You don't need to take any special steps before having an electrocardiogram (EKG). However, tell your doctor or his or her staff about the medicines you're taking. Some medicines can affect EKG results.
The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.