ECG is one of the most important non-invasive method to diagnose CAD and arrhythmia. However, clinically it still has its limitation. Because the electrical field could induce a magnetic field, the newly developed non-contact technique, magnetocardiography, was established to detect the local magnetic field component of the heart. It is safe and more convenient. In this study, we try to define and validate the magnetocardiographic patterns in the patients with cardiac arrhythmias or ischemia.

Patient enrollment:

• patients older than 18 years old,
• having received 1) 12-lead ECG examination for suspected cardiac arrhythmias or 2) stress tests for suspected coronary artery disease, will be invited.
• The patients who have medical devices made of metallic or magnetic material (ex. pacemaker, mechanical valve and arthroplasty) will be excluded to prevent the experimental bias.