An electrocardiogram monitors the electrical signals from your heart. It is typically referred to simply as an EKG, or sometimes ECG (especially outside the US). Professional models use 12 conductive leads that are attached with temporary adhesive to both sides of the chest and to a leg. A graph of the strength of each signal over time can reveal heart rhythm problems, arterial blockages, or a heart attack. A Holter monitor is a small, wearable version that is used to monitor a patient’s heart for one to several days to detect sporadic heart events that might not be detected in the physician’s office. More basic consumer devices are also available in some smart phones and from companies that also make blood pressure monitors.
