Patent attributes
Techniques for determining whether artifacts are present in a cardiac electrogram are described. According to one example, a medical device senses a cardiac electrogram via electrodes. The medical device determines a derivative, e.g., a second order derivative, the electrogram. The medical device detects beats within the derivative, e.g., by comparing a rectified version of the derivative to one or more thresholds determined based on a maximum of the rectified derivative. The medical device determines whether the beats are periodic, and determines whether artifacts are present in the cardiac electrogram based on the determination of whether the beats are periodic. The medical device may further determine whether tachyarrhythmia is present and/or whether the cardiac rhythm of the patient is treatable based on the determination of whether the beats are periodic. For example, the medical device may determine that an electrogram is not treatable when the beats are periodic.
