Abstract: In an example, a method includes receiving a cardiac signal that is sensed by an electrode at a tissue location inside the heart. Fractionations are identified in the cardiac signal. The fractionations identified at the tissue location are compared between first and second cardiac cycles of the cardiac signal. Based on the comparing, a likelihood is estimated, that the tissue location is causing a stable arrhythmia. Based on the estimated likelihood, the tissue location is indicated to a user as likely to be causing the stable arrhythmia.

Abstract: A method including processing electrocardiograph (ECG) signals taken over a heartbeat received over a plurality of channels, selecting a subset of the ECG signals captured at a point in time with a window of interest (WOI) around reference annotations and having a morphology pattern within the WOI, storing the morphology patterns, receiving continuous sets of ECG signals taken over a plurality of heartbeats over the plurality of channels and having a morphology pattern within the WOI, performing a correlation between the stored morphology patterns of the ECH signals and the morphology patterns of the continuous sets of ECH signals for each heartbeat, generating a correlation coefficient that is a measure of a goodness of fit between geometries of the ECG signals and the continuous sets of ECG signals and identifying each heartbeat having a correlation coefficient that exceeds a threshold coefficient as having been caused by an arrhythmia.

Abstract: In one embodiment, a medical system includes respective electrodes for application to a body of a subject and to output a set of respective activation signals in response to electrical activity of a heart of the subject captured over a sequence of heartbeat intervals, and a processor to classify a first heartbeat interval of the set of activation signals as a first morphological template, compute a measure of similarity between a second heartbeat interval of the set of activation signals and the first morphological template, group the second heartbeat interval of the set of activation signals in a first morphological group with the first morphological template responsively to the measure exceeding a predefined threshold, and classify the second heartbeat interval of the set of activation signals as a second morphological template responsively to the measure not exceeding the predefined threshold, and repeat the above, mutatis mutandis, for subsequent heartbeat intervals.

Abstract: An apparatus includes a shaft, configured for insertion into a body of a subject, and an expandable element coupled to a distal end of the shaft. The expandable element includes multiple electrodes arranged in a hexagonal grid when the expandable element is expanded. Other embodiments are also described.

Abstract: A method includes acquiring intracardiac unipolar signals and intracardiac bipolar signals at a given region of a heart of a patient. The unipolar signals are pruned by eliminating ones of the unipolar signals that correspond in time to respective bipolar signals. One or more unipolar signals are identified among the pruned unipolar signals, that are associated with far-field P-waves. Using the identified P-waves, a window of interest (WOI) is set on electrograms acquired in an atrium of the heart, and, using the electrograms having the set WOI, an electrophysiological (EP) map is generated, of the atrium indicative of atrial tachycardia (AT) tissue locations therein.

Abstract: In one embodiment, a medical system includes respective electrodes for application to a body of a subject and to output a set of respective activation signals in response to electrical activity of a heart of the subject captured over a sequence of heartbeat intervals, and a processor to classify a first heartbeat interval of the set of activation signals as a first morphological template, compute a measure of similarity between a second heartbeat interval of the set of activation signals and the first morphological template, group the second heartbeat interval of the set of activation signals in a first morphological group with the first morphological template responsively to the measure exceeding a predefined threshold, and classify the second heartbeat interval of the set of activation signals as a second morphological template responsively to the measure not exceeding the predefined threshold, and repeat the above, mutatis mutandis, for subsequent heartbeat intervals.

Abstract: A method, including receiving a bipolar signal from a pair of electrodes in proximity to a myocardium of a human subject, and receiving a unipolar signal from a selected one of the pair of electrodes. The method further includes delineating a window of interest (WOI) for the unipolar and bipolar signals, within the WOI computing local unipolar minimum derivatives of the unipolar signal, and times of occurrence of the local unipolar minimum derivatives, and within the WOI computing bipolar derivatives of the bipolar signal at the times of occurrence. The method also includes evaluating ratios of the bipolar derivatives to the local unipolar minimum derivatives, and when the ratios are greater than a preset threshold ratio value, assigning the times of occurrence as times of activation of the myocardium, counting a number of the times of activation; and classifying the unipolar signal according to the number.

