sentences:  A resting electrocardiogram (ECG) is recorded in the supine position using an ECG machine equipped with SAECG software; this can be done by a physician, nurse, or medical technician.Unlike standard basal ECG recording, which requires only a few seconds, SAECG recording requires a few minutes (usually about 7-10 minutes), as the machine must record multiple subsequent QRS potentials to remove interference due to skeletal muscle and to obtain a statistically significant average trace.For this reason, it is important for the patient to lie as still as possible during the recording.