A catheter includes: (a) a shaft for insertion into a heart of a patient, (b) an expandable distal-end assembly, which is coupled to the shaft and is configured to make contact with tissue of the heart, (c) at least first and second electrocardiogram (ECG) electrodes, which are coupled to an outer surface of the expandable distal-end assembly, and when placed in contact with the tissue, are configured to sense ECG signals in the tissue, and (d) a reference electrode, which is positioned within an inner volume of the distal-end assembly, and in an expanded position of the distal-end assembly, the reference electrode: (i) has no physical contact with the tissue, and (ii) is positioned at a first distance from the first ECG electrode and at a second distance from the second ECG electrode, and the difference between the first and second distances is smaller than a predefined threshold.

A catheter includes: (a) a shaft for insertion into a heart of a patient, (b) an expandable distal-end assembly, which is coupled to the shaft and is configured to make contact with tissue of the heart, (c) at least first and second electrocardiogram (ECG) electrodes, which are coupled to an outer surface of the expandable distal-end assembly, and when placed in contact with the tissue, are configured to sense ECG signals in the tissue, and (d) a reference electrode, which is positioned within an inner volume of the distal-end assembly, and in an expanded position of the distal-end assembly, the reference electrode: (i) has no physical contact with the tissue, and (ii) is positioned at a first distance from the first ECG electrode and at a second distance from the second ECG electrode, and the difference between the first and second distances is smaller than a predefined threshold.

Systems are provided for generating data representing electromagnetic states of a heart for medical, scientific, research, and/or engineering purposes. The systems generate the data based on source configurations such as dimensions of, and scar or fibrosis or pro-arrhythmic substrate location within, a heart and a computational model of the electromagnetic output of the heart. The systems may dynamically generate the source configurations to provide representative source configurations that may be found in a population. For each source configuration of the electromagnetic source, the systems run a simulation of the functioning of the heart to generate modeled electromagnetic output (e.g., an electromagnetic mesh for each simulation step with a voltage at each point of the electromagnetic mesh) for that source configuration. The systems may generate a cardiogram for each source configuration from the modeled electromagnetic output of that source configuration for use in predicting the source location of an arrhythmia.

A medical device is configured to detect an atrial tachyarrhythmia episode. The device senses a cardiac signal, identifies R-waves in the cardiac signal attendant ventricular depolarizations and determines classification factors from the R-waves identified over a predetermined time period. The device classifies the predetermined time period as one of unclassified, atrial tachyarrhythmia and non-atrial tachyarrhythmia by comparing the determined classification factors to classification criteria. A classification criterion is adjusted from a first classification criterion to a second classification criterion after at least one time period being classified as atrial tachyarrhythmia. An atrial tachyarrhythmia episode is detected by the device in response to at least one subsequent time period being classified as atrial tachyarrhythmia based on the adjusted classification criterion.

A medical device is configured to detect an atrial tachyarrhythmia episode. The device senses a cardiac signal, identifies R-waves in the cardiac signal attendant ventricular depolarizations and determines classification factors from the R-waves identified over a predetermined time period. The device classifies the predetermined time period as one of unclassified, atrial tachyarrhythmia and non-atrial tachyarrhythmia by comparing the determined classification factors to classification criteria. A classification criterion is adjusted from a first classification criterion to a second classification criterion after at least one time period being classified as atrial tachyarrhythmia. An atrial tachyarrhythmia episode is detected by the device in response to at least one subsequent time period being classified as atrial tachyarrhythmia based on the adjusted classification criterion.

Systems and methods can be used to provide an indication of heart function, such as an indication of mechanical function or hemodynamics of the heart, based on electrical data. For example, a method for assessing a function of the heart can include determining a time-based electrical characteristic for a plurality of points distributed across a spatial region of the heart. The plurality of points can be grouped into at least two subsets of points based on at least one of a spatial location for the plurality of points or the time-based electrical characteristics for the plurality of points. An indication of synchrony for the heart can be quantified based on relative analysis of the determined time-based electrical characteristic for each of the at least two subsets of points.

A conformational state of a medical device operated within a body lumen is determined by measuring, using the medical device as an electrode, an electrical parameter which varies in a correspondence with a conformational state (e.g., deployment state) of the portion of the medical device used as the electrode. The conformational state of the medical device is determined, based on the electrical parameter; and an image is presented indicating the determined conformational state. In some embodiments, the electrical parameter is a self-impedance of the portion of the medical device used as the electrode. In some embodiments, current positioning of the medical device is used as part of calibrating a parametric relationship between the electrical parameter and conformational states of the medical device.

A conformational state of a medical device operated within a body lumen is determined by measuring, using the medical device as an electrode, an electrical parameter which varies in a correspondence with a conformational state (e.g., deployment state) of the portion of the medical device used as the electrode. The conformational state of the medical device is determined, based on the electrical parameter; and an image is presented indicating the determined conformational state. In some embodiments, the electrical parameter is a self-impedance of the portion of the medical device used as the electrode. In some embodiments, current positioning of the medical device is used as part of calibrating a parametric relationship between the electrical parameter and conformational states of the medical device.

Devices, systems, and methods for treating cardiac arrhythmia are disclosed herein. In some embodiments, devices, systems, and methods disclosed herein deliver interrogating energy to tissue at a position on a wall of an anatomical structure of a patient. If the devices, systems, and methods disclosed herein detect a change in electrical activity of the anatomical structure in response to the interrogating energy, the devices, systems, and methods disclosed herein can apply irreversible therapy to the tissue. In some embodiments, the change in electrical activity corresponds to slowing or termination of a detected arrhythmia.

Devices, systems, and methods for treating cardiac arrhythmia are disclosed herein. In some embodiments, devices, systems, and methods disclosed herein deliver interrogating energy to tissue at a position on a wall of an anatomical structure of a patient. If the devices, systems, and methods disclosed herein detect a change in electrical activity of the anatomical structure in response to the interrogating energy, the devices, systems, and methods disclosed herein can apply irreversible therapy to the tissue. In some embodiments, the change in electrical activity corresponds to slowing or termination of a detected arrhythmia.