The 24-hour ambulatory ECG is the gold standard for diagnosing arrhythmias, and patients need to carry it for 24 hours, recording each heartbeat, to effectively detect the type of arrhythmia and the frequency of arrhythmia. According to the test results, the doctor will carry out targeted drug therapy or radiofrequency ablation therapy. 24-hour ambulatory ECG instrument is a precision instrument and is extremely susceptible to interference, so it is recommended to reduce strenuous activities and not to go to high magnetic field areas when doing this test. When a cell phone is dialed, its signal may interfere with this instrument, affecting the quality of the ECG and the final diagnostic result.