Abstract: In an example, a method includes receiving a cardiac signal that is sensed by an electrode at a tissue location inside the heart. Fractionations are identified in the cardiac signal. The fractionations identified at the tissue location are compared between first and second cardiac cycles of the cardiac signal. Based on the comparing, a likelihood is estimated, that the tissue location is causing a stable arrhythmia. Based on the estimated likelihood, the tissue location is indicated to a user as likely to be causing the stable arrhythmia.

Abstract: A method includes receiving a bipolar signal sensed by a pair of electrodes at a location in a heart of a patient. One or more electrocardiogram (ECG) signals are received, sensed by body-surface electrodes attached to the patient. Two or more successive QRS complexes are identified in the bipolar signal. One or more activations are detected in the bipolar signal, which occur within a window-of-interest that begins at least a given time with respect to the identified QRS complexes. The detected activations are checked whether they are late potentials, by verifying whether (i) the activations do not coincide with a predefined event observed in the ECG signals, and (ii) the activations are repeatable in the successive QRS complexes. In response to deciding that at least one of the detected activations is a late potential, the latest of the at least one of the late potentials is visualized to a user.

Abstract: A method includes receiving a bipolar signal sensed by a pair of electrodes at a location in a heart of a patient. One or more electrocardiogram (ECG) signals are received, sensed by body-surface electrodes attached to the patient. Two or more successive QRS complexes are identified in the bipolar signal. One or more activations are detected in the bipolar signal, which occur within a window-of-interest that begins at least a given time with respect to the identified QRS complexes. The detected activations are checked whether they are late potentials, by verifying whether (i) the activations do not coincide with a predefined event observed in the ECG signals, and (ii) the activations are repeatable in the successive QRS complexes. In response to deciding that at least one of the detected activations is a late potential, the latest of the at least one of the late potentials is visualized to a user.

Abstract: A method includes receiving a plurality of data points including electrical activation (EA) values measured at respective positions in at least a portion of a surface of a cardiac chamber of a heart of a patient. Using a predefined EA value criterion, the EA values in a given region of the cardiac surface are classified into multiple distinct EA wave-fronts, and multiple layers of EA values are calculated for the given region, wherein each EA layer includes the EA values found to belong to a respective and contiguous EA wave-front. The multiple EA layers are overlayed on a graphical representation of the surface. The graphical representation with the multiple overlaid EA layers is displayed to a user, with a graphical indication distinguishing between the multiple EA layers.

Abstract: In one embodiment, a medical system includes a catheter configured to be inserted into a chamber of a heart of a living subject, and including multiple electrodes configured to capture electrical activity from electrical activation signals propagating in tissue of the chamber, a display, and processing circuitry configured to automatically select bipolar signals to be captured into an electro-anatomical map from respective electrode pairs of the multiple electrodes responsively to an alignment of the respective electrode pairs with a direction of propagation of the electrical activation signals, and render the electro-anatomical map to the display.

Abstract: A method includes, based on respective signals acquired by a plurality of electrodes on an anatomical surface of a heart, computing respective local activation times (LATs) at respective locations of the electrodes. The method further includes, based on the LATs, computing respective directions of electrical propagation at the locations. The method further includes selecting pairs of adjacent ones of the electrodes such that, for each of the pairs, a vector joining the pair is aligned, to within a predefined threshold degree of alignment, with the direction of electrical propagation at the location of one of the electrodes belonging to the pair. The method further includes associating respective bipolar voltages measured by the pairs of electrodes with a digital model of the anatomical surface. Other examples are also described.

