Clinical Study on the Optimization Algorithm of Single Lead Electrocardiogram Conduction Interval

Inclusion Criteria: * Age ≥18 years; * body mass index \< 35 kg/m2; * with stable sinus rhythm; * PR interval, QRS duration, or QT interval were stable and at least one was outside the normal range; * fully understood the purpose and procedure of the trial and voluntarily signed an informed consent form. Exclusion Criteria: * There are physical disabilities that prevent safe and thorough testing; * Open wounds on the chest skin or skin allergy to patches; * Post-implantation of temporary or permanent cardiac pacemaker, ICD, CRT or CRTD, after artificial heart valve replacement, with large amounts of pericardial effusion, pericardial tamponade, pleural friction rub, pneumothorax, large amounts of pleural effusion, etc., which may affect data collection; * The patient has severe comorbidities or unstable condition, which may interfere with data collection during the study period; * Other situations where the researcher considers the subject unsuitable to participate in this trial, such as potentially increasing the risk of the trial, affecting the subject's compliance with the protocol, or affecting the subject's ability to complete the trial due to physical or psychological diseases or conditions.