Abstract: This document discusses, among other things, a modular antitachyarrhythmia therapy system. In an example, a modular antitachyarrhythmia system includes at least two separate modules that coordinate delivery an antitachyarrhythmia therapy, such as a defibrillation therapy. In another example, a modular antitachyarrhythmia therapy system includes a sensing module, an analysis module, and a therapy module.

Abstract: This document discusses, among other things, systems, devices, and methods for detecting or classifying tachyarrhythmias or making a therapy decision. In one example, a rate-dependent threshold is used for comparing atrial and ventricular rates for classifying a tachyarrhythmia as a ventricular tachyarrhythmia (VT) or a supraventricular tachyarrhythmia (SVT). In another example, the classification uses an atrial rate cutoff value, a ventricular rate cutoff value, or both. In another example, a tachyarrhythmia detection is tested over a time window with a duration that is automatically adjusted as a substantially continuously monotonically decreasing function of duration vs. rate. These techniques improve the specificity of arrhythmia detection or classification, allow anti-tachyarrhythmia therapy to be better tailored to the particular tachyarrhythmia, or provide more automatic operation making it easier for a physician to use an implantable device.

Abstract: This document discusses, among other things, a combination pacer/defibrillator that is tailored for bradycardia patients. In one example, its shock-delivery specificity exceeds its sensitivity to shockable ventricular tachyarrhythmias. In another example, its specificity exceeds 95%, or 99%, or even 99.5%. Sensitivity is programmed to a high desired sensitivity value, but only if it can be done without decreasing the specificity below the desired specificity threshold value. This can be conceptualized as “avoiding at all costs” delivering false shocks, even at the expense of failing to deliver a shock to a treatable ventricular tachyarrhythmia. Specificity enhancements include, among other things, inhibiting shock delivery when the patient is breathing or not supine, using multiple channels or a high rate VT/VF detection threshold.

Abstract: A cardiac rhythm management (CRM) system includes a programming device that identifies the device type of an implantable medical device, selects a predetermined questioning sequence based on the device type, and interacts with a user through a user interface screen by conducting a question-and-answer session according to the predetermined questioning sequence. After displaying a question and receiving an answer to the question, the programming device sets one or more programmable parameter values and/or displays a follow-up question in response to the answer. The programming device also allows the user to enter one or more programmable parameter values directly during or after the question-and-answer session. The implantable medical device is programmed to operate in one or more operational modes based on at least the answers received from the user during the question-and-answer session and the parameter values entered by the user, if any.

Abstract: A cardiac rhythm management device predicts defibrillation thresholds without any need to apply defibrillation shocks or subjecting the patient to fibrillation. Intravascular defibrillation electrodes are implanted in a heart. By applying a small test energy, an electric field near one of the defibrillation electrodes is determined by measuring a voltage at a sensing electrode offset from the defibrillation electrode by a known distance. A desired minimum value of electric field at the heart periphery is established. A distance between a defibrillation electrodes and the heart periphery is measured, either fluoroscopically or by measuring a voltage at an electrode at or near the heart periphery. Using the measured electric field and the measured distance to the periphery of the heart, the defibrillation energy needed to obtain the desired electric field at the heart periphery is estimated. In an example, the device also includes a defibrillation shock circuit and a stimulation circuit.