Abstract: Systems and methods for verifying cardiac pause episodes detected by a medical device are disclosed. A medical-device system comprises a physiological event detector to receive information about a cardiac pause episode detected by a medical device from a patient using a device-based detection algorithm. The physiological event detector uses an algorithm different from the device-based detection algorithm to generate one or more metrics including at least one entropy metric from the received information about the cardiac pause episode, and verify a presence or absence of cardiac pause in the device-detected cardiac pause episode using such metrics. The verified presence or absence of the cardiac pause may be presented to a user or a process to determine a medical condition, such as a risk of syncope in the patient.

Abstract: Systems and methods are disclosed to an ambulatory medical device comprising a cardiac signal sensing circuit configured to sense a cardiac signal representative of cardiac activity of a patient when connected to electrodes, and a control circuit. The control circuit is configured to monitor cardiac depolarizations in the sensed cardiac signal, detect a bimodal distribution of heart rate of the patient, identify cardiac depolarization intervals shorter than a predetermined interval threshold, identify premature atrial contractions (PACs) in the sensed cardiac signal that are conducted normally and conducted aberrantly, and count a number of conducted PACs and produce an alert related to PC burden of the patient based on the number.