Abstract: A method includes obtaining multiple local activation times (LATs) at different respective measurement locations on an anatomical surface of a heart. The method further includes computing respective directions of electrical propagation at one or more sampling locations on the anatomical surface, by, for each sampling location, selecting a respective subset of the measurement locations for the sampling location, constructing a set of vectors, each of at least some of the vectors including, for a different respective measurement location in the subset, three position values derived from respective position coordinates of the measurement location and an LAT value derived from the LAT at the measurement location, and computing the direction of electrical propagation at the sampling location based on a Principal Component Analysis (PCA) of a 4×4 covariance matrix for the set of vectors. The method further includes indicating the directions of electrical propagation on a display.

Abstract: Methods, apparatus, and systems for medical procedures are disclosed herein and include detecting points of an intra-cardiac area that exhibits abnormal activations, such as local abnormal ventricular activations (LAVAs). Points that exhibit such abnormal activations may be referred to as seed points that are identified during a first step of the process disclosed herein. The seed points may be identified using one or more inputs such as unipolar and bipolar mapping channels, body surface ECGs, past activations, neighboring points and the like during the first step which prioritizes high specificity over sensitivity. During a second step which prioritizes high sensitivity, electrical activations of neighboring points near the seed points are analyzed to determine if the activations are similar (e.g., have a similar time) as the abnormal activations corresponding to the corresponding seed points.

Abstract: A method includes receiving a bipolar signal sensed by a pair of electrodes at a location in a heart of a patient. One or more electrocardiogram (ECG) signals are received, sensed by body-surface electrodes attached to the patient. Two or more successive QRS complexes are identified in the bipolar signal. One or more activations are detected in the bipolar signal, which occur within a window-of-interest that begins at least a given time with respect to the identified QRS complexes. The detected activations are checked whether they are late potentials, by verifying whether (i) the activations do not coincide with a predefined event observed in the ECG signals, and (ii) the activations are repeatable in the successive QRS complexes. In response to deciding that at least one of the detected activations is a late potential, the latest of the at least one of the late potentials is visualized to a user.

Abstract: An apparatus includes a shaft, configured for insertion into a body of a subject, and an expandable element coupled to a distal end of the shaft. The expandable element includes multiple electrodes arranged in a hexagonal grid when the expandable element is expanded. Other embodiments are also described.

Abstract: A method is provided. The method is implemented by a device orientation engine being executed by one or more processors. The method includes determining a movement between each electrode group of a catheter to provide movements and determining a total movement of electrodes of the catheter. The method also includes removing a standard component from the movements and the total movement and outputting a movement indication for the catheter based on the movements and the total movement with the standard component.

Abstract: Methods, apparatus, and systems for medical procedures are disclosed herein and include detecting points of an intra-cardiac area that exhibits abnormal activations, such as local abnormal ventricular activations (LAVAs). Points that exhibit such abnormal activations may be referred to as seed points that are identified during a first step of the process disclosed herein. The seed points may be identified using one or more inputs such as unipolar and bipolar mapping channels, body surface ECGs, past activations, neighboring points and the like during the first step which prioritizes high specificity over sensitivity. During a second step which prioritizes high sensitivity, electrical activations of neighboring points near the seed points are analyzed to determine if the activations are similar (e.g., have a similar time) as the abnormal activations corresponding to the corresponding seed points.

Abstract: A method including processing electrocardiograph (ECG) signals taken over a heartbeat received over a plurality of channels, selecting a subset of the ECG signals captured at a point in time with a window of interest (WOI) around reference annotations and having a morphology pattern within the WOI, storing the morphology patterns, receiving continuous sets of ECG signals taken over a plurality of heartbeats over the plurality of channels and having a morphology pattern within the WOI, performing a correlation between the stored morphology patterns of the ECH signals and the morphology patterns of the continuous sets of ECH signals for each heartbeat, generating a correlation coefficient that is a measure of a goodness of fit between geometries of the ECG signals and the continuous sets of ECG signals and identifying each heartbeat having a correlation coefficient that exceeds a threshold coefficient as having been caused by an arrhythmia.