A method for analysis of cardiac rhythms, based on calculations of entropy and moments of interbeat intervals. An optimal determination of segments of data is provided that demonstrate statistical homogeneity, specifically with regard to moments and entropy. The invention also involves calculating moments and entropy on each segment with the goal of diagnosis of cardiac rhythm. More specifically, an absolute entropy measurement is calculated and provided as a continuous variable, providing dynamical information of fundamental importance in diagnosis and analysis. Through the present invention, standard histograms, thresholds, and categories can be avoided.

An apparatus comprises an arrhythmia detection circuit configured to: receive a cardiac signal representative of cardiac activity of a subject; apply a first arrhythmia detection criteria to the received cardiac signal; apply, in response to the applied first arrhythmia detection criteria producing a positive indication of arrhythmia, a second arrhythmia detection criteria to the received cardiac signal, wherein the second arrhythmia detection criteria is more specific to detection of arrhythmia than the first detection criteria; detect, in response to the applied first and second arrhythmia detection criteria, a sensing event indicating one or both of the first and second arrhythmia detection criteria are susceptible to false indications of arrhythmia; and adjust, in response to a detected sensing event, sensitivity or specificity of one or both of the first and second arrhythmia detection criteria.

Wearable devices are provided herein including wearable defibrillators, wearable devices for diagnosing symptoms associated with sleep apnea, and wearable devices for diagnosing symptoms associated with heart failure. The wearable external defibrillators can include a plurality of ECG sensing electrodes and a first defibrillator electrode pad and a second defibrillator electrode pad. The ECG sensing electrodes and the defibrillator electrode pads are configured for long term wear. Methods are also provided for using the wearable external defibrillators to analyze cardiac signals of the wearer and to provide an electrical shock if a treatable arrhythmia is detected. Methods are also disclosed for refurbishing wearable defibrillators. Methods of using wearable devices for diagnosing symptoms associated with sleep apnea and for diagnosing symptoms associated with heart failure are also provided.

Methods and apparatus for a three-stage ventricular cardioversion and defibrillation therapy that treats ventricular tachycardia and fibrillation at low energy levels. An implantable therapy generator adapted to generate and selectively deliver a three-stage ventricular therapy and at least two leads operably each having at least one electrode adapted to be positioned proximate the ventricle of the patient. The device is programmed to deliver a three-stage therapy via both a far-field configuration and a near-field configuration of the electrodes upon detection of a ventricular arrhythmia. The three-stage therapy includes a first stage for unpinning of one or more singularities associated with the ventricular arrhythmia, a second stage for anti-repinning of the one or more singularities, both of which are delivered via the far-field configuration of the electrodes, and a third stage for extinguishing of the one or more singularities associated delivered via the near-field configuration of the electrodes.

An implantable direct-current electrode assembly (20) has two implantable electrodes (30, 40) and a control unit (50), to which the first (30) and the second (40) electrodes are electrically connected, wherein the control unit is configured to establish a potential difference between the two electrodes, so that a direct current can flow (55) between the two electrodes. The first electrode (30) is a coil electrode configured to be provided in the right half (12) of the heart (10) having a maximum length that is predetermined by the distance between the entry of the right atrium (14) and the tricuspid valve. The counter-electrode is from the group encompassing a coil electrode (40) configured to be positioned in the coronary sinus at the height of the left atrium (24) or an heart-external coil electrode configured to be attached to the exterior wall (25) of the left atrium.

Ablation catheter comprising an elongate member with proximal and distal ends, wherein the distal end is arranged to apply a high energy electrical shock from a plurality of locations along the length of said distal end and wherein said distal end is curved. Preferably the distal end of the elongate member extends in a circle segment.

Rechargeable implantable cardioverter defibrillator including a hermetically sealed can and at least one lead, coupled with the hermetically sealed can, the hermetically sealed can including at least one high voltage capacitor, an electronic circuit, coupled with the high voltage capacitor and a rechargeable battery, coupled with the electronic circuit and the high voltage capacitor, an outer surface of the hermetically sealed can including an active section and a non-active section, the non-active section being electrically insulated from the active section, wherein a surface area of the active section acts as at least one of an electrode with the lead for forming an electric shock vector for applying a high voltage shock and a sensor for sensing electrical activity and wherein a surface area of the non-active section acts as at least one antenna for transmitting and receiving information wirelessly while also receiving electromagnetic energy to inductively charge the rechargeable battery.

Blood stagnation within a left atrial appendage (LAA) may be reduced by creating movement within the LAA. A variety of different actuatable devices, including magnetically actuated devices, may be implanted within the LAA. The actuatable device may be caused to become actuated, thereby causing the motion within the LAA. In some cases, causing the actuatable device to become actuated may include application of a magnetic field. In some cases, causing the actuatable device to become actuated may include subjecting the actuatable device to blood flow within the LAA.

A monitoring device includes a waveform acquisition unit that acquires an electrocardiographic waveform, a waveform providing unit that provides the electrocardiographic waveform to a defibrillation control device that supplies electrical energy to an electrode catheter, a reception unit that receives a trigger signal indicating a possible supply start timing of the electrical energy from the defibrillation control device, and a synchronization determination unit that determines whether the trigger signal is synchronized with the electrocardiographic waveform.

A wearable medical device is provided for monitoring the cardiac health of a patient, for example, for indications of cardiac anomalies, where the device includes ECG sensors in electrical contact with the patient's body, therapy electrodes for providing electrical therapy to the patient's heart, and a control unit having at least one touch control with force sensor disposed on its housing for contacting with a finger. Signals from the touch control may be analyzed to identify force application below a first force threshold and at or above a second force threshold below the first force threshold, and, responsive to detecting such application of force, user input may be registered. User inputs to the at least one touch control may be used to delay therapy by the therapy electrodes.