An example method includes analyzing morphology and/or amplitude of each of a plurality of electrophysiological signals across a surface of a patient's body to identify candidate segments of each signal satisfying predetermined conduction pattern criteria. The method also includes determining a conduction timing parameter for each candidate segment in each of the electrophysiological signals.

Systems and methods are provided for an electrocardiograph system. A set of electrodes is configured to detect a voltage differences between various pairs of locations on a body of a patient. A display is configured to visually represent digital signals derived from the plurality of detected voltage differences. A display interface is configured to format the digital signals for the display, such that the leads are grouped and displayed as a sequence of proper subsets or groups of the plurality of detected voltage differences. Each proper subset or lead group represents a specific anatomical structure of a heart of the patient.

A computer implemented method and system are provided for detecting premature ventricular contractions (PVCs) in cardiac activity. The method and system obtain cardiac activity (CA) signals for a series of beats, and, for at least a portion of the series of beats, calculate QRS scores for corresponding QRS complex segments from the CA signals. The method and system calculate a variability metric for QRS scores across the series of beats, calculate a QRS complex template using QRS segments from the series of beats, calculate correlation coefficients between the QRS complex template and the QRS complex segments, compare the variability metric to a variability threshold and the correlation coefficients to a correlation threshold, and designate the CA signals to include a predetermined level of PVC burden based on the comparing.

Systems, methods, devices, and techniques for estimating an ejection-fraction characteristic of a mammal. An electrocardiogram (ECG) procedure is performed on a mammal, and a computer system obtains ECG data that describes results of the ECG over a period of time. The system provides a predictive input that is based on the ECG data to an ejection-fraction predictive model, such as a neural network or other machine-learning model. In response, the ejection-fraction predictive model processes the input to generate an estimated ejection-fraction characteristic of the mammal. The system outputs the estimated ejection-fraction characteristic of the mammal for presentation to a user.

A method for arrhythmia detection within a heart signal of a patient, wherein the method is executed by a processor and comprises steps of: providing an input signal which refers to the heart signal of the patient, wherein the input signal comprises cardiac events and noise events, wherein the cardiac events are related to cardiac activity of interest of the heart of the patient, and wherein the noise events are not related to cardiac activity of interest of the heart; determining the cardiac events from the input signal in an arrhythmia detection window; evaluating the arrhythmia detection window by taking into account at least one of: (i) at least one noise event occurring before a start of the arrhythmia detection window, or (ii) at least one noise event occurring after an end of the arrhythmia detection window. Also, a device for arrhythmia detection is provided.

Techniques for determining whether a ventricular depolarization is a premature ventricular contraction (PVC) depolarization may include processing circuitry of a medical system identifying an interval from a maximum slope point to a minimum slope point for each of a plurality of ventricular depolarizations and, for each of the plurality of ventricular depolarizations as a current ventricular depolarization, determining that the intervals from the maximum slope point to the minimum slope point for the current ventricular depolarization, a preceding adjacent ventricular depolarization of the plurality of ventricular depolarizations, and a subsequent adjacent ventricular depolarization of the plurality of ventricular depolarizations satisfy one or more slope criteria. The processing circuitry determines that the current ventricular depolarization is a PVC depolarization based on the intervals from the maximum slope point to the minimum slope point satisfying the one or more slope criteria.

Electrocardiograms can be analyzed in the time-frequency domain, following conversion into time-frequency maps, to determine characteristics or features of various waveforms, such as waveform morphology and/or the amplitude(s) and location(s) (in time and/or frequency) of one or more extrema of the waveform. Based on comparison of the extrema against thresholds and/or against each other, disease conditions may be determined.

A system for processing cardiac activation information associated with a complex rhythm disorder identifies a location of the heart rhythm disorder by determining activations within cardiac signals obtained at neighboring locations of the heart and arranging the activations to identify an activation trail. The activation trail may define a rotational pattern or radially emanating pattern corresponding to an approximate core of the heart rhythm disorder.

A wearable cardioverter defibrillator (WCD) system includes a support structure that the patient may wear, and one or more sensors that may acquire patient physiological signals, such as ECG and others. A processor of the WCD system may determine diagnostics from the patient physiological signals. These diagnostics include a six-second ECG portion, heart rates as histograms, heart rates against QRS width, heart rate trends, clinical event counters, diagnostics relating to heart rate variability and about the atrial arrhythmia burden of the patient. In some embodiments, the WCD system includes a user interface with a screen that displays these diagnostics. In some embodiments, the WCD system exports these diagnostics for viewing by a different screen. When viewed, these diagnostics permit more detailed analysis of the state of the patient.

Methods and devices adapted for cardiac signal analysis. A method or device has accessible to it more than one approach to cardiac cycle rate analysis and is adapted to monitor sensing signal quality. In response to an apparent reduction in signal quality or other trigger, the method or device checks whether an arrhythmia or an actual drop in signal quality is occurring prior to modifying sensing configurations or parameters.