Remote ECG Monitoring-Based Phase I Cardiac Rehabilitation After Heart Surgery

Inclusion Criteria: * Adults aged 19 years or older * Patients diagnosed with cardiovascular disease (e.g., acute coronary syndrome, heart failure, or valvular heart disease) who have undergone cardiac surgery * Low- or intermediate-risk patients with a left ventricular ejection fraction (LVEF) of 35% or greater on echocardiography * Patients with sufficient cognitive ability to understand the cardiac rehabilitation program using a mobile device, application, and the MEMO Patch * Patients who were independently ambulatory prior to surgery * Patients capable of undergoing an exercise stress test * Patients who voluntarily provide written informed consent to participate in the study Exclusion Criteria: * High-risk patients (e.g., patients with aortic dissection, survivors of cardiac arrest or sudden cardiac death, or patients with an implantable cardioverter-defibrillator) * Patients with uncontrolled medical diseases * Patients who are unable to walk independently * Patients with contractures of the hip, knee, or ankle joints that interfere with walking * Patients with musculoskeletal or neurological disorders affecting the lower extremities * Patients with physical conditions that preclude high-intensity gait training * Patients receiving other treatments that may affect the safety or efficacy assessments * Patients who do not provide written informed consent to participate in this clinical study