of the intervals being less than a tachyarrhythmia detection interval, analyzes at least a portion of the time segment of the second cardiac electrical signal corresponding to a most recent one of the sensed R-waves to confirm the most recent one of the R-waves. The ICD updates an unconfirmed beat count in response to the most recent one of the R-waves not being confirmed and withholds detection of a tachyarrhythmia episode in response to the unconfirmed beat count being equal to or greater than a rejection threshold.

A method and system capable of identifying ectopic foci, rotors, or conduction pathways involved in reentrant arrhythmias within cardiac tissue, and then treating identified ectopic foci, rotors, and/or pathways with either lethal or sub-lethal temperatures. The system includes a medical device having one or more mapping elements and one or more treatment elements, and a computer programmable to identify ectopic foci and rotors based at least in part on signals received from the one or more mapping elements at one or more locations.

A catheterization system that includes an electrophysiologic (EP) catheter which has a lumen receiving an electrically conductive fluid delivered by a hydraulic line that is acted upon by a peristaltic pump advantageously avoids noise in intracardiac ECG signal recordings by using an electrical connection to short triboelectrical charge carried by the conductive fluid in the hydraulic line to an existing analog ground in the system. In one embodiment, the electrical connection includes an electrically conductive wire housed in the control handle and configured to provide electrical connection between the fluid and a pin on a printed circuit board housed in the control handle that is electrically connected to the analog ground. In another embodiment, the electrical connection shorts the electrically conductive fluid proximal of the control handle of the catheter.

Medical devices and methods for making and using medical devices are disclosed. An example method may include a method of identifying an activation time in a cardiac electrical signal. The method may include sensing a cardiac electrical signal, generating an approximation signal based at least in part on one or more parameters of the cardiac electrical signal, identifying a fiducial point on the approximation signal and determining, based at least in part on a timing of the fiducial point in the approximation signal, an activation time in the cardiac electrical signal.

A pair of new catheters designed to be deployed as a catheter system to allow a simultaneous acquisition of electrograms from widely dispersed electrodes in the left atrium, right atrium, and coronary sinus. The first catheter is the spiral globe catheter which has the primary shape of a spiral globe and has additional modifications to facilitate safe entry into the left atrium, to orient the primary axis of the spiral globe toward the mitral valve, and to maximize contact of electrodes to multiple areas of the left atrium. The second catheter is the right atrial and coronary sinus catheter (RA-CS catheter) which allows for electrogram acquisition from the length of the coronary sinus and dispersed areas of the right atrium. The catheter system is designed to provide adequate electrode sensor information so that panoramic mapping of the both atria and the coronary sinus may be performed.

A flexible frame comprising an electrically conductive hollow cylindrical metallic tube having a plurality of cuts along the longitudinal axis to form a plurality of conductive wires. The wires are equally spaced apart circumferentially along the longitudinal axis of the tube by a gap to electrically isolate the wires. A first electrode is mounted around the circumference of the frame along the longitudinal axis and attached to a first wire of the plurality of wires. A second electrode is mounted around the circumference of the flexible frame along the longitudinal axis at a predetermined distance from the first electrode and attached to a second wire. A non-conductive thermoplastic layer may be secured to the outer surface of the flexible frame between the first and second electrodes to form an insulation layer between the first and second electrodes.

A basket style electrical mapping catheter includes an elongated body with a proximal end and a distal end, where the proximal end has a user interface for controlling a basket-shaped electrode assembly that extends from the distal end of the elongated body. The basket-shaped electrode assembly includes a plurality of flexible splines supporting measurement electrodes configured to contact an electrically active substrate, and an expander spline disposed along a central axis of the basket-shaped catheter assembly supported a reference electrode. The orientation of the measurement electrodes relative to the reference electrode allows for electrical mapping to be conducted with greater sensitivity and specificity in order to more accurately detected diseased or damaged substrate.

A patient advisory device (“PAD”) and its methods of use. The PAD may be configured to alert the patient about an estimated brain state of the patient. In preferred embodiments, the PAD is adapted to alert the patient of the patient's brain state, which corresponds to the patient's propensity of transitioning into an ictal brain state, e.g., having a seizure. Based on the specific type of alert, the patient will be made aware whether they are highly unlikely to have a seizure for a given period of time, an elevated propensity of having a seizure, a seizure is occurring or imminent, or the patient's brain state is unknown.

An electrophysiology map, for example a map of arrhythmic substrate, can be generated by acquiring both geometry information and electrophysiology information pertaining to an anatomical region, and associating the acquired geometry and electrophysiology information as a plurality of electrophysiology data points. A user can select two (or more) electrophysiological characteristics for display, and can further elect to apply various filters to the selected electrophysiological characteristics. The user can also define various relationships (e.g., Boolean ANDs, ORs, and the like) between the selected and/or filtered characteristics. The user-selected filtering criteria can be applied to the electrophysiology data points to output various subsets thereof. These subsets can then be graphically rendered using various combinations of colorscale, monochrome scale, and iconography, for example as a three-dimensional cardiac electrophysiology model.

A catheter includes an elongated body having a longitudinal axis, a distal assembly distal the elongated body, the distal assembly having a tapered helical form comprising a larger, electrode-carrying proximal loop and a smaller, softer distal loop, and a shape-memory support member extending through at least the proximal loop. For example, the helical loop subtends at least about 720 radial degrees, with the proximal loop subtending about 360 radial degrees, and the distal loop subtending about 360 radial degrees. The softer distal loop with a straight distal end atraumatically guides the distal assembly into a tubular region so that the larger proximal loop can sit on the ostium of the tubular region with improved electrode and tissue contact.