A medical device is configured to sense an electrical signal and determine that signal to noise criteria are met based on electrical signal segments stored in response to sensed electrophysiological events. The medical device is configured to determine an increased gain signal segment from one of the stored electrical signal segments in response to determining that the signal to noise criteria are met. The medical device determines a noise metric from the increased gain signal segment. The stored electrical signal segment associated with the increased gain signal segment may be classified as a noise segment in response to the noise metric meeting noise detection criteria.

This disclosure describes methods systems, and devices for treating atrial and ventricular fibrillation. For example, this document describes a method of terminating cardiac arrhythmias that includes generating a bipolar pulsed electrical field between a first electrode positioned on a first portion of a heart of a patient and a second electrode positioned on a second portion of the heart of the patient to cause reversible electroporation of myocardial cells of the heart.

A medical electrical lead having a conductor assembly covered by an insulating layer, and a shield covering positioned adjacent or proximate to at least a portion of the insulating layer in order to shield the conductor assembly from one or more electromagnetic fields. The shield covering is formed of a polymer-matrix composite. The polymer-matrix composite includes a polymeric resin having discontinuous conductive fillers provided therein. The discontinuous conductive fillers include one or more of nano-sized metal structures and nano-sized non-metallic conductive structures. The nano-sized non-metallic conductive structures can have a coating formed of one or more metals. The nano-sized non-metallic conductive structures can be formed of carbon. In turn, the nano-sized non-metallic conductive structures can include one or more of carbon nanofibers, carbon filaments, carbon nanotubes, and carbon nanoflakes.

The embodiments described herein relate to a self-positioning, quick-deployment low profile transvenous electrode system for sequentially pacing both the atrium and ventricle of the heart in the “dual chamber” mode, and methods for deploying the same.

In some examples, processing circuitry of a medical device system determines, for each of a plurality of patient parameters, a difference metric for a current period based on a value of a patient parameter determined for the current period and a value of the patient parameter determined for an immediately preceding period, and determines a score for the current period based on a sum of the difference metrics for at least some of the plurality of patient parameters. The processing circuitry determines a threshold for the current period based on scores determined for N periods that precede the current period, compares the score for the current period to the threshold, and determines whether to generate an alert indicating that an acute cardiac event of the patient, e.g., ventricular tachyarrhythmia, is predicted, and/or deliver a therapy configured to prevent the acute cardiac event, based on the comparison.

Provided are a defibrillation catheter system, a defibrillation power supply device, and a method for controlling the device during observation of intracardiac potential and defibrillation. A defibrillation catheter system 1 includes a catheter 20; a first power supply part 6A and a second power supply part 6B connected to the catheter 20; and an electrocardiograph 40 measuring an intracardiac potential, wherein the catheter 20 is provided with a first electrode group 21 having at least a 1-1 electrode and a 1-2 electrode and a second electrode group 22 having at least a 2-1 electrode and a 2-2 electrode, the first and second electrode groups 21 and 22 are connected to the electrocardiograph 40, the 1-1 electrode and the 2-1 electrode are connected to the first power supply part 6A, and the 1-2 electrode and the 2-2 electrode are connected to the second power supply part 6B.

The defibrillating electrical apparatus is controlled such that the enabling signal generator generates an enabling signal for the (n+1)-th R wave (R.sub.n+1) when and after a first time interval (T.sub.1) as a time interval from the n-th R wave (R.sub.n) to the (n+1)-th R wave (R.sub.n+1) of an electrocardiographic waveform (50) exceeds a first predetermined time period, if the first time interval (T.sub.1) is equal to or less than the first predetermined time period, the defibrillating electrical apparatus is controlled such that the enabling signal generator generates an enabling signal for the (n+2)-th R wave (R.sub.n+2) when and after a second time interval (T.sub.2) as a time interval from the n-th R wave (R.sub.n) to the (n+2)-th R wave (R.sub.n+2) of an electrocardiographic waveform (50) exceeds a second predetermined time period.

In some examples, a coil electrode assembly includes a coil electrode including a plurality of windings and extending from an electrode proximal end to an electrode distal end, the coil electrode defining an electrode lumen from the electrode proximal end to the electrode distal end. The coil electrode assembly further includes an insulative tube extending within the lumen of the coil electrode such that the coil electrode extends along an outer surface of the insulative tube. The coil electrode is partially embedded within the insulative tube when the insulative tube is in an expanded state to maintain a spacing between the windings.

Provided are a defibrillation catheter system, a defibrillation power supply device, and a method for controlling the device during observation of intracardiac potential and defibrillation. A defibrillation catheter system 1 includes a catheter 20; a power supply part 6 connected to the catheter 20; an electrocardiograph 40 measuring an intracardiac potential; a first electrode 21 and a second electrode 22 provided on the catheter; and a changeover part 7 connected to the power supply part 6, the changeover part 7 switching between a first mode for measuring the intracardiac potential and a second mode for applying the voltage while the intracardiac potential is measured, wherein the first electrode 21 and the second electrode 22 are connected to the power supply part 6 through the changeover part 7, and the first electrode 21 and the second electrode 22 are connected to the electrocardiograph 40.

Brugada syndrome and related forms of ion channelopathies, including ventricular asynchrony of contraction, originate in the region near the His bundle or para-Hisian regions of the heart. Manifestations of Brugada syndrome can be corrected by delivering endocardial electrical stimulation coincident to the activation wave front propagated from the atrioventricular (AV) node early enough to compensate for the conduction problems that start in those regions. The stimulation can include waveforms of the same polarity delivered to a site within the region near the His bundle or para-Hisian regions of the heart associated with a low cardiac electrical asynchrony level or can include at least two single-phased superimposed waveforms of opposite polarity delivered through a pair of pacing electrodes relative to a reference electrode, which can be delivered to any site within the region near the His bundle or para-Hisian regions. Defibrillation can also be used to terminate an arrhythmia.