What position should a medical assistant place a patient in when preparing to perform a 12-lead EKG?

Placing a patient in the supine position is the correct choice when preparing to perform a 12-lead EKG. This position helps ensure that the patient is lying flat on their back, which provides optimal access to the chest for electrode placement. The supine position minimizes movement and allows for the best contact between the electrodes and the skin, which is crucial for obtaining accurate and reliable readings from the EKG.

In contrast, having a patient sit upright may cause tension or discomfort, potentially leading to movement that could affect the quality of the EKG results. The prone position, where the patient lies face down, is inappropriate for an EKG as it obstructs access to the necessary areas of the chest. Similarly, lying sideways would hinder the accurate placement of electrodes, leading to inaccurate readings. Thus, the supine position facilitates the procedure effectively, ensuring that the electrical signals from the heart are accurately captured.