In the United States, heart disease is the leading cause of death for most racial and ethnic groups, contributing to about a fourth of US deaths every year. Every 40 seconds, someone in the US has a heart attack.

While a cardiologist is equipped to deal with most cardiovascular disease, sometimes the input of a cardiovascular subspecialist is required. Electrophysiology is one such subspecialty.

An electrophysiologist, also known as a cardiac electrophysiologist or cardiac EP, is a cardiologist who focuses on testing for and treating problems involving irregular heart rhythms, also known as arrhythmias. They examine your heart’s electrical system, which sends an electrical signal through your cells in order to regulate heart rate and rhythm.